SYSTEM FOR THE REGENERATION OF A PETROL PARTICULATE FILTER

Abstract

A system comprises a soot module, a coordinator module, a regeneration module, and actuator modules. The soot module determines the current amount of soot mass in a particulate filter of a gasoline engine, the particulate filter being located downstream of the gasoline engine and receiving exhaust gas from the gasoline engine. The coordinator module generates an activation signal, a torque reserve signal, and an equivalence ratio. Based on the current amount of soot mass and the activation signal, the regeneration module generates a regeneration signal to regenerate the particulate filter. Based on the regeneration signal, the torque reserve signal, and the equivalence ratio, the actuator modules retard the ignition spark and increase the amount of airflow to the particulate filter.The actuators maintain the same amount of torque from the gasoline engine during regeneration as was output by the gasoline engine before the particulate filter regeneration.

Description

[0001] The present disclosure relates to a regeneration of particulate filters of internal combustion engines for gasoline (also referred to herein as petrol).

[0002] A gasoline internal combustion engine (ICE) typically includes an exhaust system with a catalytic converter. The exhaust system may also include a gasoline particulate filter (GPF) downstream of the catalytic converter. The GPF filters soot and particulates from the exhaust gas emitted by the gasoline internal combustion engine.

[0003] During operation of a gasoline internal combustion engine, a level of oxygen (O2) in a GPF of the gasoline internal combustion engine may be below a level required to oxidize soot in the GPF. In addition, a temperature of an exhaust gas received by the GPF may be in a temperature range (e.g., at a temperature less than a predetermined temperature) that is unsuitable for oxidation. Thus, regeneration of the GPF may not be performed and / or may not be performed efficiently during certain operating conditions. Inefficient regeneration may also occur during fuel cut-off events when there is an excess of oxygen (O2) in the GPF, but the GPF is not at a sufficient temperature for oxidation. Examples of fuel cut-off events include clutch fuel cut-off (CFCO) events.Clutch fuel cut-off (DFCO) and deceleration fuel cut-off (DFCO) events. Fuel cut-off events can occur as a result of cylinder deactivation. A cylinder deactivation system can deactivate one or more of an engine's cylinders during engine operation to conserve fuel.

[0004] DFCO is used for several reasons. DFCO can be used to provide deceleration (driveline braking) force when a vehicle's accelerator pedal is not engaged (e.g., the vehicle driver is not pressing the accelerator pedal). In high-altitude (mountainous) areas and / or areas with large elevation changes, DFCO is used to provide driveline braking, thus preventing damage to a vehicle's friction brakes.

[0005] DFCO can also be used to prevent damage to a catalytic converter. For example, a throttle position may be calibrated and fixed to provide a minimum amount of air per cylinder (APC) to an engine, thereby providing vehicle deceleration when driving downhill. Due to the fixed throttle position and / or a manual downshift of a transmission (PRNDL) shift lever (for example, shifting to a low gear such as L1 or L2), the engine's APC levels may become too low and cause a misfire. Misfire refers to incomplete combustion of an air / fuel mixture in an engine cylinder. This misfire can cause fuel to enter an exhaust system and ignite, increasing the temperature of a catalytic converter catalyst.Catalyst damage can occur when catalyst temperatures exceed a certain threshold. Using DFCO shuts off fuel, protecting the catalyst from misfire events.

[0006] DFCO can also be used to increase fuel economy. The efficiency of a gasoline engine can be low at minimum combustion (i.e., minimal air and fuel levels) due to pumping losses and other factors. Fuel shutoff is more efficient than reducing the amount of fuel delivered to an internal combustion engine.

[0007] DE 10 2012 022 153 A1 discloses a method for regenerating a particulate filter of an exhaust system for a gasoline engine. The method comprises determining a temperature of the particulate filter and / or an exhaust gas stream of the gasoline engine. As long as the temperature of the particulate filter and / or the exhaust gas stream is lower than a predetermined minimum temperature for oxidizing the soot particles, a fuel supply to at least one cylinder of the gasoline engine is shut off, and simultaneously, a combustion lambda of at least one cylinder that is not shut off is reduced to a value less than 1.If the temperature of the particulate filter and / or the exhaust gas flow corresponds at least to the predetermined minimum temperature for oxidation of the soot particles, in order to increase the oxygen content of the exhaust gas, an opening of a throttle device of the gasoline engine is enlarged in the presence of overrun operation or the combustion lambda is increased to a value greater than 1 or the fuel supply to at least the cylinder of the gasoline engine is switched off.

[0008] Further state of the art is described in DE 10 2010 046 749 A1, DE 10 2009 045 370 A1 and the article: Rußpartikelfilter, Wikipedia, version 30.10.2014.

[0009] The object of the invention is to provide a system with which it is possible to provide efficient regeneration of a particulate filter while at the same time stabilizing engine operation.

[0010] The object is solved by the subject matter of claim 1. Advantageous developments of the invention are described in the subclaims.

[0011] The present disclosure will be more fully understood from the detailed description and the accompanying drawings in which: Fig. 1 is a functional block diagram of a powertrain system including a GPF module according to the present disclosure; Fig. 2 is a functional block diagram of a control system including an engine control module with the GPF module according to the principles of the present disclosure; Fig. 3 is a functional block diagram of the GPF module according to the principles of the present disclosure; Fig. 4 is a functional block diagram of a coordinator module of the GPF module according to the principles of the present disclosure; Fig. 5 shows a regeneration process according to the principles of the present disclosure; Fig. 6 shows an equivalence ratio method according to the principles of the present disclosure; and Fig. 7 shows a torque reserve method according to the principles of the present disclosure.

[0012] Examples of regenerating a particulate filter of a gasoline engine are provided below. The examples include increasing and maintaining a temperature of the particulate filter above a predetermined threshold and increasing airflow to the particulate filter to support efficient regeneration of the particulate filter. The examples further include enabling and disabling torque reserve requests based on particulate filter temperatures to facilitate regeneration of the particulate filter and minimize regeneration time.

[0013] Fig. 1 shows a powertrain system 10 that includes an engine system 12 and a transmission system 14, which may include a torque converter clutch 15. The engine system 12 includes an engine 16 and an engine control module (ECM) 17 with a GPF module 20. The transmission system 14 includes a transmission control module (TCM) 21. The transmission system 14 may include, for example, an automatic transmission, a semi-automatic transmission, a dual-clutch transmission, etc. (here, transmission 17). The GPS module 20 controls regeneration of a GPF 22 in an exhaust system 24 of the engine 16. Operation of the GPS module 20 is described below with reference to Fig. 2-7 further described.

[0014] The powertrain system 10 includes an engine 16 that combusts an air / fuel mixture to produce drive torque for a vehicle based on driver input from a driver input module 104. Air is drawn into an intake manifold 110 through a throttle valve 112. The ECM 17 controls a throttle actuator module 116, which regulates the opening of the throttle valve 112 to control the amount of air drawn into the intake manifold 110. A brake booster 106 draws a vacuum from the intake manifold 110 when the pressure in the intake manifold 110 is less (i.e., a greater vacuum) than a pressure in the brake booster 106. The brake booster 106 assists a vehicle user in applying the vehicle's brakes.

[0015] Air from intake manifold 110 is drawn into cylinders (only one is shown) of engine 16. ECM 17 may instruct a cylinder actuator module 120 to selectively deactivate some of the cylinders, which may improve fuel economy under certain engine operating conditions. Engine 16 may operate using a four-stroke combustion cycle. The four strokes, described below, are referred to as the intake stroke, compression stroke, combustion stroke, and exhaust stroke. During each revolution of a crankshaft (not shown), two of the four strokes occur in cylinder 118.

[0016] During the intake stroke, air is drawn from the intake manifold 110 into the cylinder 118 through an intake valve 122. The ECM 17 controls a fuel actuator module 124, which regulates fuel injection to achieve a desired air / fuel ratio. Fuel may be injected into the intake manifold 110 at a central location or at multiple locations, such as near the intake valve 122 of each of the cylinders. In various implementations (not shown), fuel may be injected directly into the cylinders or into mixing chambers associated with the cylinders. The fuel actuator module 124 may pause the injection of fuel into cylinders that are deactivated.

[0017] The injected fuel mixes with air, creating an air / fuel mixture in cylinder 118. During the compression stroke, a piston (not shown) within cylinder 118 compresses the air / fuel mixture. Based on a signal from the ECM 17, a spark actuator module 126 energizes a spark plug 128 within cylinder 118, which ignites the air / fuel mixture. The ignition timing of the spark may be set relative to when the piston is at its topmost position, referred to as top dead center (TDC).

[0018] The spark actuator module 126 may be controlled by an ignition timing signal that determines how far before or after TDC the spark should be generated. Since piston position is directly related to crankshaft rotation, operation of the spark actuator module 126 may be synchronized with the crankshaft angle. In various implementations, the spark actuator module 126 may pause the provision of spark to deactivated cylinders.

[0019] During the combustion stroke, the combustion of the air / fuel mixture drives the piston downward, thereby driving the crankshaft. During the exhaust stroke, the piston begins to move upward from bottom dead center (BDC) and expels the combustion byproducts through an exhaust valve 130. The combustion byproducts are expelled from the vehicle via an exhaust system 24.

[0020] The exhaust system 24 includes a catalyst 136 and the GPF 22. A catalyst 136 receives the exhaust gas emitted by the engine 16 and reacts with various components of the exhaust gas. For example only, the catalyst may include a three-way catalyst (TWC), a catalytic converter, or other suitable exhaust catalyst. The GPF 22 may be located downstream of the catalyst 136 and filters soot from the exhaust gas received by the catalyst.

[0021] The intake valve 122 may be controlled by an intake camshaft 140, while the exhaust valve 130 may be controlled by an exhaust camshaft 142. The cylinder actuator module 120 may deactivate the cylinder 118 by disabling opening of the intake valve 122 and / or the exhaust valve 130. In various other implementations, the intake valve 122 and / or the exhaust valve 130 may be controlled by devices other than camshafts, such as electromagnetic actuators.

[0022] The times at which intake and exhaust valves 122, 130 are opened may be varied relative to piston TDC by intake and exhaust cam phasers 148, 150. A phaser actuator module 158 may control intake and exhaust cam phasers 148, 150 based on signals from ECM 17.

[0023] The powertrain system 10 may include a charging device that delivers pressurized air to the intake manifold 110. For example, Fig. 1 illustrates a turbocharger with a hot turbine 160-1 driven by hot exhaust gases flowing through the exhaust system 24. The turbocharger also includes a cold air compressor 160-2 driven by the turbine 160-1, which compresses air leading into the throttle valve 112. In various implementations, a crankshaft-driven mechanical supercharger (not shown) may compress air from the throttle valve 112 and deliver the compressed air to the intake manifold 110.

[0024] A wastegate 162 may allow exhaust gas to bypass the turbine 160-1, thereby reducing the boost (the amount of intake air compression) of the turbocharger. The ECM 17 may control the turbocharger via a boost actuator module 164. The boost actuator module 164 may modulate the boost of the turbocharger by controlling the position of the wastegate 162.

[0025] The powertrain system 10 may include an exhaust gas recirculation (EGR) valve 170 that selectively redirects exhaust gas back to the intake manifold 110. The EGR valve 170 may be positioned upstream of the turbocharger turbine 160-1. The EGR valve 170 may be controlled by an EGR actuator module 172.

[0026] The powertrain system 10 may measure the rotational speed of the crankshaft (i.e., engine speed) in revolutions per minute (RPM) using an RPM sensor 178. The temperature of the engine oil may be measured using an oil temperature (TDC) sensor 180. An engine coolant temperature may be measured using an engine coolant temperature (ECT) sensor 182. The ECT sensor 182 may be located in the engine 16 or at other locations where the coolant is circulated, such as a radiator (not shown). An engine temperature may be referred to as T ENG The temperature of the machine T ENG may be equal to or determined based on the engine temperature and / or the engine coolant temperature.

[0027] The pressure within the intake manifold 110 may be measured using a manifold absolute pressure (MAP) sensor 184. The mass flow rate of air flowing into the intake manifold 110 may be measured using a mass air flow (MAF) sensor 186. In various implementations, the MAF sensor 186 may be located in a housing that also contains the throttle valve 112.

[0028] The throttle actuator module 116 may monitor the position of the throttle valve 112 using one or more throttle position sensors (TPS) 190. The ambient temperature of air drawn into the engine 16 may be measured using an intake air temperature (IAT) sensor 192. The ECM 17 may use signals from one or more sensors to make control decisions for the powertrain system 10.

[0029] The ECM 17 may communicate with the TCM 21 to coordinate gear changes (and in particular, a gear ratio) in a transmission (not shown). For example, the ECM 17 may reduce engine torque during a gear change. The ECM 17 may communicate with a hybrid control module 196 to coordinate operation (i.e., generation of torque output) of the engine 16 and an electric motor 198.

[0030] The electric motor 198 may also serve as a generator and may be used to generate electrical energy for use by vehicle electrical systems and / or for storage in an energy storage device (e.g., a battery). The generation of electrical energy may be referred to as regenerative braking. The electric motor 198 may apply braking (negative) torque to the engine 16 to perform regenerative braking and generate electrical energy. The powertrain system 10 may also include one or more additional electric motors. In various implementations, various functions of the ECM 17, the TCM 21, and the hybrid control module 196 may be integrated into one or more modules.

[0031] Any system that varies an engine parameter may be referred to as an engine actuator. Each engine actuator receives an associated actuator value. For example, the throttle actuator module 116 may be referred to as an engine actuator, and the throttle opening area may be referred to as the associated actuator value. In the example of Fig. 1, the throttle actuator module 116 achieves the throttle opening area by adjusting an angle of the flap of the throttle valve 112.

[0032] Similarly, the ignition actuator module 126 may be referred to as an engine actuator, while the corresponding actuator value may be the amount of spark advance relative to cylinder TDC. Other actuators may include the cylinder actuator module 120, the fuel actuator module 124, the phaser actuator module 158, the boost actuator module 164, and the EGR actuator module 172. For these engine actuators, the associated actuator values ​​may include: a number of activated cylinders; a fueling rate; intake and exhaust cam phaser angles; a boost pressure; and an EGR valve opening area.

[0033] The ECM 17 may control actuator values ​​to cause the engine 16 to produce a desired engine output torque.

[0034] The powertrain system 10 may further include one or more devices and / or accessories 199 that engage and / or provide a load to the engine 16. The devices and / or accessories may include an air conditioning system, a compressor and / or clutch, an alternator, a generator, a cooling fan, etc. The ECM 17 may control the operation of the devices and / or accessories 199.

[0035] The engine system 12 may further include any number of temperature and / or pressure sensors on the exhaust system 24 for sensing temperatures and / or pressures of exhaust gas, temperatures of the catalyst 136, temperatures of the GPF 22, and / or pressures in and out of the catalyst 136 and / or the GPF 22. A temperature sensor 193 is for sensing a temperature T GPFof the GPF 22. Pressure sensors 195, 197 for detecting inlet and outlet pressures P1 and P2 of the GPF 22 are shown.

[0036] Fig. 2 shows a control system 200 that includes the ECM 17 (or a portion thereof). The ECM 17 includes the GPF module 20, which is described in more detail below. See, for example, the section labeled GPF REGENERATION and the following description. The ECM 17 also includes a driver torque module 202 that determines a driver torque request based on one or more driver inputs from the driver input module 104. The driver input may be based on a position of an accelerator pedal and / or based on a cruise control input.

[0037] An axle torque arbitration module 204 arbitrates between the driver torque request from the driver torque module 202 and other axle torque requests. Torque requests may include absolute torque requests, as well as relative torque requests and ramp-like requests. For example only, ramp-like requests may include a request to ramp torque down to a minimum engine shutdown torque or to ramp torque up from a minimum engine shutdown torque. Relative torque requests may include temporary or permanent torque reductions or increases. Each torque request may include data indicating the system or module that generated that torque request (i.e., the requestor).

[0038] The axle torque requests may include a torque reduction requested by a traction control system when positive wheel slip is detected. Positive wheel slip occurs when axle torque overcomes friction between the wheels and the road surface, and the wheels begin to slide against the road surface in a forward direction. The axle torque requests may also include a torque increase request to counteract negative wheel slip, in which a tire of the vehicle slips in the other direction relative to the road surface because the axle torque is negative.

[0039] Axle torque requests may also include brake management requests and vehicle overspeed torque requests. Brake management requests may reduce engine output torque to ensure that the engine output torque does not exceed the ability of the brakes to hold the vehicle when the vehicle is stopped. Vehicle overspeed torque requests may reduce engine output torque to prevent the vehicle from exceeding a predetermined speed. Axle torque requests may also be generated by vehicle stability control systems.

[0040] The axle torque arbitration module 204 outputs a predicted torque request and an immediate torque request based on the results of arbitrating between the received torque requests. As described below, the predicted and immediate torque requests from the axle torque arbitration module 204 may be selectively adjusted by other modules before being used to control actuators of the engine 16.

[0041] Generally, the immediate torque request is the amount of currently desired engine output torque, while the predicted torque request is the amount of engine output torque that may be required in the short term. The ECM 17 therefore controls the engine 16 to produce an engine output torque equal to the immediate torque request. However, different combinations of actuator values ​​may result in the same engine output torque. The ECM 17 may therefore adjust the actuator values ​​to allow a faster transition to the predicted torque request while still maintaining the engine output torque at the immediate torque request.

[0042] In various implementations, the predicted torque request may be based on the driver torque request. The immediate torque request may be less than the predicted torque request, such as when the driver torque request causes positive wheel slip on an icy surface. In such a case, a traction control system (not shown) may request a reduction above the immediate torque request, and the ECM 17 reduces the torque produced by the engine 16 to the immediate torque request. However, the ECM 17 controls the engine actuators so that the engine 16 can quickly resume producing the predicted torque request once positive wheel slip ceases.

[0043] Generally, the difference between the immediate torque request and the predicted torque request can be referred to as a torque reserve. The torque reserve represents the amount of torque that exceeds the immediate torque request and that the engine 16 can begin producing with minimal delay. Fast engine actuators are used to increase or decrease the engine output torque. As explained in more detail below, fast engine actuators are defined based on their ability to produce a response in the engine output torque relative to slow engine actuators.

[0044] In various implementations, fast engine actuators are capable of varying engine output torque within a range established by the slow engine actuators. In such implementations, the upper limit of the range is the predicted torque demand, while the lower limit of the range is limited by the torque capacity of the fast engine actuators.

[0045] Generally speaking, fast engine actuators can change engine output torque faster than slow engine actuators. Slow engine actuators can respond more slowly to changes in their respective actuator values ​​than fast engine actuators. For example, a slow engine actuator may have mechanical components that require time to move from one position to another in response to a change in the associated actuator value.

[0046] A slow engine actuator can also be characterized by the amount of time required for the engine output torque to begin changing once the slow engine actuator begins implementing the changed actuator value. Generally, this amount of time is longer for slow engine actuators than for fast engine actuators. Additionally, even after the engine output torque begins to change, the engine output torque may take longer to reach an engine output torque expected for the result of the changed actuator value.

[0047] For example only, the ECM 17 may set actuator values ​​for slow engine actuators to values ​​that allow the engine 16 to produce the predicted torque request when the fast engine actuators have been set to appropriate values. Meanwhile, the ECM 17 may set actuator values ​​for fast engine actuators to values ​​that, given the slow engine actuator values, cause the engine 16 to produce the immediate torque request instead of the predicted torque request.

[0048] The values ​​of fast actuators therefore cause the engine 16 to produce the immediate torque request. When the ECM 17 determines that the engine output torque is transitioning from the immediate torque request to the predicted torque request, the ECM 17 changes the actuator values ​​associated with one or more fast engine actuators to values ​​corresponding to the predicted torque request. Because the actuator values ​​associated with the slow engine actuators have already been set based on the predicted torque request, the engine 16 is able to produce the predicted torque request only after the delay attributable to the fast engine actuators. In other words, the longer delay that would otherwise result from changing the engine output torque using slow engine actuators is avoided.

[0049] For example only, when the predicted torque request is equal to the driver torque request, a torque reserve may be generated if the immediate torque request is less than the driver torque request due to a temporary torque reduction request. Alternatively, a torque reserve may be generated by increasing the predicted torque request above the driver torque request while maintaining the immediate torque request at the driver torque request.

[0050] The resulting torque reserve can be used to compensate for sudden increases in required engine output torque. For example, sudden loads from an air conditioning system or power steering pump can be compensated for by increasing the immediate torque demand. If the increase in immediate torque demand is smaller than the torque reserve, the increase can be quickly generated by using fast engine actuators. The predicted torque demand can then also be increased to restore the previous torque reserve.

[0051] As another example, a torque reserve can be used to reduce fluctuations in slow actuator values. Due to their relatively slow speed, varying values ​​of slow actuators can create control instability. Additionally, slow engine actuators may have mechanical parts that draw more power and / or can wear out faster if they are moved frequently.

[0052] Creating a sufficient torque reserve allows changes in the desired torque to be made by varying fast engine actuators across the immediate torque demand while maintaining the values ​​of the slow engine actuators. For example, to maintain a given idle speed, the immediate torque demand can vary within a range. If the predicted torque demand is set to a level above this range, then variations in the immediate torque demand that maintain the idle speed can be made using fast engine actuators without the need to adjust slow engine actuators.

[0053] Upon receiving a new actuator value, the ignition actuator module 126 may be able to change ignition timing for the following ignition event. When the ignition timing (also referred to as spark advance) for an ignition event is set to a calibrated value, maximum torque is produced in the combustion stroke immediately following the ignition event. However, spark advance that deviates from the calibrated value may reduce the amount of torque produced in the combustion stroke. Therefore, the ignition actuator module 126 may be able to vary engine output torque as soon as the next ignition event occurs by varying the spark advance.For example only, a table of ignition timings corresponding to various engine operating conditions may be determined during a calibration phase of a vehicle design, and the calibrated value is selected from the table based on current engine operating conditions.

[0054] In contrast, changes in throttle opening area take longer to affect engine output torque. The throttle actuator module 116 changes the throttle opening area by adjusting the angle of the flap of the throttle valve 112. Therefore, once a new actuator value is received, a mechanical delay exists as the throttle valve 112 moves from its previous position to a new position based on the new actuator value. Additionally, airflow changes due to throttle valve opening are subject to air transport delays in the intake manifold 110. Further, increased airflow into the intake manifold 110 is not realized as an increase in engine output torque until the cylinder 118 ingests additional air in the next intake stroke, compresses the additional air, and begins the combustion stroke.

[0055] Using throttle opening area and spark timing as an example, a torque reserve may be created by setting the throttle opening area to a value that allows engine 16 to produce a predicted torque request. Meanwhile, spark timing may be set based on an immediate torque request that is less than the predicted torque request. Although the throttle opening area creates sufficient airflow for engine 16 to produce the predicted torque request, spark timing is retarded based on the immediate torque request (reducing engine output torque). The engine output torque is therefore equal to the immediate torque request.

[0056] When additional torque is required, such as when the air conditioning compressor engages or when a traction control system determines that wheel slippage has ended, spark timing may be set based on the predicted torque request. Through the following firing event, the ignition actuator module 126 may reset spark timing to a calibrated value that allows the engine 16 to produce maximum engine output torque. Engine output torque may therefore be quickly increased to the predicted torque request without delays due to a change in throttle opening area.

[0057] The axle torque arbitration module 204 may output the predicted torque request and the immediate torque request to a propulsion torque arbitration module 206. Depending on the type of hybrid vehicle, the axle arbitration module 204 may output the predicted and immediate torque requests to the hybrid control module 196.

[0058] The predicted torque request and immediate torque request received by the propulsion torque arbitration module 206 are translated from an axle torque domain (torque at the wheels) to a propulsion torque domain (torque at the crankshaft). In some implementations, the predicted and immediate torque requests may be converted to the propulsion torque domain before being provided to the propulsion torque arbitration module 206. In some implementations, the predicted and immediate torque requests in the propulsion torque domain may be provided to the hybrid control module 196. The hybrid control module 196 may control the electric motor 198 based on one or more of the torque requests and provide the modified predicted and immediate torque requests to the propulsion torque arbitration module 206.

[0059] The propulsion torque arbitration module 206 arbitrates between propulsion torque requests comprising the converted predicted and immediate torque requests. The propulsion torque arbitration module 206 generates an arbitrated predicted torque request and an arbitrated immediate torque request based on the arbitration. The arbitrated torque requests may be generated by selecting a winning request from received requests. Alternatively or additionally, the arbitrated torque requests may be generated by modifying one of the received requests based on one or more of the received torque requests.

[0060] Other propulsion torque requests may include torque reductions for engine overspeed protection, torque increases for stall prevention, and torque reductions requested by the transmission control module 194 to adjust gear shifting. Additionally, other propulsion torque requests may include an engine lockout request, which may be initiated when a critical fault is detected. For example only, critical faults may include detection of vehicle theft, a stuck starter, electronic throttle control issues, and unexpected torque increases. In various implementations, when an engine lockout request is present, arbitration selects the engine lockout request as the winning request.When the machine shutoff request is present, the propulsion torque arbitration module 206 may output zero as the arbitrated torques.

[0061] In various implementations, a machine shutoff request may simply shut down machine 16 separately from the arbitration process. The propulsion torque arbitration module 206 may still receive the machine shutoff request so that, for example, appropriate data can be fed back to other torque requesters. For example, all other requesters may be informed that they have lost the arbitration.

[0062] A reserves / loads module 220 receives the arbitrated predicted and immediate torque requests from the propulsion torque arbitration module 206. The reserves / loads module 220 may adjust the arbitrated predicted and immediate torque requests to create a torque reserve and / or compensate for one or more loads. The reserves / loads module 220 then outputs the adjusted predicted and immediate torque requests to an actuation module 224.

[0063] The actuation module 224 receives the predicted and immediate torque requests from the reserves / loads module 220. The actuation module 224 determines how to achieve the predicted and immediate torque requests. The actuation module 224 may be machine type-specific. For example, the actuation module 224 may be implemented differently or use different control schemes for spark-ignition engines as opposed to compression-ignition engines.

[0064] In various implementations, the actuation module 224 may define a boundary between modules that are common across all machine types and modules that are machine type-specific. For example, machine types may include spark ignition and compression ignition. Modules upstream of the actuation module 224, such as the propulsion torque arbitration module 206, may be common across machine types, while the actuation module 224 and subsequent modules may be machine type-specific.

[0065] For example, in a spark-ignition engine, the actuation module 224 may vary the opening of the throttle valve 112 as a slow engine actuator, allowing a wide range of torque control. The actuation module 224 may deactivate cylinders using the cylinder actuator module 120, which also provides a wide range of torque control, but may also be slow and may affect drivability and emissions. The actuation module 224 may use ignition timing as a fast engine actuator. However, ignition timing may not need to provide as wide a range of torque control. Additionally, the amount of torque control possible with changes in ignition timing (referred to as spark reserve capacity) may vary as one or more airflow conditions change.

[0066] In various implementations, the actuation module 224 may generate an air torque request based on the predicted torque request. The air torque request may be equal to the predicted torque request, thereby controlling engine airflow actuators so that the adjusted predicted torque request may be quickly achieved by adjusting one or more actuator values ​​associated with fast engine actuators.

[0067] An air control module 228 may determine desired actuator values ​​for the engine airflow actuators based on the air torque request. For example, the air control module 228 may determine a desired manifold absolute pressure (MAP), a desired throttle area, and / or desired air per cylinder (APC). The desired MAP may be used to determine a desired boost, and the desired APC may be used to determine desired camshaft phaser positions. In various implementations, the air control module 228 may also determine a desired opening of the EGR valve 170 and other engine airflow parameters.

[0068] The actuation module 224 may also generate a spark torque request, a cylinder shutoff torque request, and a fuel mass torque request. For example only, the actuation module 224 may generate the spark torque request, the cylinder shutoff torque request, and / or the fuel mass torque request based on the immediate torque request.

[0069] The actuation module 224 may generate one or more of these requests based on the requester. As an example, the actuation module 224 may generate one of these torque requests based on the requester if a fuel shutoff control module 225 generates an immediate torque request to shut off the provision of fuel to the engine 16. The fuel shutoff control module 225 is discussed further below.

[0070] The spark torque request may be used by an ignition control module 232 to determine how much spark timing (which reduces engine output torque) needs to be retarded from a calibrated spark advance. The cylinder deactivation torque request may be used by a cylinder control module 236 to determine how many cylinders need to be deactivated. The cylinder control module 236 may instruct the cylinder actuator module 120 to deactivate one or more cylinders of the engine 16. In various implementations, a predefined group of cylinders may be deactivated together.

[0071] The cylinder control module 236 may also instruct a fuel control module 240 to stop providing fuel to deactivated cylinders and may instruct the ignition control module 232 to stop providing ignition spark to deactivated cylinders. In various implementations, the ignition control module 232 only stops providing ignition spark to a cylinder once a fuel / air mixture already present in the cylinder has been combusted.

[0072] In various implementations, the cylinder actuator module 120 may include a hydraulic system that selectively decouples intake and / or exhaust valves from the corresponding camshafts for one or more cylinders to deactivate those cylinders. For example only, valves for half of the cylinders are either hydraulically coupled or decoupled as a group by the cylinder actuator module 120. In various implementations, cylinders may be deactivated simply by stopping the provision of fuel to those cylinders, without stopping the opening and closing of the intake and exhaust valves. In such implementations, the cylinder actuator module 120 may be omitted.

[0073] The fuel control module 240 may vary the amount of fuel provided to each cylinder based on the fuel mass torque request from the actuation module 224. During normal operation of a gasoline engine, the fuel control module 240 may attempt to maintain a stoichiometric air / fuel ratio. The fuel control module 240 may therefore determine a fuel mass that achieves stoichiometric combustion when combined with the current APC. The fuel control module 240 may command the fuel actuator module 124 to inject this fuel mass for each activated cylinder.

[0074] Based on the fuel mass torque request, the fuel control module 240 may adjust the air / fuel ratio relative to stoichiometry to increase or decrease engine output torque. The fuel control module 240 may then determine a fuel mass for each cylinder that achieves the desired air / fuel ratio. In diesel systems, the fuel mass may be the primary actuator for controlling engine output torque. During fuel shutoff, the actuation module 224 may generate the fuel mass torque request so that the fuel control module 240 shuts off the provision of fuel to the engine 16.

[0075] A torque estimation module 244 may estimate a torque output of the engine 16. This estimated torque may be used by the air control module 228 to perform closed-loop control of engine airflow parameters, such as throttle area, MAF, MAP, APC, and phaser positions. For example only, torque may be determined as a function of: mass air per cylinder (APC); spark advance (S); intake cam phase position (I); exhaust cam phase position (E); air / fuel ratio (AF); oil temperature (TDC); and a number of activated cylinders (#). Additional variables may also be considered, such as the degree of opening of an exhaust gas recirculation (EGR) valve.

[0076] This relationship may be modeled by an equation and / or stored as a lookup table. The torque estimation module 244 may determine the APC based on the MAF and RPM, enabling closed-loop engine airflow parameter control based on current engine airflow conditions. The intake and exhaust cam phaser positions used may be based on actual positions, as the phasers may move to desired positions.

[0077] The torque estimation module 244 may use the actual spark advance to estimate the engine output torque. When a calibrated spark advance value is used to estimate the engine output torque, the estimated torque may be referred to as an estimated air torque or simply an air torque. The air torque is an estimate of how much torque the engine 16 can produce under current airflow conditions if spark retard has been removed (i.e., spark timing has been reset to the calibrated spark advance value) and all cylinders have been fueled.

[0078] The air control module 228 may output a desired area signal to the throttle actuator module 116. The throttle actuator module 116 then regulates the throttle valve 112 to generate the desired throttle area. The air control module 228 may generate the desired area signal based on an inverse torque model and the air torque request. The air control module 228 may use the estimated air torque and / or the MAF signal to perform closed-loop control of the engine airflow actuators. For example, the desired throttle area may be controlled to minimize a difference between the estimated air torque and the air torque request.

[0079] The air control module 228 may output a desired MAP signal to a boost scheduling module 248. The boost scheduling module 248 may use the desired MAP signal to control the boost actuator module 164. The boost actuator module 164 then controls one or more turbochargers (e.g., the turbocharger including the turbine 160-1 and the compressor 160-2) and / or mechanical superchargers. The desired MAP may also be used by the throttle actuator module 116 in controlling the throttle valve 112.

[0080] The air control module 228 may also output a desired air per cylinder (APC) signal to a phaser scheduling module 252. Based on the desired APC signal and the RPM signal, the phaser scheduling module 252 may control positions of the intake and / or exhaust cam phasers 148 and 150 using the phaser actuator module 158.

[0081] Referring back to the ignition control module 232, calibrated spark advance values ​​may vary based on various engine operating conditions. For example only, a torque relationship may be inverted to resolve to a desired spark advance. For a given torque request (T des ) the target ignition advance (S des ) as a function of the parameters T des , APC, I, E, AF, TDC, and #. This relationship may be implemented as an equation and / or a lookup table. The air / fuel ratio (AF) may be the actual air / fuel ratio as reported by the fuel control module 240.

[0082] When the spark advance is set to the calibrated spark advance, the resulting torque can be as close as possible to the mean best torque (MBT). The MBT refers to the maximum engine output torque produced for given engine airflow conditions when the spark advance is increased while using a fuel with a higher octane rating than a specified one and using stoichiometric fueling. The spark advance at which the MBT occurs is referred to as an MBT timing. The calibrated spark advance may differ slightly from the MBT timing due to, for example, fuel quality (such as when using lower-octane fuel) and environmental factors.The engine output torque produced using the calibrated spark advance may therefore be less than the MBT.

[0083] The fuel cutoff control module 225 selectively generates propulsion torque requests for fuel cutoff (FCO) events. For example only, the fuel cutoff control module 225 may generate propulsion torque requests to initiate and control execution of clutch fuel cutoff (CFCO) and deceleration fuel cutoff (DFCO) events. The fuel cutoff control module 225 may also generate propulsion torque requests for other types of FCO events.

[0084] The fuel shutoff control module 225 may generate an FCO predicted torque request and an FCO immediate torque request. Upon receipt, the propulsion torque arbitration module 206 may select the FCO torque requests from the fuel shutoff control module 225 as the arbitration winner. In this way, engine actuators are controlled based on the FCO torque requests during FCO events.

[0085] In some hybrid vehicles, the fuel shutoff control module 225 may receive a hybrid immediate torque request from the hybrid control module 196. The fuel shutoff control module 225 may generate the FCO immediate torque request based on the hybrid immediate torque request. In other hybrid vehicles, the hybrid control module 196 may provide the hybrid immediate torque request directly to the propulsion torque arbitration module 206. In such implementations, the propulsion torque arbitration module 206 may select the predicted torque request from the fuel shutoff control module 225 and the hybrid immediate torque request from the hybrid control module 196 as winning the arbitration. The engine actuators are then controlled based on these torque requests.

[0086] A power machine capacity module 274, which in Fig. 3, may determine one or more torque capacities of the engine 16. For example only, the engine capacities module 274 may determine a maximum shutdown torque capacity and a minimum shutdown torque capacity. The engine capacities module 274 may also determine one or more other engine torque capacities.

[0087] The maximum shutoff torque capacity may correspond to a maximum engine output torque achievable with the fuel supply shut off and the engine airflow actuators adjusted to minimize pumping losses during DFCO. In other words, controlling the engine airflow actuators based on the maximum shutoff torque capacity during DFCO may achieve maximum pumping loss reduction.

[0088] The minimum shutoff torque capacity may correspond to a minimum engine output torque achievable with fueling shutoff and fuel factors adjusted to maximize pumping losses during DFCO. In other words, controlling the engine airflow actuators based on the minimum shutoff torque capacity may provide a zero reduction in pumping losses experienced during DFCO. In some implementations, the minimum shutoff torque capacity and the maximum shutoff torque capacity may be provided to the hybrid control module 196.

[0089] The engine capacities module 274 may determine the maximum shutdown torque capacity and the minimum shutdown torque capacity based on the RPM, friction, and accessory loads that apply braking (i.e., negative) torque to the engine 16. Friction may be determined based on the oil temperature. The accessory loads may be provided, for example, by the power steering pump, the air conditioning (A / C) compressor, and / or other suitable loads.

[0090] The minimum shut-off torque capacity may be further determined based on a minimum APC for combustion, and the maximum shut-off torque capacity may be further determined based on a desired MAP or a desired APC. The fuel shut-off control module 225 may provide the desired MAP and / or the desired APC during DFCO. The fuel shut-off control module 225 may determine the desired MAP and the desired APC to achieve a pumping loss reduction during DFCO. In other words, the fuel shut-off control module 225 may determine the desired MAP and the desired APC to achieve a pumping loss reduction during DFCO (DPLR).

[0091] The fuel shutoff control module 225 may provide a DPLR signal to the phaser scheduling module 252 when the DPLR is to be executed. During the DPLR, the phaser scheduling module 252 may control valve timing of the intake and exhaust valves 122 and 130 to minimize valve opening overlap. Valve opening overlap may describe a period during which both the intake valve 122 and the exhaust valve 130 are open. Intake and exhaust cam phaser angles to minimize valve opening overlap and thereby minimize pumping losses may be predetermined and may be selected based on operating conditions. When the DPLR signal is not received, the phaser scheduling module 252 may adjust the timing of the intake and exhaust valves 122 and 130 based on the air torque request.For example only, during DFCO, the phaser scheduling module may eliminate valve opening overlap if no DPLR signal is received. GPF regeneration

[0092] The GPF module generates a regeneration signal REGEN, a torque reserve request signal TR REQ, an equivalence ratio request signal EQR REQ, a torque capacity request signal TC REQ, a mission profile (or mode) signal MP, a dual pulse fuel delivery (DPF) signal, and a camshaft phaser signal CAM PHAS. These signals are provided to modules of the engine control module 17, as shown in Fig. 2. The regeneration signal REGEN indicates whether the GPF 22 is to be regenerated and is provided to modules 210, 220, 224, 228, 232, 240, 244, 252. As an example, if the regeneration signal REGEN is HIGH or '1', the GPF 22 is regenerated. If the regeneration signal REGEN is LOW or '0', the GPF 22 is not regenerated.

[0093] The torque reserve request signal TR REQ indicates a requested torque reserve and is provided to the reserve / load module 220. The GPF module 20 may request a torque reserve to increase an amount of heat in the GPF module 20. By providing the torque reserve, spark timing may be retarded and airflow to the GPF may be increased. The reserve / load module 220 may receive multiple torque reserve requests from the GPF module 20 and other modules of the ECM 17 and / or external to the ECM 17. The reserve / load module 220 may provide the highest torque reserve requested.

[0094] The equivalence ratio request signal EQR REQ requests an equivalence ratio. A lean AFR is required during GPF regeneration to provide exhaust O2. An equivalence ratio may be determined as (i) a ratio of the current air / fuel ratio (AFR) to a stoichiometric AFR or (ii) a ratio of a stoichiometric AFR to a commanded equivalence ratio. The equivalence ratio may be determined via a table that provides a relationship between engine speed and an amount of air per cylinder. The equivalence ratio request signal EQR REQ is provided to the torque estimation module 244 and the fuel control module 240. The torque estimation module 244 generates the estimated air torque signal based on the regeneration signal REGEN and the equivalence ratio request signal EQR REQ.The fuel control module 240 adjusts the fuel delivery rate based on the EQR REQ.

[0095] The torque capacity request signal TC REQ indicates a torque capacity requested by the GPF module 20. The mission profile (or mode) signal MP indicates an operating mode and is provided to the RPM trajectory module 212. The mission profile signal MP may be determined based on engine speed, engine load (or an amount of air per cylinder), and / or vehicle speed. These parameters may be compared to predetermined thresholds to determine whether the engine is operating in idle mode, light-duty mode, or heavy-duty mode. The target RPM is modified in the RPM trajectory module 212 when the mission profile MP signal indicates idle mode and low vehicle speed, and when the REGEN signal is true or ("HIGH"). The RPM control module 210 generates the corresponding predicted and immediate torque signals PredictedTorque. RPM , Immediate torque RPM .

[0096] The dual-pulse DPF fueling signal indicates whether two or more pulses of fuel are to be injected per combustion cycle per cylinder. The dual-pulse DPF fueling signal is provided to the fuel control module 240, which generates the fuel rate signal based on the regeneration signal REGEN, the equivalence ratio request signal EQR REQ, the DPF signal, and / or the fuel torque request from the actuation module 224.

[0097] During GPF 22 regeneration and while a torque reserve is requested to retard spark timing to raise the temperature in the GPF, a double or multiple pulse fuel delivery may be requested to assist in stabilizing engine combustion. The camshaft phaser signal CAM PHAS may also be generated to assist in stabilizing engine combustion during GPF 22 regeneration and while the torque reserve is requested.

[0098] During regeneration of the GPF 22, the GPF module requests an increase in the idle speed of the engine 16 via the mission profile signal MP to raise a temperature of the GPF 22. The engine cannot generate sufficient heat at lower engine speeds associated with idle to regenerate the GPF 22. When calibrated to allow regeneration of a filter during an idle condition, more airflow is requested and indicated to the RPM control module 210. While the engine is operating in an idle condition, the increase in the requested idle speed allows the GPF 22 to reach a suitable temperature for regeneration. The mission profile signal MP is provided to the RPM trajectory module. The RPM control module 210 generates the predicted and immediate torque signals, PredictedTorque RPM , ImmediateTorque RPM , based on the target RPM signal.

[0099] Fig. 3 shows the GPF module 20. The GPF module 20 includes a GPF status module 280, a soot module 282, a regeneration module 284, a mode module 286, and a coordinator module 288. Fig. 4 shows the coordinator module 288. The coordinator module 288 includes a torque reserve output module 290 and an equivalent ratio output module 292. The torque reserve output module 290 includes a first threshold module 294, an equivalent ratio enable module 296, an equivalent ratio delivery module 298, and an equivalent ratio determination module 300. The equivalent ratio output module 292 includes a second threshold module 302, a torque reserve enable module 304, a torque reserve delivery module 306, an ignition timing module 308, a torque determination module 310, and a torque reserve determination module 312. The modules of Fig. 3 are with reference to the procedure of Fig. 5. The modules of Fig. 4 are with reference to the procedures of Fig. 6-7 described.

[0100] The engine systems disclosed herein may be operated using numerous methods, with exemplary methods being set forth in the Fig. 5-7. The procedures of Fig. 6-7 can be carried out while the procedure of Fig. 5 is executed. The procedure of Fig. 7 can be executed while the procedure of Fig. 6 is executed. In Fig. 5 shows a regeneration procedure. Although the following tasks mainly relate to the implementations of Fig. 5, the tasks can be easily modified for application to other implementations of the present disclosure. The tasks can be performed iteratively.

[0101] The method may begin at 314. At 316, parameters are generated and / or measured as described above. The parameters may include a temperature T GPF (322) of the GPF 22, a speed RPM (324) of the engine 16, a barometric pressure BARO (326), a pressure difference dP (328) (e.g. P2-P1) across the GPF 22, a temperature T CAT (330) of the catalyst 136, a turbo protection signal TURBO (332), a temperature T ENG(334) of the engine 16, an air quantity per cylinder (APC) signal (336), a vehicle speed signal VS (338), and an idle status signal IDLE (340). The turbo protection signal may be set to LO when, for example, the operating conditions of the turbo are suitable for regenerating the GPF 22. If the operating conditions are unsuitable for regeneration, then the turbo protection signal may be set to HI. The idle status signal IDLE may indicate whether the engine 16 is operating in an idle state (i.e., running at an idle speed).

[0102] At 318, the GPF status module 280 determines an ideal soot capacity (ISC) (342). A GPF may have an initial internal volume when new and be capable of holding a predetermined maximum amount (or mass) of soot. As the GPF is used over time, an amount of oil ash may build up in the GPF. The oil ash may not be regenerated (or combusted) from the GPF. As a result, the internal volume and / or the maximum amount (or mass) of soot the GPF can hold may decrease over time due to the buildup of oil ash. The ISC indicates the available internal volume after accounting for ash buildup for a current time. The tables may be based on: models of the GPF 22, age of the GPF 22, hours of use of the GPF 22, mileage of the respective vehicle while the GPF 22 was in use, etc. The tables may be stored in memory of the ECM 17.

[0103] At 320, the GPF status module determines a flow resistance FR (344) based on the temperature T GPF , the rotational speed RPM, the barometric pressure BARO, and the differential pressure dP. Task 320 may be executed when task 318 is executed. The flow resistance FR may be equal to the differential pressure dP (or pressure drop across the GPF 22) divided by a current volumetric flow rate through the GPF 22. The volumetric flow rate of exhaust gas may be based on the exhaust mass flow rate and the temperature T GPF be determined.

[0104] At 321, the soot module 282 determines a current amount of soot mass SM (346) in the GPF 22 based on the FR, the volume flow rate of exhaust gas flowing through the GPF 22, the temperature of the GPF 22 (the temperature T GPFand / or an inlet temperature of the GPF 22) and the current amount of oil ash present in the GPF 22. Predetermined tables and / or a model of the GPF 22 relating these parameters may be used to determine the current amount of soot mass SM. The tables and / or model may be stored in a memory of the ECM 17. The FR, the volume flow rate of exhaust gas flowing through the GPF 22, the temperature of the GPF 22, and the current amount of oil ash present in the GPF 22 may be used to determine intermediate values, which may then be used to estimate the current amount of soot mass SM.

[0105] At 323, the soot module 282 determines a soot percentage Soot% (348). Task 321 may be performed when task 320 is performed. The soot percentage Soot% may be equal to the current amount of soot mass SM divided by the ideal soot capacity ISC.

[0106] At 325, the mode module 286 determines an operating mode indicated via the mission profile signal MP (350). The mode module 286 may determine the operating mode based on the engine speed RPM, the air per cylinder APC, the vehicle speed VS, and the idle speed signal IDLE. For example, if the engine speed signal RPM and / or the idle speed signal IDLE indicate that the engine is operating at an idle speed, the mission profile signal MP may indicate operation in the idle mode. To assist in the regeneration of soot in the GPF 22, the idle speed may be increased during regeneration of the GPF 22 to increase the amount of heat out of the engine. Excess oxygen may be present in the GPF 22 to oxidize the soot trapped in the GPF 22. The increased heat output enhances oxidation of the soot.This may include setting and / or using a different idle speed profile during regeneration. If the temperature T GPF of the GPF 22 is less than a predetermined temperature (e.g., 450°C), then the idle speed may be increased from a first speed to a second speed to raise the temperature of the GPF 22. This increase in idle speed may be requested via the mission profile signal MP, which is provided to the RPM control module 210. The RPM control module 210 may then provide the immediate and predicted torque signal, ImmediateTorque RPM , PredietedTorque RPM , to increase the idle speed. Additionally, a torque reserve and a superstoichiometric EQR can be requested.

[0107] If the engine speed RPM, the air per cylinder APC, the vehicle speed VS, and / or the idle speed signal IDLE indicate that the engine is not idling and corresponding values ​​are within predetermined ranges indicating a low load condition, then the mission profile signal MP indicates operation in the low load mode. If the engine speed RPM, the air per cylinder APC, the vehicle speed VS, and / or the idle speed signal IDLE indicate that the engine is not idling and corresponding values ​​are within predetermined ranges indicating a high load condition, then the mission profile signal MP indicates operation in the high load mode. During the low load and high load modes, the RPM request (or engine speed) does not increase. The speed control module 210 does not change any operating functions during GPF regeneration (or regeneration mode).The fuel control module 240 may request a DPF during the low load mode.

[0108] At 327, the coordinator module generates a regeneration enable signal ENABLE (352) indicating whether to enable regeneration of the GPF 22. The regeneration enable signal ENABLE may be set HIGH when certain predetermined operating conditions exist. The predetermined operating conditions include engine speed RPM, temperatures T GPF , T CAT , T ENG , the turbo protection signal TURBO and the air per cylinder APC, which are within respective predetermined ranges and / or predetermined states.

[0109] At 329, the coordinator module 288 generates each of a torque request TR REQ (354), an equivalence ratio request EQR REQ (356), and a torque capacity request TC REQ (358) based on various parameters. The parameters may include, as shown, an engine speed RPM, temperatures T GPF , T CAT , T ENG, the turbo protection signal TURBO, and the amount of air per cylinder APC. The turbo request signal TR REQ may be determined at tasks 502-514, as described below. During regeneration of the GPF 22, the torque request signal TR REQ is generated to increase airflow to the GPF 22 and retard spark timing of the engine 16. The airflow to the GPF 22 may be increased by increasing airflow from the engine 16 (or further opening a throttle valve). This is done to maintain a current output torque of the engine 16. Thus, the torque output of the engine 16 during regeneration of the GPF 22 may be equal to the torque output of the engine 16 during regeneration of the GPF 22.

[0110] During regeneration, the spark is retarded to bring the GPF 22 up to a predetermined temperature for soot oxidation to occur. Air from the engine 16 is increased to maintain a consistent level of torque from the engine 16. The camshaft phaser signal CAM PHAS (359) and the dual-pulse fueling signal DPF (361) may be generated to stabilize combustion events in the engine 16, as described above. The camshaft phaser signal CAM PHAS and the dual-pulse fueling signal DPF may be generated based on the regeneration signal REGEN and / or the torque reserve request signal TR REQ.For example, camshaft phaser timing may be adjusted and / or a multi-pulse mode may be executed when (i) the regeneration signal REGEN indicates that the GPF 22 is being regenerated and / or (ii) the torque reserve request signal TR REQ requests a torque reserve for increased airflow and retarded spark timing.

[0111] The equivalence ratio request EQR REQ may be determined as described above and / or below with respect to task 404. The engine capacity module 274 may generate the torque capacity request TC REQ as described above. Task 329 may be performed when task 327 is performed. Tasks 325, 327, and 329 may be performed while tasks 318, 320, 321, and 323 are performed.

[0112] At 331, the regeneration module 284 generates the regeneration signal REGEN (317) based on the current amount of soot mass SM, the soot percentage Soot%, and the regeneration enable signal ENABLE. The regeneration signal REGEN indicates whether the GPF module and / or the ECM 17 is regenerating the GPF 22. The regeneration signal REGEN may be HIGH if, for example, the soot percentage Soot% is greater than a predetermined soot percentage threshold. The regeneration signal REGEN may be LOW if, for example, the soot percentage Soot% is less than or equal to the predetermined soot percentage threshold. The regeneration module 284 compares the soot percentage Soot% to the predetermined soot percentage threshold to determine whether to regenerate the GPF 22. The regeneration signal REGEN may be generated and / or regeneration of the GPF 22 may be indicated when the regeneration enable signal ENABLE is HIGH. The method may end at 333.

[0113] Fig. 6 illustrates an equivalence ratio method. The following tasks may be performed iteratively. The method may begin at 400. At 402, the first threshold module 294 determines a first threshold THRS1 (401) based on the engine speed RPM. As an example, the first threshold may be 450°C or another predetermined temperature. The first threshold may be different from the predetermined temperature described above at 312.

[0114] At 404, the equivalence ratio determination module 300 determines an equivalence ratio EQR (405), as described above. The equivalence ratio may be determined based on the engine speed RPM and the amount of air per cylinder APC. The equivalence ratio request EQR REQ may be equal to a stoichiometric air / fuel ratio divided by a commanded air / fuel ratio. The equivalence ratio request EQR REQ may be determined based on a profile (or map) relating the equivalence ratio request EQR REQ to the engine speed RPM and the amount of air per cylinder APC. The equivalence ratio may be less than 1 to provide lean engine operation during regeneration of the GPF 22. Lean operation may reduce the temperature of an exhaust gas and thus reduce the temperature of the GPF 22.

[0115] At 406, the equivalence ratio enable module 296 determines whether to enable the generation of the equivalence ratio request signal EQR REQ. As an example, the equivalence ratio enable module 296 compares the temperature T GPF with the first threshold. If the temperature T GPF is less than the first threshold, task 408 is executed. At 408, the equivalence ratio enable signal EQRENABLE (403) is set low. The equivalence ratio enable signal EQRENABLE is set low to maintain fueling of the engine 16 at a stoichiometric level. By disabling delivery of the equivalence ratio request signal EQR REQ, the engine 16 may be operated at a stoichiometric air / fuel ratio for a period of time to raise the temperature of the GPF 22.

[0116] When the temperature T GPFis greater than or equal to the first threshold, then task 410 is executed. At 410, the equivalence ratio enable signal EQRENABLE is set HIGH. The equivalence ratio enable signal EQRENABLE is set HIGH to enable the equivalence ratio provision module 298 to provide the equivalence ratio request signal EQR REQ to the fuel control module 240. The method may end at 412.

[0117] Fig. 7 shows a torque reserve method. The following tasks may be performed iteratively. The method may begin at 500. At 502, the second threshold module 302 determines a second threshold (503) based on the engine speed RPM. The second threshold may be the same as or different from the first threshold, as described above at 402. As an example, the first threshold may be 500°C and the second threshold may be 550°C.

[0118] At 504, the ignition timing module 308 generates an ignition angle signal SA (507) based on the engine speed RPM and the amount of air per cylinder APC. The ignition angle may be retarded during regeneration of the GPF 22. The ignition angle during regeneration may be retarded compared to the ignition angle before or after a regeneration. The ignition angle may be determined based on: ambient pressure; temperature T ENG ; whether the engine 16 is in an idle state; engine load; the engine speed RPM; a spark angle of the current operation; and / or other spark-related parameters. Multi-transform maps with a current spark angle operating point and the spark-related parameter may be used to determine the next spark angle.

[0119] At 506, the torque determination module determines a torque amount (513) based on the spark angle signal SA, the engine speed RPM, the amount of air per cylinder APC, an intake camshaft phaser position ICP (509), and an exhaust camshaft phaser position (511). The torque amount may be determined based on tables and / or profiles relating these parameters. The torque amount may relate to an output torque of the engine 16. The torque amount may relate to an amount of torque produced by the engine 16 with the current spark angle timing and air per cylinder.

[0120] At 508, an unregulated torque module 512, which may be included in the ECM 17, determines an unregulated torque T un (517). The unregulated torque T unrefers to a torque provided with spark equal to a minimum spark for the best torque output value S MBT is.

[0121] At 510, the torque reserve determination module 312 determines a torque reserve TR (515). The torque reserve TR may be equal to a difference between (i) the unregulated torque T un and (ii) an immediate torque or the torque amount determined at 506. The torque reserve may be based on a current engine output torque and the torque value determined at 506.

[0122] As an example, the ECM 17 may determine a delta spark or ΔS, which is a difference between a minimum spark S Min and a spark base S b The minimum ignition spark S Minmay be a predetermined value and relates to a minimum spark value or a minimum spark advance value when operating an engine in a multi-pulse mode, such as when operating in a double-pulse mode. The ignition base S B refers to an ignition advance that provides a minimum amount of hydrocarbons when operating in a multi-pulse mode. ΔS is determined based on the amount of air per cylinder (APC) and the engine speed (RPM). The minimum spark S Min can be determined based on the amount of air per cylinder (APC), the engine speed (RPM), the intake camshaft phaser position (ICP), and the exhaust camshaft phaser position (ECP). The minimum ignition spark (S) Min can be determined using stored table data. The ignition base S b can be calculated by subtracting ΔS from the minimum ignition spark S Min The ignition spark base S bcan be used to generate an ignition instruction signal S Final as shown by Expression 1, where S p is a proportional spark. The spark command signal S Final may relate to the ignition control signal used for the timing of the ignition spark in the cylinders of the engine 16. Expression 2 provides idle speed ignition constraints for a sum of the ignition base S b and the proportional ignition spark S b before. SFinal=Sb+Sp SMin <Sb+Sp<SMax

[0123] A torque base T b can be based on the ignition spark basis S b , the engine speed RPM, the amount of air per cylinder APC, the intake camshaft phaser position ICP, and the exhaust camshaft phaser position ECP. The torque base T b can be determined as provided by Expression 3. Tb=f(RPM, ICP, ECP, Sb, APC)

[0124] The torque base T b can be determined from the non-regulated torque T un be subtracted to generate the torque reserve TR. The torque reserve TR can be determined as provided by Expression 7. Tr=TUN−TB

[0125] The torque reserve TR can be created by setting slow engine actuators to produce a predicted torque, while setting faster engine actuators to produce an immediate torque that is less than the predicted torque. For example, a throttle valve can be opened, increasing airflow and preparing for the production of the predicted torque. Meanwhile, spark advance can be reduced (in other words, spark timing can be retarded), reducing the actual engine torque output to the immediate torque.

[0126] The difference between the predicted and immediate torques can be called the torque reserve TR, which is the same as the difference between the unregulated torque T UNand the immediate torque. When a torque reserve is available, the engine output torque can be quickly increased from the immediate torque to the predicted torque by changing a faster actuator. The predicted torque is thus achieved without waiting for a torque change to result from an adjustment of one of the slower actuators.

[0127] At 512, the torque reserve activation module 304 compares the temperature T GPF with the second threshold. If the temperature T GPF is greater than the second threshold, then task 514 is executed. At 514, the torque reserve enable signal TRENABLE is set to HIGH. If the temperature T GPF is less than or equal to the second threshold THRS2, then task 516 is executed. At 516, the torque reserve enable signal TRENABLE is set low.

[0128] At 514, the torque reserve delivery module 306 generates the torque reserve request signal TR REQ to indicate the torque reserve TR when the torque reserve enable signal TRENABLE is HIGH. Task 502 is performed if the torque reserve enable signal TRENABLE is LOW, or the method may end at 516.

[0129] The tasks described above of the Fig. 5-7 are intended as illustrative examples; the tasks may be executed sequentially, synchronously, simultaneously, continuously, during overlapping time periods, or in a different order depending on the application. Also, any of the tasks need not be executed or may be omitted depending on the implementation and / or sequence of events.

[0130] The methods described above include triggering alternative engine operation when an amount of soot accumulated in a GPF exceeds a threshold. This alternative engine operation includes requesting a torque reserve such that spark timing is retarded while an amount of airflow to the GPF is increased. The alternative engine operation is provided when an amount of torque from the engine is maintained. The engine air / fuel ratio is changed to lean operation (EQR<1), and a corresponding torque model is used to compensate to provide the same amount of output torque. As a result, the amount of output torque is not changed during regeneration, as it was prior to regeneration.GPF regeneration maintains low soot levels in the GPF to maintain efficient engine operation and performance. This also increases the durability of an engine system.

[0131] The methods described above also include accounting for drops in exhaust and / or GPF temperature due to lean operation. The methods include operating the engine at a stoichiometric air / fuel ratio until a temperature of exhaust entering the GPF and / or a temperature of the GPF is greater than a threshold. The engine is then operated at a lean air / fuel ratio to oxidize soot. Closed-loop control is provided to ensure that the GPF temperature remains above the soot oxidation threshold. The controller may alternate between operating at a stoichiometric air / fuel ratio and lean to maintain the GPF temperature above the threshold. Maintaining the GPF temperature reduces the time required to regenerate the GPF.By minimizing the time required to regenerate the GPF, the duration of inefficient engine operation with potential drivability and performance compromises is minimized.

[0132] The methods described above also include disabling a torque reserve requested during regeneration of a GPF, where the torque reserve has been requested to retard spark and maintain a current output torque. This is performed to improve a regeneration rate and engine performance. When a temperature of an exhaust gas received by the GPF and / or a temperature of the GPF is greater than a threshold, the GPF torque reserve request is disabled. The GPF torque reserve request is enabled when the temperature of the exhaust gas and / or the GPF is less than the threshold. This provides for exhaust gas enthalpy control. This temperature control adapts regeneration of the GPF to ambient conditions and other variations.

[0133] In this application, including in the following definitions, the term "module" or the term "controller" may be replaced by the term "circuit". The term "module" may refer to, be part of, or include: an application-specific integrated circuit (ASIC); a digital, analog, or mixed analog / digital discrete circuit; a digital, analog, or mixed analog / digital integrated circuit; a combinational logic circuit; a field-programmable gate array (FPGA); a processor (shared, dedicated, or group) that executes code; a memory circuit (shared, dedicated, or group) that stores code executed by the processor circuit; other suitable hardware components that provide the described functionality; or a combination of some or all of the above, as in a system-on-chip.

[0134] The module may include one or more interface circuits. In some examples, the interface circuits may include wired or wireless interfaces connected to a local area network (LAN), the Internet, a wide area network (WAN), or combinations thereof. The functionality of a particular module of the present disclosure may be distributed among multiple modules connected via interface circuits. For example, multiple modules may enable load balancing. In another example, a server (also known as a remote or cloud) module may accomplish some functions on behalf of a client module.

[0135] The term code, as used above, may include software, firmware, and / or microcode, and may refer to programs, routines, functions, classes, data structures, and / or objects. The term shared processor circuitry includes a single processor circuit that executes some or all of the code from multiple modules. The term group processor circuitry includes a processor circuit that executes some or all of the code from one or more modules along with additional processor circuitry. References to multiprocessor circuitry include multiprocessor circuits on discrete chips, multiprocessor circuits on a single chip, multiple cores of a single processor circuit, multiple threads of a single processor circuit, or a combination of the above. The term shared memory circuitry includes a single memory circuit that stores some or all of the code from multiple modules.The term group memory circuit encompasses a memory circuit that stores some or all of the code from one or more modules along with additional memories.

[0136] The term memory circuit may be a subset of the term computer-readable medium. As used herein, the term computer-readable medium does not include transient electrical or electromagnetic signals propagating through a medium (such as on a carrier wave); the term computer-readable medium may therefore be considered tangible and non-transitory. Non-limiting examples of a non-transitory, tangible computer-readable medium include non-volatile memory circuits (such as a flash memory circuit, an erasable programmable read-only memory circuit, or a masked read-only memory circuit), volatile memory circuits (such as a static random access memory circuit and a dynamic random access memory circuit), magnetic storage media (such as analog or digital magnetic tape or a hard disk drive), and optical storage media (such as a CD, a DVD, or a Blu-ray disc).

[0137] The devices and methods described in this application may be implemented partially or entirely by a special-purpose computer created by configuring a general-purpose computer to perform one or more specific functions provided as computer programs. The functional blocks and flowchart elements described above serve as software specifications that can be translated into computer programs through routine work by a person skilled in the art or programmer.

[0138] The computer programs contain processor-executable instructions stored on at least one non-transitory, tangible computer-readable medium. The computer programs may also contain and / or rely on stored data. The computer programs may include a basic input / output system (BIOS) that interacts with the hardware of the special-purpose computer, device drivers that interact with specific devices of the special-purpose computer, one or more operating systems, user applications, background services, background applications, etc.

[0139] The computer programs may comprise: (i) descriptive text for parsing, such as HTML (Hypertext Markup Language) or XML (Extensible Markup Language), (ii) assembly code, (iii) object code generated from source code by a compiler; (iv) source code for execution by an interpreter, (v) source code for compilation and execution by a just-in-time compiler, etc. By way of example only, the source code may be written using syntax from languages ​​including: C, C++, C#, Objective C, Haskell, Go, SQL, R, Lisp, Java®, Fortran, Perl, Pascal, Curl, OCaml, Javascript®, HTML5, Ada, ASP (active server pages), PHP, Scala, Eiffel, Smalltalk, Erlang, Ruby, Flash®, Visual Basic®, Lua and Python®.

Claims

[1] System comprising: a soot module (282) configured to determine a current amount of soot mass in a particulate filter (22) of a gasoline engine (16), the particulate filter (22) being disposed downstream of the gasoline engine (16) and receiving exhaust gas from the gasoline engine (16); a coordinator module (288) configured to generate an enable signal, a torque reserve signal, and an equivalence ratio, wherein the equivalence ratio is determined as (i) a ratio of a current air / fuel ratio to a stoichiometric air / fuel ratio or (ii) a ratio of a stoichiometric air / fuel ratio to a commanded air / fuel ratio; a regeneration module (284) configured to generate a regeneration signal based on the current amount of soot mass and the activation signal to regenerate the particulate filter (22); and a plurality of actuator modules configured, based on the regeneration signal, the torque reserve signal, and the equivalence ratio, to (i) retard spark of the gasoline engine (16) and (ii) increase an amount of airflow to the particulate filter (22), wherein the plurality of actuators are configured to maintain a same amount of torque out of the gasoline engine (16) during regeneration of the particulate filter (22) as is output by the gasoline engine (16) prior to regeneration of the particulate filter (22); and a particulate filter status module (280) configured to generate (i) an ideal soot capacity value and (ii) a flow resistance value based on (a) a temperature of the particulate filter (22), (b) a speed of the gasoline engine (16), (c) a barometric pressure, and (d) a pressure differential across the particulate filter (22), wherein the soot module (282) is configured to determine the current amount of soot mass based on the ideal soot capacity value and the flow resistance value; wherein, when (i) the regeneration signal indicates that the particulate filter (22) is being regenerated, and (ii) the torque reserve signal requests a torque reserve for increased airflow and retarded spark timing, camshaft phaser timing and dual pulse fueling are adjusted to stabilize combustion events in the gasoline engine (16). [2] The system of claim 1, wherein the particulate filter status module (280) is configured to generate (i) the ideal soot capacity value and (ii) the flow resistance value based on (a) the temperature of the particulate filter (22), (b) the speed of the gasoline engine (16), (c) the barometric pressure, and (d) the pressure differential across the particulate filter (22), wherein: the soot module (282) is configured to determine a soot percentage based on a current soot amount; the regeneration module (284) is configured to generate the regeneration signal based on the soot percentage; and the soot module (282) is configured to determine (i) the current amount of soot mass based on the ideal soot capacity value and the flow resistance value and (ii) the soot percentage based on the ideal soot capacity value. [3] The system of claim 1, wherein: the coordinator module (288) is configured to generate the turn-on signal, the torque reserve signal, and the equivalence ratio based on a plurality of parameters; and the plurality of parameters comprises the rotational speed of the gasoline engine (16), the temperature of the particulate filter (22), the temperature of a catalyst, the temperature of the gasoline engine (16) and an amount of air per cylinder of the gasoline engine (16). [4] The system of claim 1, further comprising a switch-on module configured to compare a temperature of the exhaust gas entering the particulate filter (22) with a predetermined threshold and to generate the switch-on signal based on the comparison, wherein: the coordinator module (288) is configured to generate the equivalence ratio that is overstoichiometric based on the comparison; and the majority of actuator modules are configured to: operating the gasoline engine (16) at the stoichiometric air / fuel ratio based on whether the equivalence ratio is established, and to increase the amount of air flow to the particulate filter (22) based on the regeneration signal and the equivalence ratio. [5] The system of claim 4, further comprising a threshold module (294) configured to compare the temperature of the particulate filter (22) to a second predetermined threshold, wherein: the coordinator module (288) is configured to generate a second enable signal and the torque reserve signal; the regeneration module (284) is configured to generate the regeneration signal to regenerate the particulate filter (22) based on the current amount of soot mass and the second enable signal; based on the regeneration signal and the equivalence ratio, (i) retard the ignition spark of the gasoline engine (16) and (ii) increase the amount of air flow to the particulate filter (22); and the coordinator module (288) is configured to generate the torque reserve signal based on the comparison of the temperature of the particulate filter (22) with the second predetermined threshold. [6] System according to claim 4, wherein: the coordinator module (288) is configured to generate the equivalence ratio when the temperature of the particulate filter (22) is greater than the predetermined threshold; and the coordinator module (288) is configured to refrain from generating the equivalence ratio when the temperature of the particulate filter (22) is less than or equal to the predetermined threshold. [7] The system of claim 4, further comprising: an ignition timing module configured to determine an ignition angle based on the speed of the gasoline engine (16) and an amount of air per cylinder of the gasoline engine (16); a torque determination module configured to determine an amount of torque based on the ignition angle; a torque reserve module configured to determine a torque reserve based on the torque amount; wherein the coordinator module (288) is configured to generate the torque reserve signal to indicate the torque reserve, and wherein the plurality of actuator modules are configured to operate the gasoline engine (16) lean based on the torque reserve signal; and an unregulated torque module configured to determine an unregulated torque value, wherein the torque reserve module is configured to determine the torque reserve based on the unregulated torque. [8] The system of claim 1, further comprising a switch-on module configured to compare a temperature of the exhaust gas entering the particulate filter (22) with a predetermined threshold and to generate the switch-on signal based on the comparison, wherein: the coordinator module (288) is configured to generate, based on the comparison, the torque reserve signal based on the temperature of the particulate filter (22); the coordinator module (288) is configured to (i) generate the torque reserve signal if the temperature of the particulate filter (22) is less than the predetermined threshold, and (ii) refrain from generating the torque reserve signal if the temperature of the particulate filter (22) is greater than or equal to the predetermined threshold; and the regeneration module (284) is configured to generate the regeneration signal based on the current amount of soot mass to regenerate the particulate filter (22).

Images