Internal combustion engine system and method for switching internal combustion engine cylinders on and off

Abstract

Internal combustion engine process comprising: via a controller, providing an engine cylinder mode range of an engine cylinder activation map, the engine cylinder mode range defined by a boundary, wherein within the boundary an actual total number of engine cylinder modes including active cylinders is increased compared to outside the boundary where all cylinders are active, the actual total number of engine cylinder modes comprising selected cylinder firing patterns and / or selected cylinder firing fractions over a predetermined number of cycles of the engine, and wherein the boundary is adjusted via the controller in response to a change in vehicle mass; Entering the combustion engine cylinder mode range in response to a change in engine speed or engine load; and Turning engine cylinders on and off according to the selected cylinder firing patterns and / or the selected cylinder firing fractions over the predetermined number of cycles of the engine in response to the change in engine speed or engine load.

Description

AREA

[0001] The present description relates to an internal combustion engine system and method for selectively activating and deactivating cylinders of an internal combustion engine to conserve fuel while meeting engine torque demands. The system and methods vary which cylinders of an internal combustion engine fire from one engine cycle to the next engine cycle. BACKGROUND AND SUMMARY

[0002] Some internal combustion engines include a fixed group of cylinders that can be selectively switched on and off in response to vehicle conditions. For example, during low vehicle driver demand conditions, a fixed group of internal combustion engine cylinders may be switched off to save fuel. If vehicle driver demand increases, the same group of cylinders can be switched back on to meet the vehicle driver demand. Such internal combustion engines can improve fuel efficiency compared to similar internal combustion engines in which all cylinders are always active during operation; however, delays in re-switching cylinders can reduce the responsiveness of the internal combustion engine, and continuously switching off the same cylinder can cause uneven degradation among internal combustion engine cylinders.

[0003] Other internal combustion engines have been developed that can turn on or off any internal combustion engine cylinder at virtually any time, depending on selected vehicle operating conditions. Furthermore, these internal combustion engines can vary which cylinders are turned on and off, so that wear between cylinders can be more even. However, these internal combustion engines can transmit vibrations associated with the turning on and off of cylinders to the vehicle and its occupants. Internal combustion engine vibrations can be mitigated so as not to disturb vehicle occupants by disallowing selected cylinder firing fractions and / or cylinder deactivation patterns during predetermined conditions. However, some vibrations may still be noticeable to vehicle occupants during some internal combustion engine operating conditions.Therefore, it may be desirable to aim to reduce the likelihood of transmission of engine vibration to vehicle occupants during a wider range of engine operating conditions.

[0004] For example, document US 2010 / 0 100 299 A1 shows an internal combustion engine in which individual cylinders are switched on or off depending on the requested engine power. It is also provided that the cylinders can be switched on and off depending on the mass of the driven vehicle or depending on a towing load acting on the vehicle.

[0005] The present invention is based on the object of creating an improved internal combustion engine system and method which avoids the aforementioned disadvantages, in particular reducing disturbing vibrations when switching cylinders on and off.

[0006] According to the invention, the stated object is achieved by an internal combustion engine method according to claim 1 and an internal combustion engine system according to claim 8. Preferred embodiments of the invention are subject to the dependent claims. Thus, an internal combustion engine method is proposed, comprising: increasing an actual total number of internal combustion engine cylinder modes including active cylinders according to an internal combustion engine cylinder mode range of an internal combustion engine cylinder activation map via a controller in response to a change in internal combustion engine speed or engine load, wherein the cylinder mode range is adjusted in response to a change in vehicle mass; and switching internal combustion engine cylinders on and off in response to the change in internal combustion engine speed or engine load.

[0007] By adjusting a range of an engine cylinder mode range of an engine cylinder activation map, it may be possible to provide the technical result of reducing the likelihood of disturbing vehicle occupants when cylinder mode changes are made. In particular, an engine speed and load range at which additional active engine cylinder modes and additional deactivated engine cylinder modes are provided may be increased or reduced in size so that cylinder modes that may affect vibrations perceived by vehicle occupants can be avoided in response to changes in vehicle mass. The mass of the vehicle and the location of the vehicle's mass may impact the transmission of vibrations associated with modes where one or more engine cylinders are deactivated.Thus, adjusting the size of one or more engine cylinder mode ranges may help avoid the potential for disturbing vehicle occupants due to vibrations that may be associated with cylinder modes in which one or more engine cylinders may be deactivated.

[0008] The present description can provide several advantages. For example, the approach can improve vehicle handling. Furthermore, the approach provides adjustments to the allowable cylinder modes in response to the location of the vehicle's mass. Furthermore, the approach can also compensate for vibrations when a trailer is being towed by the vehicle.

[0009] The above advantages as well as other advantages and features of the present description will be readily apparent from the following detailed description when read alone or in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The advantages described herein will become more fully apparent from 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. 1 is a schematic diagram of an internal combustion engine; Fig. Figure 2A is a schematic diagram of an eight-cylinder engine with two cylinder banks; Fig. Figure 2B is a schematic diagram of a four-cylinder engine with a single cylinder bank; Fig. 3A is a graph showing an example cylinder deactivation map; Fig. Figure 3B is a graph showing how cylinder deactivation can be adjusted in response to vehicle mass; Fig. 4 shows a flowchart of an exemplary method for operating an internal combustion engine; and Fig. 5A and Fig. 5B show exemplary vehicle chassis and suspension components for a vehicle incorporating cylinder deactivation. Detailed description

[0011] This description relates to the control of the activation and deactivation of internal combustion engine cylinders in response to the vehicle mass, the vehicle trailer mass, and the vehicle weight distribution. An internal combustion engine and its related components are Fig. 1 shown. Fig. 2A and Fig. 2B show exemplary configurations for the Fig. 1 described combustion engine. Fig. 3A shows an exemplary cylinder deactivation map including two cylinder mode selection ranges, with a first cylinder mode selection range located within the boundaries of a second cylinder mode selection range. A method of operating the engine of Fig. 1-2B according to Fig. The map shown in Figure 3B is Fig. 4. In the context of this disclosure, a cylinder is switched on when it combusts air and fuel during an engine cycle (e.g., two engine revolutions for a four-stroke engine). A cylinder is switched off when it does not combust air and fuel during an engine cycle. With reference to Fig. 1, an internal combustion engine 10 comprising a plurality of cylinders, one of which is in Fig. 1, is controlled by an electronic internal combustion engine control unit 12. The internal combustion engine 10 includes the combustion chamber 30 and the cylinder walls 32 with the piston 36 disposed therein and connected to the crankshaft 40.

[0012] The combustion chamber 30 is shown connected to an intake manifold 44 and an exhaust manifold 48 via a respective intake valve 52 and exhaust valve 54. Each intake and exhaust valve may be actuated by a variable intake valve operator 51 and a variable exhaust valve operator 53, which may be actuated mechanically, electrically, hydraulically, or by a combination thereof. For example, the valve actuators may be of the type described in US 2014 / 0 303 873 A1, US 6 321 704 B1, US 6 273 039 B1, and US 7 458 345 B2, which are hereby incorporated in their entirety for all intents and purposes. The intake valve operator 51 and an exhaust valve operator may open the intake valve 52 and exhaust valve 54 synchronously or asynchronously with the crankshaft 40. The position of the intake valve 52 can be determined by the intake valve position sensor 55.The position of the exhaust valve 54 can be determined by the exhaust valve position sensor 57.

[0013] The fuel injector 66 is shown positioned to inject fuel directly into the cylinder 30, known to those skilled in the art as direct injection. Alternatively, fuel may be injected into an intake port, known to those skilled in the art as single-nozzle-per-port injection. The fuel injector 66 delivers liquid fuel proportional to the pulse width of the signal from the controller 12. Fuel is supplied to the fuel injector 66 by a fuel system 175. Additionally, the intake manifold 44 is shown connected to the optional electronic throttle 62 (e.g., a butterfly valve), which adjusts a position of the throttle plate 64 to control airflow from the air cleaner 43 and air intake 42 to the intake manifold 44. The throttle 62 regulates airflow from the air cleaner 43 into the engine air intake 42 to the intake manifold 44.In one example, a two-stage high-pressure fuel system may be used to generate higher fuel pressure. In some examples, throttle 62 and throttle plate 64 may be positioned between intake valve 52 and intake manifold 44 such that throttle 62 is a port throttle.

[0014] A distributorless ignition system 88 provides an ignition spark to the combustion chamber 30 in response to the controller 12 via the spark plug 92. A wideband lambda (Universal Exhaust Gas Oxygen - UEGO) sensor 126 is shown coupled to the exhaust manifold 48, which is upstream of the catalytic converter 70. Alternatively, the UEGO sensor 126 may be replaced with a binary exhaust gas oxygen sensor.

[0015] 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.

[0016] The control 12 is in Fig. 1 as a conventional microcomputer including: a 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 illustrated as 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; a position sensor 134 coupled to an accelerator pedal 130 to detect the force applied by a human operator 132; an engine manifold pressure (MAP) measurement from pressure sensor 122 coupled to the intake manifold 44; an engine position sensor from a Hall effect sensor 118 detecting the position of the crankshaft 40; a measurement of the mass of air entering the engine from sensor 120; brake pedal position from brake pedal position sensor 154 when the human operator 132 applies the brake pedal 150; and a measurement of the throttle position from sensor 58.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.

[0017] In some examples, the internal combustion engine may be connected to an electric motor / battery system in a hybrid vehicle. Furthermore, in some examples, other internal combustion engine configurations may be employed, for example, a diesel engine. During operation, each cylinder in the internal combustion engine 10 typically undergoes a four-stroke cycle; the cycle includes the intake stroke, the compression stroke, the power stroke, and the exhaust stroke. 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 to increase the volume within the combustion chamber 30. The position where 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 commonly referred to by those skilled in the art as bottom dead center (BDC).During the compression stroke, the intake valve 52 and the exhaust valve 54 are closed. The piston 36 moves toward the cylinder head to compress the air within the combustion chamber 30. The point at which the piston 36 is at the end of its stroke and closest to the cylinder head (e.g., when the combustion chamber 30 is at its smallest volume) is commonly referred to by those skilled in the art as top dead center (TDC). In a process referred to herein as injection, fuel is introduced into the combustion chamber. In a process referred to herein as ignition, the injected fuel is ignited by known ignition means such as a spark plug 92, resulting in combustion. 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 deliver the combusted air-fuel mixture to the exhaust manifold 48, and the piston returns to TDC. It should be noted that the above is merely an example, and the timing for opening and / or closing the intake and exhaust valves may vary, such as to provide positive or negative valve overlap, late intake valve closing, or various other examples.

[0018] With reference to Fig. 2A, an exemplary multi-cylinder engine including two cylinder banks is shown. The internal combustion engine includes cylinders and associated components as shown in Fig. 1. The internal combustion engine 10 includes eight cylinders 210. Each of the eight cylinders is numbered, and the cylinder numbers are included in the cylinders. The fuel injectors 66 selectively supply fuel to each of the cylinders that are turned on (e.g., combusting fuel during an engine cycle). Cylinders 1-8 may be selectively deactivated to improve the fuel efficiency of the internal combustion engine when less than the full torque capacity of the internal combustion engine is demanded. For example, cylinders 2, 3, 5, and 8 (e.g., a fixed pattern of deactivated cylinders) may be deactivated during an engine cycle (e.g., two revolutions for a four-stroke engine) and may be deactivated for a plurality of engine cycles while engine speed and load are constant or vary slightly.During another engine cycle, a second fixed pattern of cylinders 1, 4, 6, and 7 may be deactivated. Further, other patterns of cylinders may be selectively deactivated based on vehicle operating conditions. Furthermore, engine cylinders may be deactivated such that a fixed pattern of cylinders is not deactivated over a plurality of engine cycles. Instead, cylinders that are deactivated may change from one engine cycle to the next engine cycle. Each cylinder includes variable intake valve operators 51 and variable exhaust valve operators 53. An engine cylinder may be deactivated by its variable intake valve operators 51 and variable exhaust valve operators, which keep the cylinder's intake and exhaust valves closed throughout an entire cylinder cycle.An internal combustion engine cylinder can be activated by its variable intake valve operators 51 and variable exhaust valve operators 53, which open and close the cylinder's intake and exhaust valves during a cylinder cycle. The internal combustion engine 10 includes a first cylinder bank 204, which includes four cylinders, 1, 2, 3, and 4. The internal combustion engine 10 also includes a second cylinder bank 202, which includes four cylinders, 5, 6, 7, and 8. The cylinders of each bank can be active or deactivated during an internal combustion engine cycle.

[0019] With reference to Fig. 2B, an exemplary multi-cylinder engine including a cylinder bank is shown. The internal combustion engine includes cylinders and associated components as shown in Fig. 1. The internal combustion engine 10 includes four cylinders 210. Each of the four cylinders is numbered, and the cylinder numbers are included in the cylinders. The fuel injectors 66 selectively supply fuel to each of the cylinders that are activated (e.g., combusting fuel during an engine cycle in which intake and exhaust valves open and close during a cycle of the cylinder that is active). Cylinders 1-4 may be selectively deactivated (e.g., not combusting fuel during an engine cycle in which intake and exhaust valves are held closed for an entire cycle of the deactivated cylinder) to improve engine fuel economy when less than the full torque capacity of the engine is demanded. For example, cylinders 2 and 3 (e.g.,a fixed pattern of deactivated cylinders) may be deactivated during a plurality of engine cycles (e.g., two revolutions for a four-stroke engine). During another engine cycle, a second fixed pattern of cylinders 1 and 4 may be deactivated over a plurality of engine cycles. Further, other patterns of cylinders may be selectively deactivated based on vehicle operating conditions. Additionally, engine cylinders may be deactivated such that a fixed pattern of cylinders is not deactivated over a plurality of engine cycles. Instead, cylinders that are deactivated may change from one engine cycle to the next engine cycle. In this way, the deactivated engine cylinders may rotate or change from one engine cycle to the next engine cycle.

[0020] The internal combustion engine 10 includes a single cylinder bank 250 containing four cylinders 1-4. The cylinders of the individual bank can be active or deactivated during an internal combustion engine cycle. Each cylinder includes variable intake valve operators 51 and variable exhaust valve operators 53. An internal combustion engine cylinder can be deactivated by its variable intake valve operators 51 and variable exhaust valve operators, which keep the cylinder's intake and exhaust valves closed during a cylinder cycle. An internal combustion engine cylinder can be activated by its variable intake valve operators 51 and variable exhaust valve operators 53, which open and close the cylinder's intake and exhaust valves during a cylinder cycle.

[0021] The system from Fig. 1-2B provides an internal combustion engine system comprising: an internal combustion engine having one or more cylinder deactivation mechanisms; a controller having executable instructions stored in non-volatile memory to adjust dimensions of an internal combustion engine cylinder mode range in response to a change in the mass of a vehicle. The internal combustion engine system further includes additional executable instructions to adjust the internal combustion engine cylinder mode range in response to a wheelbase of the vehicle. The internal combustion engine system further includes additional executable instructions to adjust the internal combustion engine cylinder mode range in response to the vehicle towing a trailer. The internal combustion engine system further includes additional instructions to estimate a mass of the vehicle. The internal combustion engine system further includes additional instructions to estimate a mass of a trailer coupled to the vehicle.The internal combustion engine system includes the internal combustion engine cylinder mode range defining active cylinder firing fractions and active cylinder patterns.

[0022] Now, with reference to Fig. 3A shows a plot of an exemplary cylinder activation map. The vertical axis represents engine load, or alternatively, torque, and engine load increases in the direction of the vertical axis arrow. The horizontal axis represents engine speed, and engine speed increases in the direction of the horizontal axis arrow. The cylinder mode ranges shown are not intended to be limiting, but rather are shown to illustrate the concepts described herein.

[0023] A first cylinder mode range 300 is defined by points 310, 311, 312, and 314. Lines 302, 303, 304, and 305 indicate the extent of the first cylinder mode range 300. The first cylinder mode begins at a lower engine speed, indicated at 324, and expands to a higher engine speed, indicated at 326. The first cylinder mode range 300 begins at a lower engine load 320 and expands to a higher engine load 322, except at lower engine speeds, where the first cylinder mode range 300 expands to the engine load 321.

[0024] The first cylinder mode range 300 may allow only selected cylinder firing patterns to be activated. For example, for an eight-cylinder internal combustion engine having a firing order of 1, 3, 7, 2, 6, 5, 4, 8, the first cylinder mode range may allow all eight cylinders to be active in a first cylinder firing pattern during an engine cycle (e.g., combusting air and fuel during one cycle of the internal combustion engine), allow only cylinders numbers 1, 7, 6, and 3 to be active in a second cylinder firing pattern during an engine cycle, allow only cylinders numbers 3, 2, 5, and 8 to be activated in a third cylinder firing pattern during an engine cycle, and allow only cylinders numbers 1 and 6 to be activated in a fourth cylinder firing pattern during an engine cycle. Other cylinder firing patterns may not be permitted.For example, in this example, a firing pattern of 1, 3, 7, 2 is not permitted. In the area outside the first cylinder mode range 300, only one mode in which all engine cylinders are active is permitted. Thus, within the first cylinder mode range 300, the actual number of allowable active cylinder modes is increased, and the actual number of allowable cylinder deactivation modes is increased.

[0025] The first cylinder mode range 300 may also allow only selected cylinder firing fractions over a predetermined number of engine cycles. A cylinder firing fraction may be defined as an actual total number of cylinder firing events divided by an actual total number of cylinder compression strokes over a predetermined actual total number of cylinder compression strokes. For example, if an internal combustion engine fires three times (e.g., combusting an air-fuel mixture) while rotating through ten compression strokes, the cylinder firing fraction is 0.333.Thus, for example, cylinder mode range 300 may allow a cylinder firing fraction of 1 during a predetermined total actual number of engine cycles, a cylinder firing fraction of 0.5 during a predetermined total actual number of engine cycles, and a cylinder firing fraction of 0.666 during a predetermined total actual number of engine cycles. All other cylinder firing fractions are not permitted in this example. Thus, within the first cylinder mode range 300, the actual number of allowable cylinder firing fractions is increased compared to the area outside range 300, which in this example requires all cylinders to be active.

[0026] Fig. 3A also shows a second cylinder mode range 330 defined by points 331, 332, 333, and 334. The second cylinder mode range 330 is shown located within the first cylinder mode range 300. However, in other examples, the second cylinder mode range 330 may be located outside the first cylinder mode range 300. Additionally, in other examples, additional cylinder mode ranges may be provided within the first cylinder mode range 330 or outside the first cylinder mode range 330. The second cylinder mode range 330 may allow fewer or more cylinder firing patterns and cylinder firing fractions than are included in the first cylinder mode range 300.For example, the second cylinder mode range may allow all eight cylinders to be activated in a first cylinder firing pattern during an engine cycle; only cylinders numbers 1, 7, 6, and 3 to be active in a second cylinder firing pattern during an engine cycle; only cylinders numbers 3, 2, 5, and 8 to be activated in a third cylinder firing pattern during an engine cycle; only cylinders numbers 1 and 6 to be activated in a fourth cylinder firing pattern during an engine cycle; and only cylinders 3 and 8 to be activated in a fifth cylinder firing pattern during an engine cycle. All other cylinder firing patterns are not permitted in this example.Alternatively, the second cylinder firing pattern may allow all eight cylinders to be active (e.g., combusting air and fuel during one engine cycle) in a first cylinder firing pattern during an engine cycle and allow only cylinders numbered 1, 7, 6, and 3 to be active in a second cylinder firing pattern during an engine cycle. All other cylinder firing patterns are not permitted in this example.

[0027] The second cylinder mode range 300 may also allow different selected cylinder firing fractions over a predetermined number of engine cycles compared to the first cylinder mode range. For example, the second cylinder mode range 330 may allow a cylinder firing fraction of 1 during a predetermined total actual number of engine cycles, a cylinder firing fraction of 0.5 during a predetermined total actual number of engine cycles, a cylinder firing fraction of 0.666 during a predetermined total actual number of engine cycles, and a cylinder firing fraction of 0.33 during a predetermined total actual number of engine cycles. All other cylinder firing fractions are not permitted in this example.

[0028] The Fig. The cylinder mode ranges shown in Figure 3A and other anticipated cylinder mode ranges not shown in the present description may be described as base cylinder mode ranges for a base vehicle configuration where the total mass of the vehicle is less than a threshold mass (e.g., mass of the vehicle with a single occupant, fueled, and no other additional mass added to the vehicle, such as tools or lumber). Further, as mentioned above, the engine may only operate when all engine cylinders are active when outside the first cylinder mode range 300 and outside the second cylinder mode range 330. Thus, when the engine is operating at a speed less than 320, all engine cylinders are active. Likewise, when the engine is operating at a speed greater than 322, all engine cylinders are active.When the engine enters the first cylinder mode range 300 or the second cylinder mode range 330, one of the available cylinder modes and / or firing fractions may be activated. When the engine exits the first cylinder mode range 300 or the second cylinder mode range 330, all engine cylinders are activated.

[0029] Now, with reference to Fig. 3B a history of adjustments to a cylinder connection map for a vehicle when the vehicle configuration is different than for a base vehicle configuration as in Fig. 3A. For example, the vehicle mass may include additional mass (payload) over a base vehicle configuration that includes a single occupant and fuel. The graph shows the first cylinder mode range 300 of Fig. 3A and an adjusted first cylinder mode range 300a that compensates for additional mass added to the vehicle (e.g., 500 kg). In this example, the size of the first cylinder mode range 300 decreases (e.g., the first cylinder mode occupies a smaller engine speed and load range) as mass is added to the vehicle, but the size of the first cylinder mode range may also increase depending on the application.

[0030] Points 310a, 312a, 314a, and 311a define the extents of the first cylinder mode range 300a when the vehicle mass is increased from the base vehicle mass to the maximum gross vehicle weight. The first cylinder mode range can be adjusted to a size between the first cylinder mode range 300 and the first cylinder mode range 300a via interpolating endpoint values. For example, a point defining the first cylinder mode range when the vehicle mass is greater than a base mass but less than a gross vehicle weight can be established by interpolating between points defining the first cylinder mode when the vehicle mass is the base mass and points defining the first cylinder mode when the vehicle mass is a gross vehicle weight.Thus, for points 310 and 310a, which define a low engine speed and a high level of engine load of the first cylinder mode range, a point lying along a straight line between point 310 and 310a can be determined by determining an equation of a straight line between point 310 and point 310a and finding a point along the line corresponding to the vehicle mass between the base vehicle and a vehicle with a gross vehicle weight.

[0031] For example, if point 310 is located at (500, 0.5) and point 310a is located at (600, 0.3), the equation of the line is y=(0.5-0.3) / (500-600)x+b, where b=1.5 and m=(0.2 / - 100) according to a straight line equation (y=mx+b, where m is the slope of the line and b is the offset of the line, y is the value (load) of the vertical axis, and x is the value (speed) of the horizontal axis). The length of the straight line is determined by the Pythagorean theorem: D=(x2−x1)2+(y2−y1)2, where D is the distance of the line x1, x2, y1 and y2 are the endpoints of the line, and the engine speed and load locations of the endpoints. A ratio of the change in vehicle mass to the length of the line is the basis for determining where on the line a vehicle mass (e.g., new vehicle mass) lies between the base vehicle mass and the vehicle at gross vehicle weight on the line. The new vehicle mass is then the basis for determining where the new point on the line representing the new vehicle mass lies. So, for example, if the length of the line is 1 and the vehicle mass between the base vehicle mass and the gross vehicle mass increases by 500 kg, a ratio of 500 / 1 is a basis for determining where a 300 kg increase in vehicle mass lies on the line. In particular, 300 to 500 is 0.6 to 1.Thus, the position on the line between points 310 and 310a corresponding to a 300 kg increase in vehicle mass from the base vehicle mass is the point on the line between 310 and 310a where the distance from point 310 is 0.6 times (e.g., the distance of the line for the 300 kg increase in vehicle mass) the distance of the line between 310 and 310a (e.g., 1). The new point (x2, y2) for the 300 kg increase in vehicle mass is solved by applying the Pythagorean theorem for a distance of 0.6 and x1=500 and y1=0.5 for the line y=(0.2 / -100)x+1.5. In a similar manner, other points defining the first cylinder mode range (e.g., points between 311 and 311a, points between 314 and 314a, and points between 312 and 312a) can be determined for different vehicle masses.

[0032] Additionally, the size of the first cylinder mode range may be adjusted according to the manner in which the vehicle weight is supported between the front suspension of the vehicle and the vehicle weight supported by the rear suspension of the vehicle. Further, the first cylinder mode range may be adjusted based on whether the vehicle mass includes mass from a trailer towed by the vehicle. For example, a location of a point along a straight line between points 310 and 310a may be adjusted in response to vehicle weight supported by the front suspension of the vehicle and vehicle weight supported by the rear suspension of the vehicle, as well as for a portion of the total vehicle mass that is a trailer.

[0033] In particular, a length of a vehicle mass-based line corresponding to a position along the line between 310 and 310a is adjusted by an empirically determined factor for vehicle weight supported by the front suspension of the vehicle and vehicle weight supported by the rear suspension of the vehicle and an empirically determined factor for mass of a trailer towed by the vehicle. In one example, the length of the line between a base cylinder mode range boundary (e.g., 310 from Fig. 3B) and a cylinder mode range limit determined based on the gross vehicle weight (e.g. 310a from Fig. 3B) is adjusted to change the size of an engine cylinder mode range (e.g., increase or decrease an engine speed / load limit) when a larger fraction of the vehicle's weight is supported by the vehicle's rear suspension than the vehicle's front suspension, or if there is a change in the amount of mass supported by the vehicle's front or rear suspension. Thus, in the above example, the value of 0.6 corresponding to the length of the line extending from point 310 can be multiplied by a factor of 0.95 for vehicle weight supported by the vehicle's front suspension and vehicle weight supported by the vehicle's rear suspension, and a factor of 0.92 for trailer mass, so that the length of the line extending from point 310 is 0.6*0.95*0.92=0.5244.The new point that defines the extent of the first cylinder mode range and compensates for the vehicle weight carried by the front suspension and the vehicle weight carried by the rear suspension, as well as trailer mass, is determined using the Pythagorean theorem for a distance of 0.5244 and x1=500 and y1=0.5 for the line y=(0.2 / -100)x+1.5. The other points that define the first cylinder mode range can be determined in a similar manner.

[0034] Fig. 3B also includes the second cylinder mode range 330a defined by points 333a, 332a, 330a, and 331a, which corresponds to a vehicle mass different from the vehicle mass that is the basis for the second cylinder mode range 330. The points between points 333 and 333a, between points 332 and 332a, between points 330 and 330a, and between points 331 and 331a can be found in a similar manner to the points between the first cylinder mode range 300a for a vehicle mass greater than a base vehicle mass and the first cylinder mode range 300 for a base vehicle mass.

[0035] It should be noted that the method described herein is merely a non-limiting method for adjusting cylinder mode ranges for changes in vehicle mass, trailer weight, and vehicle weight supported by the vehicle's front suspension and vehicle weight supported by the vehicle's rear suspension. However, other ways of adjusting cylinder mode ranges are anticipated. For example, instead of interpolating between points defining a base vehicle cylinder mode range and a maximum gross vehicle weight cylinder mode range, a set of cylinder mode ranges may be provided for each incremental increase in vehicle weight (e.g., for each 50 kg increase in vehicle mass), and the active cylinder mode range corresponds to a cylinder mode range for the current vehicle mass plus or minus a predetermined amount of mass.The vehicle weight supported by the vehicle's front suspension and the vehicle weight supported by the vehicle's rear suspension, as well as the trailer mass, can provide an offset value for the vehicle mass, so that the selected cylinder mode range can be different from the cylinder mode range corresponding only to the vehicle mass.

[0036] Thus, as the vehicle mass increases or decreases, the size of the cylinder mode ranges may increase or decrease to reduce the likelihood of vibrations that may be associated with cylinder deactivation being transmitted to vehicle occupants. Furthermore, the size of the cylinder mode ranges may increase or decrease to reduce the likelihood of vibrations that may be related to vehicle weight supported by the vehicle's front suspension and vehicle weight supported by the vehicle's rear suspension and / or trailer mass being transmitted to vehicle occupants. Referring now to Fig. 4 shows a flowchart describing ways to switch cylinder firing fractions and cylinder firing patterns in response to vehicle mass, vehicle weight supported by the vehicle's front suspension, vehicle weight supported by the vehicle's rear suspension, and trailer towing conditions. The method of Fig. 4 can be inserted into the system Fig. 1-2B and cooperate with it. Furthermore, at least sections of the procedure can be Fig. 4 may be integrated as executable instructions stored in a non-volatile memory, while other parts of the method may be performed via a controller that transforms operating states of devices and actuators in the physical world.

[0037] At 402, method 400 determines the vehicle wheelbase and gross vehicle weight. The vehicle wheelbase is a physical distance between the front axle of the vehicle and the rear axle of the vehicle. The vehicle gross vehicle weight is the maximum weight of the vehicle without any trailer being towed by the vehicle. The vehicle wheelbase and gross vehicle weight may be determined by accessing values ​​stored in controller memory. The values ​​may be stored in memory at the time of vehicle manufacture. Method 400 proceeds to 404.

[0038] At 404, method 400 judges whether a trailer is coupled to the vehicle. In one example, method 440 may judge that a trailer is coupled to a vehicle in response to a condition of a trailer hitch electrical connector. If method 400 judges that a trailer is coupled to the vehicle, the answer is yes and method 400 proceeds to 420. Otherwise, the answer is no and method 400 proceeds to 406.

[0039] At 406, method 400 estimates the mass of the vehicle. In one example, the mass of the vehicle may be estimated via a vehicle ride height sensor. Specifically, the output of the vehicle ride height sensor is used to index a table of empirically determined vehicle mass estimates based on ride height sensor outputs. In other examples, the vehicle mass may be estimated as the vehicle accelerates using the following equations: F=m*a Tw / RR=F Tw=m*a*RR=RR*m*g*sin(θ) where F is the force accelerating the vehicle, m is the estimate of the vehicle mass, Tw is the torque at the vehicle wheel, RR is the vehicle wheel rolling radius, g is the gravity constant, and θ is the road angle. The road angle may be determined via an inclinometer or accelerometer, and the values ​​of g and RR may be stored in controller memory. After estimating the vehicle mass, method 400 proceeds to 408.

[0040] At 408, method 400 estimates the weight supported by the front suspension of the vehicle and the weight supported by the rear suspension of the vehicle. In one example, vehicle weight supported by the front suspension of the vehicle and vehicle weight supported by the rear suspension of the vehicle are estimated via the output of vehicle ride height sensors (e.g., vehicle ride height sensor of the front suspension and vehicle ride height sensor of the rear suspension). The output of the vehicle ride height sensors is an input to a function of empirically determined values ​​that outputs an estimate of the vehicle weight supported by the front suspension of the vehicle and the vehicle weight supported by the rear suspension of the vehicle. Method 400 proceeds to 410.

[0041] At 410, the method 400 adjusts cylinder actuation maps in response to vehicle mass and vehicle weight supported by the front suspension of the vehicle and vehicle weight supported by the rear suspension of the vehicle. In one example, the vehicle includes base cylinder actuation maps corresponding to the wheelbase of the vehicle and the gross vehicle weight of the vehicle, and different versions of the same vehicle model may have different gross vehicle weights and different wheelbases. For example, a first vehicle (e.g.,Truck) has a first wheelbase for a short bed and a first gross vehicle weight, a second vehicle has a second wheelbase for a long bed and a second gross vehicle weight, where the first wheelbase is shorter than the second wheelbase, the first gross vehicle weight is less than the second gross vehicle weight, and the first vehicle is the same vehicle model as the second vehicle. Thus, the first vehicle and the second vehicle may have different cylinder switching maps even if the first and second vehicles are the same vehicle model (e.g., both vehicles are Ford® F-150 trucks). A first cylinder switching map may be stored in control memory of the first vehicle, while a second cylinder switching map may be stored in control memory of the second vehicle.Alternatively, a vehicle may include multiple cylinder firing maps stored in memory, and cylinder firing maps corresponding to the vehicle wheelbase and gross vehicle weight are activated based on the determined vehicle wheelbase and gross vehicle weight to provide a basis for adjusting cylinder firing fraction and cylinder firing patterns during varying vehicle operating conditions.

[0042] For example, a base cylinder connection card similar to the one used in Fig. 3A, in response to the vehicle wheelbase and gross vehicle weight. Furthermore, if the vehicle weight has increased from a base vehicle weight, the base cylinder activation map may be retrieved from memory in response to the increase in vehicle mass as with respect to Fig. 3B. For example, the range of engine speed and load at which additional cylinder modes can be engaged may be reduced in response to an increase in vehicle mass. The increase in vehicle mass compared to the base vehicle mass may be caused by passengers in the vehicle or cargo (e.g., lumber, steel, or other cargo) or attachments (e.g., tool boxes). Furthermore, the range of engine speed and load at which additional cylinder modes can be engaged (e.g., 300 from Fig. 3A) in response to vehicle weight supported by the front suspension of the vehicle and vehicle weight supported by the rear suspension of the vehicle being increased or reduced as described with reference to Fig. 3B. A cylinder connection map with the range of speed and load can be reduced in size by reducing the engine speed range and engine load range, as in Fig. 3B, wherein the size of the first cylinder mode region 300 is reduced to the first cylinder mode region 300a.

[0043] Engine cylinders are activated and deactivated in response to engine speed and engine load. Furthermore, engine cylinders are activated and deactivated in response to cylinder mode ranges adjusted for vehicle mass, vehicle mass supported by the vehicle's front suspension, and vehicle mass supported by the vehicle's rear suspension. After adjusting the engine cylinders for activation and deactivation, method 400 proceeds to exit.

[0044] At 420, method 400 estimates the total vehicle mass as described at 406. The total vehicle mass includes the mass of the vehicle and the mass of the trailer coupled to the vehicle. After estimating the vehicle mass, method 400 proceeds to 422.

[0045] At 422, method 400 estimates the vehicle mass supported by the front suspension of the vehicle and the mass supported by the rear suspension of the vehicle, as described at 408. Further, method 400 subtracts a mass from the determined mass to be supported by the rear suspension of the vehicle based on the difference in the mass of the entire vehicle and the mass of the vehicle supported via the front and rear suspensions of the vehicle. For example, if the total mass of the vehicle, including the trailer coupled to the vehicle, is estimated to be 3200 kg, and the front suspension of the vehicle is estimated to support 1430 kg, and the rear suspension of the vehicle is estimated to support 770 kg, the original mass of the trailer is estimated to be 1000 kg. However, because the vehicle may be carrying weight from the trailer (e.g.,To estimate the mass the vehicle can support (e.g., trailer tongue mass), a fraction of the mass supported by the vehicle's rear suspension may be subtracted from the mass supported by the vehicle's rear suspension and added to the trailer mass. In one example, an empirically estimated amount of mass may be subtracted from the mass supported by the vehicle's rear suspension and added to the trailer mass. The empirical amount of mass may be a function of the trailer mass estimate before the tongue mass is added to the trailer mass. Method 400 proceeds to 424.

[0046] At 424, method 400 estimates the mass of the trailer being towed by the vehicle. Specifically, the mass supported by the front suspension of the vehicle and the mass supported by the rear suspension of the vehicle determined at 422 are subtracted from the total vehicle mass estimated at 420 to provide the estimate of the mass of the trailer being towed by the vehicle. Method 400 proceeds to 426.

[0047] At 426, method 400 adjusts cylinder activation maps in response to vehicle mass (without trailer), vehicle mass supported by the vehicle's front suspension, vehicle mass supported by the vehicle's rear suspension, and trailer mass. In one example, the vehicle includes base cylinder activation maps corresponding to the vehicle's wheelbase and gross vehicle weight, and different versions of the same vehicle model may have different gross vehicle weights and wheelbases, as described at 410.

[0048] A basic cylinder connection card, which is similar to the one used in Fig. 3A, may be retrieved from memory in response to the vehicle wheelbase and gross vehicle weight. Furthermore, if the vehicle mass has increased from a base vehicle weight, the base cylinder activation map may be modified in response to the increase in vehicle mass as with respect to Fig. 3B. In one example, the range of engine speed and load at which additional cylinder modes can be engaged may be reduced in response to an increase in vehicle mass. The increase in vehicle mass relative to the base vehicle mass may be caused by passengers in the vehicle or cargo (e.g., lumber, steel, or other cargo) or attachments (e.g., tool boxes). Furthermore, the range of engine speed and load at which additional cylinder modes can be engaged (e.g., 300 from Fig. 3A) in response to vehicle weight supported by the front suspension of the vehicle and vehicle weight supported by the rear suspension of the vehicle being increased or reduced as described with reference to Fig. 3B. A cylinder connection map with the range of speed and load can be reduced in size by reducing the engine speed range and engine load range, as in Fig. 3B, wherein the size of the first cylinder mode range 300 is reduced to the first cylinder mode range 300a. In addition, the size of the cylinder activation map cylinder mode range may be increased and decreased by increasing the cylinder mode range 300 in response to trailer mass as described with reference to Fig. 3B. The mass of the vehicle may affect the transfer of vibration energy through the vehicle. Furthermore, the location of the mass relative to the engine may affect the transfer of vibration energy through the vehicle. The mass of a trailer being towed by the vehicle may have less effect on the transfer of vibration energy compared to mass of weight supported via the vehicle's front suspension. Nevertheless, the mass of a towed trailer may have some effect on the transfer of vibration energy through the vehicle. Thus, by adjusting the size or engine speed and load range of cylinder mode spans in cylinder activation maps, the likelihood of vehicle occupants being disturbed due to cylinder activation and deactivation may be reduced.

[0049] The engine cylinders are activated and deactivated in response to engine speed and engine load. Furthermore, engine cylinders are activated and deactivated in response to cylinder mode ranges adjusted for vehicle mass, vehicle weight supported by the vehicle's front suspension, vehicle weight supported by the vehicle's rear suspension, and trailer mass. After adjusting the engine cylinders for activation and deactivation, method 400 proceeds to the end.

[0050] Thus, the procedure Fig. 4 provides an internal combustion engine method comprising: increasing an actual total number of engine cylinder modes including active cylinders according to an engine cylinder mode range of an engine cylinder activation map via a controller in response to a change in engine speed or engine load, wherein the cylinder mode range is adjusted in response to a change in vehicle mass; and activating and deactivating engine cylinders in response to the change in engine speed or engine load. The method further comprises estimating the change in vehicle mass based on acceleration of a vehicle. The method includes active cylinders combusting air and fuel.

[0051] In some examples, the method further comprises increasing, via the controller, an actual total number of engine cylinder modes including deactivated cylinders according to the engine cylinder mode range of the engine cylinder activation map in response to the change in engine speed or engine load. The method includes where adjusting the cylinder mode range in response to a change in vehicle mass includes reducing a range of engine speeds, wherein the actual total number of engine cylinder modes is increased in response to an increase in vehicle mass.The method also includes adjusting the cylinder mode range in response to a change in vehicle mass including reducing a range of engine loads, wherein the actual total number of engine cylinder modes is increased in response to an increase in vehicle mass. The method includes adjusting the cylinder mode range in response to a change in vehicle mass including increasing a range of vehicle speeds, wherein the actual total number of engine cylinder modes is increased in response to a reduction in vehicle mass.

[0052] The procedure from Fig. 4 also provides an internal combustion engine method comprising: adjusting, via a controller, an engine cylinder mode range of an engine cylinder switching map in response to a change in the location of a vehicle load from a vehicle front suspension to a vehicle rear suspension; and switching engine cylinders on and off via the controller in response to a change in engine speed or engine load such that an engine enters the engine cylinder mode range. The method includes where adjusting the engine cylinder mode range includes increasing an engine speed range and an engine load range, which are extents of the engine cylinder mode range.The method includes where adjusting the engine cylinder mode range includes reducing an engine speed range and an engine load range that are dimensions of the engine cylinder mode range.

[0053] In some examples, the method further includes further adjusting, via the controller, the engine cylinder mode range in response to a vehicle towing a trailer. The method includes where the engine cylinder mode range identifies active cylinder modes and active cylinder patterns. The method further includes limiting the cylinder mode range based on engine speed and engine load. The method further includes adjusting boundaries of a plurality of cylinder mode ranges in response to the mass of a vehicle.

[0054] Now, with reference to Fig. 5A shows an exemplary vehicle. The vehicle 500 includes the Fig. 1 and the transmission 505. The transmission 505 transmits the torque from the engine 10 via the drive shaft 512 to the rear axle 514. The transmission 505 is also shown with an optional transfer case 510, which can transmit engine torque via the drive shaft 513 to the front axle 520. The suspension 502A and 502B supports the mass of the vehicle 500 and allows relative movement between the wheels 550 and the vehicle chassis 501. An example of the suspension 502A and 502B is shown in Fig. 5B. A front side 590 of the vehicle 500 includes the engine 10, while a rear side 591 of the vehicle 500 includes the rear axle 514. In other examples, the front axle 520 may be omitted. In still other examples, the engine 10 may deliver torque to the wheels 550 at the front side 590 of the vehicle without delivering torque to the rear side 591 of the vehicle 500. A portion of the vehicle mass may be supported on the front side 590 of the vehicle 500 (e.g., the front suspension) by the front suspension 502A. A portion of the vehicle mass may be supported on the rear side 591 of the vehicle 500 by the rear suspension 502B.

[0055] Now, with reference to Fig.5B shows an example of the front suspension 502A and rear suspension 502B. The suspension 502A / 502B includes an upper control arm 530, a ride height sensor 535, a lower control arm 556, and a wheel hub 554. The wheel hub 535 supports the wheel 550, and the chassis 501 is shown coupled to the upper control arm 530 and the lower control arm 556. The spring 555 provides a force to separate the upper control arm 530 from the lower control arm 556, thereby supporting the mass of the vehicle 500. A similar arrangement may be found at each wheel 550 of the vehicle 500.

[0056] It should be noted that the example control and estimation routines included herein may be used with various internal combustion engine and / or vehicle system configurations. The control methods and routines disclosed herein may be stored as executable instructions in non-transitory memory and executed by the control system, including the controller in combination with the various sensors, actuators, and other engine hardware. The specific routines described herein may represent one or more of any number of processing strategies, such as event-driven, interrupt-driven, multitasking, multithreading, and the like. Accordingly, various illustrated acts, operations, and / or functions may be performed in the illustrated order, in parallel, or in some cases, may be omitted.Likewise, the processing order is not necessarily required to achieve the features and advantages of the exemplary embodiments described herein, but rather is provided for ease of illustration and description. One or more of the illustrated acts, operations, and / or functions may be performed repeatedly depending on the particular strategy employed. Furthermore, at least a portion of the described acts, operations, and / or functions may graphically represent code to be programmed into non-transitory memory of the computer-readable storage medium in the control system.The control actions may also transform the operating state of one or more sensors or actuators in the physical world when the described actions are performed by executing the instructions in a system that includes the various engine hardware components in combination with one or more controllers.

[0057] This concludes the description. A reading of this description by a person skilled in the art will reveal many changes and modifications without deviating from the spirit and scope of the description. For example, this description can be applied to I3, I4, I5, V6, V8, V10, and V12 engines operating on natural gas, gasoline, diesel, or alternative fuel configurations.

Claims

[1] Internal combustion engine process comprising: via a controller, providing an engine cylinder mode range of an engine cylinder activation map, the engine cylinder mode range defined by a boundary, wherein within the boundary an actual total number of engine cylinder modes including active cylinders is increased compared to outside the boundary where all cylinders are active, the actual total number of engine cylinder modes comprising selected cylinder firing patterns and / or selected cylinder firing fractions over a predetermined number of cycles of the engine, and wherein the boundary is adjusted via the controller in response to a change in vehicle mass; Entering the combustion engine cylinder mode range in response to a change in engine speed or engine load; and Turning engine cylinders on and off according to the selected cylinder firing patterns and / or the selected cylinder firing fractions over the predetermined number of cycles of the engine in response to the change in engine speed or engine load. [2] The method of claim 1, further comprising estimating the change in vehicle mass based on acceleration of a vehicle. [3] The method of claim 1, wherein active cylinders combust air and fuel. [4] The method of claim 1, wherein the actual total number of engine cylinder modes including activated cylinders further includes deactivated cylinders according to the engine cylinder mode range of the engine cylinder activation map. [5] The method of claim 1, wherein adjusting the boundary of the combustion cylinder mode range in response to the change in vehicle mass includes reducing a range of engine speeds, increasing the actual total number of engine cylinder modes in response to an increase in vehicle mass. [6] The method of claim 1, wherein adjusting the boundary of the combustion cylinder mode range in response to the change in vehicle mass includes reducing a range of engine loads, increasing the actual total number of engine cylinder modes in response to an increase in vehicle mass. [7] The method of claim 1, wherein adjusting the boundary of the combustion cylinder mode range in response to the change in vehicle mass includes increasing a range of vehicle speeds, wherein the actual total number of engine cylinder modes is increased in response to a decrease in vehicle mass. [8] Internal combustion engine system comprising: an internal combustion engine including one or more cylinder deactivation mechanisms; a controller having executable instructions stored in non-volatile memory to adjust dimensions of an engine cylinder mode range of an engine cylinder activation map, the engine cylinder mode range defined by a boundary, within which boundary the actual total number of engine cylinder modes including activated cylinders is increased compared to outside the boundary where all cylinders are activated, in response to a change in mass of a vehicle, the change in vehicle mass including a manner in which vehicle weight is supported between a front suspension and a rear suspension of the vehicle. [9] The internal combustion engine system of claim 8, further comprising additional executable instructions to adjust the internal combustion engine cylinder mode range in response to a wheelbase of the vehicle. [10] The internal combustion engine system of claim 8, further comprising additional executable instructions to adjust the internal combustion engine cylinder mode range in response to the vehicle towing a trailer. [11] The internal combustion engine system of claim 8, further comprising additional executable instructions to estimate a mass of the vehicle. [12] The internal combustion engine system of claim 8, further comprising additional executable instructions to estimate a mass of a trailer coupled to the vehicle. [13] The internal combustion engine system of claim 8, wherein the internal combustion engine cylinder mode range defines active cylinder firing fractions and active cylinder patterns.

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