SYSTEM AND METHOD FOR REGULATING ENGINE KNOCKING

Abstract

Method for operating an engine, comprising the following: Assessing whether knocking is present in a cylinder burning air and fuel by receiving an input to a control system; Adjusting, via the control, a rate of advance ignition supplied to the cylinder after it has been judged that knocking is present in the cylinder in response to a possibility by which the cylinder was previously shut down.

Description

Area

[0001] The present description relates to systems and methods for regulating knock of an internal combustion engine. The systems and methods may be applied to engines that include engine cylinder deactivation. Background and brief presentation

[0002] An engine may include a knock control system to reduce engine knock. The knock system may retard the ignition timing of a cylinder exhibiting knock to reduce the possibility of engine wear. The ignition timing for the cylinder may subsequently be advanced as knocking is suppressed to increase engine efficiency. The ignition advance rate is a constant value. Advancing the ignition timing after retarding the ignition timing may result in further engine knock indications if the ignition advance rate is too high. On the other hand, if the ignition advance rate is too low, the engine's fuel efficiency may deteriorate. Therefore, it may be desirable to provide a way to adjust the ignition advance rate that improves engine efficiency but does not result in engine knock in a short period of time.

[0003] US 2016 / 0 146 127 A1 discloses systems and methods for controlling the advance ignition of an engine. One method allows the engine to be operated with a pre-delivery calibration before delivery, which is deactivated after delivery.

[0004] The document US 2014 / 0 278 010 A1 discloses systems and methods for detecting engine knock. Indicators are generated based on the current operating conditions of the engine. A module for detecting engine noise is also used.

[0005] The present invention solves the problem of increasing the efficiency of an internal combustion engine and reducing the possibility of engine wear by regulating the occurrence of engine knocking.

[0006] The problem is solved by the features of the independent patent claims. Advantageous developments of the invention are described in the subclaims.

[0007] The inventors of the present invention have recognized the above-mentioned disadvantages and developed a method of operating an engine, comprising: judging whether knocking is present in a cylinder that combusts air and fuel by receiving an input to a controller; adjusting, via a controller, a rate of ignition advance supplied to the cylinder after judging that knocking is present in the cylinder, in response to a possibility that the cylinder was previously deactivated.

[0008] By adjusting a rate of spark advance delivered to a cylinder after judging that knock is present in the cylinder, in response to a way in which a cylinder was previously deactivated, it may be possible to provide the technical result of improving engine fuel efficiency while reducing engine knock. For example, the engine cylinders may be deactivated by terminating fuel flow to the cylinders while continuing to operate the cylinder's intake and exhaust valves, or by other methods described herein. Airflow through the cylinders quickly cools the cylinder. If a driver quickly increases a torque request and knock occurs as a result, spark timing may be retarded to regulate knock.However, the ignition advance rate can be set to a higher level because the cylinder has cooled down and knock is expected to return more slowly. Conversely, if the engine cylinders have been deactivated by stopping fuel flow to the cylinders and closing the intake and exhaust valves for an engine cycle, the engine cylinders cannot cool down very quickly because flow through the cylinders is restricted. If a driver quickly increases a torque demand and knock occurs under these circumstances, the ignition timing can also be retarded to control knock. However, the ignition advance rate can be set to a lower level because the cylinder has not cooled down as much as if the cylinders were deactivated with working valves. Consequently, knock can be expected to return more quickly.By reducing the ignition advance rate, the possibility of engine knock returning after ignition has been retarded in response to a previous knock event can be reduced.

[0009] The present description can provide several advantages. For example, the approach can improve the vehicle's fuel efficiency. Additionally, the approach can reduce the possibility of engine knock recurring after a knock event. Furthermore, the approach can improve the vehicle's drivability.

[0010] The foregoing advantages, as well as other advantages and features of the present description, will be readily apparent from the following detailed description when read in isolation or in conjunction with the accompanying drawings.

[0011] It should be understood that the foregoing Summary is provided to introduce, in a simplified manner, a selection of concepts that are further described in the Detailed Description. It is not intended to identify important or crucial features of the claimed subject matter, the scope of which is defined solely in the claims following the Detailed Description. Furthermore, the claimed subject matter is not limited to implementations that overcome disadvantages noted above or in any part of this disclosure. Brief description of the drawings

[0012] The advantages described herein will become more fully apparent upon reading an example of an embodiment, referred to herein as the detailed description, whether read in isolation or with reference to the drawings, in which: Fig. Figure 1A is a schematic representation of a single cylinder of an engine; Fig. 1B is a schematic representation of the engine according to Fig. 1A, which is integrated into a drive train; Fig. 2A-2F show example valve designs for four-cylinder engines with cylinders that can be deactivated; Fig. 3A and Fig. 3B shows exemplary patterns of activated and deactivated cylinders of a four-cylinder engine; Fig. 4A-4C show example valve designs for an eight-cylinder engine with cylinders that can be deactivated; Fig. 5A shows exemplary camshafts for a hydraulically operated valve deactivation system; Fig. 5B shows exemplary shutoff valve actuators for the hydraulically operated valve shutoff system shown in Fig. 5A; Fig. 5C shows an exemplary valve actuator for the hydraulically operated valve deactivation system used in Fig. 5A; Fig. 5D shows an exemplary cylinder and valve deactivation sequence for the hydraulically operated valve deactivation system used in Fig. 5A; Fig. 6A shows an exemplary camshaft for an alternative hydraulically operated valve deactivation system; Fig. 6B shows a cross-section of a camshaft and a socket for the hydraulically operated valve deactivation system used in Fig. 6A; Fig. 6C shows exemplary valve shutoff valve actuators for the hydraulically operated valve shutoff system shown in Fig. 6A; Fig. 6D is an exemplary cylinder and valve deactivation sequence for the hydraulically operated valve deactivation system shown in Fig. 6A; Fig. 7 is a flow diagram of an example method for operating an engine with cylinder and valve deactivation; Fig. 8A is a flow diagram of an exemplary method for selectively activating and deactivating cylinders and cylinder valves of an engine with both deactivation and non-deactivation intake valves and only non-deactivation exhaust valves; Fig. 8B is a block diagram for estimating an amount of oil in a deactivated cylinder; Fig. 9 is an exemplary sequence for activating and deactivating cylinders and cylinder valves of an engine, with both deactivation and non-deactivation intake valves and only non-deactivation exhaust valves; Fig. 10 is a flow diagram of an exemplary method for selectively activating and deactivating cylinders and cylinder valves of an engine, with both deactivation and non-deactivation intake valves and with non-deactivation and deactivation exhaust valves; Fig. 11 is a flow diagram of a method for determining available cylinder modes; Fig. 12 is a flow diagram of a method for evaluating whether or not cylinder deactivation may occur in response to cylinder activation / deactivation activity; Fig. 13 is a sequence that performs cylinder activation and deactivation according to the method of Fig. 12 shows; Fig. 14 is a flowchart of a method for evaluating engine fuel consumption as a basis for selectively allowing cylinder deactivation; Fig. 15 is a flowchart of a method for evaluating engine fuel consumption as a basis for selectively allowing cylinder deactivation; Fig. 16 is a flow diagram of a method for evaluating cam phasing of an engine to select engine cylinder modes; Fig. 17 is a sequence showing selecting engine cylinder modes in response to cam phasing of an engine; Fig. 18 is a flow diagram of a method for selecting an engine cylinder mode in response to engine fuel consumption based on operating an engine in different transmission gears; Fig. 19 is a sequence showing selecting transmission gears and an actual total number of cylinders engaged for improving fuel consumption of an engine; Fig. 20 is a flow diagram of a method for selecting different engine cylinder modes while operating a vehicle in different deceleration modes; Fig. 21 is a sequence for operating an engine cylinder in different cylinder modes based on operating a vehicle in different deceleration modes; Fig. 22 is a flowchart for determining whether conditions exist for operating an engine in different modes of a variable displacement engine (VDE); Fig. Figure 23 is a flow diagram of a method for regulating the pressure in the intake manifold of an engine; Fig. 24 is a sequence illustrating the regulation of the pressure in the intake manifold of an engine according to the method of Fig. 23 shows; Fig. 25 is a flow diagram of a method for regulating the pressure in the intake manifold of an engine; Fig. 26 is an operating sequence for regulating the pressure in the intake manifold of an engine; Fig. 27A and Fig. 27B shows a flowchart for adjusting engine actuators to improve mode changes of engine cylinders; Fig. 28A and Fig. 28B shows sequences for enhancing cylinder mode changes; Fig. Figure 29 is a flow chart for supplying fuel to an engine during cylinder mode changes; Fig. 30 is a sequence showing fuel delivery to an engine during cylinder mode changes; Fig. 31 is a flow diagram of a method for regulating engine oil pressure during cylinder mode changes; Fig. 32 is a sequence showing oil pressure regulation during cylinder mode changes; Fig. 33 is a flow diagram of a method for improving knock control of an engine during cylinder mode changes; Fig. 34 is a sequence showing the knock control of an engine over different engine cylinder modes; Fig. 35 is a flow diagram of a method for adjusting spark gain; Fig. 36 is a sequence showing adjustable spark gain; Fig. 37 is a flowchart of a method for determining a knock reference value depending on cylinder mode; Fig. 38 is a sequence showing a selection of a knock reference value; Fig. 39 is a flow diagram of a method for selecting engine cylinder modes when valve wear is present; Fig. 40 is a flowchart of a sequence for selecting engine cylinder modes when valve wear is present; Fig. 41 is a flowchart for interrogating an oxygen sensor in response to cylinder deactivation; and Fig. 42 is a flowchart for interrogating a camshaft sensor in response to cylinder deactivation. Detailed description

[0013] This description relates to systems and methods for selectively switching on and off cylinders and cylinder valves of an internal combustion engine. The engine may be Fig. 1A-6D. Different procedures and expected operating sequences for an engine that includes shut-off valves are shown in Fig. 7-42. The different methods can be used together and with the Fig. 1A-6D shown systems.

[0014] It will be Fig. 1A, in which an internal combustion engine 10 comprising a plurality of cylinders, one cylinder of which is in Fig. 1A, is controlled by the electronic engine controller 12. The engine 10 consists of a cylinder head casting 35 and block 33, which include a combustion chamber 30 and cylinder walls 32. The piston 36 is positioned therein and reciprocates via a connection to the crankshaft 40. A flywheel 97 and a ring gear 99 are coupled to the crankshaft 40. A starter 96 (e.g., a low voltage electric machine (operating at less than 30 volts)) includes a pinion shaft 98 and a pinion gear 95. The pinion shaft 98 can selectively drive the pinion gear 95 to engage the ring gear 99. The starter 96 can be mounted directly in the front of the engine or the rear of the engine. In some examples, the starter 96 can selectively supply torque to the crankshaft 40 via a belt or chain. In one example, the starter 96 is in a ground state when it is not engaging the engine crankshaft.

[0015] The combustion chamber 30 is shown communicating with the intake manifold 44 and the exhaust manifold 48 via an intake valve 52 and an exhaust valve 54, respectively. Each intake and exhaust valve may be operated by an intake camshaft 51 and an exhaust camshaft 53. The position of the intake camshaft 51 may be determined by the intake cam sensor 55. The position of the exhaust camshaft 53 may be determined by the exhaust cam sensor 57. An angular position of the intake valve 52 may be offset relative to the crankshaft 40 via the phasing device 59. An angular position of the exhaust valve 54 may be offset relative to the crankshaft 40 via the phasing device 58. The valve actuators shown in detail below can transfer mechanical energy from the intake camshaft 51 to the intake valve 52 and from the exhaust camshaft 53 to the exhaust valve 54.Furthermore, in other examples, a single camshaft may operate the intake valve 52 and the exhaust valve 54.

[0016] A fuel injector 66 is shown arranged to inject fuel directly into the cylinder 30, known to those skilled in the art as direct fuel injection. An optional fuel injector 67 is shown arranged to inject fuel into the cylinder 30 via an intake manifold, known to those skilled in the art as port fuel injection. The fuel injectors 66 and 67 deliver liquid fuel proportional to the pulse widths from the controller 12. The fuel is delivered to the fuel injectors 66 and 67 by a fuel system (not shown) that includes a fuel tank, a fuel pump, and a fuel rail (not shown). In one example, a two-stage, high-pressure fuel system may be used to generate higher fuel pressures.

[0017] Additionally, the intake manifold 44 is illustrated as communicating with the turbocharger compressor 162 and the engine air intake 42. In other examples, the compressor 162 may be a supercharger compressor. A shaft 161 mechanically couples the turbocharger turbine 164 to the turbocharger compressor 162. An optional electronic throttle or central throttle 62 adjusts a position of a throttle plate 64 to regulate airflow from the compressor 162 to the intake manifold 44. The pressure in the boost chamber 45 may be related to a throttle inlet pressure because the inlet of the throttle 62 is located within the boost chamber 45. The throttle outlet is located in the intake manifold 44. In some examples, a charge motion control valve 63 is located downstream of the throttle 62 and upstream of the intake valve 52 in an airflow direction into the engine 10 and is operated by the controller 12 to regulate airflow into the combustion chamber 30.A compressor recirculation valve 47 can be selectively adjusted to a variety of positions between fully open and fully closed. A wastegate 163 can be adjusted via the controller 12 to allow exhaust gases to selectively bypass the turbine 164 to control the speed of the compressor 162. An air cleaner 43 cleans air entering the engine air intake 42.

[0018] A distributorless ignition system 88 provides an ignition spark to the combustion chamber 30 in response to the controller 12 via a spark plug 92. A wideband oxygen (UEGO) sensor 126 is shown coupled to the exhaust manifold 48, which is located upstream of the catalytic converter 70. Alternatively, the UEGO sensor 126 may be replaced with a binary oxygen sensor. A pressure sensor 127 is shown as an exhaust pressure sensor disposed in the exhaust manifold 48. Alternatively, the pressure sensor 127 may be disposed as a cylinder pressure sensor in the combustion chamber 30. The spark plug 92 may serve as an ion sensor for the ignition system 88.

[0019] In one example, the catalyst 70 may include multiple catalyst modules. In another example, multiple emission control devices, each including multiple modules, may be used. In one example, the catalyst 70 may be a three-way catalyst. Further, the catalyst 70 may include a particulate filter.

[0020] The control 12 is in Fig. 1A as a conventional microcomputer, including: microprocessor unit 102, input / output channels 104, read-only memory 106 (e.g., non-volatile memory), random access memory 108, keep-alive memory 110, and a conventional data bus. The controller 12 is shown receiving various signals from sensors coupled to the engine 10, in addition to those signals previously discussed, including: engine coolant temperature (ECT) from temperature sensor 112 coupled to a cooling sleeve 114; an engine mount with built-in vibration and / or motion sensors 117 that can provide feedback for compensating for and evaluating engine noise, vibration, and harshness; a position sensor 134 coupled to an accelerator pedal 130 for sensing the force exerted by a foot 132; anda position sensor 154 coupled to a brake pedal 150 for sensing the force exerted by a foot 152; a measurement of engine intake pressure (MAP) from pressure sensor 122 coupled to intake manifold 44; an engine position sensor from a Hall sensor 118 sensing the position of a crankshaft 40; a measurement of the air mass entering the engine from sensor 120;and a measurement of throttle position from sensor 68. Atmospheric pressure may also be sensed for processing by controller 12 (sensor not shown). In a preferred aspect of the present description, engine position sensor 118 generates a predetermined number of evenly spaced pulses every revolution of the crankshaft, from which engine speed (RPM) can be determined. Controller 12 may also receive information from other sensors 24, which may include, but are not limited to, engine oil pressure sensors, ambient pressure sensors, and engine oil temperature sensors.

[0021] During operation, each cylinder in the engine 10 typically undergoes a four-stroke cycle: The cycle includes the intake stroke, the compression stroke, the power stroke, and the exhaust stroke. One cylinder cycle for a four-stroke engine corresponds to two revolutions of the engine, and one engine cycle also corresponds to two revolutions. During the intake stroke, the exhaust valve 54 generally closes and the intake valve 52 opens. Air is introduced into the combustion chamber 30 via the intake manifold 44, and the piston 36 moves toward the bottom of the cylinder, increasing the volume in the combustion chamber 30. The position at which the piston 36 is near the bottom of the cylinder and at the end of its stroke (e.g., when the combustion chamber 30 is at its largest volume) is typically referred to by those skilled in the art as bottom dead center (BDC).

[0022] During the compression stroke, the intake valve 52 and the exhaust valve 54 are closed. The piston 36 moves toward the cylinder head casting 35, compressing the air in the combustion chamber 30. The point at which the piston 36 is at the end of its stroke and closest to the cylinder head casting 35 (e.g., when the combustion chamber 30 is at its smallest volume) is typically referred to by those skilled in the art as top dead center (TDC). In a process referred to below as injection, fuel is introduced into the combustion chamber. In a process referred to below as ignition, the injected fuel is ignited by known ignition means, such as a spark plug 92, resulting in combustion.

[0023] During the power stroke, the expanding gases push the piston 36 back to BDC. The crankshaft 40 converts piston motion into rotating shaft torque. Finally, during the exhaust stroke, the exhaust valve 54 opens to release the combusted air-fuel mixture to the exhaust manifold 48, and the piston returns to TDC. It should be noted that the foregoing is merely an example, and that the timing for opening and / or closing the intake and exhaust valves may vary, for example, to provide positive or negative valve overlap, late intake valve closing, or various other examples.

[0024] The driver demand torque may be determined based on the position of the accelerator pedal 130 and the vehicle speed. For example, the accelerator pedal position and vehicle speed may be input into a table that outputs a driver demand torque. The driver demand torque may represent a desired engine torque or a torque at a location along a driveline including the engine. The engine torque may be determined from the driver demand torque by adjusting the driver demand torque, gear ratios, axle ratios, and other driveline components.

[0025] It will now Fig. 1B, where Fig. 1B is a block diagram of a vehicle 125 including a powertrain 100. The powertrain according to Fig. 1B includes the Fig. 1A. The powertrain 100 may be driven by the engine 10. Engine torque may be adjusted via an engine torque actuator 191, which may be a fuel injector, a camshaft, a throttle, or other device. The engine crankshaft 40 is shown coupled to a torque converter 156. In particular, the engine crankshaft 40 is mechanically coupled to a torque converter impeller 285. A torque sensor 41 provides torque feedback and may be used to evaluate engine noise, vibration, and harshness. The torque converter 156 also includes a turbine 186 for outputting torque to a transmission input shaft 170. The transmission input shaft 170 mechanically couples the torque converter 156 to the automatic transmission 158. The torque converter 156 also includes a torque converter bypass clutch 121 (TCC).Torque is transferred directly from impeller 185 to turbine 186 when the TCC is locked. The TCC is electrically operated by controller 12. Alternatively, the TCC may be hydraulically locked. In one example, the torque converter may be referred to as a component of the transmission.

[0026] When the torque converter clutch 121 is fully disengaged, the torque converter 156 transfers engine torque to the automatic transmission 158 via fluid transfer between the torque converter turbine 186 and the torque converter impeller 185, enabling torque increase. In contrast, when the torque converter clutch 121 is fully engaged, the engine's output torque is transferred directly to an input shaft 170 of the transmission 158 via the torque converter clutch. Alternatively, the torque converter clutch 121 may be partially engaged, allowing the amount of torque directly delivered to the transmission to be adjusted.The controller 12 may be configured to adjust the amount of torque transferred through the torque converter 121 by adjusting the torque converter lock-up clutch in response to various engine operating conditions or based on a driver-based engine operating request.

[0027] The automatic transmission 158 includes gears (e.g., reverse and gears 1-6) 136 and forward clutches 135 for the gears. The gears 136 (e.g., 1-10) and clutches 135 can be selectively engaged to propel a vehicle. The torque output from the automatic transmission 158 can, in turn, be transmitted to the wheels 116 to propel the vehicle via an output shaft 160. Specifically, the automatic transmission 158 can transmit input drive torque at the input shaft 170 in response to a vehicle driving condition before transmitting output drive torque to the wheels 116.

[0028] Furthermore, a frictional force may be applied to the wheels 116 by applying the wheel brakes 119. In one example, the wheel brakes 119 may be applied in response to the driver, as in Fig. 1A, a driver depresses a brake pedal with their foot. In other examples, the controller 12 or a controller coupled to the controller 12 may cause the wheel brakes to be applied. Similarly, a frictional force on the wheels 116 may be reduced by releasing the wheel brakes 119 in response to the driver removing their foot from a brake pedal. Further, the vehicle brakes may apply a frictional force to the wheels 116 via the controller 12 as part of an automated engine stop process.

[0029] The controller 12 may be configured to receive inputs from the motor 10 as shown in Fig. 1A in detail, and control a torque output of the engine and / or the operation of the torque converter, transmission, clutches, and / or brakes accordingly. As an example, engine torque output may be controlled by adjusting a combination of spark timing, fuel pulse width, fuel pulse sampling, and / or air charge by controlling throttle opening and / or valve timing, valve lift, and boost pressure for turbocharged or supercharged engines. In the case of a diesel engine, the controller 12 may control the engine torque output by controlling a combination of fuel pulse width, fuel pulse sampling, and air charge. In all cases, engine control may be performed on a cylinder-by-cylinder basis to control engine torque output.The controller 12 may also control the torque output and electrical energy generation from a DISG by adjusting the current flowing to field and / or armature windings of the DISG, as is known in the art.

[0030] If the conditions for idle shutdown are met, the controller 12 may initiate an engine shutdown by cutting off fuel and / or ignitions to the engine. However, in some examples, the engine may continue to rotate. To maintain a certain level of torsional stress in the transmission, the controller 12 may further ground rotating elements of the transmission 158 to a housing 159 of the transmission and thereby to the frame of the vehicle. If the conditions for engine restart are met and / or a vehicle operator desires to start the vehicle, the controller 12 may restart the engine 10 by cranking the engine 10 and resuming cylinder combustion.

[0031] The intake manifold 44 of the engine 10 is in pneumatic communication with a vacuum reservoir 177 via valve 176. The vacuum can provide vacuum to the brake booster 178, the heating / ventilation / cooling system 179, the wastegate actuator 180, and other vacuum-operated systems. In one example, the valve 176 can be a solenoid valve that can be selectively opened and closed to allow or prevent communication between the intake manifold 44 and vacuum pickups 178-180. Additionally, a vacuum source 183, such as a pump or ejector, can selectively provide vacuum to the engine intake manifold 44 so that the engine 10 can be restarted if there is a leak through the restrictor 62, wherein the pressure in the engine intake manifold is less than atmospheric pressure.The vacuum source 183 can also selectively supply vacuum to the vacuum receivers 178-180 via a three-way valve 171, for example, when the vacuum level in the vacuum reservoir 177 is below a threshold. The volume of the intake manifold 44 can be adjusted via a variable plenum volume valve 175.

[0032] At this point, Fig. 2A, which illustrates an exemplary configuration of engine 10. In this configuration, engine 10 is an inline four-cylinder engine having a first valve configuration. The portions of the engine's combustion chambers formed in cylinder head casting 35, which may also be referred to as part of a cylinder, are numbered 1-4 according to cylinder numbers 1-4 as indicated for each engine cylinder 200. In this example, each combustion chamber is illustrated with two intake valves and two exhaust valves. Deactivation intake valves 208 are illustrated as poppet valves with an X through the poppet valve stem.

[0033] Shutdown exhaust valves 204 are shown as poppet valves with an X through the poppet valve stem. Non-shutdown inlet valves 206 are shown as poppet valves. Non-shutdown exhaust valves 202 are also shown as poppet valves.

[0034] Camshaft 270 is shown in mechanical communication with non-deactivation exhaust valves 202 via non-deactivation exhaust valve actuators 250. Camshaft 270 is also shown in mechanical communication with non-deactivation intake valves 206 via non-deactivation intake valve actuators 251. Camshaft 270 is shown in mechanical communication with deactivation exhaust valves 204 via deactivation exhaust valve actuators 252. Camshaft 270 is also shown in mechanical communication with deactivation intake valves 208 via deactivation intake valve actuators 253. In the figure, some intake and exhaust valves are not shown with activity reduction valve actuators, however, each valve is accompanied by a valve actuator (e.g., the non-deactivation valves are accompanied by non-deactivation valve actuators and the deactivation valves are accompanied by deactivation valve actuators).

[0035] In this configuration, cylinders 2 and 3 are shown with deactivation intake valves 208 and deactivation exhaust valves 204. Cylinders 1 and 4 are shown with non-deactivation intake valves 206 and non-deactivation exhaust valves 202. However, the non-deactivation intake valves 206 and non-deactivation exhaust valves 202 can be replaced with deactivation intake valves and deactivation exhaust valves so that all engine cylinders can be selectively deactivated.

[0036] The interpretation according to Fig. 2A allows for joint or separate deactivation of cylinders 2 and 3. Since both the intake and exhaust valves of cylinders 2 and 3 are deactivating, these cylinders are deactivated by closing both the intake and exhaust valves for an entire engine cycle and ending fuel flow to cylinders 2 and 3. For example, with a firing order of 1-3-4-2, the engine can fire in a sequence of 1-2-1-2 or 1-3-2-1-4-2 or 1-3-2-1-3-2-1-4-2 or other combinations in which cylinders 1 and 2 combust air and fuel. However, if each of cylinders 1-4 included deactivation intake and exhaust valves, cylinders 1 and 2 might not fire (e.g., combust air and fuel) during some engine cycles.For example, the engine's firing order may be 3-4-3-4, or 1-3-2-1-3-2, or 3-4-2-3-4-2, or other combinations in which cylinders 1 and 2 do not combust air or fuel during an engine cycle. It is noteworthy that a deactivated cylinder may trap exhaust gases or fresh air, depending on whether fuel is injected into the cylinder and combusted before the exhaust valves are deactivated in a closed position.

[0037] Fig. 2A also shows a first knock sensor 203 and a second knock sensor 205. The first knock sensor 203 is located closer to cylinders 1 and 2. The second knock sensor 205 is located closer to cylinders 3 and 4. The first knock sensor may be used to detect knock from cylinders 1 and 2 during some conditions and knock from cylinders 1-4 during other conditions. Likewise, the second knock sensor 205 may be used to detect knock from cylinders 3 and 4 during some conditions and knock from cylinders 1-4 during other conditions. Alternatively, the knock sensors may be mechanically coupled to the engine block.

[0038] It will now Fig. 2B, which shows an alternative exemplary configuration of the engine 10. In this configuration, the engine 10 is an inline four-cylinder engine in which a portion of the cylinders are provided with only deactivation intake valves. Portions of the engine's combustion chambers formed in the cylinder head casting 35 are again numbered 1-4, as indicated in the case of the engine cylinders 200. Each cylinder is shown with two intake valves and two exhaust valves. Cylinders 1-4 include non-deactivation exhaust valves 202 and no non-deactivation exhaust valves. Cylinders 1 and 4 also include non-deactivation intake valves 206 and no non-deactivation intake valves. Cylinders 2 and 3 include deactivation intake valves 208 and no non-deactivation intake valves.

[0039] Camshaft 270 is shown in mechanical communication with non-deactivation exhaust valves 202 via non-deactivation exhaust valve actuators 250. Camshaft 270 is also in mechanical communication with non-deactivation intake valves 206 via non-deactivation intake valve actuators 251. Camshaft 270 is also in mechanical communication with deactivation intake valves 208 and deactivation intake valve actuators 253. In the figure, some intake and exhaust valves are not shown with activity reduction valve actuators, however, each valve is accompanied by a valve actuator (e.g., the non-deactivation valves are accompanied by non-deactivation valve actuators, and the deactivation valves are accompanied by deactivation valve actuators).

[0040] The interpretation according to Fig. 2B allows for joint or separate deactivation of cylinders 2 and 3 via deactivation intake valves 208. The exhaust valves of cylinders 2 and 3 continue to close and open during an engine cycle as the engine rotates. Since only the intake valves of cylinders 2 and 3 deactivate, these cylinders are deactivated by closing only the intake valves for an entire engine cycle, terminating fuel flow to cylinders 2 and 3. Again, with a 1-3-4-2 firing order, the engine can fire in a 1-2-1-2 or 1-3-2-1-4-2 or 1-3-2-1-3-2-1-4-2 order, or other combinations in which cylinders 1 and 2 combust air and fuel. It is notable that in this design, a deactivated cylinder will inhale exhaust gas and expel exhaust gas during the exhaust stroke of the deactivated cylinder.Specifically, exhaust gas is drawn into the deactivated cylinder when the exhaust valve of the deactivated cylinder opens near the beginning of the exhaust stroke, and exhaust gas is expelled from the deactivated cylinder when the piston of the cylinder approaches top dead center in the exhaust stroke before the exhaust valve closes.

[0041] In other examples, cylinders 1 and 4 may include deactivation intake valves, while cylinders 2 and 3 may include non-deactivation intake valves. Otherwise, the valve arrangement may be the same.

[0042] At this point, Fig. 2C, which shows an alternative exemplary engine configuration of engine 10. In this configuration, engine 10 is an inline four-cylinder engine, and all engine cylinders include deactivation intake valves 208, and none of the cylinders include deactivation exhaust valves. Portions of the engine's combustion chambers formed in cylinder head casting 35 are again numbered 1-4, as indicated in the case of engine cylinders 200. Each cylinder is shown with two intake valves and two exhaust valves. Cylinders 1-4 include deactivation intake valves 208 and no deactivation intake valves. Cylinders 1-4 also include non-deactivation exhaust valves 202 and no deactivation exhaust valves. Engine 10 is also shown with a first knock sensor 220 and a second knock sensor 221.

[0043] Camshaft 270 is shown in mechanical communication with non-deactivation exhaust valves 202 via non-deactivation exhaust valve actuators 250. Camshaft 270 is also in mechanical communication with deactivation intake valves 208 and deactivation intake valve actuators 253. In the figure, some intake and exhaust valves are not shown with activity reduction valve actuators, however, each valve is accompanied by a valve actuator (e.g., the non-deactivation valves are accompanied by non-deactivation valve actuators, and the deactivation valves are accompanied by deactivation valve actuators).

[0044] The interpretation according to Fig. 2C allows cylinders 1-4 to be deactivated in any combination during an engine cycle by only deactivating the intake valves of cylinders 1-4. The exhaust valves of cylinders 1-4 continue to close and open during an engine cycle as the engine rotates. Furthermore, cylinders 1-4 can be deactivated by closing only the intake valves and stopping fuel flow to cylinders 1-4 for an entire engine cycle, or combinations thereof. With a firing order of 1-3-4-2, the engine can fire in a sequence of 1-2-1-2 or 1-3-2-1-4-2 or 1-3-2-1-3-2-1-4-2 or other combinations of cylinders 1-4, since each cylinder can be deactivated individually and without deactivating the other engine cylinders. It is noteworthy that in this design, a deactivated cylinder inhales exhaust gas and expels exhaust gas during the exhaust stroke of the deactivated cylinder.Specifically, exhaust gas is drawn into the deactivated cylinder when the exhaust valve of the deactivated cylinder opens near the beginning of the exhaust stroke, and exhaust gas is expelled from the deactivated cylinder when the piston of the cylinder approaches top dead center in the exhaust stroke before the exhaust valve closes.

[0045] At this point, Fig. 2D, which shows an alternative engine design of the engine 10. The system according to Fig. 2D is with the system according to Fig. 2A, except that the system is Fig. 2D includes an intake camshaft 271 and an exhaust camshaft 272. The portions of the engine's combustion chambers formed in the cylinder head casting 35, which may also be referred to as part of a cylinder, are numbered 1-4 according to the cylinder numbers 1-4, as indicated for each engine cylinder 200.

[0046] Camshaft 271 is shown in mechanical communication with non-deactivation exhaust valves 202 via non-deactivation exhaust valve actuators 250. Camshaft 272 is shown in mechanical communication with non-deactivation intake valves 206 via non-deactivation intake valve actuators 251. Camshaft 271 is shown in mechanical communication with deactivation exhaust valves 204 via deactivation intake valve actuators 252. Camshaft 272 is shown in mechanical communication with deactivation intake valves 208 via deactivation intake valve actuators 253. In the figure, some intake and exhaust valves are not shown with activity reduction valve actuators, however, each valve is accompanied by a valve actuator (e.g., the non-deactivation valves are accompanied by non-deactivation valve actuators and the deactivation valves are accompanied by deactivation valve actuators).

[0047] At this point, Fig. 2E, which shows an alternative engine design of the engine 10. The system according to Fig. 2E is with the system according to Fig. 2B, except that the system is Fig. 2E includes an intake camshaft 271 and an exhaust camshaft 272. The portions of the engine's combustion chambers formed in the cylinder head casting 35, which may also be referred to as part of a cylinder, are numbered 1-4 according to the cylinder numbers 1-4, as indicated for each engine cylinder 200.

[0048] Camshaft 271 is shown in mechanical communication with non-deactivation exhaust valves 202 via non-deactivation exhaust valve actuators 250. Camshaft 272 is in mechanical communication with non-deactivation intake valves 206 via non-deactivation intake valve actuators 251. Camshaft 272 is also in mechanical communication with deactivation intake valves 208 and deactivation intake valve actuators 253. In the figure, some intake and exhaust valves are not shown with activity reduction valve actuators, however, each valve is accompanied by a valve actuator (e.g., the non-deactivation valves are accompanied by non-deactivation valve actuators and the deactivation valves are accompanied by deactivation valve actuators).

[0049] At this point, Fig. 2F, which shows an alternative engine design of the engine 10. The system according to Fig. 2F is equipped with the system Fig. 2C, except that the system is Fig. 2F includes an intake camshaft 271 and an exhaust camshaft 272. The portions of the engine's combustion chambers formed in the cylinder head casting 35, which may also be referred to as part of a cylinder, are numbered 1-4 according to the cylinder numbers 1-4, as indicated for each engine cylinder 200.

[0050] Camshaft 271 is shown in mechanical communication with non-deactivation exhaust valves 202 via non-deactivation exhaust valve actuators 250. Camshaft 272 is shown in mechanical communication with deactivation intake valves 208 and deactivation intake valve actuators 253. In the figure, some intake and exhaust valves are not shown with activity reduction valve actuators, however, each valve is accompanied by a valve actuator (e.g., the non-deactivation valves are accompanied by non-deactivation valve actuators, and the deactivation valves are accompanied by deactivation valve actuators).

[0051] The Fig. The shut-off valve actuators shown in 2A-2F can be operated by a lever type (see e.g. Fig. 6B), sleeve type (see, for example, US Patent Application Publication US 2014 / 0 303 873 A1 entitled “Position Detection For Lobe Switching Camshaft System,” filed on December 12, 2013, and incorporated herein by reference for all purposes), a cam type, or a lash adjuster type. Furthermore, any of the Fig. 2A-2F are mechanically connected to one and the same block 33, in Fig. 1A. The signals shown in the Fig. 2A-2F may be formed from the same casting, and the shut-off and non-shut-off valve actuators for each cylinder head design may be varied as shown in Fig. 2A-2F.

[0052] It will now Fig. 3A, which shows an example cylinder deactivation pattern. In Fig. 3A, cylinder 4 of engine 10 is shown crossed with an X to indicate that cylinder 4 can be deactivated during an engine cycle while cylinders 1, 2, and 3 remain activated. Activated cylinders are shown without an X to indicate that the cylinders are activated. A cylinder can be deactivated via the Fig. 2C may be deactivated during an engine cycle. Alternatively, cylinder 1 may be the only deactivated cylinder during an engine cycle if the engine 10 is operated as shown in Fig. 2C. Cylinder 2 may be the only deactivated cylinder during an engine cycle when the engine 10 is operated as shown in Fig. 2A, Fig. 2B and Fig. 2C. Similarly, cylinder 3 may be the only deactivated cylinder during an engine cycle when the engine 10 is operated as in Fig. 2A, Fig. 2B and Fig. 2C. The 200 cylinders are shown in a row.

[0053] It will now Fig. 3B, which shows a different cylinder deactivation pattern. In Fig. 3B, cylinders 2 and 3 of engine 10 are shown crossed with an X to indicate that cylinders 2 and 3 may be deactivated during an engine cycle while cylinders 1 and 4 remain activated. Activated cylinders are shown without an X to indicate that the cylinders are activated. Cylinders 2 and 3 may be deactivated via the Fig. 2A, Fig. 2B and Fig. 2C are deactivated during an engine cycle. Alternatively, cylinders 1 and 4 may be the only deactivated cylinders during an engine cycle when the engine 10 is operated as shown in Fig. 2C. In the Fig. 2 and Fig. The deactivated cylinders shown in Figure 3 are cylinders whose valves are closed to prevent fuel flow from the engine intake manifold to the engine exhaust manifold while the engine is running, and where fuel injection to the deactivated cylinders ceases. Sparks provided to the deactivated cylinders may also be stopped. The 200 cylinders are shown in a row.

[0054] In this way, individual cylinders or groups of cylinders can be deactivated. Furthermore, deactivated cylinders can be reactivated from time to time to reduce the possibility of engine oil entering the engine cylinders. For example, a cylinder can fire 1-4-1-4-1-4-2-1-4-3-1-4-1-4 to reduce the possibility of oil entering cylinders 2 and 3 after cylinders 2 and 3 have been deactivated.

[0055] At this point, Fig. 4A, which illustrates another exemplary configuration of the engine 10. The portions of the engine's combustion chambers formed in the cylinder heads 35 and 35a, which may also be referred to as part of a cylinder, are numbered 1-8 according to cylinder numbers 1-8 as indicated for each engine cylinder. The engine 10 includes a first cylinder bank 401, including cylinders 1-4 in the cylinder head casting 35, and a second cylinder bank 402, including cylinders 5-8 in the cylinder head casting 35a. In this configuration, the engine 10 is a V-eight engine including deactivation intake valves 208 and non-deactivation intake valves 206. The engine 10 also includes deactivation exhaust valves 204 and non-deactivation exhaust valves 202. The valves regulate the airflow from the engine intake manifold to the engine exhaust manifold via the engine cylinder 200.In some examples, the deactivation exhaust valves 204 may be replaced with non-deactivation exhaust valves 202 to reduce system costs while maintaining the capacity to deactivate engine cylinders (e.g., terminating fuel flow to the deactivated cylinder and terminating airflow from an engine intake manifold to an engine exhaust manifold via a cylinder while the engine is rotating). Accordingly, in some examples, the engine 10 may include only non-deactivation exhaust valves 202 in combination with deactivation intake valves 208 and non-deactivation intake valves 206.

[0056] In this example, cylinders 5, 2, 3, and 8 are shown as having valves that are always on, so that air flows from the engine intake manifold to the engine exhaust manifold via cylinders 5, 2, 3, and 8 when the engine is running. Cylinders 1, 6, 7, and 4 are shown as having valves that are selectively deactivated in closed positions, so that air does not flow from the engine intake manifold to the engine exhaust manifold via cylinders 1, 6, 7, and 4, respectively, when the valves in the corresponding cylinders are deactivated in a closed state during an engine cycle. In other examples, such as in Fig. 4B, the cylinders that have valves always on are cylinders 5 and 2. The actual total number of cylinders that have valves always on may be based on vehicle mass and engine displacement or other considerations.

[0057] The valves 202, 204, 206, and 208 are opened and closed via a single camshaft 420. The valves 202, 204, 206, and 208 may be in mechanical communication with the single camshaft 320 via pushrods and conventional lash adjusters or deactivation adjusters or hydraulic cylinders, as shown in US patent application Ser. No. 2003 / 0145722A1 entitled "Hydraulic Cylinder Deactivation with Rotary Sleeves," filed February 1, 2002, and incorporated herein by reference for all purposes. Alternatively, the valves 202, 204, 206, and 208 may be controlled via conventional roller cam followers and / or via valve actuators, as shown in Fig. 6A, Fig. 6B and Fig. 5C. In still other examples, the valves may have shrouded cams, as shown in US patent application Ser. No. 2014 / 0303873 A1.

[0058] Camshaft 420 is shown in mechanical communication with non-deactivation exhaust valves 202 via non-deactivation exhaust valve actuators 250. Camshaft 420 is also in mechanical communication with non-deactivation intake valves 206 via non-deactivation intake valve actuators 251. Camshaft 420 is also in mechanical communication with deactivation intake valves 208 and deactivation intake valve actuators 253. Camshaft 420 is also in mechanical communication with deactivation exhaust valves 204 via deactivation intake valve actuators 252. In the figure, some intake and exhaust valves are not shown with activity reduction valve actuators, however, each valve is accompanied by a valve actuator (e.g., the non-deactivation valves are accompanied by non-deactivation valve actuators and the deactivation valves are accompanied by deactivation valve actuators).

[0059] At this point, Fig. 4A, which illustrates another exemplary configuration of the engine 10. The portions of the engine's combustion chambers formed in the cylinder heads 35 and 35a, which may also be referred to as part of a cylinder, are numbered 1-8 according to cylinder numbers 1-8 as indicated for each engine cylinder. The engine 10 includes a first cylinder bank 401, including cylinders 1-4 in the cylinder head casting 35, and a second cylinder bank 402, including cylinders 5-8 in the cylinder head casting 35a. In this configuration, the engine 10 is also a V-eight engine including deactivation intake valves 208 and non-deactivation intake valves 206. The engine 10 also includes deactivation exhaust valves 204 and non-deactivation exhaust valves 202. The valves regulate the airflow from the engine intake manifold to the engine exhaust manifold via the engine cylinder 200.Valves 202, 204, 206, and 208 are operated by an intake camshaft 51 and an exhaust camshaft 53. Each cylinder bank comprises an intake camshaft 51 and an exhaust camshaft 53.

[0060] In some examples, the deactivation exhaust valves may be replaced with non-deactivation exhaust valves 204 to reduce system costs while maintaining the capacity to deactivate engine cylinders (e.g., terminating fuel flow to the deactivated cylinder and terminating airflow from an engine intake manifold to an engine exhaust manifold via a cylinder while the engine is rotating). Accordingly, in some examples, the engine 10 may include only non-deactivation exhaust valves 202 in combination with deactivation intake valves 208 and non-deactivation intake valves 206.

[0061] In this example, cylinders 5 and 2 are shown as having always-on valves so that air flows from the engine intake manifold to the engine exhaust manifold via cylinders 5 and 2 when the engine is running. Cylinders 1, 3, 4, 6, 7, and 8 are shown as having intake and exhaust valves that are selectively deactivated in closed positions so that air does not flow from the engine intake manifold to the engine exhaust manifold via cylinders 1, 3, 4, 6, 7, and 8, respectively, when the valves in the corresponding cylinders are deactivated in a closed state. In this example, the cylinders are deactivated by deactivating the intake and exhaust valves of the cylinder being deactivated. For example, cylinder 3 may be deactivated so that air does not flow through cylinder 3 via deactivating valves 208 and 204.

[0062] Valves 202, 204, 206 and 208 are opened and closed by four camshafts. Valves 202, 204, 206 and 208 can be opened and closed by the Fig. 6A, Fig. 6B and Fig. 5C, the valve actuators or hydraulic cylinders or tappets that can deactivate the valves are in mechanical communication with a camshaft. Fig. 4A and Fig. The engines shown in Figure 4B have a firing order of 1-5-4-2-6-3-7-8.

[0063] The engine 10 is also shown with a first knock sensor 420, a second knock sensor 421, a third knock sensor 422, and a fourth knock sensor 423. Accordingly, the first cylinder bank 401 includes the first knock sensor 420 and the second knock sensor 421. The first knock sensor 420 may detect knock in cylinder numbers 1 and 2. The second knock sensor 421 may detect knock in cylinder numbers 3 and 4. The second cylinder bank 402 includes the third knock sensor 422 and the fourth knock sensor 423. The third knock sensor 422 may detect knock in cylinders 5 and 6. The fourth knock sensor 423 may detect knock in cylinders 7 and 8.

[0064] The exhaust camshaft 53 is shown in mechanical communication with the non-deactivation exhaust valves 202 via the non-deactivation exhaust valve actuators 250. The intake camshaft 51 is in mechanical communication with the non-deactivation intake valves 206 via the non-deactivation intake valve actuators 251. The exhaust camshaft 53 is also in mechanical communication with the deactivation exhaust valves 204 and deactivation intake valve actuators 252. The intake camshaft 51 is also in mechanical communication with the deactivation intake valves 208 via the deactivation intake valve actuators 253. In the figure, some intake and exhaust valves are not shown with activity reduction valve actuators, however, each valve is accompanied by a valve actuator (e.g., the non-deactivation valves are accompanied by non-deactivation valve actuators and the deactivation valves are accompanied by deactivation valve actuators).

[0065] The Fig. The cylinder head design shown in Figure 4B can be integrated into vehicles that have a lower mass than the vehicles in which the cylinder head design shown in Fig. 4A is included. The design according to Fig. 4B can be integrated into a vehicle with lower mass, since vehicles with lower mass can use only two cylinders to travel at a constant highway speed. Conversely, the design according to Fig. 4A in vehicles with higher mass, as vehicles with a higher mass can use four cylinders to travel at a constant highway speed. Likewise, the cylinder heads used in the Fig. 2A-2F and have a lower actual total number of non-deactivating cylinders, are integrated into vehicles with lower mass. The Fig. The cylinder heads shown in Figures 2A-2F, which have a higher total actual number of cylinders that are not deactivating, can be integrated into vehicles with higher mass. In addition, the number of cylinders in the cylinder head castings shown in Fig. 2A-4C, which are not deactivating cylinders, are based on the vehicle's axle ratio. For example, if a vehicle has a lower axle ratio (e.g., 2.69:1 compared to 3.73:1), a cylinder head design with a lower actual total number of non-deactivating cylinders may be selected, thus improving highway driving efficiency. Accordingly, different vehicles with different masses and axle ratios may include the same engine block and cylinder head castings, but the actual total number of deactivating and non-deactivating valve actuators may vary between different vehicles.

[0066] At this point, Fig. 4C, which illustrates another exemplary configuration of the engine 10. The portions of the engine's combustion chambers formed in the cylinder heads 35 and 35a, which may also be referred to as part of a cylinder, are numbered 1-8 according to cylinder numbers 1-8 as indicated for each engine cylinder. The engine 10 includes a first cylinder bank 401, including cylinders 1-4 in the cylinder head casting 35, and a second cylinder bank 402, including cylinders 5-8 in the cylinder head casting 35a. In this configuration, the engine 10 is also a V-eight engine including deactivation intake valves 208 and non-deactivation intake valves 206. The engine 10 also includes non-deactivation exhaust valves 202. The valves regulate the airflow from the engine intake manifold to the engine exhaust manifold via the engine cylinder 200. The valves 202, 206 and 208 are operated via an intake camshaft 51 and an exhaust camshaft 53.Each cylinder bank comprises an intake camshaft 51 and an exhaust camshaft 53.

[0067] In this example, all engine exhaust valves 202 are non-deactivating. The exhaust camshaft 53 is shown in mechanical communication with the non-deactivating exhaust valves 202 via the non-deactivating exhaust valve actuators 250. The intake camshaft 51 is in mechanical communication with the non-deactivating intake valves 206 via the non-deactivating intake valve actuators 251. The intake camshaft 51 is also in mechanical communication with the deactivating intake valves 208 via the deactivating intake valve actuators 253. In the figure, some intake and exhaust valves are not shown with activity reduction valve actuators, however, each valve is accompanied by a valve actuator (e.g., the non-deactivating valves are accompanied by non-deactivating valve actuators and the deactivating valves are accompanied by deactivating valve actuators).

[0068] The Fig. The shut-off valve actuators shown in 4A-4C can be operated by a lever type (see e.g. Fig. 6B), sleeve type (see, for example, US Patent Application Publication US 2014 / 0 303 873 A1 entitled “Position Detection For Lobe Switching Camshaft System,” filed on December 12, 2013, and incorporated herein by reference for all purposes), a cam type, or a lash adjuster type. Furthermore, any of the Fig. 4A-4C are mechanically connected to one and the same block 33, in Fig. 1A. The signals shown in the Fig. 4A-4C may be formed from the same casting, and the deactivation and non-deactivation valve actuators for each cylinder head design may be varied as shown in Fig. 4A-4C. Likewise, the Fig. 4A-4C may be formed from one and the same casting, and the deactivation and non-deactivation valve actuators for each cylinder head design may be varied as shown in Fig. 4A-4C.

[0069] At this point, Fig. 5A, which illustrates an exemplary valve drive system. The depicted embodiment may represent a mechanism for an inline four-cylinder engine or one of two mechanisms for a V-8 engine. Similar mechanisms with four different numbers of engine cylinders are possible. The valve drive system 500 includes an intake camshaft 51 and an exhaust camshaft 53. A chain, pulley, or belt 599 mechanically couples the camshaft 51 and the camshaft 53 so that they rotate together at a same speed. In particular, the chain 599 mechanically couples a drive gear 520 to a drive gear 503.

[0070] The exhaust camshaft 53 includes cylindrical pivot bearings 504a, 504b, 504c, and 504d, which rotate in respective valve bodies 501a, 501b, 501c, and 501d. The valve bodies 501a, 501b, 501c, and 501d are shown integrated into an exhaust camshaft base 502, which may be part of a cylinder head casting 35. Discontinuous measuring grooves 571a, 571b, 571c, and 571d are integrated into the bearing journals 504a, 504b, 504c, and 504d. The discontinuous measuring grooves 571a, 571b, 571c, and 571d may be Fig. 1A to allow oil flow through the journals 504a, 504b, 504c and 504d in accordance with a desired engine crankshaft angle range, so that the Fig. 5B are switched off at a desired crank angle, thereby stopping the air flow from the engine cylinders. The lands 505a, 505b, 505c and 505d prevent oil flow to the Fig. 5B when the corresponding lands cover respective valve body outlets 506, 508, 510 and 512.

[0071] The oil can be fed via the valve body outlets 506, 508, 510 and 512 to the Fig. 5B. Pressurized oil from the oil pump 580 can selectively flow through the valve body inlets 570, 572, 574, and 576, the metering grooves 571a, 571b, 571c, and 571d, and the valve body outlets when the lands are not blocking the valve body inlets and outlets 506, 508, 510, and 512. The pressurized oil can deactivate the valve actuators, as described in more detail below. The lands 505a, 505b, 505c, and 505d selectively open and close access to the valve bodies 501a, 501b, 501c, and 501d for pressurized oil from the oil pump 580 as the exhaust camshaft 53 rotates. The exhaust camshaft 53 also includes cams 507a, 507b, 509a, 509b, 511a, 511b, 513a and 513b to open and close the exhaust valves as the cam lift increases and decreases in response to the rotation of the exhaust camshaft.

[0072] In one example, pressurized oil selectively flows through metering groove 571a via valve body inlet 570 to the exhaust valve actuators for cylinder number one. Cams 507a and 507b can provide a mechanical force to lift the exhaust valves of cylinder number one of a four- or eight-cylinder engine as exhaust camshaft 53 rotates. Similarly, pressurized oil selectively flows through metering groove 571b via valve body inlet 572 to the exhaust valve actuators for cylinder number two. Cams 509a and 509b can provide a mechanical force to lift the exhaust valves of cylinder number two of the four- or eight-cylinder engine as exhaust camshaft 53 rotates. Similarly, pressurized oil selectively flows through metering groove 571c via valve body inlet 574 to the exhaust valve actuators for cylinder number three.Cams 511a and 511b can provide mechanical force to lift the exhaust valves of cylinder number three of a four- or eight-cylinder engine when exhaust camshaft 53 rotates. Additionally, pressurized oil selectively flows through metering groove 571d via valve body inlet 576 to the exhaust valve actuators for cylinder number four. Cams 513a and 513b can provide mechanical force to lift the exhaust valves of cylinder number four of a four- or eight-cylinder engine when exhaust camshaft 53 rotates. Thus, exhaust camshaft 53 can provide force to open the poppet valves of a cylinder bank.

[0073] The intake camshaft 51 includes cylindrical journals 521a, 521b, 521c, and 521d, which rotate within respective valve bodies 540a, 540b, 540c, and 540d. The valve bodies 540a, 540b, 540c, and 540d are shown integrated into an intake camshaft base 522, which may be part of a cylinder head casting 35. Continuous metering grooves 551a, 551b, 551c, and 551d are integrated into the journals 521a, 521b, 521c, and 521d. However, in some examples, the continuous metering grooves 551a, 551b, 551c, and 551d may be omitted, and the oil may be supplied directly to the intake valve actuators by a pump 580.

[0074] Pressurized oil flows via a passage or conduit 581 from the oil pump 580 to control valves 586, 587, 588, and 589. The control valve 586 can be opened to allow oil to flow into the valve body inlet 550, the metering groove 551a, and the valve body outlet 520a before flowing via passage 520b to the intake valve actuators of cylinder number one. Pressurized oil is also supplied to the inlet 570 via a passage or conduit 524c. Thus, closing the valve 586 can prevent deactivation of the intake and exhaust valves of cylinder number one. The outlet 506 supplies oil to the accumulator 506b and the exhaust valve actuators for cylinder number one.

[0075] The selective operation of the intake and exhaust valves for cylinder number two is similar to the selective operation of the intake and exhaust valves for cylinder number one. Specifically, pressurized oil flows via passage or channel 581 from oil pump 580 to valve 587, which can be opened to allow oil to flow into valve body inlet 552, metering groove 551b, and valve body outlet 524a before the oil flows via passage 524b to the intake valve actuators of cylinder number two. Pressurized oil is also supplied to valve body inlet 572 via a passage or line 524c. Thus, closing valve 587 can prevent deactivation of the intake and exhaust valves of cylinder number two. Outlet 508 supplies oil to accumulator 508b and the exhaust valve actuators for cylinder number two.

[0076] The selective operation of the intake and exhaust valves for cylinder number three is similar to the selective operation of the intake and exhaust valves for cylinder number one. For example, pressurized oil flows via passage or channel 581 from oil pump 580 to valve 588, which can be opened to allow oil to flow into valve body inlet 554, metering groove 551c, and valve body outlet 526a before flowing to the intake valve actuators of cylinder number three via passage 526b. Pressurized oil is also supplied to valve body inlet 574 via a passage or line 526c. Thus, closing valve 588 can prevent deactivation of the intake and exhaust valves of cylinder number three. Outlet 510 supplies oil to accumulator 510b and the exhaust valve actuators for cylinder number three.

[0077] The selective operation of the intake and exhaust valves for cylinder number four is also similar to the selective operation of the intake and exhaust valves for cylinder number one. Specifically, pressurized oil flows via passage or channel 581 from oil pump 580 to valve 589, which can be opened to allow oil to flow into valve body inlet 556, metering groove 551d, and valve body outlet 528a before flowing to the intake valve actuators of cylinder number four via passage 528b. Pressurized oil is also supplied to control valve body inlet 576 via a passage or line 528c. Thus, closing valve 589 can prevent deactivation of the intake and exhaust valves of cylinder number four. Outlet 512 supplies oil to accumulator 512b and the exhaust valve actuators for cylinder number four.

[0078] The Fig. The intake valve actuators shown in Figure 5B can be urged by cams 523a-529b to drive the intake valves of a cylinder bank. Specifically, cams 523a and 523b each drive two intake valves of cylinder number one. Cams 525a and 525b each drive two intake valves of cylinder number two. Cams 527a and 527b each drive two intake valves of cylinder number three. Cams 529a and 529b each drive two intake valves of cylinder number four.

[0079] Thus, the intake and exhaust valves of a cylinder bank can be individually turned on and off. Furthermore, as noted previously in some examples, oil can be supplied directly from valves 586-589 to the intake valve actuators, allowing the continuous metering grooves 551a-551d to be omitted to reduce system costs, if desired.

[0080] The oil pump 580 supplies a cooling nozzle 535 for spraying the piston 36, in Fig. 1A, also supplies oil via a cooling nozzle flow control valve 534. The oil pressure in the channel 581 can be regulated via a quick drain valve 532 or by adjusting the oil pump displacement actuator 533, which adjusts the displacement of the oil pump 580. The Fig. Controller 12, shown in Figure 1A, may be in electrical communication with cooling nozzle flow control valve 534, oil pump displacement actuator 533, and quick dump valve 532. The oil pump displacement actuator may be a solenoid valve, a linear actuator, or other known displacement actuator.

[0081] At this point, Fig. 5B, which shows an exemplary deactivation inlet valve actuator 549 and exhaust valve actuator 548 for the hydraulically operated valve deactivation system shown in Fig. 5A. The intake camshaft 51 rotates so that the cam 523a selectively lifts the intake follower 545, which selectively opens and closes the intake valve 52. A steering shaft 544 provides a selective mechanical linkage between the intake follower 545 and the intake valve contact member 547. A passage 546 allows pressurized oil to flow into Fig. 5C, allowing intake valve 52 to be deactivated (e.g., remain in a closed position during an engine cycle). Intake valves 52 may be activated when oil pressure in passage 546 is low.

[0082] Likewise, the exhaust camshaft 53 rotates so that the cam 507a selectively lifts the exhaust follower 543, which selectively opens and closes the exhaust valve 54. A steering shaft 542 provides a selective mechanical linkage between the exhaust follower 543 and an exhaust valve contact member 540. The passage 541 allows the oil to Fig. 5C, so that the exhaust valve 54 can be turned on (e.g., open and closed during an engine cycle) or turned off (e.g., remain in a closed position during an engine cycle).

[0083] At this point, Fig. 5C, which shows an exemplary exhaust valve actuator 548. The intake valve actuators include similar components and operate similarly to the exhaust valve actuator. Therefore, a description of the intake valve actuators is omitted for brevity.

[0084] The exhaust follower 543 is shown with the oil passage 565 extending into the camshaft follower 564. The oil passage 565 is in fluid communication with the port 568 in the steering shaft 542. A piston 563 and a locking pin 561 selectively lock the follower 543 to the exhaust valve contact member 540, causing the exhaust valve contact member 540 to move in response to the movement of the follower 543 when oil is not acting on the piston 563. The exhaust valve driver 548 is in an on state during such conditions.

[0085] The piston 563 can be acted upon by the oil pressure within the oil passages 567 and 565. The piston 563 is moved from its inward position by high pressure oil in the passage 565, which acts against the force of a spring 569. Fig. 5C (e.g., its normally on state) to its off state. Spring 565 pulls piston 563 into a normally locked position, which allows exhaust valve contact member 540 to drive exhaust valve 54 when the oil pressure in passage 565 is low.

[0086] The locking pin 561 stops at a position (e.g., an unlocked position) where the follower 543 is no longer locked to the exhaust valve contact member 540, thereby deactivating the exhaust valve 54 when the normally locked locking pin 561 is fully displaced by high-pressure oil acting on the piston 563. The camshaft follower 564 is steered according to the movement of the cam 507a when the exhaust valve driver 548 is in a deactivated state. The exhaust valve 54 and the exhaust valve contact member 540 remain stationary when the piston locking pin 561 is in its unlocked position.

[0087] Thus, oil pressure can be used to selectively switch the intake and exhaust valves on and off via intake and exhaust valve actuators. Specifically, the intake and exhaust valves can be switched off by allowing oil to flow to the intake and exhaust valve actuators. It is noteworthy that the intake and exhaust valve actuators can be selectively switched on and off via the Fig. 5C can be switched on and off. Fig. 5B and Fig. 5C depicts the deactivating valve actuators with the steering shaft attached. Other types of deactivating valve actuators are possible and compatible with the invention, including deactivating roller rocker arms, deactivating lifters, or deactivating lash adjusters.

[0088] At this point, Fig. 5D, which shows a valve and cylinder deactivation sequence for the mechanism according to Fig. 5A-5C. The valve shutdown sequence can be controlled by the system after Fig. 1A and 5A-5C are provided.

[0089] The first representation from above in Fig. Figure 5D is a plot of exhaust cam groove width versus crank angle. The vertical axis represents the exhaust cam groove width measured at the location of the oil outlet, such as passage 506, after Fig. 5A. The groove width increases in the direction of the arrow on the vertical axis. The horizontal axis represents the engine crank angle, with zero being the compression stroke at top dead center for the cylinder whose intake and exhaust grooves are shown. In this example, the exhaust groove 571a corresponds to Fig. 5A. The crank angles for the exhaust groove width correspond to the crank angle in the third illustration from the top in Fig. 5D.

[0090] The second illustration from the top in Fig. Figure 5D is a plot of intake cam groove width versus crank angle. The vertical axis represents the intake camshaft groove width, and the groove width increases in the direction of the vertical axis arrow. The horizontal axis represents the engine crank angle, with zero being the compression stroke at top dead center for the cylinder whose intake and exhaust grooves are plotted. In this example, the intake groove 551a corresponds to Fig. 5A. The crank angles for the intake groove width correspond to the crank angle in the third illustration from the top in Fig. 5D.

[0091] The third illustration from the top in Fig. Figure 5D is a plot of intake and exhaust valve lift versus engine crank angle. The vertical axis represents valve lift, and valve lift increases in the direction of the vertical axis arrow. The horizontal axis represents engine crank angle, and the three plots are scaled according to crank angle. The thin solid line 590 represents the intake valve lift for cylinder number one when its intake valve driver is on. The thick solid line 591 represents the exhaust valve lift for cylinder number one when its exhaust valve driver is on. The thin dashed lines 592 represent the intake valve lift for cylinder number one when its intake valve driver is on. The thin dashed line 593 represents the exhaust valve lift for cylinder number one when its exhaust valve driver is on.The vertical lines AD represent crank angles of interest for the sequence.

[0092] According to the figure, the intake valve lift for cylinder number one rises and falls before the crank angle A. An oil control valve, such as 586 after Fig. 5A, is closed before crank angle A to prevent deactivation of the intake and exhaust valves. According to the figure, the intake valve lift 590 increases before crank angle A during the intake stroke of cylinder number one. Pressurized oil sufficient to deactivate the intake valves is not present in the continuous intake camshaft groove before crank angle A.

[0093] At crank angle A, the oil control valve (e.g. 586 after Fig. 5A) to deactivate the intake and exhaust valves. The width of the continuous intake camshaft groove is pressurized with oil after the oil control valve has been opened, allowing the locking pin of the intake valve drive to be moved while the camshaft lobe for the intake valve of cylinder number one is on a base circle. The exhaust crankshaft groove 571a is also pressurized with oil at crank angle A. The exhaust 506 is not pressurized with oil at angle A because the land 505a (in Fig. 5A) the valve body outlet 506 (in Fig. 5A). Therefore, only the intake valve deactivation begins at crank angle A. The intake valve actuator locking pin is released from its normal position before crank angle C to prevent the intake valve from opening.

[0094] At crank angle B, the land of exhaust camshaft journal 521a for cylinder number one makes way for discontinuous groove 571a, allowing oil to reach the exhaust valve actuator for cylinder number one. At crank angle B, oil can flow to the intake valve actuator and exhaust valve actuator; however, because the exhaust valve is partially lifted at crank angle B, the exhaust valve operates until the exhaust valve closes near crank angle C. The exhaust valve actuator locking pin is released from its normally engaged position before crank angle D to prevent the exhaust valve from opening.

[0095] At crank angle C, the intake valve does not open because the intake valve actuator is deactivated for the engine cycle. Furthermore, the exhaust valve actuator locking pin is released from its normal position before crank angle D to prevent the exhaust valve from opening. Consequently, the exhaust valve does not open for the cylinder cycle. The intake and exhaust valves can remain deactivated until the intake and exhaust actuators are reactivated by reducing the oil pressure to the intake and exhaust valve actuators.

[0096] The intake and exhaust valves can be reactivated by deactivating the oil control valve 586 and allowing the oil pressure in the intake and exhaust valve actuators to be reduced, or by quickly removing the oil pressure from the intake and exhaust valve actuators via a quick dump valve (not shown).

[0097] The oil reservoir 506b maintains the oil pressure in the oil passage 506 during the portion of the cycle after crank angle D, when the land of the exhaust cam groove blocks the passage 506. During the time when the oil supply from the pump is interrupted, the oil reservoir 506b compensates for oil leakage by varying clearances. The oil reservoir 506b may comprise a dedicated piston and spring, or it may be connected to the locking mechanism, such as the one shown in Fig. 5C shown mechanism.

[0098] At this point, Fig. 6A, which shows a camshaft for an alternative hydraulically operated valve deactivation system. The camshaft 420 can be inserted into the Fig. 4A shown motor system can be integrated.

[0099] In this example, camshaft 420 may be an intake camshaft or an exhaust camshaft, or a camshaft that drives both the intake and exhaust valves. The intake and exhaust valves of each engine cylinder may be individually turned on and off. Camshaft 420 includes a drive gear 619 that allows crankshaft 40 to Fig. 1A drives the camshaft 420 via a chain. The camshaft 420 includes four journals 605a-605d having webs 606a-606d and discontinuous grooves 608a-608d. The camshaft base 602 includes stationary grooves 610a (in Fig. 6B) for each of the valve bodies 670a, 670b, 670c, and 670d. The stationary grooves 610a are arranged to align with the discontinuous grooves 608a-608d. The camshaft 420 also includes cams. In one example, the camshaft 420 can operate both the intake and exhaust valves as the camshaft 420 rotates. Specifically, cam 620 operates an intake valve of cylinder number one, and cam 622 operates an exhaust valve of cylinder number one. Cam 638 operates an intake valve of cylinder number two, and cam 639 operates an exhaust valve of cylinder number two. Cam 648 operates an intake valve of cylinder number three, and cam 649 operates an exhaust valve of cylinder number three. Cam 658 operates an intake valve of cylinder number four and cam 659 operates an exhaust valve of cylinder number four.

[0100] The camshaft base 602 includes valve bodies 670a, 670b, 670c, and 670d to support and provide oil passages leading to the camshaft grooves. Specifically, the valve body 670a includes an inlet 613, a first outlet 612, and a second outlet 616. The first outlet 612 provides oil to the exhaust valve actuators. The second outlet 616 provides oil to the intake valve actuators. The valve body 670b includes an inlet 633, a first outlet 636, and a second outlet 632. The first outlet 636 provides oil to the exhaust valve actuators. The second outlet 632 provides oil to the intake valve actuators. The valve body 670c includes an inlet 643, a first outlet 646, and a second outlet 642. The first outlet 646 provides oil to the exhaust valve actuators. The second outlet 642 provides oil to the intake valve actuators.The valve body 670d includes an inlet 653, a first outlet 656, and a second outlet 652. The first outlet 656 provides oil to the exhaust valve actuators. The second outlet 652 provides oil to the intake valve actuators. The passages 616, 632, 642, and 652 supply oil to the intake valve actuators 649 (in . Fig. 6C) through a channel or passage 692, pressurized oil from the oil pump 690 for the respective cylinder numbers 1-4 when the control valves 614, 634, 644 and 654 are switched on and open. The outlets 612, 636, 646 and 656 can be supplied to the exhaust valve actuators 648 (in Fig. 6C) supply oil pressure when control valves 614, 634, 644, and 654 are open. Discontinuous grooves 608a-608d selectively provide an oil path between inlets 613, 633, 643, and 653 and valve body outlets 612, 636, 646, and 656 leading to the exhaust valve actuators. Bearing journals 605a-605d are partially defined by discontinuous grooves 608a-608d. Oil reservoirs 609a-609d provide oil to keep the exhaust valves deactivated when land 606a covers passage 612 for brief periods of time.

[0101] It will now Fig. 6B, which shows a cross-section of a valve body 670a and associated components. The camshaft 420 is coupled to the camshaft base 602 via the cover cap 699. The cover cap covers the stationary groove 610a formed in the camshaft base 602. The camshaft 420 includes the discontinuous groove 608a, which is axially aligned with the stationary groove 610a. The valve 614 selectively allows oil to flow to the intake valve actuators via the passage 616 and into the stationary groove 610a. The land 606a selectively covers and covers the outlet 612, which provides oil to the accumulator 609a and the exhaust valve actuators while the camshaft 420 rotates.

[0102] At this point, Fig. 6C, which illustrates an exemplary deactivation inlet valve actuator 649 and deactivation outlet valve actuator 648 for the hydraulically operated valve deactivation system shown in Fig. 6A. The camshaft 420 rotates so that the cam 620 selectively lifts the intake follower 645, which selectively opens and closes the intake valve 52. A steering shaft 644 provides a selective mechanical linkage between the intake follower 645 and the intake valve contact member 647. The intake valve driver 649 and the exhaust valve driver 648 include the same components and operate in the same manner as the Fig. 5C. A passage 646 allows pressurized oil to flow into Fig. 5C, so that the intake valve 52 can be deactivated (e.g., remain in a closed position during an engine cycle). The intake valve 52 can be activated (e.g., be open and closed during an engine cycle) when the oil pressure in the passage 646 is low.

[0103] Likewise, cam 622 rotates to selectively lift exhaust follower 643, which selectively opens and closes exhaust valve 54. A steering shaft 642 provides a selective mechanical linkage between exhaust follower 643 and an exhaust valve contact member 640. A passage 641 allows oil to flow into Fig. 5C, so that the intake valve 54 can be deactivated (e.g., remain in a closed position during an engine cycle). The low oil pressure in the passage 641 activates the exhaust valve 54 (e.g., opens and closes it during an engine cycle) when the Fig. 5C, the piston 563 is returned to its normal or home position via the spring 569.

[0104] In this way, a single cam can drive the intake and exhaust valves. Furthermore, the intake and exhaust valves driven by the single cam can be deactivated via the intake and exhaust valve actuators 648 and 649.

[0105] At this point, Fig. 6D, which shows a valve and cylinder deactivation sequence for the mechanism according to Fig. 6A-6C. The valve shutdown sequence can be performed by the system after Fig. 1A and 6A-6C are provided.

[0106] The first representation from above in Fig. Figure 6D is a plot of the exhaust cam groove width at the passage leading to the exhaust valve drive, relative to the crankshaft. The vertical axis represents the exhaust camshaft groove width, and the groove width increases in the direction of the vertical axis arrow. The horizontal axis represents the engine crank angle, with zero being the compression stroke at top dead center for the cylinder whose intake and exhaust grooves are depicted. In this example, the exhaust groove corresponds to the width of groove 608a after Fig. 6A, measured at the oil outlet 612. The crank angles for the outlet groove width correspond to the crank angle in the third illustration from the top in Fig. 6D.

[0107] The second illustration from the top in Fig. Figure 6D is a plot of intake and exhaust valve lift versus engine crank angle. The vertical axis represents valve lift, and valve lift increases in the direction of the vertical axis arrow. The horizontal axis represents engine crank angle, and the three plots are scaled according to crank angle. The thin solid line 690 represents the intake valve lift for cylinder number one when its intake valve driver is on. The thick solid line 691 represents the exhaust valve lift for cylinder number one when its exhaust valve driver is on. The thin dashed lines 692 represent the intake valve lift for cylinder number one when its intake valve driver is on. The thin dashed line 693 represents the exhaust valve lift for cylinder number one when its exhaust valve driver is on.The vertical lines AD represent crank angles of interest for the sequence.

[0108] According to the figure, the intake valve lift for cylinder number one rises and falls before the crank angle A. An oil control valve, such as 614 after Fig. 6A, is closed before crank angle A to prevent deactivation of the intake and exhaust valves. According to the figure, the intake valve lift 690 increases before crank angle A during the intake stroke of cylinder number one. Pressurized oil sufficient to deactivate the intake valves is not present in the continuous intake camshaft groove before crank angle A.

[0109] At crank angle A, the oil control valve (e.g. 614 after Fig. 6A) to deactivate the intake and exhaust valves. The stationary groove width (e.g. 608a after Fig. 6B) and the passage 616 are pressurized with oil after the oil control valve has been opened, so that the locking pin of the intake valve drive can be moved while the outlet 616 is covered by the web 606a. Thus, the outlet 616 at angle A is not pressurized with oil, since the web 606a (in Fig. 6A) covers the valve body outlet 616. Therefore, only the intake valve deactivation begins at crank angle A. The intake valve actuator locking pin is released from its normal position before crank angle C to prevent the intake valve from opening.

[0110] At crank angle B, the land of the exhaust camshaft land 606a for cylinder number one makes way for the discontinuous groove 608a, allowing oil to reach the exhaust 616 and the exhaust valve actuator for cylinder number one. At crank angle B, oil can flow to the intake valve actuator and the exhaust valve actuator; however, because the exhaust valve is partially lifted at crank angle B, the exhaust valve operates until the exhaust valve closes near crank angle C. The exhaust valve actuator locking pin is released from its normally engaged position before crank angle D to prevent the exhaust valve from opening.

[0111] At crank angle C, the intake valve does not open because the intake valve actuator is deactivated for the engine cycle. Furthermore, the exhaust valve actuator locking pin is released from its normal position before crank angle D to prevent the exhaust valve from opening. Consequently, the exhaust valve does not open for the cylinder cycle. The intake and exhaust valves can remain deactivated until the intake and exhaust actuators are reactivated by reducing the oil pressure to the intake and exhaust valve actuators.

[0112] The intake and exhaust valves can be reactivated by deactivating the oil control valve 614 and allowing the oil pressure in the intake and exhaust valve actuators to be reduced, or by quickly removing the oil pressure from the intake and exhaust valve actuators via a quick dump valve (not shown).

[0113] The oil reservoir 609a maintains the oil pressure in the oil passage 616 during the portion of the cycle after crank angle D, when the land of the exhaust cam groove blocks the passage 616. During the time when the oil supply from the pump is interrupted, the oil reservoir 609a compensates for oil leakage by varying clearances. The oil reservoir 609a may comprise a dedicated piston and spring, or it may be connected to the locking mechanism, such as the one shown in Fig. 5C shown mechanism.

[0114] As a result, the system provides Fig. 1A-6D, a vehicle system comprising: an engine; and a controller including non-transitory executable instructions that, when executed by the controller, cause the controller to estimate a temperature in a cylinder that is deactivated and adjust a spark advance speed for the cylinder after the cylinder is reactivated in response to an indication of knock in the cylinder and based on the temperature in the cylinder, and adjust a mode in which the cylinder was previously deactivated. The vehicle system includes where the mode in which the cylinder was previously deactivated is a mode in which air does not flow through the cylinder. The vehicle system includes where the mode in which the cylinder was previously deactivated is a mode in which air does flow through the cylinder.The vehicle system includes where the temperature in the cylinder when the cylinder was deactivated is based on the airflow through the cylinder. The vehicle system further includes additional instructions to reactivate the first cylinder in response to an actual total number of engine revolutions since the first cylinder was deactivated. The vehicle system includes where the advance rate is an ignition boost.

[0115] It is noteworthy that the systems according to Fig. 1A-6D can be operated to provide a desired engine torque when the actual total number of activated cylinders can remain constant, while the activated cylinders that make up the actual total number of activated cylinders can vary from engine cycle to engine cycle. Additionally, the actual total number of cylinders combusting air and fuel during an engine cycle to produce the desired engine torque can vary from engine cycle to engine cycle, if desired. This can be referred to as a rolling variable displacement engine.For example, a four-cylinder engine with a firing order of 1-3-4-2 may fire cylinders 1 and 3 on a first engine cycle, cylinders 3 and 2 on a subsequent engine cycle, cylinders 1-3-2 on a subsequent engine cycle, cylinders 3-4-2 on a subsequent engine cycle, and so on to provide a constant desired engine torque.

[0116] At this point, Fig. 7, which shows a method for operating an engine with deactivation cylinders and valves. The method according to Fig. 7 can be integrated into the system that is Fig. 1A-6C. The method may be included as executable instructions stored in non-volatile memory. The method of Fig. 7 may be performed in conjunction with the system hardware and other methods described herein to transform an operating state of an engine or its components.

[0117] At 702, method 700 determines the engine hardware configuration. In one example, the engine hardware configuration may be stored in memory at the time of manufacture. The engine hardware configuration information may include, among other things, information including an actual total number of engine cylinders, an actual total number of engine cylinders that do not include deactivation intake and exhaust valves, an actual total number of engine cylinders that include deactivation exhaust valves, an actual total number of engine cylinders that include deactivation intake valves, identities (e.g.,Cylinder numbers (cylinder numbers) of cylinders that include deactivation intake valves, identities of cylinders that include deactivation exhaust valves, identities of cylinders that do not include deactivation intake and deactivation exhaust valves, engine knock sensor positions, an actual total number of engine knock sensors, and other system configuration parameters. Method 700 reads the vehicle configuration information from memory and proceeds to 704.

[0118] At 704, method 700 assesses whether cylinder deactivation is available via deactivation intake and / or exhaust valves based on system configuration information retrieved at 702. If method 700 assesses that cylinder deactivation is not available or possible via intake and / or exhaust valves, the answer is no, and method 700 proceeds to exit. Otherwise, the answer is yes, and method 700 proceeds to 706.

[0119] At 706, method 700 assesses whether only intake-only cylinder deactivation is available. In other words, method 700 assesses whether only the intake valves of the engine cylinders can be deactivated (e.g., kept closed for an entire engine cycle) to deactivate the cylinders while continuing to operate all exhaust valves of all engine cylinders while an engine is rotating. In some engine configurations, it may be desirable to deactivate only the intake valves of the cylinders to be deactivated to reduce system cost. Fig. 2B and Fig. 2C show two examples of such an engine configuration. The cylinder's intake and exhaust valves may be deactivated in a closed state in which they are not opened from a closed position over an engine cycle. Method 700 may judge that only the intake valves of the engine cylinders may be deactivated to deactivate the engine cylinders, while all engine exhaust valves of the engine cylinders continue to operate as the engine rotates, based on the hardware configuration determined at 702. If method 700 judges that only the intake valves of the engine cylinders may be deactivated to deactivate the engine cylinders, while all engine exhaust valves of the engine cylinders continue to operate as the engine rotates, the answer is yes, and method 700 proceeds to 708. Otherwise, the answer is no, and method 700 proceeds to 710.

[0120] At 708, the method 700 determines engine cylinders whose intake valves may be deactivated and exhaust valves continue to operate when the engine is rotating. Based on the method of Fig. 8, the method may determine engine cylinders whose intake valves may be deactivated while the exhaust valves continue to operate. Method 700 proceeds to 712 after determining the engine cylinders whose intake valves may be deactivated.

[0121] At 710, method 700 determines the engine cylinders whose intake valves and exhaust valves may be deactivated when the engine is rotating. The method may be based on the method of Fig. 10 Determine the engine cylinders whose intake and exhaust valves can be deactivated. Method 700 proceeds to 712 after all engine cylinders whose intake and exhaust valves can be deactivated have been determined.

[0122] At 712, method 700 determines the allowed or permitted cylinder modes for operating the engine. A cylinder mode determines how many engine cylinders are activated and which cylinders are activated (e.g., cylinder numbers 1, 3, and 4). Method 700 determines the allowed cylinder modes according to the method of Fig. 11. Method 700 proceeds to 714 after the allowable cylinder modes are determined.

[0123] At 714, method 700 adjusts the engine oil pressure in response to the cylinder modes. Method 700 adjusts the engine oil pressure according to the method of Fig. 31. Method 700 proceeds to 716 after the engine oil pressure is adjusted.

[0124] At 716, method 700 deactivates the selected cylinders according to the allowed cylinder modes. Method 700 deactivates the intake and / or exhaust valves to deactivate the selected cylinders according to the allowed cylinder modes determined at 712. For example, if the engine is a four-cylinder engine and the allowed cylinder mode includes three cylinders activated, method 700 deactivates one cylinder. The particular cylinders that are activated and the cylinders that are deactivated may be based on the cylinder modes. The cylinder modes may change with vehicle operating conditions, such that an equal total actual number of cylinders may be activated and an equal total actual number of cylinders may be deactivated, but the cylinders that are activated and deactivated may change from cylinder cycle to cylinder cycle.The valve operation of deactivated cylinders is based on the cylinder deactivation mode associated with the deactivated cylinder. For example, if the permitted cylinder modes include the cylinder deactivation modes from the procedure described in . Fig. 20, then the valves in the deactivated cylinders can be opened according to the Fig. 20 described cylinder deactivation modes.

[0125] If a plurality of actual total numbers of activated cylinders are permitted, the actual total number of activated cylinders is activated in a respective cylinder mode that provides the lowest fuel consumption while providing the desired driver demand torque. Furthermore, the permitted transmission gears associated with the enabled permitted cylinder mode may be engaged.

[0126] Method 700 may deactivate intake and / or exhaust valves via the systems described herein or via other known valve deactivation systems. If an engine knock sensor or other sensor indicates that engine noise exceeds a threshold or vibration exceeds a threshold immediately after changing cylinder modes, a different actual total number of cylinders activated and a different transmission gear may be selected (e.g., the transmission gear and cylinder mode prior to changing cylinder mode, which may be a larger actual total number of cylinders activated). The knock sensor may be interrogated at an engine crankshaft interval outside an engine knock range to prevent mode changes based on knock. Knock sensor output from within the knock range may be precluded from reactivating a cylinder in response to engine vibration.

[0127] The engine cylinders may be deactivated by maintaining the intake valves in closed positions throughout an engine cycle. Furthermore, fuel injection to deactivated cylinders may also be discontinued. Spark delivery to deactivated cylinders may also be discontinued. In some examples, the exhaust valves of cylinders being deactivated are also maintained in closed positions throughout the engine cycle while the intake valves are deactivated, thus trapping gases in the deactivated cylinders. Method 700 proceeds to 718 after select engine cylinders have been deactivated via intake and exhaust valves.

[0128] At 718, method 700 regulates engine knock in response to cylinder deactivation. Method 700 regulates engine knock according to the method of Fig. 33-38. After adjusting engine knock, the procedure proceeds from step 700 to step 720.

[0129] At 720, method 700 performs a cylinder deactivation diagnosis. Method 700 performs the cylinder diagnosis according to the method of Fig. 39-40. Procedure 700 moves to the end after performing the cylinder diagnosis.

[0130] At this point, Fig. 8A, which shows a method for determining cylinders whose intake valves can be deactivated. The method according to Fig. 8 can be integrated into the system that is Fig. 1A-6C. The method may be included as executable instructions stored in non-volatile memory. The method of Fig. 8 may be performed in conjunction with the system hardware and other methods described herein to transform an operating state of an engine or its components.

[0131] At 802, method 800 selects an actual total number of cylinders for the engine. The actual total number of cylinders may be based on vehicle mass and power requirements. In some examples, the engine will include four cylinders, while in other examples, the engine will include six or eight cylinders. Further, the actual total number of engine cylinders with valves that remain energized at all times while the engine is rotating is determined. In one example, the actual total number of cylinders, including valves (e.g., intake and exhaust poppet valves) that remain energized while the engine is rotating, is based on a power level required for the vehicle to operate at a desired speed (e.g., 60 KPH).If the engine has the capacity to provide the power measure with two or more cylinders, the engine may be manufactured with two cylinders including valves that remain always on (e.g., open and close across an engine cycle). If the engine has the capacity to provide the power measure with four or more cylinders, the engine may be manufactured with four cylinders including valves that remain always on. The remaining cylinders are provided with deactivation intake valves and non-deactivation exhaust valves. Method 800 proceeds to 804 after the actual total number of engine cylinders and the actual total number of cylinders with valves that remain always on are determined.

[0132] At 804, the engine is constructed with non-deactivation intake valve actuators and non-deactivation exhaust valve actuators in the engine cylinders that remain activated while the engine is rotating. The remaining engine cylinders are provided with deactivation intake valve actuators and non-deactivation exhaust valve actuators. Method 800 proceeds to 806 after the engine has been populated with deactivation and non-deactivation valves.

[0133] At 806, method 800 estimates an amount of oil in the cylinders with intake valves that are deactivated during an engine cycle, such that the intake valves do not open during an engine cycle or a cycle of the cylinder in which the intake valves are operating. In one example, the amount of oil in the engine cylinders is estimated based on the Fig. 8B. Method 800 estimates the oil quantities in each engine cylinder, with the cylinder's intake valves deactivated and the cylinder deactivated such that airflow through the cylinder is substantially eliminated (e.g., below 10% of airflow through the cylinder during idle conditions). The oil quantity in each cylinder is rechecked every engine cycle. Method 800 proceeds to 808 after the oil quantity in each cylinder is determined.

[0134] Furthermore, at 806, method 800 may estimate the quality of the engine oil. The engine oil quality may be an estimate of the contaminants in the engine oil. The engine oil quality may be assigned a value from 0 to 100, where zero corresponds to oil at the end of its useful life and one hundred corresponds to fresh oil. In one example, the oil quality estimate is based on the running time of the engine, the engine load during the running time, and the engine speed during the running time. For example, the average load and speed of the engine over the running time of the engine may be determined. The average engine load and speed are entered into a table with empirically determined values, and the table outputs an oil quality value.It may be desirable to limit the amount of time cylinder deactivation is available in response to oil quality, as poor oil quality may increase engine wear during cylinder deactivation and / or increase engine emissions during cylinder deactivation.

[0135] Method 800 may also determine an actual total number of particulate regenerations since a last engine oil change. A particulate filter may be regenerated by increasing the particulate filter temperature and burning the carbonaceous soot stored in the particulate filter. Each time the particulate filter is regenerated after an engine oil change, an actual total number of particulate filter regenerations increases.

[0136] At 808, method 800 prevents cylinders containing more than a limit amount of oil from being deactivated. In other words, if a cylinder with deactivated intake valves (e.g., intake valves that remain closed throughout an engine cycle) contains more than a limit amount of oil, the cylinder is reactivated (e.g., the cylinder intake and exhaust valves open and close during an engine cycle, and air and fuel are combusted within the cylinder) so that oil entry into the cylinder can be limited. The cylinder is reactivated by energizing the intake valve driver and supplying spark and fuel to the cylinder. When the cylinder is reactivated, it remains activated at least until an amount of oil in the cylinder is below a limit amount.Furthermore, the amount of temporal overlap between intake valve and exhaust valve opening may be increased in response to the amount of oil in the deactivated cylinder exceeding a threshold. By increasing the amount of temporal overlap between intake valve and exhaust valve opening in response to the amount of oil in a cylinder exceeding a threshold, it may be possible to evacuate oil vapors from the cylinder to improve the stability and emissions of a subsequent combustion event. Furthermore, a cylinder may be deactivated in response to an amount of oil in one cylinder, while a second cylinder may be deactivated during a same engine cycle, such that a total actual number of activated engine cylinders remains constant during an engine cycle. The cylinders may be activated and deactivated as described elsewhere herein.For example, one cylinder can be turned on by opening the intake and exhaust valves during one cylinder's cycle. The second cylinder can be turned off by closing the intake valves or the intake and exhaust valves and keeping them closed during one cylinder's cycle.

[0137] When a cylinder with deactivation intake valves and non-deactivation exhaust valves is deactivated by keeping the deactivated cylinder's intake valves closed during a deactivated cylinder cycle while the exhaust valves continue to open and close, the exhaust valve closure timing control may be adjusted in response to cylinder deactivation so that losses due to cylinder compression and expansion may be reduced. Method 800 proceeds to the end after the cylinders containing more than a threshold amount of oil are reactivated.

[0138] At 808, the cylinders may not be deactivated in response to the oil quality being below a threshold, or they may be reactivated (e.g., combusting air and fuel in the cylinders). Further, in response to an actual total number of particulate filter regenerations since a last engine oil change being above a threshold, method 800 may activate the engine cylinders or prevent the engine cylinders from deactivating. These actions may improve vehicle emissions and / or reduce engine wear.

[0139] At this point, Fig. 8B, which shows a block diagram of an exemplary empirical model for estimating the amount of oil in an engine cylinder. The amount of oil in each deactivated cylinder can be estimated using a model similar to Model 850, although the variables in the described functions or tables may have different values ​​depending on the cylinder number.

[0140] Model 850 estimates a base oil quantity entering cylinders driving deactivated intake valves (e.g., intake valves that remain in a closed position throughout an engine or cylinder cycle) and exhaust valves at block 852. The cylinder oil quantities are determined empirically and incorporated into a table or function stored in the controller's memory. In one example, the table or function is maintained by engine speed and cylinder or exhaust pressure. The table or function outputs an oil quantity in the cylinder. The oil quantity is passed to block 854.

[0141] At block 854, the amount of oil in a cylinder is multiplied by a scalar or a real number that adjusts the amount of oil in response to oil temperature. The viscosity of the oil may vary with oil temperature, and the amount of oil that may enter a deactivated cylinder may vary with oil temperature. Since oil viscosity may decrease with oil temperature, the amount of oil that may enter a deactivated cylinder may increase with oil temperature. In one example, block 854 includes a plurality of empirically determined scalars for various oil temperatures. The amount of oil from block 852 is multiplied by the scalar in block 854 to determine the amount of oil in the engine cylinder as a function of oil temperature.

[0142] At 856, a scalar based on the engine or cylinder compression ratio (CR) is multiplied by the output of block 854 to determine the amount of oil in the engine cylinder as a function of oil temperature and the engine compression ratio. In one example, the amount of oil in the cylinder is increased for higher cylinder compression ratios because a vacuum is created in the cylinder after the exhaust valve closes. The value of 856 is determined empirically and stored in memory.

[0143] At 858, the amount of oil in the cylinder is multiplied by a value that is a function of the exhaust valve closing position or the trapped cylinder volume. The value decreases as the timing of exhaust valve closing is retarded from the exhaust stroke at top dead center because an additional volume of exhaust gas is trapped in the cylinder as the exhaust valve closing retard increases. The value decreases as the timing of exhaust valve closing is advanced from the exhaust stroke at top dead center because an additional volume of exhaust gas is trapped in the cylinder as the exhaust valve closing advance increases. The function of 858 is determined empirically and stored in memory. The amount of oil in the cylinder is passed to block 860.

[0144] At block 860, the amount of oil in a cylinder is multiplied by a scalar that adjusts the amount of oil in response to engine temperature. Engine temperature can affect clearances between engine components, and the amount of oil entering the cylinder can vary with engine temperature and clearances between engine components. In one example, block 860 includes a plurality of empirically determined scalars for different engine temperatures. The amount of oil entering the cylinder decreases as engine temperature increases, as clearances between engine components may decrease as engine temperature increases. Block 860 outputs an estimate for oil in an engine cylinder.

[0145] It will now Fig. 9, which shows an exemplary operating sequence for a four-cylinder engine. In this example, engine cylinders number two and three can be selectively switched on and off by switching the intake valves of cylinders number two and three on and off. The four-cylinder engine has a firing order of 1-3-4-2 when combusting air and fuel. The vertical markers at time T0-T7 represent relevant times in the sequence. The representations after Fig. 9 are temporally aligned and occur simultaneously.

[0146] The first representation from above in Fig. Figure 9 is a plot of estimated oil in cylinder number two versus time. The vertical axis represents an estimated oil quantity in cylinder number two, and the estimated oil quantity in cylinder number two increases in the direction of the vertical axis arrow. The horizontal axis represents time, and time increases from the left side of the plot to the right side of the plot. The horizontal line 902 represents a limit for the oil quantity in cylinder number two that must not be exceeded.

[0147] The second illustration from the top in Fig. Figure 9 is a plot of estimated oil in cylinder number three versus time. The vertical axis represents an estimated oil quantity in cylinder number three, and the estimated oil quantity in cylinder number three increases in the direction of the vertical axis arrow. The horizontal axis represents time, and time increases from the left side of the plot to the right side of the plot. The horizontal line 904 represents a limit for the oil quantity in cylinder number three that must not be exceeded.

[0148] The third illustration from the top in Fig. Figure 9 is a plot of the number of requested working cylinders. The number of requested working cylinders can be a function of driver demand torque, engine speed, and other operating conditions. The vertical axis represents the requested number of working engine cylinders, and the requested number of working engine cylinders is shown along the vertical axis. The horizontal axis represents time, and time increases from the left side of the plot to the right side of the plot.

[0149] The fourth illustration from the top in Fig. Figure 9 is a plot of the operating state of cylinder number two versus time. The vertical axis represents the operating state of cylinder number two. Cylinder number two is operating, burning air and fuel, with the intake and exhaust valves opening and closing during an engine cycle when the trace is at a higher level near the vertical axis arrow. Cylinder number two is not operating, burning air and fuel when the trace is at a lower level near the horizontal axis. The intake valves are closed for the entire engine cycle when the trace is near the horizontal axis, and the exhaust valves open and close during an engine cycle when the trace is at the lower level near the horizontal axis arrow.

[0150] The fifth illustration from the top in Fig. Figure 9 is a plot of the operating state of cylinder number three versus time. The vertical axis represents the operating state of cylinder number three. Cylinder number three is operating, burning air and fuel, with the intake and exhaust valves opening and closing during an engine cycle when the trace is at a higher level near the vertical axis arrow. Cylinder number three is not operating, burning air and fuel when the trace is at a lower level near the horizontal axis. The intake valves are closed for the entire engine cycle when the trace is near the horizontal axis, and the exhaust valves open and close during an engine cycle when the trace is at the lower level near the horizontal axis arrow.

[0151] At time T0, the estimated oil quantity in cylinder number two is low. The estimated oil quantity in cylinder number three is also low. The engine is operating with four cylinders on (e.g., cylinders burning air and fuel), as indicated by the requested number of cylinders being four and the operating states of cylinders number two and three being on (e.g., the cylinder operating state traces are at higher levels). Cylinders number one and four are always on when the engine is running and burning air and fuel.

[0152] At time T1, the estimated oil quantities in cylinders two and three are low. The number of requested operating cylinders is reduced from four to three. The requested number of engine cylinders may be reduced in response to lower driver demand torque. Cylinder three is deactivated in response to the requested number of cylinders being three (e.g., combustion in cylinder three is halted, the intake valves of cylinder three are deactivated so they do not open and close during an engine cycle, fuel delivery to the cylinder is stopped, spark delivery to the cylinder may be stopped, and the exhaust valves of cylinder three continue to open and close during each engine cycle). Cylinder two continues to operate with intake valves and combustion on.

[0153] Between time T1 and time T2, the estimated oil quantity in cylinder number two remains low and constant. The estimated oil quantity in cylinder number three increases. The oil quantity in cylinder number three increases because a vacuum can form in cylinder number three after the exhaust valves of cylinder number three close, since the intake valves of cylinder number three are deactivated.

[0154] At time T2, the amount of oil in cylinder number three equals or exceeds threshold 904. Therefore, cylinder number three is re-enabled, which increases the pressure in the cylinder and forces oil out of the cylinder past the cylinder rings, thereby reducing the amount of oil in cylinder number three. However, because the requested number of cylinders is three, cylinder number two is deactivated (e.g., combustion in cylinder number two is halted, the intake valves of cylinder number two are deactivated so they do not open and close during an engine cycle, fuel delivery to the cylinder is stopped, spark delivery to the cylinder can be stopped, and the exhaust valves of cylinder number two open and close during each engine cycle). This provides the requested number of operating cylinders even if a cylinder's oil quantity is at or above a threshold.The estimated oil quantity in cylinder number two is at a lower level. The operating state of cylinder number two is low, indicating that cylinder number two is deactivated. The operating state of cylinder number three is high, indicating that cylinder number three is activated.

[0155] At time T3, the number of requested working cylinders is two, and the estimated oil quantity in cylinder number two is low. Cylinder number three is deactivated in response to the low oil quantity in cylinder number three and the number of requested working cylinders. Cylinder number two remains in a deactivated state. The oil quantity in cylinder number two continues to increase.

[0156] At time T4, the oil quantity in cylinder number two exceeds the threshold level 902, and the number of requested operating cylinders is two. Cylinder number two is reactivated to evacuate oil from cylinder number two. Cylinder number three remains deactivated, so the number of combusting cylinders is close to the requested number of operating cylinders. Shortly after time T4, cylinder number two is reactivated in response to the estimated oil quantity in cylinder number two being low.

[0157] At time T5, the oil quantity in cylinder number three exceeds the threshold level 904, and the number of requested operating cylinders is two. Cylinder number three is reactivated to evacuate oil from cylinder number three. Cylinder number two remains deactivated, so the number of combusting cylinders is close to the requested number of operating cylinders. Shortly after time T5, cylinder number three is reactivated in response to the estimated oil quantity in cylinder number three being low.

[0158] At time T6, the oil quantity in cylinder number two exceeds the threshold level 902, and the number of requested operating cylinders is two. Cylinder number two is reactivated to evacuate oil from cylinder number two. Cylinder number three remains deactivated, so the number of combusting cylinders is close to the requested number of operating cylinders. Shortly after time T6, cylinder number two is reactivated in response to the estimated oil quantity in cylinder number two being low.

[0159] At time T7, the requested number of operating cylinders is increased in response to an increase in driver demand torque. The operating states of cylinders two and three transition to on to indicate that cylinders two and three have been reactivated in response to the number of operating cylinders. The estimated oil quantity in cylinders two and three is reduced by activating cylinders two and three.

[0160] For example, engine cylinders can be selectively deactivated and activated to save fuel and reduce oil in the engine cylinders. Furthermore, the activated cylinders can be deactivated to reduce oil in the engine cylinders and attempt to meet the requested number of operating cylinders. Activating cylinders to remove oil from the cylinders takes priority over deactivating cylinders to meet the requested number of operating cylinders, thus reducing oil consumption.

[0161] At this point, Fig. 10, which shows a method for determining cylinders whose intake valves can be deactivated. The method according to Fig. 10 can be integrated into the system that is Fig. 1A-6C. The method may be included as executable instructions stored in non-volatile memory. The method of Fig. 10 may be performed in conjunction with the system hardware and other methods described herein to transform an operating state of an engine or its components.

[0162] At 1002, method 1000 selects an actual total number of cylinders for the engine. The actual total number of cylinders may be based on vehicle mass and power requirements. In some examples, the engine will include four cylinders, while in other examples, the engine will include six or eight cylinders. Further, the actual total number of engine cylinders with valves that remain energized at all times while the engine is rotating is determined. In one example, the actual total number of cylinders, including valves (e.g., intake and exhaust poppet valves) that remain energized while the engine is rotating, is based on a power level required for the vehicle to operate at a desired speed (e.g., 60 KPH).If the engine has the capacity to provide the power measure with four or more cylinders, the engine may be manufactured with four cylinders including valves that remain always on (e.g., open and close across an engine cycle). If the engine has the capacity to provide the power measure with six or more cylinders, the engine may be manufactured with six cylinders including valves that remain always on. The remaining cylinders are provided with deactivation intake valves and non-deactivation exhaust valves. Method 1000 proceeds to 1004 after determining the actual total number of engine cylinders and the actual total number of cylinders with valves that remain always on.

[0163] At 1004, the engine is constructed with non-deactivation intake valve actuators and non-deactivation exhaust valve actuators in the engine cylinders that remain activated while the engine is rotating. The remaining engine cylinders are provided with deactivation intake valve actuators and deactivation exhaust valve actuators. Method 1000 proceeds to 1006 after the engine is populated with deactivation and non-deactivation valves.

[0164] At 1006, method 1000 estimates an amount of oil in the cylinders with intake valves that are deactivated during an engine cycle, such that the intake valves do not open during an engine cycle or a cycle of the cylinder in which the intake valves are operating. In one example, the amount of oil in the engine cylinders is estimated based on the Fig. 8B; however, the results obtained in Fig. 8B may include different variable values ​​than those for an engine with cylinders deactivated via intake valve closure alone over an engine cycle. Method 1000 estimates the oil amounts in each engine cylinder with the cylinder's intake valves deactivated and with the cylinder deactivated such that airflow through the cylinder is substantially eliminated (e.g., below 10% of airflow through the cylinder during idle conditions). The amount of oil in each cylinder is rechecked every engine cycle. Method 1000 proceeds to 1008 after the amount of oil in each cylinder is determined.

[0165] At 1008, method 1000 prevents cylinders containing more than a limit amount of oil from being deactivated. In other words, if a cylinder with deactivated intake and exhaust valves (e.g., intake and exhaust valves that remain closed throughout an engine cycle) contains more than a limit amount of oil, the cylinder is reactivated (e.g., the cylinder intake and exhaust valves open and close during an engine cycle, and air and fuel are combusted within the cylinder) so that oil entry into the cylinder may be limited. The cylinder is reactivated via energizing the intake valve driver and supplying spark and fuel to the cylinder. Method 1000 proceeds to exit after the cylinders containing more than a limit amount of oil are reactivated.

[0166] At this point, Fig. 11, which shows a method for determining available cylinder modes for an engine. The method according to Fig. 11 can be integrated into the system that is Fig. 1A-6C. The method may be included as executable instructions stored in non-volatile memory. The method of Fig. 11 may be performed in conjunction with the system hardware and other methods described herein to transform an operating state of an engine or its components.

[0167] At 1102, method 1100 evaluates the engine cylinder mode activity against thresholds to determine whether changing cylinder modes represents too much activity or is appropriate. If the cylinder mode is changed too frequently, vehicle occupants may become aware of the cylinder mode switching, making the cylinder mode switching undesirable. Method 1100 evaluates the cylinder mode switching according to the method of Fig. 12 and goes to 1106.

[0168] At 1106, method 1100 evaluates which cylinder modes can provide a requested amount of engine braking torque. Method 1100 proceeds to the method of Fig. 14 to determine which cylinder modes can provide the requested amount of engine braking torque. Method 1100 proceeds to 1108 after determining which cylinder modes can provide the requested amount of braking torque.

[0169] At 1108, method 1100 evaluates whether changing the cylinder mode will reduce fuel consumption. Method 11 proceeds to the method of Fig. 15 to determine whether changing the cylinder mode can save fuel. Method 1100 proceeds to 1112 after determining whether changing the cylinder mode will save fuel.

[0170] At 1112, method 1100 evaluates a cam phase control rate to determine the cylinder mode. The cam phase control rate is a rate at which a cam torque-actuated pointer changes a position of an engine's cam relative to a position of the engine's crankshaft. Because cam torque-actuated phase actuators for variable valve timing rely on valve spring force for operation, and because deactivating a cylinder's valves reduces the reaction force provided by the valve springs, the use of some cylinder modes may not be desirable when high rates of cam phase change are desired. Method 1100 evaluates the cam phase rate for available cylinder modes according to the method of Fig. 16 and then goes to 1114.

[0171] At 1114, method 1100 evaluates different transmission gears to select the cylinder mode. Method 1100 evaluates different transmission gears to select the cylinder mode according to the method of Fig. 18. Method 1100 proceeds to 1116 after different transmission gears are evaluated to select the cylinder mode.

[0172] At 1116, method 1100 evaluates tow and pull modes to select the cylinder mode. Method 1100 evaluates the tow and pull modes to select the cylinder mode according to the method of Fig. 20. Method 1100 proceeds to 1118 after the tow and pull modes are evaluated to select the cylinder mode.

[0173] At 1118, method 1100 assesses whether selected conditions for selecting the cylinder mode exist. Method 1100 determines whether conditions for determining the cylinder mode exist according to the method of Fig. 22. Method 1100 proceeds to 1120 after determining whether conditions exist for selecting the cylinder mode.

[0174] At 1120, method 1100 regulates the engine intake manifold absolute pressure (MAP) during conditions where one or more cylinders are deactivated via deactivation of the intake and / or exhaust valves of the engine cylinders. Furthermore, fueling and spark delivery to the cylinder are terminated when the cylinder is deactivated. Method 1100 regulates the MAP according to the method of Fig. 23 and goes to 1121.

[0175] At 1121, method 1100 regulates the absolute engine intake pressure (MAP) during conditions in which one or more cylinders are activated via activation of the intake and / or exhaust valves of the engine cylinders. Furthermore, fueling to the cylinder and spark delivery to the cylinder are activated when the cylinder is activated. Method 1100 regulates the MAP according to the method of Fig. 25 and goes to 1122.

[0176] At 1122, method 1100 regulates engine torque during the cylinder mode change. Method 1100 regulates engine torque according to the method of Fig. 27A, before moving on to 1124.

[0177] At 1124, method 1100 regulates the fuel supplied to the engine to change cylinder modes. Method 1100 regulates the fuel supplied to the engine according to the method of Fig. 29. Method 1100 proceeds to end after the fuel flow to the engine has been regulated.

[0178] At this point, Fig. 12, in which a method for evaluating whether or not a change in cylinder mode exceeds activity limits is shown. The method according to Fig. 12 can be integrated into the system that is Fig. 1A-6C. The procedure according to Fig. 12 may be contained as executable instructions stored in non-volatile memory. The method according to Fig. 12 may be performed in conjunction with the system hardware and other methods described herein to transform an operating state of an engine or its components.

[0179] At 1202, method 1200 judges whether the present execution of method 1200 is a first execution of method 1200 since the vehicle and engine were stopped and turned off. Method 1200 may judge that the present execution of method 1200 is a first execution since the vehicle was turned on after the vehicle was turned off (e.g., stopped without an immediate intention to restart). In one example, method 1200 judges that the present execution is a first execution if a value in memory is zero and the method has not been executed since a driver requested the vehicle to start via a push button or key. If method 1200 judges that the present execution of method 1200 is a first execution of method 1200 since the engine was stopped, the answer is yes, and method 1200 proceeds to 1220.Otherwise, the answer is no and method 1200 proceeds to 1204.

[0180] At 1220, method 1200 determines values ​​for the variables PAYBACK TIME and VDE_BUSY. The PAYBACK TIME variable is a period of time required in a newly selected cylinder mode or variable displacement (VDE) engine mode to cover the fuel costs of switching from one cylinder mode or VDE mode to the next cylinder mode or VDE mode. The fuel costs may be due to reducing engine torque via spark retard or another setting used to regulate engine torque during mode switches. The VDE_BUSY variable is a value that is a basis for determining whether or not cylinder mode or VDE switching is occurring at a higher than desired frequency. The value is updated based on the number of cylinder mode or VDE switches and the period of time spent in a cylinder mode or VDE mode.VDE_BUSY is initially set to zero, and PAYBACK TIME is empirically determined and stored in memory. In one example, the PAYBACK TIME variable can vary depending on the cylinder mode being exited and the cylinder mode being entered. There can be VDE_BUSY variables for each cylinder mode, as shown in . Fig. 13. The method 1200 proceeds to 1204 after the variable values ​​have been determined.

[0181] At 1204, method 1200 judges whether the engine exits a valve deactivation mode. Method 1200 may judge that the engine exits a valve deactivation mode when valves of one or more cylinders are turned on in an engine cycle (e.g., when intake valves transition from not opening and closing during an engine cycle to opening and closing during an engine cycle). If method 1200 judges that the engine exits a valve deactivation mode and valves of at least one cylinder are turned back on during an engine cycle, the answer is yes and method 1200 proceeds to 1208. Otherwise, the answer is no and method 1200 proceeds to 1230.

[0182] At 1230, method 1200 judges whether the engine is operating in a valve deactivation mode. Method 1200 may judge that the engine is operating in a valve deactivation mode if the intake and / or exhaust valves of an engine cylinder remain closed and do not open and close during an engine cycle. If method 1200 judges that the engine is operating in a valve deactivation mode, the answer is yes and method 1200 proceeds to 1232. Otherwise, the answer is no and method 1200 proceeds to 1210.

[0183] At 1232, method 1200 counts a measure of time during which one or more cylinders have valves in a deactivated state to determine a period of time during which the engine is in a deactivated mode. The engine may have more than one deactivated mode, and the time in each deactivated mode may be determined. For example, an eight-cylinder engine may deactivate two cylinders or four cylinders to provide two deactivated modes. The first deactivated mode is when two cylinders are deactivated, and the second deactivated mode is when four cylinders are deactivated. Method 1200 determines the period of time during which the engine has two deactivated cylinders and the period of time during which the engine has four deactivated cylinders.Method 1200 proceeds to 1210 after determining a period of time during which one or more engine cylinders are in a deactivation mode.

[0184] At 1208, method 1200 determines a period of time to add or subtract from the VDE_OFF-LOADED variable based on a period of time during which one or more cylinders have deactivated valves and the PAYBACK TIME. A larger number is added to the VDE_OFF-LOADED variable if the engine has deactivated cylinders in a mode for a short period of time relative to the PAYBACK TIME. For example, if an eight-cylinder engine operates with valves on in four cylinders for four seconds, method 1200 may add a value of 120 to the VDE_OFF-LOADED variable if the PAYBACK TIME variable is 20. On the other hand, if an eight-cylinder engine operates with valves on in four cylinders for 19 seconds, method 1200 may add a value of 40 to the VDE_BUSY variable if the PAYBACK TIME variable is 20.If the eight-cylinder engine operates with valves on in four cylinders for 45 seconds, method 1200 may add a value of -10 to the VDE_OFFSET variable when the PAYBACK TIME variable is 20. The value added to VDE_OFFSET may be a linear or nonlinear function of the difference between the amount of time the engine spends in cylinder deactivation mode and the PAYBACK TIME value. Method 1200 proceeds to method 1210 after setting the value of VDE_OFFSET.

[0185] At 1210, method 1200 subtracts a predetermined amount or value from the VDE_BUSY variable. For example, method 1210 may subtract a value of 5 from the VDE_BUSY variable. Subtracting a predetermined amount from the VDE_BUSY variable may drive the VDE_BUSY variable toward a value of zero. The VDE_BUSY variable is constrained to positive values ​​greater than zero. Method 1200 proceeds to 1212 after the predetermined amount is subtracted from the VDE_BUSY variable.

[0186] At 1212, method 1200 judges whether cylinder valve deactivation is requested to reduce the number of activated cylinders. Cylinder valve deactivation may be requested in response to lower driver demand torque or other driving conditions. If method 1200 judges that cylinder valve deactivation is requested by the present cylinder mode or VDE mode, the answer is yes and method 1200 proceeds to 1214. Otherwise, the answer is no and method 1200 proceeds to 1240.

[0187] At 1240, method 1200 judges whether cylinder valve reactivation is requested to increase the number of activated cylinders (e.g., if the intake valves of two cylinders are requested to be reactivated in response to an increase in driver demand torque). Cylinder valves may be reactivated to reactivate a cylinder valve. The cylinder may be reactivated in response to an increase in driver demand torque or another condition. If method 1200 judges that cylinder valve reactivation is requested, the answer is yes and method 1200 proceeds to 1244. Otherwise, the answer is no and method 1200 proceeds to 1242.

[0188] At 1244, the procedure 1200 allows the reactivation of deactivated cylinder valves and cylinders. The cylinder valves can be activated via the Fig. 6A and Fig. 6B or other known mechanisms. After allowing the reactivation of deactivated cylinder valves, method 1200 proceeds to the end. The valves may be deactivated according to the method of Fig. 22 can be switched on.

[0189] At 1242, method 1200 does not permit the activation or deactivation of any number of cylinder valves other than those currently activated or deactivated. In other words, the current value of the number of activated valves and cylinders is maintained. After maintaining the current number of activated and deactivated cylinders, method 1200 proceeds to exit.

[0190] At 1214, method 1200 judges whether a period of time since a cylinder valve re-energization request is greater than the value of the variable VDE_OFFBUSY. If so, the answer is yes, and method 1200 proceeds to 1216. Otherwise, the answer is no, and method 1200 proceeds to 1242. In this manner, cylinder valve deactivation can be delayed until a period of time between a cylinder mode or VDE mode change is greater than the value of VDE_OFFBUSY, which increases as the cylinder valve deactivation frequency increases and decreases as the cylinder valve deactivation frequency decreases.

[0191] At 1216, method 1200 allows deactivation of selected cylinder valves to deactivate selected cylinders. Deactivation of fuel supplied to the cylinders and termination of spark delivery to the cylinders may also be permitted. The valves may be deactivated according to the method of Fig. 22 be switched off.

[0192] At this point, Fig. 13, in which an engine operating sequence according to the method of Fig. 12. The vertical lines at time points T1300-T1314 represent relevant time points in the sequence. Fig. 13 shows six representations, and the representations are time-aligned and occur simultaneously. In this example, deactivating a cylinder means deactivating at least the intake valves of the cylinder being deactivated such that the deactivated intake valves remain in closed states throughout an engine cycle. In some examples, the exhaust valves of deactivated cylinders are also deactivated such that the exhaust valves remain in a closed state throughout a cycle of the engine. Spark and fuel are not delivered to deactivated cylinders, so no combustion occurs in deactivated cylinders. Alternatively, cylinder deactivation may involve terminating combustion and fuel injection to a cylinder while the cylinder's valves continue to operate.

[0193] The first representation from above in Fig. Figure 13 is a plot of cylinder deactivation request versus time. Engine cylinders can be deactivated in response to the cylinder deactivation request. The vertical axis represents the cylinder deactivation request, and the horizontal axis represents time. Time increases from the left side of the figure to the right side of the figure. In this example, the engine is an eight-cylinder engine and can operate with four, six, or eight cylinders activated. The numbers on the vertical axis indicate which cylinders are requested or not requested for deactivation. For example, if the trace is at level eight, no cylinders are requested for deactivation. If the trace is at level six, two cylinders are requested for deactivation. If the trace is at level four, four cylinders are requested for deactivation.A cylinder deactivation request may be based on driver torque demand or other vehicle conditions. In some examples, only the intake valves of a cylinder are deactivated to deactivate a cylinder. In other examples, both the intake valves and the exhaust valves are deactivated to deactivate a cylinder. When a cylinder is deactivated, spark delivery and fuel flow to that cylinder cease.

[0194] The first representation from above in Fig. Figure 13 is a plot of cylinder activation state versus time. The cylinder activation state provides the actual operating state of engine cylinders. The vertical axis represents the cylinder activation state, and the horizontal axis represents time. The numbers on the vertical axis indicate which cylinders are activated. For example, if the trace is at level eight, all cylinders are activated. If the trace is at level six, six cylinders are activated. Four cylinders are activated when the trace is at level four. The horizontal axis represents time, and time increases from the left side of the figure to the right side of the figure.

[0195] In the third illustration from the top in Fig. Figure 13 is a graph showing the time the engine is in first cylinder mode, in this example, six-cylinder operation. The vertical axis represents the time in first cylinder mode, and the time in first cylinder mode increases in the direction of the vertical axis arrow. The horizontal axis represents time, and time increases from the left side of the figure to the right side.

[0196] In the fourth illustration from the top in Fig. Figure 13 is a graph showing the time the engine is in the second cylinder mode, in this example, four-cylinder operation. The vertical axis represents the time in the second cylinder mode, and the time in the second cylinder mode increases in the direction of the vertical axis arrow. The horizontal axis represents time, and time increases from the left side of the figure to the right side.

[0197] The fifth illustration from the top in Fig. Figure 13 is a plot of the value of the VDE_BUSY variable for the first cylinder valve deactivation mode, in this example, six-cylinder operation. The vertical axis represents the value of the VDE_BUSY variable in the first cylinder mode. This value corresponds to a period of time that must elapse after a request to activate the first cylinder mode is made before the first cylinder mode can be activated. The horizontal axis represents time, and time increases from the left side of the figure to the right side of the figure.

[0198] The sixth illustration from the top in Fig. Figure 13 is a plot of the value of the VDE_BUSY variable for the second cylinder mode, in this example, four-cylinder operation. The vertical axis represents the value of the VDE_BUSY variable in the second cylinder mode. This value corresponds to a period of time that must elapse after a request to activate the second cylinder mode is made before the second cylinder mode can be activated. The horizontal axis represents time, and time increases from the left side of the figure to the right side of the figure.

[0199] At time T1300, the engine is operating with all valves and cylinders energized, indicated by a cylinder activation state value of eight. The cylinder deactivation request does not request deactivation of any valves or cylinders, and the time period in the first and second cylinder modes is zero. The VDE_OFFSET variable for the first cylinder mode, which deactivates cylinders, is zero. The VDE_OFFSET variable for the second cylinder mode, which deactivates cylinders, is also zero.

[0200] At time T1301, the cylinder deactivation request changes state to request deactivation of the valves of two cylinders, so the eight-cylinder engine operates with six cylinders on. The cylinder deactivation state changes state to indicate that the engine is operating with six cylinders on and with two cylinders deactivated. Time accumulates in the first cylinder mode because the engine is in the first cylinder mode (e.g., operating with six cylinders on). Time does not accumulate in the second cylinder mode because the engine is not operating in the second cylinder mode (e.g., operating with four cylinders on). The variables VDE_OFF for the first cylinder mode and VDE_OFF for the second cylinder mode are zero because the engine has not exited the first or second cylinder mode.

[0201] At time T1302, the cylinder deactivation request changes state to request no cylinder valves be deactivated, so the engine is operating as an eight-cylinder engine. The cylinder deactivation state changes state to indicate that the engine is operating with eight cylinders activated and no valves deactivated. Time accumulation in the first cylinder mode ends because the engine is operating with all cylinder valves activated and as an eight-cylinder engine. No time accumulates in the second cylinder mode because the engine is not operating in the second cylinder mode. The VDE_OFF value for the first cylinder mode increments based on the amount of time the engine was in the first cylinder mode.

[0202] At time T1303, the cylinder deactivation request changes state again to request deactivation of the valves of two cylinders, so the eight-cylinder engine operates with six cylinders on. The cylinder deactivation state does not change state because the VDE_OFFSET value for the first cylinder mode is greater than the PAYBACK TIME variable (not shown). The VDE_OFFSET value for the first cylinder mode decreases because a predetermined period of time is subtracted from the first cylinder mode VDE_OFFSET each time the procedure is executed. No time accumulates in the second cylinder mode because the engine is not operating in the second cylinder mode (e.g., operating with four cylinders on). VDE_OFFSET for the second cylinder mode is zero because the engine has not exited the second cylinder mode.

[0203] At time T1304, the VDE_OFFSET value for the first cylinder mode is equal to or less than the value for the PAYBACK TIME variable, thus deactivating the cylinder valves to provide six-cylinder operation, as indicated by the cylinder activation state transitioning to the level indicating six-cylinder engine operation. The time period in the first cylinder mode begins to increase. The time period in the second cylinder mode remains at zero. The VDE_OFFSET value for the first cylinder valve deactivation mode continues to decrease, and the VDE_OFFSET value for the second cylinder valve deactivation mode remains at zero.

[0204] At time T1305, the cylinder deactivation request transitions to a value of eight. The cylinder activation state also transitions to a value of eight based on the cylinder deactivation request. The time in the first cylinder mode is short, causing the VDE_OFF value for the first cylinder mode to increase by a large amount. The VDE_OFF value for the second cylinder mode is zero because the engine has not been in the second cylinder mode. Shortly thereafter, the cylinder deactivation request transitions to a value of six to request valve deactivation in two engine cylinders, allowing the engine to operate as a six-cylinder engine combusting air-fuel mixtures in six of eight cylinders. However, the engine does not transition to six-cylinder operation, as indicated by the cylinder activation state maintaining a value of eight.The engine does not switch to six-cylinder mode and deactivates the valves of two cylinders because the value for VDE_OFFLOADED for the first cylinder mode is greater than the value for the variable PAYBACK TIME (not shown).

[0205] At time T1306, the engine transitions to six-cylinder mode, in which the cylinder valves in two engine cylinders are deactivated to deactivate two cylinders. Fuel and spark are not provided to the two deactivated cylinders. The cylinder activation state transitions to a value of six to indicate that the engine is operating in six-cylinder mode with the cylinder valves deactivated in two cylinders. The period in the first cylinder mode begins to increase. The period in the second cylinder mode remains at zero. The VDE_OFF-LOADED value for the first cylinder mode continues to decrease, and the VDE_OFF-LOADED value for the second cylinder mode remains at zero.

[0206] At time T1307, the cylinder deactivation request transitions to eight to request eight cylinders on. The period of time the engine operates in the first cylinder mode is long, correcting the VDE_OFF-LOADED value for the first mode to a low value. The cylinder activation state transitions to a value of eight to indicate that the engine has all eight cylinders and valves on. The period of time in the second cylinder mode is zero, and the VDE_OFF-LOADED value for the second cylinder mode is zero.

[0207] At time T1308, the cylinder deactivation request transitions to a value of six in response to a reduced driver demand torque (not shown). At almost the same time, the cylinder activation state based on the cylinder deactivation request also transitions to a value of six. The period in the first cylinder mode begins to increase, and the period in the second cylinder mode remains at zero. The VDE_OFF values ​​for the first and second valve deactivation modes are zero.

[0208] At time T1309, the cylinder deactivation request transitions to a value of four in response to the driver demand torque (not shown). The cylinder activation state also transitions to a value of four in response to the cylinder deactivation request value. The time in the first cylinder mode transitions to zero, and the VDE_OFF value for the first cylinder mode is set to zero. The time in the second cylinder mode begins to increase, and the VDE_OFF value for the second cylinder valve deactivation mode remains at a value of zero.

[0209] At time T1310, the cylinder valve deactivation request transitions back to a value of six in response to the driver demand torque (not shown) increasing. The cylinder activation state transitions back to a value of six in response to the cylinder deactivation request. The VDE_OFF value for the second cylinder valve deactivation mode is increased in response to the brief period during which the engine is operating in four-cylinder mode. The period in the first cylinder mode begins to increase, and the period in the second cylinder mode is set to zero.

[0210] At time T1311, the cylinder deactivation request transitions back to a value of four in response to the driver demand torque (not shown) decreasing. The cylinder activation state remains at a value of six because the VDE_OFFSET value for the second cylinder mode is greater than the value of the PAYBACK TIME variable (not shown). The time in the first cylinder mode continues to increase, and the time in the second cylinder mode remains at zero. The VDE_OFFSET value for the first cylinder valve deactivation mode remains at zero.

[0211] At time T1312, the cylinder deactivation request transitions back to a value of six in response to the driver demand torque (not shown) increasing. The cylinder activation state is at a value of six based on the cylinder deactivation request value. The time in the first cylinder mode continues to increase, and the time in the second cylinder mode is zero. The VDE_OFF value for the second cylinder mode continues to decrease because the engine has not transitioned out of the second cylinder mode.

[0212] At time T1313, the cylinder deactivation request transitions to a value of four in response to the driver demand torque (not shown) decreasing. The cylinder activation state remains at a value of six because the VDE_OFFSET value for the second cylinder mode is greater than the value of the PAYBACK TIME variable (not shown). Therefore, the valves of two cylinders are deactivated even though the cylinder deactivation request is at a value of four. The period in the first cylinder mode continues to increase, and the period in the second cylinder mode remains at zero. The VDE_OFFSET value for the first cylinder mode remains at zero.

[0213] At time T1314, the cylinder deactivation request remains at a value of four, and the cylinder activation state transitions to a value of four in response to the amortization time value (not shown). Therefore, the valves of four cylinders are deactivated and four cylinders are activated. The time in the first cylinder mode transitions to zero, and the VDE_OFF-LOADED value for the first cylinder mode is set to zero. The time in the second cylinder mode begins to increase, and the VDE_OFF-LOADED value for the second cylinder mode continues to decrease.

[0214] At time T1315, the cylinder deactivation request transitions to a value of eight to request the activation of all cylinder valves and cylinders. The cylinder activation state transitions to a value of eight to indicate that all cylinder valves and cylinders are activated. The duration in the second cylinder mode is long, which sets the VDE_OFF value for the second valve mode low, allowing a smooth transition to four-cylinder mode, in which the cylinder valves of four cylinders are activated.

[0215] Therefore, it can be observed that the activation of the different cylinder modes can be prevented based on the amount of time spent in a cylinder mode relative to a payback period. Furthermore, the cylinder modes are not locked in response to cylinder mode switching activity. Instead, the activation of the different cylinder modes can be delayed for varying periods of time to reduce a driver's perception of cylinder mode switching activity.

[0216] At this point, Fig. 14, which shows a method for evaluating engine braking torque in available cylinder modes as a basis for selectively allowing cylinder deactivation. The method according to Fig. 14 can be integrated into the system that is Fig. 1A-6C. The procedure according to Fig. 14 may be contained as executable instructions stored in non-volatile memory. The method according to Fig. 14 may be performed in conjunction with the system hardware and other methods described herein to transform an operating state of an engine or its components.

[0217] At 1402, method 1400 determines a desired engine torque and a current engine speed. The engine speed may be determined via an engine position or speed sensor. A period of time it takes for an engine to move between two positions is the engine speed. The desired engine torque may be determined from a driver demand torque. In one example, the driver demand torque is based on the accelerator pedal position and the vehicle speed. The accelerator pedal position and vehicle speed are entered into a table of empirically determined driver demand torque values. The driver demand torque value corresponds to a desired torque at a position along the driveline. The position along the driveline may be the engine crankshaft, the transmission input shaft, the transmission output shaft, or the vehicle wheel.If the driver demand torque is an engine torque, the output from the table is the desired or requested engine torque. Torques at other points along the driveline can be determined by setting a desired torque at one point based on gear ratios, torque multiplication devices, losses, and clutch torque capacities.

[0218] For example, if driver demand torque is wheel torque, engine torque can be determined by multiplying the driver demand torque (or desired wheel torque) by the gear ratios between the wheel and the engine. If the powertrain includes a torque converter, the desired wheel torque can be further divided by the torque converter's torque multiplication factor to determine engine torque. Torque transmitted through clutches can be estimated as a multiplier. For example, if a clutch is at zero slippage, the torque input to the clutch equals the torque output from the clutch, and the multiplier value is one. The torque input to the clutch multiplied by one equals the torque output from the clutch.If the clutch is slipping, the multiplier is a value from 0 to a number less than one. The multiplier value may be based on the clutch's torque capacity. Method 1400 proceeds to 1404.

[0219] At 1404, method 1400 determines cylinder modes that can provide the desired engine torque. In one example, an engine torque table may be provided that describes the maximum engine torque output as a function of cylinder mode and engine speed. The desired engine torque is compared to the engine cylinder valve timing and atmospheric pressure compensated outputs from the engine torque table, which is populated after the cylinder mode at the current engine speed, current atmospheric pressure, and current cylinder valve timing (e.g., intake valve closure timing). If the engine torque table outputs a torque value that is greater than the desired engine torque plus an offset torque, the cylinder mode corresponding to the torque output from the table may be determined to be a cylinder mode that provides the desired engine torque.The values ​​stored in the motor torque table can be determined empirically and stored in the controller memory.

[0220] An example of an engine braking torque table is shown in Fig. 1. This is an engine torque table for a four-cylinder engine. The engine torque table can include torque output values ​​for three cylinder modes: a two-cylinder on mode, a three-cylinder on mode, and a four-cylinder on mode. The engine torque table can also include a variety of engine speeds. The torque values ​​between the engine speeds can be interpolated. Table 1: Table 1. Motordrehzahl Angeschaltete Zylinder 500 1000 2000 3000 4000 2 39 48 52 49 43 3 58 74 79 76 65 4 77 96 104 100 88

[0221] Thus, Table 1 contains rows with the engaged cylinder modes and columns with the engine speed. In this example, Table 1 outputs the torque values ​​in units of Nm. The engine braking torque values ​​output by the braking torque table can be adjusted using functions based on ignition timing from minimum spark for best torque (MBT); intake valve closing from a nominal intake valve closing time, engine air-fuel ratio, and engine temperature. The functions output empirically determined multipliers that modify the engine braking torque value output by the engine braking torque table. The desired engine braking torque is compared with the modified value output by the engine braking torque table.Note that the desired wheel torque may be converted to a desired engine torque by multiplying the desired wheel torque by the gear ratio between the wheels and the engine. Further, determining the engine torque may include modifying the wheel torque according to the torque multiplication of the transmission's torque converter. Additionally or alternatively, cylinder modes, which include different firing orders or energized cylinders in an engine cycle, may also be a basis for entering and storing values ​​in an engine braking torque table. Method 1400 proceeds to 1406.

[0222] At 1406, the method allows 1400 cylinder modes that can provide the desired engine torque to be allowed. The allowed cylinder modes can be Fig. 7 can be switched on.

[0223] An example using Table 1: Table 1 is populated by engine speed and cylinder mode. The cylinder mode starts at a minimum value, in this example two, and is incremented until it reaches the maximum cylinder mode. For example, if the engine is operating at 1000 RPM and the desired engine torque is 54 Nm, Table 1 will output a value of 48 Nm, which corresponds to 1000 RPM and cylinder mode two (e.g., two cylinders activated), 74 Nm, which corresponds to 1000 RPM and cylinder mode three (e.g., three cylinders activated), and 96 Nm, which corresponds to 1000 RPM and cylinder mode four (e.g., four cylinders activated). The cylinder mode with two cylinders activated at 1000 RPM is not allowed because two cylinders activated lack the capacity to provide the desired 74 Nm of torque. The cylinder modes with three and four cylinders are allowed.In some examples, the desired engine torque plus a specified offset is compared to values ​​output from the table. If the desired engine torque plus the specified offset is greater than an output from the table, the cylinder mode corresponding to the table output is disallowed. Allowed and disallowed cylinder modes may be indicated by variable values ​​stored in memory. For example, if three-cylinder mode is allowed at 1000 RPM, a variable in memory corresponding to three-cylinder mode at 1000 RPM may be set to a value of one. If cylinder mode three is disallowed at 500 RPM, a variable in memory corresponding to cylinder mode three at 500 RPM may be set to a value of zero. Method 1400 proceeds to exit.

[0224] Therefore, the engine cylinder modes and the engine braking torque available in the cylinder modes can be used to determine which cylinder mode the engine operates in. Furthermore, cylinder modes with lower fuel consumption can be given selection priority, thus saving fuel.

[0225] At this point, Fig. 15, which shows a method for evaluating the engine's fuel consumption in available cylinder modes as a basis for selectively allowing cylinder deactivation. The method according to Fig. 15 can be integrated into the system that is Fig. 1A-6C. The procedure according to Fig. 15 may be contained as executable instructions stored in non-volatile memory. The method according to Fig. 15 may be performed in conjunction with the system hardware and other methods described herein to transform an operating state of an engine or its components.

[0226] At 1502, method 1500 determines a desired engine torque and a current engine speed. The engine speed may be determined via an engine position or speed sensor. Method 1500 proceeds to 1504.

[0227] At 1504, the method 1500 determines cylinder modes that can provide the desired engine torque. In one example, the cylinder modes that can provide the desired engine torque are as shown in Fig. 14 described.

[0228] At 1506, the procedure 1500 estimates the fuel consumption in cylinder modes that are permitted. The permitted cylinder modes are taken from 1406 in Fig. 14. In one example, a brake-specific fuel table or function that is based on cylinder modes from the approved cylinder modes to Fig. 14, engine speed, and desired engine torque. The values ​​stored in the brake-specific fuel table can be determined empirically and stored in the controller's memory. The brake-specific fuel consumption value can be adjusted using functions based on ignition timing from minimum spark for best torque (MBT); intake valve closing from a nominal intake valve closing time; engine air-fuel ratio; and engine temperature. The functions output empirically determined multipliers that modify the brake-specific fuel consumption value output from the table.The brake-specific fuel values ​​for each permitted cylinder mode at the current engine speed are output from the brake-specific fuel table. For example, based on the example described at 1406, the actual number of cylinders activated is three and four, since three- and four-cylinder modes provide the desired engine torque. Method 1500 proceeds to 1508.

[0229] At 1508, method 1500 compares the fuel consumption for the permitted cylinder modes that can provide the requested torque. In one example, the current engine fuel consumption, which can be determined from the current engine fuel flow rate, is compared to values ​​output from the brake-specific fuel table for permitted cylinder modes. The comparison may be performed by subtracting the values ​​output from the brake-specific fuel table from the current engine fuel consumption rate. Alternatively, the comparison may be based on dividing the current engine fuel consumption value by the values ​​output from the brake-specific fuel table. Cylinder modes that provide a percentage improvement in engine fuel economy greater than a threshold compared to the current cylinder mode are permitted.

[0230] Therefore, the cylinder modes and fuel consumption in the cylinder modes can be used to determine which cylinder mode the engine operates in. Furthermore, cylinder modes with lower fuel consumption can be given selection priority, thus saving fuel.

[0231] At this point, Fig. 16, which shows a method for evaluating a cam phase control rate for cam torque actuated cam phase adjustment. The method according to Fig. 16 can be integrated into the system that is Fig. 1A-6C. The procedure according to Fig. 16 may be contained as executable instructions stored in non-volatile memory. The method according to Fig. Method 1600 may be performed in conjunction with the system hardware and other methods described herein to convert an operating state of an engine or its components. Method 1600 may be performed for each camshaft of the engine.

[0232] At 1602, method 1600 determines engine conditions. The engine conditions may include, among other things, an actual total number of cylinder valves deactivated during an engine cycle, engine speed, driver demand torque, vehicle speed, engine temperature, and ambient temperature. Method 1600 proceeds to 1604 after the operating conditions are determined.

[0233] At 1604, method 1600 judges whether one or more cylinder valves are deactivated. Method 1600 may judge that one or more cylinders are deactivated based on a value of a bit stored in memory, an output from a sensor that measures valve actuator position, cylinder pressure sensors, or other sensors. If method 1600 judges that one or more cylinder valves are deactivated, the answer is yes and method 1600 proceeds to 1606. Otherwise, the answer is no and method 1600 proceeds to 1634.

[0234] At 1606, method 1600 assesses whether an adjustment of the camshaft position relative to the crankshaft position is desired. For example, method 1600 assesses whether it is desirable to advance the camshaft timing by 5 degrees relative to the crankshaft timing, such that the intake or exhaust valves open 5 degrees of crankshaft rotation earlier after the camshaft position has been adjusted. The camshaft position may be adjusted in response to the driver demand torque and engine speed. If the driver demand torque increases rapidly and the engine speed increases rapidly, it may be desirable to adjust the camshaft position relative to the crankshaft position at a faster rate so that the engine provides a desired level of torque and engine emissions.In one example, method 1600 determines whether adjustment of the camshaft position relative to the crankshaft position is desired based on a current camshaft position relative to the crankshaft position and a change in driver demand torque and engine speed. If method 1600 determines that adjustment of the camshaft position is desired, the answer is yes and method 1600 proceeds to 1608. Otherwise, the answer is no and method 1600 proceeds to 1634. In some examples, 1606 may be omitted, and method 1600 may simply proceed to 1608.

[0235] At 1608, method 1600 determines a desired rate of change in camshaft position relative to crankshaft position. In one example, method 1600 determines a desired rate of change in camshaft position based on a rate of change in driver demand torque. If the rate of change in driver demand torque is low, then the rate of change in camshaft position relative to crankshaft position is low. If the rate of change in driver demand torque is high, then the rate of change in camshaft position relative to crankshaft position is high. For example, the camshaft may be advanced at 0.5 degrees of crankshaft rotation per second when a change in driver demand torque is low (e.g., 5 Nm / second). However, if the change in driver demand torque is high (e.g., 200 Nm / second), the camshaft may be advanced at 5 degrees of crankshaft rotation per second.In one example, the desired rate of change in camshaft position relative to crankshaft position is determined empirically and stored in a table or function in memory. The table or function is populated based on a rate of change in driver demand torque, and the table or function outputs a desired rate of change in camshaft position relative to crankshaft position. Method 1600 proceeds to 1610 after the desired rate of change in camshaft position is determined.

[0236] At 1610, method 1600 judges whether an actual total number of energized cylinder valves (e.g., valves that open and close during an engine cycle) currently operating is sufficient to move the camshaft relative to the crankshaft at the desired rate. In one example, a table or function describes a camshaft rate of position change relative to the crankshaft position based on an actual total number of energized cylinder valves. The table is populated with the actual total number of energized valves, and it outputs a rate of change of the camshaft position relative to the crankshaft position. The values ​​in the table or function are empirically determined and stored in memory. The output from the table or function is compared to the value determined at 1608.If the camshaft rate of position change from 1610 is greater than the camshaft rate of position change from 1608, the answer is yes and method 1600 proceeds to 1634. Otherwise, the answer is no and method 1600 proceeds to 1612.

[0237] At 1612, method 1600 judges whether the camshaft drives both the intake and exhaust valves. In one example, a bit in memory determines that the camshaft drives only the intake valves if a value of the bit is zero. If the value of the bit is one, then the camshaft drives both the intake and exhaust valves. If method 1600 judges that the camshaft drives both the intake and exhaust valves, the answer is yes and method 1600 proceeds to 1630. Otherwise, the answer is no and method 1600 proceeds to 1614.

[0238] At 1614, method 1600 judges whether the camshaft is an intake camshaft. Method 1600 may judge whether the camshaft is an intake camshaft based on a value of a bit stored in memory. The bit may be programmed at the time of manufacture. If method 1600 judges that the camshaft is an intake camshaft, the answer is yes and method 1600 proceeds to 1616. Otherwise, the answer is no and method 1600 proceeds to 1620.

[0239] At 1620, method 1600 allows for the activation of one or more deactivated exhaust valves. In one example, the desired rate of change in exhaust camshaft position relative to the crankshaft position determined at 1608 is used to populate a table or function of empirically determined values ​​describing an actual total number of valves that must operate to provide the desired rate of adjustment of exhaust camshaft position relative to crankshaft position. Method 1600 requests or allows driving the actual total number of exhaust valves output by the table or function. The exhaust valves may be activated with or without activation of the cylinders comprising the exhaust valves being activated.If driver demand torque increases, the cylinders with exhaust valves being turned on may be turned on to increase engine torque while increasing the camshaft position change. If driver demand torque decreases, the cylinders with exhaust valves being turned on may not be turned on, thus reducing fuel consumption. Method 1600 proceeds to 1634.

[0240] At 1634, method 1600 moves the camshaft and drives valves for operating conditions that caused the camshaft to be moved. The camshaft may be moved while valves are energized to move the camshaft to a desired position as quickly as possible. Once the camshaft reaches its desired position relative to the crankshaft position, the cylinder valves may be deactivated based on vehicle conditions other than the desired rate of change in the camshaft position. Thus, valves may be reactivated to improve a rate at which a camshaft position moves relative to a crankshaft position. The engine cylinders may also be reactivated when the cylinder valves are reactivated. Method 1600 proceeds to end after the camshaft begins to move to its desired new position based on driver demand torque and engine speed.

[0241] At 1616, method 1600 allows for the activation of one or more deactivated intake valves. In one example, the desired rate of change in intake camshaft position relative to the crankshaft position determined at 1608 is used to populate a table or function of empirically determined values ​​describing an actual total number of valves that must operate to provide the desired rate of adjustment of intake camshaft position relative to crankshaft position. Method 1600 requests or allows the actual total number of intake valves output by the table or function to be driven. The cylinders that include the intake valves that are activated may be activated or they may not combust air and fuel during engine cycles in which intake valves are operated.In one example, cylinders with intake valves that are turned on combust air and fuel over the course of engine cycles in response to an increase in driver demand torque. Cylinders with intake valves that are turned on may not combust air and fuel during engine cycles in response to a decrease in driver demand torque. Deactivated intake valves may be used as in . Fig. 22 described.

[0242] Additionally, method 1600 may increase an amount of boost provided to the engine so that the additional boost can blow exhaust gases out of the cylinder before the exhaust valve of the cylinder being reactivated is closed. By removing exhaust gases from the cylinder, combustion stability may improve, and the cylinder may provide additional power. Additionally, an amount of overlap (e.g., opening time) between the intake and exhaust valves of the cylinder may be increased to further allow pressurized air from the intake manifold to clear the cylinder being activated. Method 1600 proceeds to 1634 after the intake valves are activated.

[0243] At 1630, method 1600 assesses whether engine noise, vibration, and harshness (NVH) are below threshold levels when one or more cylinders are reactivated and combustion occurs in the reactivated cylinders. In one example, method 1600 assesses whether reactivating one or more cylinders, including combustion of air and fuel in the reactivated cylinder, results in higher than desired NVH based on an output from a table or function describing engine and / or powertrain NVH. The table is populated via engine speed, driver demand torque, and the cylinder mode being activated (e.g., four- or six-cylinder mode). The table outputs a numerical value that is empirically determined, for example, via a microphone or accelerometer.If the output value is below a threshold, the answer is yes and procedure 1600 proceeds to 1632. Otherwise, the answer is no and procedure 1600 proceeds to 1640.

[0244] At 1632, method 1600 allows one or more cylinders to be energized by energizing the cylinder's valves and supplying fuel, air, and spark to the cylinder. The cylinder begins combusting air and fuel when reenergized. Therefore, if reenergizing one or more cylinders to increase the camshaft rate of position change causes little intrusive NVH, the cylinder is reenergized by reenergizing the cylinder's valves and commencing combustion in the reenergized cylinder. Method 1600 proceeds to 1634.

[0245] At 1640, method 1600 allows for the activation of one or more valves of a deactivated cylinder that is not combusting air and fuel. If the cylinder includes deactivated intake and exhaust valves, only the cylinder's exhaust valves may be activated to improve the rate of adjustment of the camshaft position relative to the crankshaft position. By reactivating the cylinder's exhaust valves alone, cam torque may be increased to improve the rate of adjustment of the camshaft position relative to the crankshaft position without allowing air to flow through the cylinder. Stopping airflow through the cylinder may help keep the catalyst temperature high and maintain a desired amount of oxygen in the catalyst.When both the cylinder's intake and exhaust valves are reactivated, air can flow through the cylinder after the intake and exhaust valves are activated. Spark and fuel are not delivered to cylinders with reactivated valves, preventing NVH from deteriorating. Method 1600 proceeds to 1642.

[0246] At 1642, method 1600 increases an amount of fuel supplied to an activated cylinder combusting air and fuel to enrich the mixture combusted by the activated cylinder when air flows through the cylinder for which one or more valves are permitted to be activated at 1640. By enriching the mixture of an activated cylinder combusting air and fuel while air flows through a cylinder, it may be possible to maintain desired levels of hydrocarbons and oxygen in a catalyst so that the catalyst can efficiently convert exhaust gases.For example, if cylinder number eight of an eight-cylinder engine has its own intake and exhaust valves reactivated while cylinder number eight is not combusting air and fuel, the air-fuel ratio of cylinder number one, which is combusting air and fuel, may be enriched to improve or maintain catalyst efficiency. Method 1600 proceeds to 1634 after the air-fuel ratio of at least one cylinder has been enriched.

[0247] Now with reference to Fig. 17 shows a sequence for operating an engine according to the method of Fig. 16. The vertical lines at time points T1700-T1704 represent relevant time points in the sequence. Fig. Figure 17 shows six representations, and the representations are time-aligned and occur simultaneously. In this example, the engine is a four-cylinder engine with a firing order of 1-3-4-2. Cylinders 2 and 3 have deactivation valve actuators to deactivate cylinders 3 and 4. The valves of cylinders 1 and 4 remain open at all times.

[0248] The first representation from above in Fig. Figure 17 is a plot of a camshaft motion request versus time. A camshaft motion request is a request to change a camshaft position relative to a crankshaft position. For example, if a camshaft has a lobe that begins to open an intake valve of an engine's number one cylinder 370 degrees of crankshaft rotation before top dead center of the compression stroke (e.g., crankshaft position at zero degrees), then the camshaft position can be moved relative to the crankshaft so that the camshaft lobe begins to open the engine's number one cylinder's intake valve at 380 degrees of crankshaft rotation before top dead center of the compression stroke. Accordingly, in this example, the camshaft's relative position is advanced by 10 degrees of crankshaft rotation relative to the crankshaft position.

[0249] The vertical axis represents the camshaft motion request. The camshaft motion request trace is at a higher level and is asserted when it is desired to move the engine camshaft relative to the engine crankshaft. The camshaft motion request trace is at a lower level and is not asserted when it is not desired to move the engine camshaft relative to the engine crankshaft. The horizontal axis represents time, and time increases from the left side of the figure to the right side of the figure.

[0250] The second illustration from the top in Fig. Figure 17 is a plot of camshaft position versus time. The vertical axis represents the camshaft position, and the camshaft is advanced further in the direction of the arrow on the vertical axis. The horizontal axis represents time, and time increases from the left side of the figure to the right side.

[0251] The third illustration from the top in Fig. Figure 17 is a representation of the state of the deactivation cylinder intake valve. In this example, the deactivation cylinder can be cylinder number two or cylinder number three. The state of the deactivation cylinder intake valve indicates whether the intake valve of the deactivation cylinder is on (e.g., opening and closing during an engine cycle) or off (e.g., held closed for an entire engine cycle). The vertical axis represents the state of the deactivation cylinder intake valve. The deactivation cylinder intake valve is on when the trace is at a higher level near the vertical axis arrow. The deactivation cylinder intake valve is off when the trace is at a lower level near the horizontal axis. The horizontal axis represents time, and time increases from the left side of the figure to the right side of the figure.

[0252] The fourth illustration from the top in Fig. Figure 17 is a representation of the state of the deactivation cylinder exhaust valve. In this example, the deactivation cylinder may be cylinder number two or cylinder number three. The state of the deactivation cylinder exhaust valve indicates whether the exhaust valve of the deactivation cylinder is on (e.g., opening and closing during an engine cycle) or off (e.g., held closed during an engine cycle). The vertical axis represents the state of the deactivation cylinder exhaust valve. The deactivation cylinder exhaust valve is on when the trace is at a higher level near the vertical axis arrow. The deactivation cylinder exhaust valve is off when the trace is at a lower level near the horizontal axis. The horizontal axis represents time, and time increases from the left side of the figure to the right side of the figure.

[0253] The fifth illustration from the top in Fig. Figure 17 is a diagram of the deactivation cylinder fuel flow state. In this example, the deactivation cylinder may be cylinder number two or cylinder number three. The deactivation cylinder fuel flow state indicates whether fuel is flowing to the deactivation cylinder or not. The vertical axis represents the deactivation cylinder fuel flow state. Fuel flows to the deactivation cylinder when the deactivation cylinder fuel flow trace is at a higher level near the vertical axis arrow. Fuel does not flow to the deactivation cylinder when the deactivation cylinder fuel flow trace is at a lower level near the horizontal axis. The horizontal axis represents time, and time increases from the left side of the figure to the right side of the figure.

[0254] The sixth illustration from the top in Fig. Figure 17 is a graph of the air-fuel ratio of the activated cylinder. In this example, the activated cylinder can be cylinder number 1 or cylinder number 4. The vertical axis represents the air-fuel ratio of the activated cylinder, and the air-fuel ratio increases (e.g., becomes leaner) in the direction of the vertical axis arrow. The horizontal axis represents time, and time increases from the left side of the figure to the right side of the figure. The horizontal line 1702 represents a stoichiometric air-fuel ratio.

[0255] At time T1700, there is no camshaft motion request, and the camshaft is relatively retarded. The deactivation cylinder intake valve state indicates that the deactivation cylinder intake valve is deactivated (e.g., not opening during an engine cycle). The deactivation cylinder exhaust valve state indicates that the deactivation cylinder exhaust valve is deactivated (e.g., not opening during an engine cycle). The activated cylinder is operating at a stoichiometric air-fuel ratio, and no fuel is flowing to the deactivation cylinder, as indicated by the deactivation cylinder fuel flow state being at a low level.

[0256] At time T1701, the camshaft motion request is asserted, requesting a change in camshaft position relative to an engine crankshaft position. The request may be initiated via an increase in driver demand torque or a change in another operating condition. The rate of change of the engine camshaft position relative to the engine crankshaft position (not shown) is greater than that achievable with the deactivation cylinder intake and exhaust valves deactivated because driving fewer valves provides less torque to actuate camshaft motion. Therefore, the deactivation cylinder intake and exhaust valves are reactivated, indicated by the deactivation cylinder intake and exhaust valve states transitioning to higher stages to indicate that the deactivation cylinder intake and exhaust valves are reactivated.Additionally, fuel flows to the deactivation cylinder, and combustion begins in the deactivation cylinder (not shown). The camshaft position is advanced while the deactivation cylinder intake and exhaust valves are activated. The air-fuel ratio of the activated cylinders is stoichiometric.

[0257] At time T1702, the camshaft motion request transitions to an unasserted state. The camshaft motion request may transition to unasserted when the camshaft reaches its destination. Furthermore, fuel flow to the deactivation cylinder stops, and combustion in the deactivation cylinder stops (not shown). The camshaft position reaches a moderately advanced position, and its position is maintained. The air-fuel ratios of the activated cylinders remain stoichiometric.

[0258] At time T1703, the camshaft motion request is reasserted, requesting a change in camshaft position relative to an engine crankshaft position. The request may be initiated via an increase in driver demand torque or a change in another operating condition. The rate of change of the engine camshaft position relative to the engine crankshaft position (not shown) is greater than that achievable with deactivation cylinder intake and exhaust valves deactivated because driving fewer valves provides less torque to actuate camshaft motion.Consequently, the deactivation cylinder's intake and exhaust valves are re-enabled, indicated by the deactivation cylinder intake and exhaust valve states transitioning to higher states to indicate that the deactivation cylinder's intake and exhaust valves are re-enabled. Fuel flow to the deactivation cylinders remains paused. In this example, combustion is not re-initiated in the deactivation cylinders because re-enablement of the deactivation cylinders is expected to produce greater than desired NVH levels. The camshaft position is advanced while the deactivation cylinder intake and exhaust valves are on.The air-fuel ratio of the activated cylinders is enriched so that when the enriched exhaust gas from the activated cylinders meets oxygen from the deactivated cylinders, stoichiometric exhaust gases are provided to the catalyst.

[0259] At time T1704, the camshaft motion request transitions to an unasserted state. The camshaft motion request may transition to unasserted when the camshaft reaches its destination. Further, the intake and exhaust valves of the deactivating cylinder are energized, as indicated by the deactivating cylinder intake and exhaust valve states. The camshaft position reaches a fully advanced position and is maintained. The air-fuel ratios of the energized cylinders return to stoichiometric air-fuel ratios by leaning the air-fuel mixtures of the deactivating cylinders.

[0260] For example, cylinder intake and exhaust valves that have been deactivated can be reactivated to provide faster engine camshaft position adjustments. Furthermore, stoichiometric exhaust gases can be supplied to a catalyst to maintain catalyst efficiency, regardless of whether air or exhaust gases are flowing from the deactivated cylinders.

[0261] At this point, Fig. 18, which shows a method for judging whether or not to shift transmission gears when evaluating cylinder mode changes. The method according to Fig. 18 can be integrated into the system that is Fig. 1A-6C. The procedure according to Fig. 18 may be contained as executable instructions stored in non-volatile memory. The method according to Fig. 18 may be performed in conjunction with the system hardware and other methods described herein to transform an operating state of an engine or its components.

[0262] At 1802, method 1800 determines a desired wheel torque. In one example, the desired wheel torque is based on the accelerator pedal position and the vehicle speed. For example, the accelerator pedal position and vehicle speed are entered into a table that outputs a desired wheel torque. The values ​​in the table may be empirically determined and stored in the controller's memory. In other examples, the accelerator pedal position and vehicle speed may be entered into a table that outputs a desired engine braking torque or torque at another powertrain location (e.g., transmission input shaft). The output from the table is multiplied by gear ratios between the torque location (e.g., engine), torque converter multiplication, and powertrain torque losses to estimate the desired wheel torque. Method 1800 proceeds to 1804.

[0263] At 1804, method 1800 determines the currently selected transmission gear. Method 1800 may determine the currently selected transmission gear via a value of a location in the controller's memory. For example, a variable in the memory may have a value range of 1-10, indicating the currently selected gear ratio. Method 1800 proceeds to 1806.

[0264] At 1806, method 1800 estimates the engine fuel consumption in cylinder modes that can provide the desired wheel torque in the current transmission gear. Method 1800 determines the engine brake-specific fuel consumption in the current transmission gear according to the method of Fig. 15. The procedure 1800 goes to 1808.

[0265] At 1808, method 1800 estimates the engine fuel consumption in cylinder modes that can provide the desired wheel torque in the next higher transmission gear. For example, if the transmission is currently in 3rd gear, the engine fuel consumption to provide equivalent wheel torque with the transmission in 4th gear is determined. In one example, method 1800 determines the engine brake-specific fuel consumption in the next higher transmission gear as follows: The current vehicle speed is divided by the gear ratio between the engine and the wheels, including the next higher transmission gear, to estimate the engine speed in the next higher transmission gear. The current wheel torque is divided by the gear ratio between the engine and the wheels to estimate the engine torque to provide equivalent wheel torque in the next higher transmission gear.The gear ratio between the engine and the wheels may also compensate for the torque converter, if present. Method 1800 determines cylinder modes that provide the desired wheel torque in the next higher transmission gear according to the method of . Fig. 14 using the estimate of the engine torque in the next higher transmission gear that provides a wheel torque equivalent to the current wheel torque. It should be noted that the present wheel torque may be the desired wheel torque. The estimated engine fuel consumption is then calculated as described in the method description of Fig. 15. Procedure 1800 proceeds to 1810.

[0266] At 1810, method 1800 estimates the engine fuel consumption in cylinder modes that can provide the desired wheel torque in the next lower transmission gear. For example, if the transmission is currently in 3rd gear, the engine fuel consumption to provide equivalent wheel torque with the transmission in 2nd gear is determined. In one example, method 1800 determines the engine brake-specific fuel consumption in the next lower transmission gear as follows: The current vehicle speed is divided by the gear ratio between the engine and the wheels, including the next lower transmission gear, to estimate the engine speed in the next higher transmission gear. The current wheel torque is divided by the gear ratio between the engine and the wheels to estimate the engine torque to provide equivalent wheel torque in the next lower transmission gear.The gear ratio between the engine and the wheels may also compensate for the torque converter, if present. Method 1800 determines cylinder modes that provide the desired wheel torque in the next lower transmission gear according to the method of [ ]. Fig. 14 using the estimate of the engine torque in the next lower transmission gear that provides a wheel torque equivalent to the current wheel torque. It should be noted that the present wheel torque may be the desired wheel torque. The estimated engine fuel consumption is then calculated as described in the method description of Fig. 15. The procedure from 1800 continues to 1812.

[0267] In some examples, method 1800 estimates engine fuel consumption in cylinder modes that can provide the desired wheel torque for all transmission gears. For example, if the transmission is currently in 3rd gear and the transmission includes five forward gears, the engine fuel consumption for providing equivalent wheel torque with the transmission in gears 1, 2, 4, and 5 is determined. In this way, it may be possible to select which gear provides the greatest improvement in vehicle fuel economy.

[0268] At 1812, method 1800 allows engagement of transmission gears and cylinder modes that provide a percentage reduction in engine fuel consumption greater than a threshold compared to the current cylinder mode and transmission gear. In one example, the engine brake-specific fuel consumption in engine cylinder modes that provide the desired engine torque or wheel torque in the next higher transmission gear is divided by the engine brake-specific fuel consumption in the current cylinder mode and transmission gear. If the result is greater than a threshold, the engine cylinder modes that provide the desired engine torque or wheel torque in the next higher transmission gear are allowed.Similarly, the engine fuel consumption in engine cylinder modes that provide the desired engine torque or wheel torque in the next lower transmission gear is compared to the engine fuel consumption in the current cylinder mode and current transmission gear. If the result is above a threshold, the engine cylinder modes that provide the desired engine torque or wheel torque in the next lower transmission gear are permitted. Additionally, method 1800 may require that an expected noise level and an expected vibration level in a new gear (e.g., a higher or lower gear than the current transmission gear) be below threshold noise and vibration levels. The noise and vibration levels may be as in . Fig. 22. Furthermore, the transmission may be shifted back to its previous gear state if an engine knock sensor or other sensor detects engine vibration that exceeds a threshold following a transmission gear change.

[0269] Now with reference to Fig. 19 shows a sequence for operating an engine according to the method of Fig. 18. The vertical lines at time points T1900-T1905 represent relevant time points in the sequence. Fig. Figure 19 shows four plots, and the plots are time-aligned and occur simultaneously. In this example, the vehicle is maintained at a constant speed, and the requested wheel torque is varied to maintain the constant vehicle speed. The vehicle includes a four-cylinder engine.

[0270] The first representation from above in Fig. Figure 19 is a plot of requested wheel torque versus time. In one example, the requested wheel torque is based on the accelerator pedal position and vehicle speed. The requested wheel torque increases in the direction of the vertical axis arrow. The horizontal axis represents time, and time increases from the left side of the figure to the right side of the figure.

[0271] The second illustration from the top in Fig. Figure 19 is a graph of the engaged transmission gear versus time. The vertical axis represents the currently engaged transmission gear, and the transmission gears are indicated on the vertical axis. The horizontal axis represents time, and time increases from the left side of the figure to the right side.

[0272] The third illustration from the top in Fig. Figure 19 is a plot of the actual total number of engine cylinders activated versus time. The actual total number of engine cylinders activated is shown on the vertical axis. The horizontal axis represents time, and time increases from the left side of the figure to the right side.

[0273] The fourth illustration from the top in Fig. Figure 19 is a plot of estimated engine fuel consumption versus time. The vertical axis represents estimated engine fuel consumption, and estimated engine fuel consumption increases in the direction of the vertical axis arrow. The horizontal axis represents time, and time increases from the left side of the figure to the right side of the figure. Trace 1902 represents engine fuel consumption when the engine is operating with the transmission in third gear. Trace 1904 represents engine fuel consumption when the engine is operating with the transmission in second gear.

[0274] At time T1900, the requested wheel torque is at a lower intermediate level and the transmission is in third gear. The actual total number of engine cylinders engaged is two, and the estimated engine fuel consumption is at an intermediate level.

[0275] Between time T1900 and time T1901, the requested wheel torque gradually increases. The engaged or current transmission gear is third gear, and the actual total number of engaged engine cylinders is two. The estimated engine fuel consumption for operating the engine in second gear is higher than the estimated engine fuel consumption for operating the engine in third gear.

[0276] At time T1901, the wheel torque has increased to a value at which the estimated engine fuel consumption for operating the engine while the transmission is in second gear is less than the estimated engine fuel consumption for operating the engine while the transmission is in third gear. Therefore, the transmission is downshifted to increase the vehicle's fuel efficiency.

[0277] The number of cylinders activated remains at a value of two, and the estimated fuel consumption increases with increasing requested wheel torque.

[0278] At T1902, the number of activated cylinders increases from two to three in response to the increase in requested wheel torque. The requested wheel torque and engine fuel consumption continue to increase. The transmission remains in second gear.

[0279] At T1903, the number of activated cylinders increases from three to four in response to the increase in requested wheel torque. The requested wheel torque and engine fuel consumption continue to increase. The transmission remains in second gear as the requested wheel torque increases.

[0280] At time T1904, the requested wheel torque decreases and has dropped to a level where the estimated engine fuel consumption to operate the vehicle in third gear is less than the estimated engine fuel consumption to operate the vehicle in second gear. Therefore, the transmission gear is shifted to third gear. The actual total number of activated cylinders is also decreased in response to the decreasing requested wheel torque.

[0281] At 1904, the requested wheel torque has dropped to a level where the actual total number of activated cylinders is reduced from three to two. The transmission remains in third gear, and the estimated engine fuel consumption decreases as the requested engine torque decreases.

[0282] At this point, Fig. 20, which shows a method for evaluating tow / pull modes to select the cylinder mode or VDE mode. The method according to Fig. 20 can be integrated into the system that is Fig. 1A-6C. The procedure according to Fig. 20 may be contained as executable instructions stored in non-volatile memory. The method according to Fig. 20 may be performed in conjunction with the system hardware and other methods described herein to transform an operating state of an engine or its components.

[0283] It may be more desirable to drive a cylinder with closed intake and exhaust valves and with air or exhaust trapped within the cylinder during an engine cycle because the vehicle can coast longer since the trapped air or exhaust provides a spring-like function that reduces cylinder braking torque. Furthermore, closing the intake and exhaust valves limits airflow to the catalyst in the exhaust system, so excess fuel may not need to be added to the engine exhaust to consume excess oxygen in the catalyst. However, during tow / haul and hill descent modes, it may be desirable to provide higher levels of cylinder braking torque, so it may be desirable to open and close intake and exhaust valves.

[0284] At 2002, method 2000 judges whether the engine is or should be in deceleration fuel cut-off mode. In deceleration fuel cut-off mode, one or more engine cylinders may be deactivated by stopping fuel flow to the cylinders. Further, gas flow through one or more cylinders may be stopped via deactivating intake valves, or intake and exhaust valves, of a cylinder that is deactivated in closed positions as the engine rotates through an engine cycle. Thus, deactivated cylinders do not combust air or fuel. In one example, method 2000 judges that the engine should be in deceleration fuel cut-off mode when driver demand decreases from a higher value to a lower value and vehicle speed is above a threshold speed.If Procedure 2000 judges that the engine should be in fuel-cut mode for deceleration, the answer is yes and Procedure 2000 proceeds to Procedure 2004. Otherwise, the answer is no and Procedure 2000 proceeds to Procedure 2020.

[0285] At 2020, Method 2000 drives all engine cylinders, and all cylinder valves are activated. Furthermore, all engine cylinders combust air and fuel mixtures. Alternatively, fewer than all engine cylinders may be activated if driver demand torque is low. Method 2000 proceeds to the end after the cylinders are activated.

[0286] At 2004, method 2000 judges whether the vehicle is in a tow or pull mode. In one example, method 2000 judges that the vehicle is in a tow or pull mode based on an operating state of a push button, switch, or variable in memory. If method 2000 judges that the vehicle is in a tow or pull mode, the answer is yes and method 2000 proceeds to 2006. Otherwise, the answer is no and method 2000 proceeds to 2030.

[0287] A vehicle may have a transmission that shifts according to a first shift schedule (e.g., transmission shifts based on driver demand torque and vehicle speed) when the vehicle is not in a tow or haul mode. The vehicle's transmission shifts according to a second shift schedule when in a tow or haul mode. The second shift schedule may upshift at higher driver demand torques and higher vehicle speeds than the first shift schedule. The second shift schedule may downshift at higher vehicle speeds to increase driveline braking.

[0288] At 2006, method 2000 determines a desired amount of engine braking torque for cylinders that are not combusting air and fuel. In one example, the desired amount of engine braking torque may be an empirically determined input to a table or function. The table or function may be populated using driver demand torque, vehicle speed, and transmission gear. The table outputs the desired engine braking torque (e.g., a negative braking torque that the engine provides to the powertrain to decelerate the vehicle powertrain). Method 2000 proceeds to 2008 after the desired engine braking torque is determined.

[0289] At 2008, method 2000 shifts the transmission gears according to a second gear shift schedule. For example, the transmission may upshift from first to second gear when the driver demand torque is above 50 Nm and the vehicle speed is 16 KPH. The second transmission gear shift schedule upshifts transmission gears at higher engine speeds and higher vehicle speeds than the first transmission gear shift schedule. The second transmission gear shift schedule also downshifts transmission gears at higher engine speeds and higher vehicle speeds than the first transmission gear shift schedule to provide additional engine braking compared to the first transmission gear shift schedule. The second transmission gear shift schedule upshifts transmission gears at lower engine speeds and lower vehicle speeds than the third transmission gear shift schedule.The second transmission shift map downshifts transmission gears at lower engine speeds and lower vehicle speeds than the third transmission shift map to provide less engine braking compared to the third transmission shift map. Method 2000 proceeds to 2010 after the transmission gears are shifted according to the second transmission shift map.

[0290] At 2010, method 2000 determines the cylinder deactivation mode of each deactivated cylinder to achieve the desired engine braking torque provided across deactivated cylinders. Note that cylinder deactivation mode is different from cylinder mode. Cylinder deactivation mode defines how the valves of a deactivated cylinder are driven, while cylinder mode defines the actual total number of activated cylinders and the cylinders that are activated. In one example, a cylinder with intake and exhaust valves that open and close during an engine cycle without fuel injection (e.g., a first cylinder deactivation mode) and combustion is assigned a first braking torque. A cylinder with intake valves held closed throughout an engine cycle and exhaust valves that open and close throughout the engine cycle without fuel injection (e.g.,A cylinder with intake and exhaust valves held closed throughout an engine cycle without fuel injection (e.g., a third cylinder deactivation mode) is assigned a second braking torque. The first braking torque is greater than the second braking torque, and the second braking torque is greater than the third braking torque. Therefore, the engine cylinders can provide three levels of braking torque in three different cylinder deactivation modes, and the desired braking torque can be provided by driving different cylinders at different levels of braking torque generation.

[0291] Furthermore, the assigned braking torque values ​​for each of the three cylinder deactivation modes can be adjusted by adjusting the timing of intake valve closure. For example, the assigned braking torque values ​​can be increased by delaying the timing of intake valve closure. Similarly, the assigned braking torque values ​​can be decreased by advancing the timing of intake valve closure.In one example, a valve timing compensation function, fed via intake valve closure timing outputs, outputs a value multiplied by the assigned first braking torque, the assigned second braking torque, and the assigned third braking torque to provide valve timing compensated cylinder braking torque values ​​used to determine valve timing compensated braking torque values ​​provided by the cylinders in the various cylinder modes. Additionally, an atmospheric pressure compensation function, fed after atmospheric pressure, outputs a value multiplied by the valve timing compensated braking torque values ​​to provide atmospheric pressure and valve timing compensated braking torque values ​​provided by the cylinders in the various cylinder deactivation modes.The intake and exhaust valve timing for each cylinder deactivation mode can be adjusted to increase or decrease the braking torque provided by the three cylinder deactivation modes based on atmospheric pressure and the desired engine braking torque. For example, if atmospheric pressure decreases and the desired braking torque increases, the intake valve timing can be retarded in each of the three cylinder deactivation modes to compensate for the lower atmospheric pressure and higher desired braking torque.

[0292] In one example, method 2000 determines the valve actuation for the engine cylinders according to the desired engine braking torque and the amount of valve timing and atmospheric pressure compensated braking torque each cylinder provides in the various operating modes. For example, in the case of a four-cylinder engine whose desired engine braking torque is 2.5 Nm, the deactivation modes of each cylinder are based on the valve timing and atmospheric pressure compensated braking torques the cylinders provide in the three different cylinder deactivation modes described above. If a cylinder provides 0.25 Nm of braking torque in the first cylinder deactivation mode, 0.5 Nm in the second cylinder deactivation mode, and 1 Nm in the third cylinder deactivation mode, the four-cylinder engine operates with two cylinders in the third cylinder deactivation mode and two cylinders in the first cylinder deactivation mode.

[0293] The cylinder deactivation mode for each cylinder may be determined using method 2000, which evaluates the engine braking torque for all engine cylinders operating in the first cylinder deactivation mode. If the engine braking torque to operate the engine with all cylinders in the first cylinder deactivation mode is greater than or equal to the desired engine braking torque, then all engine cylinders are allowed to operate in the first cylinder deactivation mode, in which the intake and exhaust valves are held closed while the engine rotates over the course of one engine cycle. If the engine braking torque to operate the engine with all cylinders in the first cylinder deactivation mode is less than the desired engine braking torque, then an engine braking torque is determined to operate the engine with one cylinder in the second cylinder deactivation mode and three cylinders in the first cylinder deactivation mode.If the engine braking torque for operating the engine with one cylinder in the second cylinder deactivation mode and three cylinders in the first cylinder deactivation mode is greater than or equal to the desired engine braking torque, one cylinder is permitted to operate in the second cylinder deactivation mode and three cylinders are permitted to operate in the first cylinder deactivation mode. Otherwise, an engine torque for operating the engine with two cylinders in the second cylinder deactivation mode and two cylinders in the first cylinder deactivation mode is determined. In this manner, the cylinder deactivation modes of each cylinder can be sequentially incremented from the first cylinder deactivation mode to the third cylinder deactivation mode until the engine cylinder deactivation modes that provide the desired engine braking torque are determined.

[0294] If the vehicle is not in tow / haul or hill descent mode, it may be determined to be in a fuel-saving mode during deceleration conditions. Therefore, an actual number of engine cylinders with intake and exhaust valves held closed during an engine cycle and not combusting air and fuel may be increased to improve the vehicle's coast-down time and fuel economy. For example, the intake and exhaust valves of all engine cylinders may be commanded to be held closed during an engine cycle. Method 2000 proceeds to 2050.

[0295] At 2050, method 2000 allows deactivation of the engine cylinders and their deactivation modes that provide the desired engine braking torque. According to the cylinder deactivation modes, the valves are allowed to be on or off, and no fuel is injected into the cylinders, so that no combustion occurs in the cylinders during the deceleration fuel deactivation mode.

[0296] At 2030, method 2000 judges whether the vehicle is in a hill descent mode. In one example, method 2000 judges that the vehicle is in a hill descent mode based on an operating state of a push button, a switch, or a variable in memory. If method 2000 judges that the vehicle is in a hill descent mode, the answer is yes and method 2000 proceeds to 2032. Otherwise, the answer is no and method 2000 proceeds to 2040.

[0297] In one example, the vehicle is regulated to a requested or desired speed when the accelerator pedal is not applied via regulating the negative torque generated in hill descent mode via the engine and vehicle brakes. The vehicle may activate hill descent mode via a release of the accelerator pedal. Furthermore, engine braking in hill descent mode may be regulated via adjusting the engine valve timing. Furthermore, the transmission gears may be shifted to provide desired braking at the vehicle wheels via the engine.

[0298] At 2032, method 2000 determines a desired amount of engine braking torque for cylinders that are not combusting air and fuel. In one example, the desired amount of engine braking torque may be an empirically determined input to a table or function. The table or function may be specific to the hill descent mode and different from the table or function for the tow / haul mode. The table or function may be populated via the driver demand torque, vehicle speed, and transmission gear. The table outputs the desired engine braking torque (e.g., a negative braking torque that the engine provides to the powertrain to decelerate the vehicle powertrain). Method 2000 proceeds to 2034 after the desired engine braking torque is determined.

[0299] At 2034, method 2000 shifts the transmission gears according to a third gear shift schedule. The third transmission gear shift schedule upshifts transmission gears at higher engine speeds and higher vehicle speeds than the first and second transmission gear shift schedules. The third transmission gear shift schedule also downshifts transmission gears at higher engine speeds and higher vehicle speeds than the first and second transmission gear shift schedules to provide additional engine braking compared to the first and second transmission gear shift schedules. Method 2000 proceeds to 2010 after the transmission gears are shifted according to the third transmission gear shift schedule.

[0300] At 2040, method 2000 determines a desired amount of engine braking torque for cylinders that are not combusting air and fuel. In one example, the desired amount of engine braking torque may be an empirically determined input to a table or function. The table or function may be specific to the fuel cut-off mode, other than tow / haul mode or hill descent mode. The table or function may be populated via the driver demand torque, vehicle speed, and transmission gear. The table outputs the desired engine braking torque (e.g., a negative braking torque that the engine provides to the powertrain to decelerate the vehicle powertrain). Method 2000 proceeds to 2042 after the desired engine braking torque is determined.

[0301] At 2042, method 2000 shifts the transmission gears according to a first gear shift schedule. The first transmission gear shift schedule upshifts transmission gears at lower engine speeds and lower vehicle speeds than the second and third transmission gear shift schedules. The first transmission gear shift schedule also downshifts transmission gears at lower engine speeds and lower vehicle speeds than the second and third transmission gear shift schedules to provide less engine braking compared to the second and third transmission gear shift schedules. Method 2000 proceeds to 2010 after the transmission gears are shifted according to the first transmission shift schedule.

[0302] This allows cylinders to operate in different modes, where valves can be turned on or off to regulate engine braking while stopping fuel flow to the engine cylinders. Different cylinders can operate in different modes to provide the desired engine braking torque.

[0303] Now with reference to Fig. 21 shows a sequence for operating an engine according to the method of Fig. 20. The vertical lines at time points T2100-T2108 represent relevant time points in the sequence. Fig. 21 shows six representations and the representations are aligned in time and occur simultaneously.

[0304] The first representation from above in Fig. Figure 21 is a plot of a deceleration fuel cut-off state versus time. The vertical axis represents the deceleration fuel cut-off state. The engine is in deceleration fuel cut-off mode when the trace is at a higher level near the vertical axis arrow. The engine is not in deceleration fuel cut-off mode when the trace is at a lower level near the horizontal axis. The horizontal axis represents time, and time increases from the left side of the figure to the right side of the figure.

[0305] The second illustration from the top in Fig. Figure 21 is a plot of downhill mode versus time. The vertical axis represents downhill mode, and the vehicle is in downhill mode when the trace is at a higher level near the vertical axis arrow. The vehicle is not in downhill mode when the trace is at a lower level near the horizontal axis. The horizontal axis represents time, and time increases from the left side of the figure to the right side of the figure.

[0306] The third illustration from the top in Fig. Figure 21 is a plot of the towing / hauling state versus time. The vertical axis represents the towing / hauling mode, and the vehicle is in towing / hauling mode when the tracing is at a higher level near the vertical axis arrow. The vehicle is not in towing / hauling mode when the tracing is at a lower level near the horizontal axis. The horizontal axis represents time, and time increases from the left side of the figure to the right side of the figure.

[0307] The fourth illustration from the top in Fig. Figure 21 is a graph of gear ratio versus time. The vertical axis represents the gear ratio, and gear ratios are indicated on the vertical axis. The horizontal axis represents time, and time increases from the left side of the figure to the right side.

[0308] The fifth illustration from the top in Fig. Figure 21 is a plot of the cylinder poppet valve state versus time. The vertical axis represents the state of the cylinder poppet valve. The poppet valve state can be on (e.g., poppet valves open and close during an engine cycle), off (e.g., poppet valves do not open and close during an engine cycle), partially on (PA) (e.g., intake valves are held closed during an engine cycle and exhaust valves open and close over the engine cycle). The horizontal axis represents time, and time increases from the left side of the figure to the right side of the figure.

[0309] The sixth illustration from the top in Fig. Figure 21 is a graph of fuel injection state versus time. The vertical axis represents the fuel injection state, and the fuel injection state is on when the trace is near the vertical axis arrow. Fuel injection is off when the trace is near the horizontal axis. The horizontal axis represents time, and time increases from the left side of the figure to the right side of the figure.

[0310] At time 2100, the engine cylinders are energized, and the cylinder valves are opening and closing throughout the engine cycle as the engine rotates and combusts air and fuel, as the poppet valves are energized and no fuel cutoff for deceleration is indicated. The vehicle is neither in hill descent nor tow / haul mode. The vehicle's transmission is in third gear, and all cylinder poppet valves are energized (e.g., opening and closing throughout the engine cycle). Fuel injection is energized, and fuel is being delivered to the engine cylinders.

[0311] At 2101, the engine enters fuel cut-off deceleration mode. The engine may enter fuel cut-off deceleration mode in response to a low driver demand torque and the vehicle speed being above a threshold. The vehicle is neither in hill descent nor tow / haul mode. The vehicle's transmission is in third gear, and all cylinder poppet valves are deactivated (e.g., not opening and closing over the engine cycle). The cylinder poppet valves are deactivated, causing the engine cylinders to deactivate in a third cylinder deactivation mode in response to a low engine braking torque (not shown). Exhaust or fresh air is also trapped within the cylinder, creating a spring-like effect on the piston. The closed intake and exhaust valves reduce engine pumping losses and may increase the distance the vehicle coasts.Closing the engine's intake and exhaust valves also stops the engine from pumping fresh air to the catalyst in the exhaust system, so the catalyst isn't cooled as much as if fresh air were flowing to the catalyst. Furthermore, the amount of oxygen stored in the catalyst isn't increased, allowing the catalyst's efficiency to remain high when the engine cylinders resume combustion. Fuel injection to the engine's cylinders is also stopped, so no combustion occurs in the engine cylinders.

[0312] At time 2102, the engine exits the deceleration fuel cutoff mode, and the cylinder poppet valves are re-enabled, as indicated by the poppet valve state history. Fuel injection is also re-enabled, and combustion begins in the engine cylinder. The engine may exit the deceleration fuel cutoff mode in response to an increase in driver demand torque or vehicle speed below a threshold. The vehicle is neither in hill descent mode nor in tow / haul mode. The vehicle's transmission is in third gear.

[0313] At time 2103, the vehicle enters hill descent mode. The vehicle can enter hill descent mode by a driver pressing a push button or other input device. The vehicle is not in fuel cut-off deceleration mode, and it is not in tow / haul mode. The vehicle's transmission is in third gear, and the cylinder poppet valves are on. Additionally, fuel is being injected into engine cylinders, and the engine is combusting air and fuel.

[0314] At time 2104, the engine enters the fuel cut-off mode for deceleration while in hill descent mode. The vehicle is not in tow / haul mode, and the transmission is in third gear. The cylinder poppet valves are partially deactivated in response to a mid-level engine braking torque request while the engine is rotating (e.g., intake valves are held closed during an engine cycle, and exhaust valves open and close during the engine cycle). The engine cylinders are in a second cylinder deactivation mode when the engine braking torque is at the mid-level. However, engine cylinders may enter the first mode if the vehicle is accelerating at a higher rate than desired. Similarly, the engine cylinders may enter the third cylinder deactivation mode if the vehicle is decelerating faster than desired.Fuel injection is turned off, so there is no combustion in engine cylinders.

[0315] At time 2105, the vehicle exits the deceleration fuel cutoff mode in response to increasing driver demand torque or increasing vehicle speed below a threshold speed (not shown). The vehicle remains in hill descent mode, and the transmission is in third gear. The vehicle is not in tow / haul mode, and the cylinder poppet valves are re-enabled. Fuel injection to the engine cylinders is also re-enabled, allowing the engine cylinders to resume combustion of air and fuel.

[0316] Between time 2105 and time 2106, the vehicle exits hill descent mode. The driver can request exit from hill descent mode by providing an input to the vehicle or engine controller. The other engine / vehicle states remain at their previous levels.

[0317] At time 2106, the vehicle enters tow / haul mode. The vehicle may enter tow / haul mode by a driver pressing a pushbutton or switch that provides an input to the vehicle or engine controller. The other engine / vehicle states remain at their previous levels.

[0318] At time 2107, the engine enters fuel cut-off deceleration mode in response to low driver demand torque and a vehicle speed exceeding a threshold speed. The vehicle is also in tow / haul mode. The vehicle's transmission is briefly downshifted to second gear after entering fuel cut-off deceleration mode to increase engine braking via an increase in engine speed (not shown). In response to a higher level engine braking torque request (not shown), all engine cylinder poppet valves remain energized. Fuel injection to the engine cylinders is terminated, and the engine does not combust air and fuel when the engine is rotating. Driving all cylinder valves while the engine throttle is closed (not shown) increases engine pumping losses and engine braking torque.

[0319] At 2108, the vehicle exits the deceleration fuel cutoff mode in response to reducing an increase in driver demand torque or engine speed to a level below a threshold. The vehicle remains in tow / haul mode, and the cylinder poppet valves remain enabled.

[0320] In this way, cylinder modes can be used in which cylinder poppet valves are driven differently to vary the engine braking torque, allowing a desired engine braking torque to be provided by the vehicle's engine. Furthermore, some engine cylinders can be in a first operating mode, while other engine cylinders are in a second or third operating mode, allowing the desired engine braking torque to be provided.

[0321] At this point, Fig. 22, in which a method for selecting a cylinder mode from available cylinder modes is shown. The method according to Fig. 22 can be integrated into the system that is Fig. 1A-6C. The procedure according to Fig. 22 may be contained as executable instructions stored in non-volatile memory. The method according to Fig. 22 may be performed in conjunction with the system hardware and other methods described herein to transform an operating state of an engine or its components.

[0322] At 2202, method 2200 assesses whether baseline conditions exist to enable cylinder modes in which cylinders may be deactivated. The baseline conditions may include, but are not limited to, engine temperature above a threshold, exhaust aftertreatment temperature above a threshold, battery state of charge above a threshold, and engine speed above a threshold. Method 2200 checks whether the conditions exist or not by monitoring various system sensors. If method 2200 assesses that baseline conditions for cylinder deactivation and variable displacement engine operation exist, the answer is yes and method 2200 proceeds to 2204. Otherwise, the answer is no and method 2200 proceeds to 2220.

[0323] At 2220, method 2200 requests that all engine cylinders be turned on and combusting air and fuel. The intake and exhaust valves of the turned-on cylinders open and close during an engine cycle, allowing air and combustion products to flow through the turned-on cylinders. Spark and fuel delivery are also turned on, allowing fuel-air mixtures to be combusted in the turned-on cylinders. Method 2200 proceeds to end.

[0324] At 2204, method 2200 estimates noise, vibration, and harshness (NVH) in the available cylinder modes. In one example, a noise table outputs empirically determined expected levels of audible noise for the engine / vehicle. The noise table is populated via the actual total number of engine cylinders engaged, engine speed, and engine torque. A vibration table outputs empirically determined expected levels of audible noise for the engine / vehicle. The vibration table is populated via cylinder mode, engine speed, and engine torque. The values ​​for noise and vibration are output for the current engine speed, the engine speed after a transmission gear shift, the current driver demand torque, and the driver demand torque after a transmission shift. Additionally, method 2200 may use the outputs of vibration sensors (e.g.,an engine knock sensor) and acoustic sensors to threshold levels, with the purpose of eliminating currently engaged cylinder deactivation modes that cannot provide a desired level of noise and vibration. Method 2200 proceeds to 2206.

[0325] At 2206, method 2200 evaluates noise and vibration outputs from the noise and vibration tables. If the expected noise level from a table output exceeds a threshold, or if the expected vibration level from a table output exceeds a threshold, the cylinder mode that provided the expected noise and vibration is excluded from the currently available cylinder modes. For example, if the expected engine noise for operating a four-cylinder engine in a second cylinder mode with two cylinders on at 2000 RPM exceeds a threshold at the current driver demand torque or the driver demand torque after a transmission shift, then the second cylinder mode at 2000 RPM is excluded from a list of available cylinder modes.

[0326] Alternatively, or additionally, method 2200 may compare noise and vibration sensor outputs to thresholds. If engine noise exceeds a threshold in a currently enabled cylinder mode, the currently enabled cylinder mode is excluded from the available cylinder modes so that a cylinder mode providing less engine noise may be selected. Similarly, if engine noise exceeds a threshold in a currently enabled cylinder mode, the currently enabled cylinder mode is excluded from the available cylinder modes so that a cylinder mode providing less engine noise may be selected.

[0327] Additionally, method 2200 may allow for cylinder modes where the expected cylinder blowby air (e.g., the airflow from the engine intake manifold to the engine exhaust manifold not involved in combustion) is expected to be below a threshold immediately after a cylinder mode change. It may be desirable to avoid cylinder mode changes when the cylinder blowby air is above the threshold to avoid interfering oxygen in a downstream engine catalyst. The engine cylinder blowby amount may be determined in accordance with U.S. Patent Publication US 2013 / 0 111 900 A1, filed November 9, 2011, which is hereby incorporated by reference in its entirety for all purposes. In one example, a table or function outputs an engine or cylinder blowby amount based on cylinder mode, engine speed, and cylinder valve timing.If the output from the table is below the limit, cylinder mode can be permitted. Procedure 2200 proceeds to 2208.

[0328] At 2208, the method allows 2200 cylinder modes that are available and that have not been excluded from the available cylinder modes. Furthermore, transmission gears that are available and have not been excluded are allowed. Cylinder modes may be allowed such that they ultimately result in operating the engine at 716 in Fig. 7 can be selected. A cylinder mode in which all engine cylinders are turned on is always a permitted cylinder mode unless engine or valve wear is present. In one example, a matrix containing cells representing cylinder modes is used to track permitted and excluded cylinder modes. Cylinder modes can be permitted by inserting a value of one into cells corresponding to available cylinder modes. Cylinder modes can be excluded by inserting a value of zero into cells corresponding to cylinder modes that are unavailable or have been excluded from engine operation. As previously noted, different cylinder modes can have an equal number of total actual cylinders turned on while having different cylinders turned on.For example, if it is determined desirable to operate three cylinders of a four-cylinder engine to meet the driver demand torque, cylinder mode numbers three and four may be permitted, with cylinder mode three having a firing order of 1-3-2 and cylinder mode four having a firing order of 3-4-2. During one engine cycle, cylinder mode three may be engaged. During a subsequent engine cycle, cylinder mode four may be engaged. In this manner, the engine firing order may be varied while maintaining an actual total number of engaged cylinders. Method 2200 proceeds to exit.

[0329] In this way, it can be identified which cylinder deactivation modes should be enabled or excluded. Furthermore, any basic conditions must be met before available cylinder modes can be made permissible for engine operation.

[0330] At this point, Fig. 23, which shows a method for regulating engine intake manifold absolute pressure (MAP) during a deceleration fuel cut-off mode. The method according to Fig. 23 can be integrated into the system that is Fig. 1A-6C. The procedure according to Fig. 23 may be contained as executable instructions stored in non-volatile memory. The method according to Fig. 23 may be performed in conjunction with the system hardware and other methods described herein to transform an operating state of an engine or its components.

[0331] At 2302, method 2300 judges whether the engine is or should be in deceleration fuel cut-off mode. In deceleration fuel cut-off mode, one or more engine cylinders, which may include all engine cylinders, may be shut down by stopping fuel flow to the cylinders. Further, gas flow through one or more cylinders may be stopped via shutting off intake valves, or intake and exhaust valves, of a cylinder that is shut down in closed positions as the engine rotates through an engine cycle. In one example, method 2300 judges that the engine should be in deceleration fuel cut-off mode when driver demand decreases from a higher value to a lower value and vehicle speed is above a threshold speed.If method 2300 judges that the engine should be in fuel cut-off mode for deceleration, the answer is yes and method 2300 proceeds to 2304. Otherwise, the answer is no and method 2300 proceeds to 2320.

[0332] At 2320, method 2300 operates the engine to provide a desired amount of torque. The desired amount of torque may be a driver demand torque or may be based on the driver demand torque. The engine valves are turned on as requested to provide the desired torque, and the engine combusts air and fuel to provide the desired torque. Method 2300 proceeds to exit after the desired amount of torque is provided.

[0333] At 2304, method 2300 determines a desired intake manifold pressure and an actual total number of cylinder intake valve opening events (e.g., the intake valves of each cylinder open once during an intake stroke of the cylinder with opening intake valves) or intake strokes of cylinders introducing air to reduce the intake manifold pressure to a desired intake manifold pressure. The actual total number of cylinder intake valve opening events may be a better indicator of intake manifold pressure than the time required to pump down the intake manifold pressure. In one example, the methods described in U.S. Patent US 6,708,102 B2 or U.S. Patent US 6,170,475 B1, which are hereby incorporated by reference for all purposes, may be used to estimate the pressure in the intake manifold for a desired number of intake valve opening events or intake strokes in the future.For example, in response to the activation of the fuel-cutoff mode for deceleration, the throttle may follow a predetermined path from its current position to a fully closed position. The predicted throttle position may be estimated from the predetermined path using the following equation: θ(k+1)=θ(k)+[θ(k)−θ(k−1)]

[0334] Where θ(k + 1) is the estimate of the throttle position at the next engine intake event; θ(k) is the measured throttle position at the current engine intake event; and θ(k - 1) is the measured throttle position at the previous engine intake event.

[0335] The gas in the engine's intake manifold is fresh air, and the pressure in the engine intake manifold is directly related to the cylinder air charge. The throttle position, the pressure in the intake manifold, the temperature in the intake manifold, and the engine speed are determined by various engine sensors. The starting point for determining the development of the pressure in the intake manifold is a standard dynamic model, which regulates the change in the pressure in the intake manifold as follows: Pm=RTV(MAF−Mcyl) where T is the temperature in the intake manifold as measured by the intake manifold temperature sensor, V is the volume of the intake manifold, R is the specific gas constant, MAF is the mass flow rate in the intake manifold and M cyl is the flow rate into the cylinder. The mass flow rate into the cylinders (M cyl) is represented as a linear function of the pressure in the intake manifold, where the slope and the y-intercept depend on the engine speed and the ambient conditions as follows: Mcyl=α1(N)Pm−α2(N)PambPamb_nom where P amb and P amb_nom represent the current ambient pressure and the nominal value for the ambient pressure (e.g., 101 kPa). The engine pumping parameters α1(N) and α2(N) are regressed from the static engine mapping data obtained at nominal ambient conditions. After substituting this expression into the dynamic equation for the intake manifold pressure and differentiating both sides to obtain the rate of change for the intake manifold pressure, one obtains: P¨m=RTV[ddtMAF−α1P˙m−α˙1Pm−α˙2PambPamb_nom]

[0336] The dynamics governing the change in engine speed are slower than the intake manifold dynamics. A good compromise between performance and simplicity is to retain α1 (slope) and omit α2 (y-intercept). With this simplification, the second derivative of P m given by: P¨M=RTV[ddtMAF−α1P˙m−α˙1Pm]

[0337] To discretize the above equation, dP m (k) as a discrete version of the time derivative of P m defined, i.e. dP m (k)=(P m (k+1)-P m (k)) / Δt, which gives us: dPm(k+1)=(1−ΔTα1(N(k)RTV)dPm+RTV[MAF(k+1)−MAF(K−1)]−RTV[α1(N(k+1))−α1(N(k))]Pm(k)

[0338] Thus, the equation defines the predicted rate of change of intake manifold pressure around one engine event in the future, which is used to determine future intake manifold pressure values. However, the signals from the next (k+1) time point are not available at time k. To implement the right-hand side, instead of its value at time k+1, we use the one-event-before predicted value for the MAF signal at time k, which was obtained using the one-event-before-the-throttle-position prediction, as follows: MAF+1(k)=PambPamb_nomTamb_nomTambC(θ+1(k))Fn_Untersonic(Pm(k)+ΔtdP+1m(k−1)Pamb) where P amb and P amb_nom represent the current and nominal (ie 101 kPa) absolute ambient pressure, T amb and T amb_nomrepresents the current and nominal (i.e., 300 K) absolute ambient temperature, and C(e) is the throttle sound flow characteristic obtained from the static engine data. Fn_subsonic is the standard correction for subsonic flow: FnSubsonic={14.96501[(PmPamb)1.42959−(PmPamb)1.7148] if PmPamb≥0.528451.0 if PmPamb<0.52845} where P m (k) is the current intake manifold pressure measurement. For in-vehicle implementation, the Fn_Subsonic function can be implemented as a tabulated pressure ratio lookup function. In this case, the slope range should be limited to prevent oscillation under wide-open throttle conditions, possibly by extending the zero crossing of the function to a pressure ratio value just above 1.

[0339] Several different choices are available to obtain the quantity MAF(k) to be used to determine the future rate of change of intake manifold pressure. The following formula, which uses the previous value for the predicted throttle position and the current value for intake manifold pressure, provides the best performance in terms of overshoot and stability at wide-open throttle: MAF(k)=PambPamb_nomTamb_nomTambC(θ+1(k−1))Fn_Untersonic(Pm(k)Pamb)

[0340] To avoid predicting the engine speed, instead of using the current value of α1 from the prediction one step before, we approximate α1 by subtracting the old value of one event from the current one. The above changes result in the dP m -signal the value predicted for the time derivative for P m, ie the rate of change of the future pressure in the intake manifold: dPn+1(k)=(1−Δtα1(N(k))RTV)dPm+1(k−1)+RTV[MAF+1(k)−MAF(k)]−RTV[α1(N(k))−α1(N(k−1))]Pm(k)

[0341] It should be noted that the value for dP m +1 (k) depends only on the signals available at intake event k. Therefore, it can be used to predict intake manifold pressure as follows: Pm+1(k)=Pm(k)+ΔtdPm+1(k−1) Pm+2(k)=Pm(k)+ΔtdPm+1(k−1)+ΔtdPm+1(k) where P m +1 (k) and P m +2(k) Predictions are one and two steps ahead of the intake manifold pressure. The equations for the evolution of the intake manifold pressure are extended beyond two intake events in the future, to a number of intake events that provide the desired intake manifold pressure. In one example, the desired intake manifold pressure may be empirically determined and stored in memory during deceleration mode. For example, the desired intake manifold pressure may be empirically determined and stored in memory based on atmospheric pressure and vehicle speed. In one example, the desired engine intake manifold pressure is a pressure in the intake manifold when the engine is operating at idle speed when the driver demand torque is zero or substantially zero (e.g., less than 10 Nm). Further, the desired engine intake manifold pressure may be adjusted depending on the ambient pressure.For example, if ambient pressure increases, the desired engine intake manifold pressure may be decreased. Method 2300 proceeds to 2306 after determining the desired engine intake manifold pressure and the number of cylinder intake events required to achieve the desired engine intake manifold pressure.

[0342] At 2306, method 2300 fully closes the engine throttle and completes all engine intake events after the number of intake events determined at 2304 to provide the desired engine intake manifold pressure has been performed. For example, if it is determined at 2304 that the desired intake manifold pressure is 75 kPa and that the desired intake manifold pressure can be achieved if the throttle closes in four cylinder intake valve opening events, cylinder intake valves, and in some cases exhaust valves, are closed, such that a total effective number of cylinder intake events after the deceleration fuel cutoff is enabled is four.In this way, the cylinder valves are closed based on an actual total number of intake valve opening events since a deceleration fuel cut-off mode request to provide a desired intake manifold pressure. Once the cylinder valves are closed, the engine may be started without needing to evacuate air from the intake manifold. Consequently, less fuel may be used to enrich the engine exhaust to improve catalyst efficiency. Furthermore, the engine may operate with less spark retard when cylinders are reactivated because the cylinder charge is below full charge. Method 2300 proceeds to 2308.

[0343] At 2308, method 2300 closes the engine intake manifold for all vacuum consumers. Vacuum consumers may include, but are not limited to, vacuum reservoirs; vehicle brakes; heating, ventilation, and cooling systems; and vacuum actuators such as turbocharger wastegates. When the vacuum in some systems (e.g., brakes) is reduced below a threshold, the systems may be closed via opening a valve 176, as shown in Fig. 1B, vacuum may again access the engine intake manifold. Further, during such conditions, the valves may be reactivated so that the engine may provide additional vacuum to vacuum consumers. In one example, selective access to the pressure in the engine intake manifold is provided to vacuum consumers via one or more solenoid valves. Method 2300 proceeds to 2310.

[0344] At 2310, method 2300 operates a vacuum source to maintain the intake manifold pressure of the engine at the desired level. When air is leaking from the throttle, the intake manifold pressure may increase, so if the engine is restarted with the intake manifold pressure at atmospheric pressure, more fuel may be used to start the engine than desired. Consequently, if the engine is restarted with a higher intake manifold pressure than desired, the engine's fuel consumption may increase more than desired. Therefore, the vacuum source may be turned on in response to the intake manifold pressure being higher than the desired intake manifold pressure, so that the intake manifold pressure is lower than atmospheric pressure (e.g., there is a vacuum in the intake manifold).Electrical energy generated from the vehicle's kinetic energy or a battery may be supplied to the vacuum source. Additionally, the vacuum source may be activated to evacuate air from the vacuum reservoir in response to a slight negative pressure in the vacuum reservoir. Method 2300 proceeds to 2312.

[0345] At 2312, method 2300 ceases fuel flow and spark delivery to engine cylinders. Air introduced during intake events after the throttle begins to close, where the intake events correspond to the actual number of intake valve opening events determined at 2304, is combined with fuel and combusted before terminating fuel and spark delivery to engine cylinders. Method 2300 proceeds to 2314.

[0346] At 2314, method 2300 assesses whether conditions exist to exit fuel cut-off for deceleration. In one example, fuel cut-off for deceleration may be exited in response to a driver demand torque being above a threshold or vehicle speed being below a threshold. If method 2300 assesses that conditions exist to exit fuel cut-off for deceleration mode, the answer is yes, and method 2300 proceeds to 2316. The engine continues to rotate during fuel cut-off for deceleration because some of the engine's kinetic energy may be transferred to the engine. Otherwise, method 2300 returns to 2310.

[0347] At 2316, method 2300 reactivates the cylinder valves so that the valves open and close during an engine cycle. Fuel flow and spark discharge are also provided to the cylinders. Combustion is resumed in the cylinders, and the engine throttle position is adjusted to provide the desired engine airflow and engine torque. The cylinder valve timing and throttle positions may be empirically determined values ​​stored in memory, which is populated based on engine speed and engine demand torque (e.g., driver demand torque). Method 2300 proceeds to exit.

[0348] In this way, the pressure in the engine's intake manifold can be regulated to improve cylinder reactivation and combustion in engine cylinders so that fuel consumption can be reduced and catalyst balance (e.g., the balance between hydrocarbons and oxygen in the catalyst) can be restored, with less fuel being delivered to the engine and / or catalyst.

[0349] Now with reference to Fig. 24 shows a sequence for operating an engine according to the method of Fig. 23. The vertical lines at time points T2400-T2408 represent relevant time points in the sequence. Fig. 24 shows six representations and the representations are aligned in time and occur simultaneously.

[0350] The first representation from above in Fig. Figure 24 is a plot of a deceleration fuel cut-off state versus time. The vertical axis represents the deceleration fuel cut-off state. The engine is in deceleration fuel cut-off mode when the trace is at a higher level near the vertical axis arrow. The engine is not in deceleration fuel cut-off mode when the trace is at a lower level near the horizontal axis. The horizontal axis represents time, and time increases from the left side of the figure to the right side of the figure.

[0351] The second illustration from the top in Fig. Figure 24 is a plot of absolute engine manifold pressure (MAP) versus time. The vertical axis represents MAP, and MAP increases in the direction of the vertical axis arrow. The horizontal axis represents time, and time increases from the left side of the figure to the right side of the figure. The horizontal line 2402 represents a desired MAP during the deceleration fuel cut-off mode.

[0352] The third illustration from the top in Fig. Figure 24 is a plot of engine throttle position versus time. The vertical axis represents engine throttle position, and engine throttle position increases in the direction of the vertical axis arrow. The horizontal axis represents time, and time increases from the left side of the figure to the right side of the figure.

[0353] The fourth illustration from the top in Fig. Figure 24 is a plot of the state of the vacuum source versus time. The vertical axis represents the operating state of the vacuum source (e.g., the operating state of the vacuum pump), and the vacuum source is on when the trace is near the vertical axis arrow. The vacuum source is off when the trace is near the horizontal axis. The horizontal axis represents time, and time increases from the left side of the figure to the right side of the figure.

[0354] The fifth illustration from the top in Fig. Figure 24 is a graph of the fuel supply state versus time. The vertical axis represents the fuel supply state, and fuel is supplied to the engine cylinders when the trace is near the vertical axis arrow. Fuel is not supplied to the engine cylinders when the trace is near the horizontal axis. The horizontal axis represents time, and time increases from the left side of the figure to the right side of the figure.

[0355] The sixth illustration from the top in Fig. Figure 24 is a plot of the vacuum pickup state versus time. The vertical axis represents the vacuum pickup state, and the vacuum pickup state is on when the trace is near the vertical axis arrow. The vacuum pickups are not on when the trace is near the horizontal axis. Vacuum pickups are not in pneumatic communication with the engine intake manifold when the vacuum pickup trace is at a lower level. Vacuum pickups are in pneumatic communication with the engine intake manifold when the vacuum pickup trace is at a higher level. The horizontal axis represents time, and time increases from the left side of the figure to the right side of the figure.

[0356] At time T4200, the engine is not in deceleration fuel cut-off mode, indicated by the deceleration fuel cut-off state at a lower level. The engine MAP is relatively high, indicating a higher engine load. The throttle position is largely open, and the vacuum device state is off, indicating that the vacuum source is not engaged. Fuel is being supplied to engine cylinders, indicated by the high fuel state. The vacuum pickups are operating and capable of tapping vacuum based on the vacuum pickup state.

[0357] At time 2402, the engine transitions to the deceleration fuel cut-off mode, indicated by the desired fuel cut-off state trace increasing from a lower level to a higher level. The engine may enter the deceleration fuel cut-off mode in response to a reduction in driver demand torque and the vehicle speed being above a threshold. The throttle is also closed in response to entering the deceleration fuel cut-off mode. Likewise, fuel flow to engine cylinders is shut off, indicated by the fuel state trace being at a lower level. The vacuum pickup state decreases to a lower level to indicate that the vacuum pickups are blocked from receiving vacuum from the engine intake manifold.By blocking airflow from vacuum pickups into the engine intake manifold, intake manifold pressure may be reduced so that a large amount of fuel is not needed to restart the engine with stoichiometric air-fuel ratios in engine cylinders. Cylinder valves are also closed in response to entry into deceleration fuel cut-off mode. A total actual number of intake valve opening events may be performed in response to activation of deceleration fuel cut-off mode before airflow through engine cylinders is stopped by closing cylinder intake valves over one or more engine cycles while the engine continues to rotate. The total actual number of intake valve opening events may be a number that provides a desired engine intake manifold pressure.In some examples, engine intake valves and exhaust valves may be closed across an engine cycle in response to a deceleration fuel cut-off mode being activated.

[0358] Between 2402 and 2404, the MAP is reduced and the engine remains in fuel cut-off mode for deceleration. The MAP is reduced to a level of the desired MAP 2402. In one example, the MAP is reduced to a desired MAP 2402 by opening cylinder intake valves an actual total number of times based on an estimate of intake manifold pressure reaching 2402.

[0359] At 2404, the MAP rises to a level above 2402 due to air leakage from the engine throttle or other airflow into the engine intake manifold. The vacuum source is turned on in response to the increased MAP, lowering the MAP to 2402. The engine remains in deceleration fuel cut-off mode and the throttle remains closed. The engine continues to rotate (not shown) and fuel flow to the engine cylinders is stopped. The cylinder intake valves remain deactivated and closed (not shown) through each engine cycle. The vacuum source is turned off in response to the MAP being lower than 2402, shortly after it is turned on. The vacuum source state indicates the ON and OFF states of the vacuum source.

[0360] At 2406, the MAP increases a second time to a level above 2402 due to air leakage from the engine throttle or other airflow into the engine intake manifold. The vacuum source is turned on in response to the increased MAP, lowering the MAP to 2402. The engine remains in deceleration fuel cut-off mode and the throttle remains closed. The engine continues to rotate (not shown) and fuel flow to the engine cylinders is stopped. The cylinder intake valves remain deactivated and closed (not shown) through each engine cycle. The vacuum source is turned off in response to the MAP being lower than 2402, shortly after it is turned on. The vacuum source state indicates the ON and OFF states of the vacuum source.

[0361] At time T2408, the engine exits the deceleration fuel cut-off mode while intake manifold pressure is low. The engine may exit the deceleration fuel cut-off mode in response to an increase in driver demand torque. The lower intake manifold pressure may reduce the use of spark retard and conserve fuel to reactivate engine cylinders and the catalyst in the engine exhaust system. The engine cylinders are reactivated by delivering fuel to the cylinders and reactivating cylinder valves (not shown). The vacuum pickups are also reactivated by enabling communication between the vacuum pickups and the engine intake manifold. MAP increases as the throttle is opened.

[0362] In this way, MAP can be controlled during deceleration fuel-cut mode to reduce fuel consumption. Furthermore, powertrain torque disturbances can be reduced because the engine is started with a lower air charge compared to starting with atmospheric pressure in the engine intake manifold.

[0363] At this point, Fig. 25, which shows a method for controlling absolute engine intake pressure during cylinder reactivation after entering a deceleration fuel cut-off mode. The method according to Fig. 25 can be integrated into the system that is Fig. 1A-6C. The procedure according to Fig. 25 may be contained as executable instructions stored in non-volatile memory. The method according to Fig. 25 may be performed in conjunction with the system hardware and other methods described herein to transform an operating state of an engine or its components.

[0364] At 2502, method 2500 judges whether the cylinders and valves are deactivated during a deceleration fuel cut-off mode. In one example, method 2500 may judge that engine cylinders are deactivated (e.g., not combusting air and fuel mixtures while the engine is rotating) and valves are deactivated (e.g., held closed, not opening and closing while the engine is rotating over an engine cycle) when a bit in memory is a predetermined value. Note that all or only a portion of the engine cylinders may be deactivated. If method 2500 judges that the engine cylinders and valves are deactivated during the deceleration fuel cut-off mode, the answer is yes, and method 2500 proceeds to 2504. Otherwise, the answer is no, and method 2500 proceeds to 2540.

[0365] At 2540, method 2500 operates engine cylinders and valves to provide a desired torque. The desired torque may be based on an accelerator pedal position or a torque determined by a controller. The engine cylinders are turned on by supplying fuel to the cylinders. The valves are turned on by activating valve actuators. Further, volumetric efficiency actuators are adjusted to different positions than at 2508 for a same engine speed and torque demand to improve vehicle emissions and fuel economy. Method 2500 proceeds to end.

[0366] At 2504, method 2500 judges whether cylinder reactivation is requested. Cylinder reactivation may be requested in response to an increase in driver demand torque or a vehicle speed below a threshold speed. If method 2500 judges that cylinder reactivation is requested, the answer is yes and method 2500 proceeds to 2506. Otherwise, method 2500 proceeds to 2550.

[0367] At 2550, procedure 2500 maintains the cylinders in a deactivated state. The cylinders are not supplied with fuel, and the cylinder valves remain deactivated. Procedure 2500 proceeds to the end.

[0368] At 2506, method 2500 judges whether the engine intake manifold pressure exceeds a desired threshold pressure. If the engine intake manifold pressure is above a threshold pressure, engine cylinders may produce more torque than desired, or spark timing may be retarded to reduce engine torque. If the engine intake manifold pressure is greater than desired, cylinders may burn more fuel than desired to provide stoichiometric exhaust gases. Therefore, it may be desirable to reduce the engine intake manifold pressure as early as possible when deactivating engine cylinders so that fuel can be conserved. If method 2500 judges that the intake manifold pressure exceeds the threshold pressure, the answer is yes and method 2500 proceeds to 2508. Otherwise, the answer is no and method 2500 proceeds to 2520.The limit pressure can vary with engine speed, vehicle speed and ambient pressure.

[0369] At 2520, method 2500 adjusts engine volumetric efficiency actuators and engine throttle based on engine speed and driver demand torque. In one example, the driver demand torque is based on the accelerator pedal position and vehicle speed. The engine volumetric efficiency actuators may include, but are not limited to, engine camshafts, charge motion control valves, and variable plenum volume valves. The positions of the volumetric efficiency actuators may be empirically determined and stored in a table in memory that is maintained via the driver demand torque and engine speed. Different tables output different positions for the camshafts, charge motion control valves, and variable plenum volume valves. Method 2500 proceeds to 2522.

[0370] At 2522, method 2500 reactivates the engine cylinders and cylinder valves. The cylinders are reactivated by supplying fuel and spark to the cylinders. The cylinder poppet valves are reactivated by reactivation valve actuators. The valve actuators may be part of a Fig. 5B, other valve actuators described herein, or other known valve actuators. Activating the valve actuators causes the intake valves to open and close during an engine cycle. After the engine cylinders are activated, method 2500 proceeds to exit.

[0371] At 2508, method 2500 commands engine volumetric efficiency actuators to increase engine volumetric efficiency before reactivating engine cylinders and valves. The volumetric efficiency actuators are commanded to increase engine volumetric efficiency at the current engine speed and current driver demand torque, compared to adjusting the volumetric efficiency actuators in response to engine speed and driver demand torque. In one example, cylinder charge motion control valves are fully opened to reduce resistance to flow entering the engine cylinders. Further, intake valve timing and exhaust valve timing are adjusted via camshaft timing to provide no intake and exhaust valve overlap (e.g., opening intake and exhaust valves simultaneously).Furthermore, intake valve timing may be advanced or retarded to maximize in-cylinder air at the time of intake valve closure. The variable plenum volume valve is adjusted to minimize intake manifold volume. Engine throttle is not adjusted when adjusting engine volumetric efficiency actuators. Engine boost pressure may also be increased to increase engine volumetric efficiency via closing a turbocharger wastegate or bypass valve. Method 2500 proceeds to 2510 after the engine volumetric efficiency actuators are adjusted.

[0372] At 2510, method 2500 reactivates the engine cylinders and cylinder valves. The cylinders are reactivated by supplying fuel and spark to the cylinders. The cylinder poppet valves are reactivated by sequence valve actuators. The valve actuators may be part of a sequence as described in Fig. 5B, other valve actuators described herein, or other known valve actuators. Activating the valve actuators causes the intake valves to open and close during an engine cycle. After activating the engine cylinders, method 2500 proceeds to 2512.

[0373] At 2512, method 2500 judges whether the engine intake manifold pressure is at a desired pressure. The desired pressure may be determined empirically and based on engine speed and driver demand torque. If method 2500 judges that the engine intake manifold pressure is at the desired engine intake manifold pressure, the answer is yes, and method 2500 proceeds to 2514. Otherwise, the answer is no, and method 2500 returns to 2512.

[0374] At 2514, method 2500 commands engine volumetric efficiency actuators and engine throttle based on engine speed and driver demand torque. The positions of the volumetric efficiency actuators may be determined empirically and stored in a table in memory, which is maintained based on driver demand torque and engine speed. Different tables output different positions for the camshafts, charge motion control valves, and variable plenum volume valves. Method 2500 proceeds to the end.

[0375] Now with reference to Fig. 26 shows a sequence for operating an engine according to the method of Fig. 25. The vertical lines at time points T2600-T2405 represent relevant time points in the sequence. Fig. 26 shows six representations and the representations are aligned in time and occur simultaneously.

[0376] The first representation from above in Fig. Figure 24 is a plot of cylinder deactivation request versus time. The vertical axis represents the cylinder deactivation request. Cylinder deactivation is requested when the cylinder deactivation request trace is at a higher level near the vertical axis arrow. Cylinder deactivation is not requested when the cylinder deactivation request trace is at a lower level near the horizontal axis. The horizontal axis represents time, and time increases from the left side of the figure to the right side of the figure.

[0377] The first representation from above in Fig. Figure 26 is a plot of cylinder state versus time. The vertical axis represents the cylinder state. The cylinder is shut down when the cylinder state trace is at a lower level near the horizontal axis. The cylinder is not shut down when the cylinder state trace is at a higher level near the vertical axis. The horizontal axis represents time, and time increases from the left side of the figure to the right side of the figure.

[0378] The third illustration from the top in Fig. Figure 26 is a plot of engine intake manifold pressure versus time. The vertical axis represents engine intake manifold pressure, and engine intake manifold pressure increases in the direction of the vertical axis arrow. The horizontal axis represents time, and time increases from the left side of the figure to the right side of the figure. Horizontal line 2602 represents a desired engine intake manifold pressure during a deceleration shutdown. The level at 2602 may represent the same pressure as when the engine is operating at idle speed and there is no driver demand torque.

[0379] The fourth illustration from the top in Fig. Figure 26 is a plot of the engine's volumetric efficiency actuator state versus time. The vertical axis represents the engine's volumetric efficiency actuator state, and the engine's volumetric efficiency actuator increases the engine's volumetric efficiency in the direction of the vertical axis arrow. The engine's volumetric efficiency actuator state decreases the engine's volumetric efficiency when the trace is near the horizontal axis. The horizontal axis represents time, and time increases from the left side of the figure to the right side of the figure.

[0380] The fifth illustration from the top in Fig. Figure 26 is a plot of engine throttle position versus time. The vertical axis represents the engine throttle position, and the throttle opening increases as the trace is closer to the vertical axis arrow. The throttle opening decreases as the trace is closer to the horizontal axis. The horizontal axis represents time, and time increases from the left side of the figure to the right side of the figure.

[0381] The sixth illustration from the top in Fig. Figure 26 is a plot of driver demand torque versus time. The vertical axis represents driver demand torque, and driver demand torque increases toward the vertical axis. Driver demand torque decreases when the driver demand torque trace is near the horizontal axis. The horizontal axis represents time, and time increases from the left side of the figure to the right side of the figure.

[0382] At time T2600, the cylinder deactivation request is not asserted, and the cylinder state is asserted to indicate that engine cylinders are on and combusting air and fuel. The engine intake manifold pressure is at a higher level, and the engine throttle position is open more than a midpoint. The engine volumetric efficiency actuators (e.g., camshafts, charge motion control valves, and variable plenum volume valves) are in the midpoint position to provide a midpoint level of engine volumetric efficiency. The driver demand torque is at a midpoint.

[0383] At time T2601, the cylinder deactivation request is asserted. The cylinder deactivation request is asserted in response to a decrease in driver demand torque, and the engine may be in fuel cut-off mode for deceleration. The engine throttle position is also decreased in response to the decrease in driver demand torque. The cylinder state transitions to unasserted to indicate that engine cylinders are deactivated in response to the cylinder deactivation request. The pressure in the engine intake manifold decreases in response to the throttle closing. The cylinder intake valves of cylinders are closed after the throttle closes and after an actual total number of cylinder intake events have reduced the pressure in the intake manifold to a desired level 2602. The cylinder exhaust valves may also be closed (not shown).The engine's intake valves are kept closed for one or more engine cycles when the cylinders are deactivated. Fuel flow to the cylinders is also shut off (not shown). The position of the engine volumetric efficiency actuators remains unchanged.

[0384] Between time T2601 and time T2602, the engine's intake manifold pressure (MAP) increases in response to air escaping into the engine intake manifold. Air is not evacuated from the engine intake manifold because the cylinder intake valves are closed. The cylinder deactivation request remains asserted, and the cylinders remain deactivated. The throttle position remains in a fully closed state, and driver demand remains low.

[0385] At time T2602, the position of the engine volumetric efficiency actuators is adjusted to increase engine volumetric efficiency in anticipation of reactivation of engine cylinders. The engine volumetric efficiency actuators are not adjusted to positions based on engine speed and driver demand torque. Rather, they are adjusted to positions that increase engine volumetric efficiency beyond engine volumetric efficiency positions the actuators provide when adjusted in response to engine speed and driver demand torque. In this example, the position of volumetric efficiency actuators is adjusted in response to engine intake manifold pressure exceeding a desired engine intake manifold pressure 2602. By adjusting the volumetric efficiency actuators in response to MAP, undesirable changes in the volumetric efficiency actuator positions can be avoided.The pressure in the engine intake manifold increases from a pressure below 2602 to a pressure above 2602. However, the engine volumetric efficiency actuators may be adjusted for a predetermined period of time after cylinders are deactivated or in response to a request to reactivate engine cylinders. Alternatively, the position of the engine volumetric efficiency actuators may be adjusted to increase engine volumetric efficiency in response to the cylinder deactivation request. In one example, camshaft timing is advanced or retarded to maximize the air introduced from the engine intake manifold into engine cylinders (e.g., camshaft timing is adjusted to provide higher cylinder pressure at the time of intake valve closure).Furthermore, the overlap between the intake valve opening and exhaust valve opening is set to zero or negative to reduce airflow into the cylinder from the exhaust system (not shown). The engine throttle position and driver demand torque remain unchanged.

[0386] At time T2603, the cylinder deactivation request is transitioned to unasserted in response to an increase in driver demand torque. The cylinder deactivation request may transition to unasserted in response to an increase in driver demand torque or a vehicle speed that is below a threshold speed (not shown). Shortly thereafter, the engine cylinders are re-enabled (e.g., intake and exhaust valves open and close each engine cycle, and spark and fuel are combusted within the engine cylinders), indicated by the cylinder state transitioning to the cylinder-on indication. Further, the position of the volumetric efficiency actuators is adjusted to a position based on engine speed and driver demand torque. The throttle position shifts in response to the driver demand torque.

[0387] Between time T2603 and time T2604, driver demand torque increases and then decreases. The throttle position also increases and decreases in response to the driver demand torque. The pressure in the engine's intake manifold increases and then decreases below 2602.

[0388] At time T2604, cylinder deactivation is requested a second time. However, because the engine intake manifold pressure is below level 2602, the position of the volumetric efficiency actuators is not adjusted. The engine cylinders are deactivated (e.g., combustion in the cylinders is inhibited by stopping fuel flow and spark delivery to the cylinders, and cylinder valves are also deactivated, keeping them closed for one or more engine cycles), as indicated by the cylinder state trace transitioning to a lower level.

[0389] At time T2605, the cylinder deactivation request transitions to unasserted in response to the vehicle speed being below a threshold (not shown). The engine cylinders are also reactivated, indicated by the cylinder state trace transitioning to a higher level. The volumetric efficiency actuator positions are not adjusted in response to the deactivation request being unasserted because the engine intake manifold pressure is lower than 2602.

[0390] In this way, MAP can be regulated when exiting a cylinder deactivation state to save fuel and reduce torque disturbances. The volumetric efficiency actuators are adjusted to increase the amount of air introduced into the engine cylinders so that the pressure in the engine's intake manifold is reduced soon after the engine cylinders are reactivated.

[0391] At this point, Fig. 27A and Fig. 27B, which shows a method for determining engine torque over cylinder modes. The method according to the Fig. 27A and Fig. 27B can be integrated into the system that is Fig. 1A-6C. The procedure according to Fig. 27A and Fig. 27B can be included as executable instructions stored in non-volatile memory. The method according to the Fig. 27A and Fig. 27B may be performed in conjunction with the system hardware and other methods described herein to transform an operating state of an engine or its components.

[0392] At 2702, method 2700 assesses whether there is a request to decrease an actual total number of active cylinders (e.g., cylinders with valves that open and close during an engine cycle and cylinders that combust air and fuel during an engine cycle). Method 2700 may assess that there is a request to decrease an actual total number of active cylinders in response to a decrease in driver demand torque, vehicle speed being above a threshold, and / or other conditions. If method 2700 assesses that there is a request to decrease an actual total number of active cylinders, the answer is yes and method 2700 proceeds to 2704. Otherwise, the answer is no and method 2700 proceeds to 2714.

[0393] At 2704, method 2700 determines a desired advance for volumetric efficiency actuators to decrease an actual total number of activated cylinders. The advance for the volumetric efficiency actuators is a period of time between a time at which positions of volumetric efficiency actuators are adjusted to decrease a total number of activated cylinders and a time at which cylinder deactivation begins. Adjusting the advance time for the volumetric efficiency actuators may smooth engine torque and provide time for the volumetric efficiency actuators to reach desired positions before cylinder deactivation begins, so that the engine does not provide more or less torque than desired. In one example, the advance time is empirically determined and stored in memory.

[0394] Furthermore, the advance time value stored in memory may be adjusted based on a difference between the desired cylinder air charge and the actual cylinder air charge during a transition that decreases the actual total number of cylinders activated. The advance time value is retrieved from memory. Method 2700 proceeds to 2706.

[0395] At 2706, method 2700 arranges engine volumetric efficiency actuators, including an amount of boost pressure provided by a turbocharger, to increase the engine volumetric efficiency. For example, boost pressure may be increased, charge movement control valves may be fully opened, plenum volume intake valves may be arranged to decrease intake manifold volume, compressor bypass valves may be at least partially closed, and camshaft timing is adjusted to maximize cylinder filling at the time of intake valve closure. Engine boost pressure may be increased via closing a wastegate or closing the compressor bypass valve. Adjusting the positions of engine volumetric efficiency actuators increases the volumetric efficiency of cylinders that remain energized after the actual total number of energized cylinders is decreased. Further, the engine's central throttle may be adjusted at the same time (e.g.,simultaneously) at least partially closed, at which time the aforementioned engine volumetric efficiency actuators are adjusted. Closing the central throttle maintains the engine airflow rate while engine volumetric efficiency actuators are adjusted to increase the engine volumetric efficiency. Method 2700 proceeds to 2708.

[0396] At 2708, selected cylinders are deactivated after the lead time expires. The cylinders are deactivated by keeping the cylinder's intake valves closed for one or more engine cycles while the engine is rotating. In some examples, exhaust valves of the cylinders being deactivated may also be kept closed for one or more engine cycles while the engine is rotating. Further, fuel flow and spark are not delivered to cylinders being deactivated. While the cylinders are deactivated, the central throttle is snapped open and fueling is increased to activated cylinders such that torque generated by activated cylinders counteracts any torque loss due to cylinder deactivation. Method 2700 proceeds to 2710.

[0397] At 2710, method 2700 adjusts spark timing in response to an error between a desired engine airflow and an actual engine airflow. The desired engine airflow is the engine airflow based on the driver demand torque at the time of the cylinder deactivation request. The actual engine airflow is the airflow measured using an airflow sensor. For example, if the actual engine airflow is greater than the desired engine airflow, the engine airflow error is negative and spark timing is retarded to maintain engine torque. If the actual engine airflow is less than the desired engine airflow, the engine airflow error is positive and spark timing is advanced to maintain engine torque. Method 2700 proceeds to 2712.

[0398] At 2712, method 2700 assesses whether the engine volumetric efficiency actuators are in their desired positions. For example, method 2700 assesses whether the actual engine boost pressure matches the desired engine boost pressure. Further, method 2700 assesses whether the actual camshaft timing matches the desired camshaft timing. Similarly, method 2700 assesses whether the actual position of the charge motion control valve matches the desired position of the charge motion control valve. Method 2700 may assess that volumetric efficiency actuators are in their desired positions based on one or more sensors, such as an intake manifold pressure sensor. If the engine volumetric efficiency actuators are in their desired positions, the answer is yes and method 2700 proceeds to 2714.Otherwise, the answer is no and method 2700 returns to 2706 to provide more time to shift the engine volumetric efficiency actuators.

[0399] At 2714, method 2700 adjusts the engine's central throttle to provide a desired engine torque. The desired engine torque may be based on a driver demand torque. Method 2700 proceeds to 2720.

[0400] At 2720, method 2700 assesses whether there is a request to increase an actual total number of active cylinders (e.g., cylinders with valves that open and close during an engine cycle and cylinders that combust air and fuel during an engine cycle). Method 2700 may assess that there is a request to increase an actual total number of active cylinders in response to an increase in driver demand torque, vehicle speed being below a threshold, and / or other conditions. If method 2700 assesses that there is a request to increase an actual total number of active cylinders, the answer is yes and method 2700 proceeds to 2722. Otherwise, the answer is no and method 2700 proceeds to exit.

[0401] At 2722, the engine commands volumetric efficiency actuators, including an amount of boost pressure provided by a turbocharger, to decrease the volumetric efficiency of the engine. For example, boost pressure may be decreased, charge motion control valves may be at least partially closed, plenum volume intake valves are commanded to increase intake manifold volume, and camshaft timing is adjusted to reduce cylinder filling at the time of intake valve closure. Adjusting the positions of engine volumetric efficiency actuators decreases the volumetric efficiency of cylinders that are activated before the actual total number of activated cylinders is decreased. Further, the central throttle of the engine is at least partially opened at the same time (e.g., simultaneously) that the aforementioned engine volumetric efficiency actuators are adjusted.Opening the central throttle maintains the engine airflow rate while adjusting engine volumetric efficiency actuators to decrease the engine volumetric efficiency.

[0402] Additionally, in some examples, a time overlap of intake valve and exhaust valve opening of engine cylinders (e.g., activated cylinders and / or cylinders being activated) may be increased in response to a turbocharger wastegate position one cylinder cycle prior to cylinder reactivation. The turbocharger wastegate position may be indicative of the exhaust pressure in deactivated cylinders, which include exhaust valves opening and closing while the cylinder is deactivated. However, in other examples, the amount of overlap may be based on an amount of residual exhaust gas in the cylinder. For example, the amount of overlap may be increased as the amount of residual exhaust gas in the cylinder increases.If the deactivated cylinders include non-deactivation exhaust valves, boost pressure may be reduced less than if the cylinder is configured with deactivation exhaust valves because the exhaust density in cylinders with non-deactivation cylinders may be higher for all other things being equal, as the exhaust in cylinders with non-deactivation cylinders may be cooler. Method 2700 proceeds to 2724.

[0403] At 2724, selected cylinders are re-enabled. The cylinders are re-enabled by opening and closing intake valves of the cylinders over one or more engine cycles while the engine is rotating. In some examples, the exhaust valves of the re-enabled cylinders may also be opened and closed over one or more engine cycles while the engine is rotating. Further, fuel flow and spark are delivered to cylinders that are re-enabled. As the cylinders are re-enabled, the central throttle is snapped shut and fueling is reduced to energized cylinders such that torque generated by energized cylinders counteracts an increase in torque due to the re-enablement of cylinders. Method 2700 proceeds to 2726.

[0404] At 2726, method 2700 adjusts spark timing in response to an error between a desired engine airflow and an actual engine airflow. The desired engine airflow is the engine airflow based on the driver demand torque at the time of the cylinder deactivation request. For example, if the actual engine airflow is greater than the desired engine airflow, the engine airflow error is negative, and spark timing is retarded to maintain engine torque. If the actual engine airflow is less than the desired engine airflow, the engine airflow error is positive, and spark timing is advanced to maintain engine torque. Method 2700 proceeds to 2728.

[0405] At 2728, method 2700 assesses whether the engine volumetric efficiency actuators are in their desired positions. For example, method 2700 assesses whether the actual engine boost pressure matches the desired engine boost pressure. Further, method 2700 assesses whether the actual camshaft timing matches the desired camshaft timing. Similarly, method 2700 assesses whether the actual position of the charge motion control valve matches the desired position of the charge motion control valve. Method 2700 may assess that volumetric efficiency actuators are in their desired positions based on one or more sensors, such as an intake manifold pressure sensor. If the engine volumetric efficiency actuators are in their desired positions, the answer is yes and method 2700 proceeds to 2714.Otherwise, the answer is no and method 2700 returns to 2706 to provide more time to shift the engine volumetric efficiency actuators.

[0406] At 2730, method 2700 adjusts the engine's central throttle to provide a desired engine torque. The desired engine torque may be based on a driver demand torque. Method 2700 proceeds to exit.

[0407] In this way, the positions of an engine's volumetric efficiency actuators can be adjusted as the actual total number of active cylinders increases or decreases. By moving the volumetric efficiency actuators at the same time as the engine's central throttle is moved, disturbances to engine torque can be reduced and the engine's fuel consumption can be reduced.

[0408] At this point, Fig. 28A, which describes a sequence for operating an engine according to the method of the Fig. 27A and Fig. 27B. The engine in the sequence is a four-cylinder engine with a firing order of 1-3-4-2. The vertical lines at time T2800-T2804 represent relevant times in the sequence. Fig. Figure 28A shows five representations, and the representations are time-aligned and occur simultaneously.

[0409] The first representation from above in Fig. Figure 28A is a plot of a desired number of activated engine cylinders (e.g., cylinders with intake and exhaust valves opening and closing during an engine cycle and cylinders in which combustion is occurring) versus time. The vertical axis represents the desired number of activated engine cylinders, and the desired number of activated engine cylinders is listed along the vertical axis. The horizontal axis represents time, and time increases from the left side of the figure to the right side of the figure.

[0410] The second illustration from the top in Fig. Figure 28A is a plot of an actual number of activated engine cylinders (e.g., cylinders with intake and exhaust valves opening and closing during an engine cycle and cylinders in which combustion occurs) versus time. The vertical axis represents the actual number of activated engine cylinders, and the actual number of activated engine cylinders is listed along the vertical axis. The horizontal axis represents time, and time increases from the left side of the figure to the right side of the figure.

[0411] The third illustration from the top in Fig. Figure 28A is a plot of the engine volumetric efficiency actuator position (e.g., wastegate position for adjusting engine boost pressure, camshaft position, charge motion control valve position, plenum actuator position) versus time. The vertical axis represents the engine volumetric efficiency actuator position, and the actuator position increases the engine volumetric efficiency in the direction of the vertical axis arrow. The actuator position decreases the engine volumetric efficiency near the horizontal axis. The horizontal axis represents time, and time increases from the left side of the figure to the right side of the figure.

[0412] The fourth illustration from the top in Fig. Figure 28A is a plot of the central throttle position versus time. The vertical axis represents the central throttle position, and the central throttle position increases in the direction of the vertical axis arrow. The horizontal axis represents time, and time increases from the left side of the figure to the right side of the figure.

[0413] The fifth illustration from the top in Fig. Figure 28A is a plot of ignition timing versus time. The vertical axis represents the ignition timing, and the ignition timing increases in the direction of the vertical axis arrow. The ignition timing is retarded near the horizontal axis. The horizontal axis represents time, and time increases from the left side of the figure to the right side of the figure.

[0414] At time T2800, the desired actual total number of engine cylinders is four and the actual total number of active cylinders is four. The engine's volumetric efficiency actuators are positioned to provide a lower level of volumetric efficiency. For example, a wastegate is opened to reduce boost pressure, cam timing is advanced to reduce cylinder filling, a plenum valve is positioned to increase intake manifold volume, and the charge motion control valves are closed to decrease volumetric efficiency. The engine throttle is partially open, and spark timing is advanced to a midpoint.

[0415] At time 2801, the desired actual total number of active cylinders transitions from four to two. The desired actual total number of active cylinders may be reduced in response to a reduction in driver demand torque (not shown) or other conditions. The actual total number of active cylinders remains at a value of four because no cylinder was deactivated in response to the desired actual total number of active cylinders. The volumetric efficiency actuator position provides a low level of engine volumetric efficiency, and the throttle position is at a medium level. Spark timing is advanced to a medium level.

[0416] Between time T2801 and time T2802, the position of the volumetric efficiency actuator is changed to increase the engine's volumetric efficiency, and the throttle begins to close. The desired total number of cylinders activated and the actual total number of cylinders activated remain constant. The ignition timing also remains constant.

[0417] At time T2802, spark timing is retarded in response to an error between the actual engine airflow being greater than the desired engine airflow. Retarding spark timing shortens engine torque, allowing engine torque to be held constant. The position of the volumetric efficiency actuator continues to change to increase the engine volumetric efficiency, and the throttle begins to close. The desired total number of cylinders fired and the actual total number of cylinders fired remain constant.

[0418] At time T2803, the cylinder valves are deactivated. The cylinder valves can be deactivated via Fig. 5B, other valve actuators described herein, or other known valve actuators may be deactivated. In one example, valve actuators are deactivated to deactivate cylinder intake valves. Cylinder exhaust valves may also be deactivated. The throttle position is increased to open the throttle, allowing additional air to flow into the two cylinders that remain activated. Increasing the throttle position increases intake manifold pressure (MAP), which increases airflow into the activated engine cylinders. Airflow to the deactivated cylinders is terminated when the intake valves of the cylinders to be deactivated are deactivated and held closed. Spark timing begins to be retarded as the air charge of activated cylinders increases.The engine's volumetric efficiency actuator remains unchanged, and the desired actual total number of cylinders activated remains at a value of two. The actual total number of cylinders activated also remains two, since no engine cylinders were deactivated.

[0419] At time T2804, the actual total number of active cylinders changes from four to two. The intake valves of two cylinders (e.g., cylinders 2 and 3) are deactivated (not shown), and the throttle position remains constant. The ignition timing no longer changes, and the engine's volumetric efficiency actuator does not change its position.

[0420] In this way, the positions of the volumetric efficiency actuators and engine throttle can be adjusted before cylinder valves are deactivated, thus consuming less fuel during cylinder mode transitions. Furthermore, spark timing can be adjusted in response to a cylinder air charge error instead of in response to a change in engine throttle position, allowing for a shorter spark retard.

[0421] At this point, Fig. 28B, which describes a sequence for operating an engine according to the method of the Fig. 27A and Fig. 27B. The engine in the sequence is a four-cylinder engine with a firing order of 1-3-4-2. The vertical lines at time T2820-T2823 represent relevant times in the sequence. Fig. Figure 28B shows five representations and the representations are time-aligned and occur simultaneously.

[0422] The first representation from above in Fig. Figure 28B is a plot of a desired number of activated engine cylinders (e.g., cylinders with intake and exhaust valves opening and closing during an engine cycle and cylinders in which combustion is occurring) versus time. The vertical axis represents the desired number of activated engine cylinders, and the desired number of activated engine cylinders is listed along the vertical axis. The horizontal axis represents time, and time increases from the left side of the figure to the right side of the figure.

[0423] The second illustration from the top in Fig. Figure 28B is a plot of an actual number of activated engine cylinders (e.g., cylinders with intake and exhaust valves opening and closing during an engine cycle and cylinders in which combustion is occurring) versus time. The vertical axis represents the actual number of activated engine cylinders, and the actual number of activated engine cylinders is listed along the vertical axis. The horizontal axis represents time, and time increases from the left side of the figure to the right side of the figure.

[0424] The third illustration from the top in Fig. Figure 28B is a plot of the engine volumetric efficiency actuator position (e.g., wastegate position for adjusting engine boost pressure, camshaft position, charge motion control valve position, plenum actuator position) versus time. The vertical axis represents the engine volumetric efficiency actuator position, and the actuator position increases the engine volumetric efficiency in the direction of the vertical axis arrow. The actuator position decreases the engine volumetric efficiency near the horizontal axis. The horizontal axis represents time, and time increases from the left side of the figure to the right side of the figure.

[0425] The fourth illustration from the top in Fig. Figure 28B is a plot of central throttle position versus time. The vertical axis represents the central throttle position, and the central throttle position increases in the direction of the vertical axis arrow. The horizontal axis represents time, and time increases from the left side of the figure to the right side of the figure.

[0426] The fifth illustration from the top in Fig. Figure 28B is a plot of ignition timing versus time. The vertical axis represents the ignition timing, and the ignition timing increases in the direction of the vertical axis arrow. The ignition timing is retarded near the horizontal axis. The horizontal axis represents time, and time increases from the left side of the figure to the right side of the figure.

[0427] At time T2820, the desired actual total number of engine cylinders is two and the actual total number of active cylinders is two. The engine's volumetric efficiency actuators are positioned to provide a higher level of volumetric efficiency. For example, a wastegate is closed to increase boost pressure, cam timing is retarded to increase cylinder filling, a plenum valve is positioned to reduce intake manifold volume, and the charge motion control valves are opened to increase volumetric efficiency. The engine throttle is partially open, and spark timing is advanced to a lower intermediate level.

[0428] At time 2821, the desired actual total number of cylinders on transitions from two to four. The desired actual total number of cylinders on may be increased in response to the increase in driver demand torque (not shown) or other conditions. The actual total number of cylinders on remains at a value of two because no cylinder was re-energized in response to the desired actual total number of cylinders on. The volumetric efficiency actuator position provides a higher level of engine volumetric efficiency, and the throttle position is at a mid-level. Spark timing is advanced to a lower mid-level.

[0429] Between time T2821 and time T2822, the position of the volumetric efficiency actuator is changed to reduce the engine's volumetric efficiency, and the throttle begins to open. The desired total number of cylinders fired and the actual total number of cylinders fired remain constant. The ignition timing is constant.

[0430] At time T2822, the re-connection of cylinder valves begins. The cylinder valves can be Fig. 5B, other valve actuators described herein, or other known valve actuators may be re-energized. In one example, valve actuators are re-energized to re-energize cylinder intake valves. Cylinder exhaust valves may also be re-energized. The throttle position is reduced to close the throttle so that less air flows into the two cylinders that are activated. By reducing the throttle position, intake manifold pressure (MAP) decreases, reducing airflow into the activated engine cylinders. Air flows into the re-energizing cylinders as the intake valves of the cylinders to be re-energized open and close. Spark timing begins to advance as the air charge of activated cylinders decreases.The engine's volumetric efficiency actuator does not change its position, and the desired actual total number of activated cylinders remains at a value of four. The actual total number of activated cylinders remains two because no engine cylinders were reactivated.

[0431] At time T2823, the actual total number of activated cylinders changes from two to four. The intake valves of two cylinders (e.g., cylinders 2 and 3) are activated again (not shown), and the throttle position remains constant. The ignition timing no longer changes, and the engine's volumetric efficiency actuator does not change its position.

[0432] In this way, the positions of the volumetric efficiency actuators and engine throttle can be adjusted before cylinder valves are re-enabled, thus reducing fuel consumption during cylinder mode transitions. Furthermore, spark timing can be adjusted in response to a cylinder air charge fault instead of in response to a change in engine throttle position, allowing for a smaller spark retard.

[0433] At this point, Fig. 29, which shows a method for controlling engine fuel injection during cylinder reactivation after entering a cylinder deactivation mode. The method according to Fig. 29 can be integrated into the system that is Fig. 1A-6C. The procedure according to Fig. 29 may be contained as executable instructions stored in non-volatile memory. The method according to Fig. 29 may be performed in conjunction with the system hardware and other methods described herein to transform an operating state of an engine or its components.

[0434] At 2902, method 2900 judges whether one or more engine cylinders are deactivated (e.g., intake valves are held closed over an engine cycle as the engine rotates, and no combustion occurs in the deactivated cylinders). In one example, method 2900 may judge that one or more cylinders are deactivated based on a value of a variable stored in memory or an output from one or more sensors. If method 2900 judges that one or more engine cylinders are deactivated, the answer is yes and method 2900 proceeds to 2904. Otherwise, the answer is no and method 2900 proceeds to 2903.

[0435] At 2903, method 2900 operates engine cylinders and valves to provide a desired torque. The desired torque may be based on an accelerator pedal position or a torque determined by a controller. The engine cylinders are turned on by supplying fuel to the cylinders. The valves are turned on by activating valve actuators. Method 2900 proceeds to end.

[0436] At 2904, method 2900 judges whether cylinder reactivation is requested. Cylinder reactivation may be requested in response to an increase in driver demand torque or a vehicle speed below a threshold speed. If method 2900 judges that cylinder reactivation is requested, the answer is yes and method 2900 proceeds to 2906. Otherwise, method 2900 proceeds to 2905.

[0437] At 2905, method 2900 maintains the cylinders in a deactivated state. The cylinders are not fueled, and the cylinder valves remain deactivated. Method 2900 proceeds to end.

[0438] At 2906, method 2900 assesses whether the engine is operating in a direct fuel injection (DI) only region or whether there is a change in requested engine torque that exceeds a threshold. An engine with both port and direct fuel injectors may operate only the direct fuel injector within a first defined engine operating region (e.g., a defined engine speed and torque output range). Similarly, an engine with both port and direct fuel injectors may operate only port fuel injectors within a second defined engine operating region. Further, fuel may be delivered to an engine via port and direct fuel injectors in some engine operating regions.The method determines engine speed and torque and then determines whether the engine is operating in a region where only direct fuel injection is enabled. If so, the answer is yes and method 2900 proceeds to 2908. Otherwise, the answer is no and method 2900 proceeds to 2920.

[0439] At 2920, method 2900 turns on one or more engine cylinders by supplying spark and fuel to the deactivated cylinders. Additionally, valves of the deactivated cylinders that have been held closed for one or more engine cycles are turned on to open and close over an engine cycle. Fuel is injected into the cylinders via port fuel injectors because the engine is operating in a direct injection-only engine operating region and because the rate of change of requested engine torque is below the threshold. After turning on one or more deactivated cylinders, method 2900 proceeds to exit.

[0440] At 2908, method 2900 reactivates one or more engine cylinders by reactivating the cylinder valves and supplying fuel, air, and spark to the deactivated cylinders. The engine cylinders are reactivated so that the valves, which were held closed for one or more engine cycles, open and close during one or more engine cycles. The previously deactivated cylinders are fueled by injecting fuel directly into the cylinders.

[0441] Direct injection offers the ability to combust air and fuel in previously deactivated cylinders sooner than port fuel injection, as direct fuel injectors can inject fuel during a compression stroke of a cylinder cycle (e.g., later in the cylinder cycle), whereas a port fuel injector must inject fuel during an intake stroke of the cylinder cycle or earlier to support combustion during the cylinder cycle. Therefore, if cylinder reactivation is requested after a cylinder's intake stroke, fuel can be injected during the cylinder's compression stroke to support combustion in the cylinder during the compression stroke.In this way, direct injection may enable combustion in a deactivated cylinder in less than 180 degrees of crankshaft rotation from the degree of crankshaft rotation where cylinder activation is requested, wherein port fuel injection to a previously deactivated cylinder may be more than 180 degrees of crankshaft rotation from the degree of crankshaft rotation where cylinder activation is requested to participate in combustion.

[0442] If the cylinder is operating in a range where fuel is only injected into the cylinders via a manifold, except during engine cycles where the cylinders are reactivated, the cylinders may be reactivated by injecting fuel directly into the cylinders for a predetermined number of engine cycles or cylinder intake events. Port fuel injection may be reactivated in the recently reactivated cylinders after the predetermined number of engine cycles or cylinder intake events, at which point direct fuel injection to the recently reactivated cylinders is discontinued.In this way, the previously deactivated cylinders can start sooner, and direct injection to the cylinders can be terminated after the predetermined number of engine cycles or cylinder intake events, allowing mixture preparation in the cylinders to improve shortly after the cylinders are reactivated. This may be particularly desirable during conditions where the rate of change in requested engine torque exceeds a threshold, allowing the driver to achieve a faster torque response to the driver's demand.

[0443] If the engine is operating in a region where only direct injection is provided to the engine cylinders, direct injection resumes to the deactivated cylinders, and the cylinders operate with enhanced charge cooling. Direct fuel injection may continue in the engine cylinders until engine operating conditions change. Method 2900 proceeds to 2910.

[0444] At 2910, method 2900 assesses whether it is permissible to inject fuel via the intake manifold or whether only direct fuel injection (DI) is desired. Port fuel injection may be initiated after a predetermined actual total number of cylinder intake events since the request to activate one or more cylinders. The predetermined actual total number of events ensures that fuel is injected via direct fuel injection into previously deactivated cylinders in a timely manner and that fuel mixture conditioning improves promptly after the deactivated cylinders are reactivated. Alternatively, only direct fuel injection may be desired ...

Claims

[1] A method of operating an engine, comprising: Assessing whether knock is present in a cylinder that combusts air and fuel by receiving an input to a controller; Setting, via the controller, a rate of spark advance applied to the cylinder after judging that knock is present in the cylinder in response to a way in which the cylinder was previously deactivated. [2] The method of claim 1, wherein the rate is a first rate when the option at which the cylinder is deactivated is to stop supplying fuel to the cylinder and not to stop supplying air to the cylinder. [3] The method of claim 2, wherein the rate is a second rate when the means by which the cylinder is deactivated is to stop supplying fuel to the cylinder, introduce air into the cylinder, combust air and fuel in the cylinder, and maintain the intake and exhaust valves of the cylinder closed throughout an entire engine cycle without venting the combustion byproducts. [4] The method of claim 3, wherein the second rate is greater than the first rate when the cylinder is shut down by ceasing the supply of fuel to the cylinder and not by ceasing the supply of air to the cylinder. [5] The method of claim 1, wherein the input is a knock sensor, an ion sensor, or a pressure sensor, wherein the rate is a third rate when the means by which the cylinder is deactivated comprises introducing air into the cylinder, combusting air and fuel in the cylinder, ceasing fuel flow to the cylinder, venting the contents of the cylinder, then keeping the cylinder valves closed throughout an entire engine cycle, and wherein the rate is a fourth rate when the means by which the cylinder is deactivated comprises ceasing fuel injection into the cylinder, introducing air into the cylinder and fuel in the cylinder, ceasing fuel flow to the cylinder, venting the contents of the cylinder, and then keeping the cylinder valves closed throughout an entire engine cycle. [6] The method of claim 1, further comprising retarding spark delivered to the cylinder in response to an indication of knock in the cylinder. [7] The method of claim 1, further comprising: advancing the ignition delivered to the cylinder at a first rate in response to the cylinder previously being deactivated by terminating fuel flow to the cylinder without terminating air flow to the cylinder; and Advancing the ignition delivered to the cylinder at a second rate in response to the cylinder previously being shut down by terminating fuel and air flow to the cylinder. [8] The method of claim 7, further comprising retarding spark delivered to the cylinder in response to an indication of knock in the first cylinder. [9] The method of claim 8, wherein the first rate is greater than the second rate. [10] Vehicle system comprising: an engine; and a controller, including non-transitory executable instructions that, when executed by the controller, cause the controller to estimate a temperature in a cylinder that is deactivated and adjust an ignition advance rate for the cylinder after the cylinder is reactivated in response to an indication of knock in the cylinder and based on the temperature in the cylinder, and adjust a mode in which the cylinder was previously deactivated. [11] The vehicle system of claim 10, wherein the mode in which the cylinder was previously deactivated is a mode in which air does not flow through the cylinder. [12] The vehicle system of claim 10, wherein the mode in which the cylinder was previously deactivated is a mode in which air flows through the cylinder. [13] The vehicle system of claim 10, wherein the temperature in the cylinder when the cylinder has been deactivated is based on the air flow through the cylinder. [14] The vehicle system of claim 10, further comprising additional instructions to re-enable the first cylinder in response to an actual total number of engine revolutions since the first cylinder was deactivated. [15] The vehicle system of claim 10, wherein the pre-ignition rate is an ignition gain.

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