Compression ratio method and system for particulate filter regeneration

Abstract

Methods and systems for enabling regeneration of a particulate filter of an engine system are provided. In one embodiment, a method includes receiving, by a processor, a request for particulate filter regeneration; determining, by the processor, at least one of a compression ratio and an expansion ratio in response to the request; generating, by the processor, control signals to actuators of the engine system to adjust the at least one of the compression ratio and the expansion ratio to achieve a desired exhaust gas temperature; generating, by the processor, control signals to the actuators of the engine system to optimize torque output based on the desired exhaust gas temperature, an engine speed, and a desired engine load; and initiating, by the processor, regeneration of the particulate filter based on the command signals.

Description

Technical Field

[0001] This invention generally relates to the regeneration of particulate filters in the exhaust system of gasoline engines, and more specifically, to methods and systems for controlling the regeneration of particulate filters based on variable compression ratio and torque output. Background Technology

[0002] A gasoline engine may be equipped with an exhaust system that includes a filter for removing particulate matter from the exhaust gas stream. The particulate filter may include a housing containing a multi-channel substrate / medium that traps particles as exhaust gas passes through. One such substrate may include a honeycomb structure through which exhaust gas passes. The substrate / medium is regenerated to remove accumulated particles, for example, by subjecting the unit to conditions including temperature and gas composition to burn off the particles.

[0003] Some systems initiate regeneration by actively increasing the temperature of the exhaust gas passing through the particulate filter. However, actively increasing the exhaust gas temperature may impair engine torque performance.

[0004] Therefore, it is desirable to provide improved methods and systems that allow for particulate filter regeneration while optimizing engine torque performance. Furthermore, other desirable features and characteristics of the invention will become apparent from the following detailed description and appended claims, taken in conjunction with the accompanying drawings and the foregoing technical and background information. Summary of the Invention

[0005] A method and system for regenerating a particulate filter for an engine system are provided. In one embodiment, the method includes: receiving a request for particulate filter regeneration by a processor; determining, in response to the request, at least one of a compression ratio and an expansion ratio by the processor; generating a control signal by the processor to an actuator of the engine system to adjust the at least one of the compression ratio and the expansion ratio to achieve a desired exhaust temperature; generating a control signal by the processor to the actuator of the engine system to optimize torque output based on the desired exhaust temperature, engine speed, and desired engine load; and initiating particulate filter regeneration by the processor based on a command signal.

[0006] In various embodiments, the compression ratio is increased to raise the exhaust temperature.

[0007] In various embodiments, the expansion ratio is reduced to increase the exhaust temperature.

[0008] In various embodiments, the actuators of the engine system used to optimize torque are related to valve timing.

[0009] In various embodiments, the actuators of the engine system used to optimize torque are related to ignition timing.

[0010] In various embodiments, the actuators of the engine system used to optimize torque are related to injection timing.

[0011] In various embodiments, the actuators of the engine system used to optimize torque are associated with the compression ratio or expansion ratio.

[0012] In various embodiments, the method includes determining a control signal based on a model predictive control model to adjust at least one of the compression ratio and the expansion ratio.

[0013] In various embodiments, the method includes determining a control signal based on a proportional-integral-differential model to adjust at least one of the compression ratio and the expansion ratio.

[0014] In various embodiments, the method includes determining control signals based on a model predictive control model to optimize torque output.

[0015] In various embodiments, the method includes determining a control signal based on a proportional-integral-differential model to optimize torque output.

[0016] In another embodiment, a system includes an internal combustion engine configured to change at least one of a compression ratio and an expansion ratio; a processor communicating with the engine system, configured to: receive a request for particulate filter regeneration; determine at least one of the compression ratio and expansion ratio in response to the request; generate a control signal to an actuator of the engine system to adjust at least one of the compression ratio and expansion ratio to achieve a desired exhaust temperature; generate a control signal to the actuator of the engine system to optimize torque output based on the desired exhaust temperature, engine speed, and desired engine load; and initiate particulate filter regeneration based on a command signal.

[0017] In various embodiments, the compression ratio is increased to increase the exhaust temperature.

[0018] In various embodiments, the expansion ratio is reduced to increase the exhaust temperature.

[0019] In various embodiments, the actuators of the engine system used to optimize torque are related to valve timing.

[0020] In various embodiments, the actuators of the engine system used to optimize torque are related to ignition timing.

[0021] In various embodiments, the actuators of the engine system used to optimize torque are related to injection timing.

[0022] In various embodiments, the actuators of the engine system used to optimize torque are related to the compression ratio or expansion ratio.

[0023] In various embodiments, the processor is further configured to determine a control signal to adjust at least one of the compression ratio and the expansion ratio based on at least one of a proportional-integral-derivative model and a model predictive control model.

[0024] In various embodiments, the processor is further configured to determine control signals to optimize torque output based on at least one of a proportional-integral-differential model and a model predictive control model. Attached Figure Description

[0025] Exemplary embodiments will now be described in conjunction with the following accompanying drawings, wherein the same reference numerals denote the same elements, in which:

[0026] Figure 1 This is a functional diagram of a vehicle, according to an exemplary embodiment, including a drive system with a particulate filter and a control system; and

[0027] Figure 2 According to an exemplary embodiment, startup and Figure 1 A flowchart illustrating the process of regenerating particulate filters related to vehicles and control systems. Detailed Implementation

[0028] The following detailed description is merely exemplary in nature and is not intended to limit application and use. Furthermore, it is not intended to be bound by any express or implied theory presented in the foregoing technical field, background art, summary of the invention, or the following detailed description. As used herein, the term "module" refers to any hardware, software, firmware, electronic control components, processing logic, and / or processor device, employed individually or in any combination, including but not limited to: application-specific integrated circuits (ASICs), electronic circuits, processors (shared, dedicated, or grouped), and memory executing one or more software or firmware programs, combinational logic circuits, and / or other suitable components providing the said functionality.

[0029] Embodiments of this disclosure can be described herein based on functional and / or logical block components and various processing steps. It should be understood that such block components can be implemented by any number of hardware, software, and / or firmware components configured to perform specified functions. For example, embodiments of this disclosure can employ various integrated circuit components, such as memory elements, digital signal processing elements, logic elements, lookup tables, etc., which can perform various functions under the control of one or more microprocessors or other control devices. Furthermore, those skilled in the art will understand that embodiments of this disclosure can be practiced in conjunction with any number of systems, and the systems described herein are merely exemplary embodiments of this disclosure.

[0030] For the sake of brevity, conventional techniques related to signal processing, data transmission, signaling, control, and other functional aspects of the system (as well as the various operating components of the system) will not be described in detail here. Furthermore, the connecting lines shown in the various figures included herein are intended to represent exemplary functional relationships and / or physical connections between various elements. It should be noted that many alternative or additional functional relationships or physical connections may exist in the embodiments of this disclosure.

[0031] Figure 1 A vehicle 100 is shown, which has a regeneration system 10 according to an exemplary embodiment. In various embodiments, the regeneration system 10 initiates the regeneration of the particulate filter (PF) based on the compression ratio and torque output.

[0032] In some embodiments, vehicle 100 includes an automobile. It is understood that vehicle 100 can be any of a variety of different types of automobiles, such as sedans, vans, trucks, or sport utility vehicles (SUVs), and in some embodiments can be two-wheel drive (2WD) (i.e., rear-wheel drive or front-wheel drive), four-wheel drive (4WD), or all-wheel drive (AWD), and / or various other types of vehicles. In some embodiments, vehicle 100 may also include trucks, boats, aircraft, and / or one or more other types of vehicles. Furthermore, in various embodiments, it should be understood that vehicle 100 may include any number of other types of mobile platforms that generate exhaust gases.

[0033] In the illustrated embodiment, vehicle 100 includes a body 110 that substantially surrounds the other components of vehicle 100. Also in the illustrated embodiment, vehicle 100 includes a plurality of axles 112 and wheels 114. Each wheel 114 is rotatably coupled to one or more axles 112 near a corresponding corner of the body 110 to facilitate movement of vehicle 100. In one embodiment, vehicle 100 includes four wheels 114, although this can vary in other embodiments (e.g., for trucks and certain other vehicles).

[0034] Vehicle 100 also includes a control system 102 and a drive system 104. Drive system 104 drives wheels 114 to rotate forward or backward. In the illustrated embodiment, drive system 104 includes engine system 150. Engine system 150 typically includes multiple components and subsystems, including engine 52, intake system 54, fuel system 56, exhaust system 58, valve system 60, and ignition system 62. In various embodiments, engine system 150 is a four-stroke internal combustion engine, wherein a piston in each cylinder completes the intake stroke, compression stroke, combustion stroke, and exhaust stroke while rotating the crankshaft to drive engine 52. Intake system 54 delivers air to the cylinders via a throttle valve and controls the mass flow rate of the air. Fuel system 56 delivers fuel to the cylinders and controls its timing and quantity via multiple injectors. Valve system 60 includes multiple valves to control the inflow and outflow of air / gas into and out of the cylinders. Ignition system 62 includes multiple spark plugs that ignite combustion in the cylinders.

[0035] Exhaust system 58 delivers combustion gases from engine 52 to the environment and includes aftertreatment devices such as a three-way catalytic converter 72 and a particulate filter 74. For example, exhaust system 58 directs exhaust gases through the aftertreatment devices and exits through, for example, an exhaust pipe. The aftertreatment devices can be arranged in any of several different configurations. For example, as shown, particulate filter 74 can be downstream of three-way catalytic converter 72, or in other embodiments upstream of three-way catalytic converter 72. In some embodiments, particulate filter 74 may internally include a three-way catalyst, with or without a separate three-way catalytic converter 72. The catalyst in three-way catalytic converter 72 and / or particulate filter 74 is configured to convert hydrocarbons, carbon monoxide, and nitrogen oxides into harmless elements or compounds. Particulate filter 74 captures particulate matter and includes an internal substrate.

[0036] In this embodiment, engine 52 is configured as a variable compression ratio (VCR) engine, wherein the compression ratio (CR) and expansion ratio (ER) of each cylinder (i.e., the ratio of the cylinder volume when the piston is at bottom dead center (BDC) to the cylinder volume when the piston is at top dead center (TDC)) can be changed mechanically. The cylinder ratio can be changed by actuator 76 of actuator mechanism 78. In various embodiments, the ratio can vary between a first lower ratio and a second higher ratio, where the cylinder volume when the piston is at BDC is smaller than the cylinder volume when the piston is at TDC, and the ratio is higher in the second higher ratio. In various other embodiments, there can be a predetermined number of step compression ratios between the lower first ratio and the higher second ratio. Furthermore, the ratio can vary continuously between the lower first ratio and the higher second ratio (to any ratio in between). In various embodiments, for each cylinder, the ratio can vary independently during the compression stroke and during the expansion stroke.

[0037] It is understood that various actuators 76 and mechanisms 78 can be used to mechanically change the compression ratio and expansion ratio. For example, the engine's gear ratio can be changed by a mechanism 78 that alters the piston position or the cylinder head volume (i.e., the clearance volume in the cylinder head). In another example, mechanism 78 may include a hydraulically acting piston, a pneumatically acting piston, or a mechanically acting piston. Furthermore, mechanism 78 may include a multi-link mechanism, a bent-bar mechanism, or other variable compression / expansion ratio mechanism.

[0038] In various embodiments, the control system 102 provides instructions for controlling the drive system 104, including instructions for controlling the engine system 150. In various embodiments, the control system 102 includes an engine control unit (ECU) for the engine system 150. Furthermore, in various embodiments, among other functions, the control system 102 selectively controls the operation of the CR components to achieve an exhaust temperature sufficient to initiate regeneration of particulate soot buildup in the particulate filter 74, while simultaneously achieving desired torque output. In various embodiments, the control system 102 is configured according to the following... Figure 2 The process is further described in 200 steps to provide these functions.

[0039] like Figure 1 As shown, in various embodiments, the control system 102 includes a sensor array 120 and a controller 130. In various embodiments, the sensor array 120 includes sensors for measuring observable conditions and generating sensor data based thereon. Figure 1 As shown, in various embodiments, sensor array 120 includes one or more engine sensors 122. In various embodiments, the engine sensors 122 are attached to, disposed within, or otherwise positioned near engine system 150, enabling the measurement of various temperatures, positions, speeds, and other observable parameters. In some embodiments, sensor array 120 may also include one or more other sensors 124, for example, for engine operation. For example, in some embodiments, other sensors 124 may include one or more ignition sensors for detecting when engine 52 is started and / or running, etc.

[0040] In various embodiments, controller 130 is coupled to sensor array 120 and provides instructions for controlling engine system 150 (including controlling regenerative start-up) based on sensor data. Figure 1 As shown, controller 130 includes a computer system. In some embodiments, controller 130 may also include sensor array 120 and / or one or more other vehicle components. Furthermore, it should be understood that controller 130 may differ from... Figure 1The illustrated embodiment. For example, controller 130 may be coupled to or utilize one or more remote computer systems and / or other control systems, for example, as part of one or more of the aforementioned vehicle devices and systems.

[0041] In the illustrated embodiment, the computer system of controller 130 includes a processor 132, a memory 134, an interface 136, a storage device 138, and a bus 140. The processor 132 performs the computational and control functions of controller 130 and may include any type of processor or multiple processors, a single integrated circuit such as a microprocessor, or any suitable number of integrated circuit devices and / or circuit boards that work together to implement the functions of a processing unit. During operation, processor 132 executes one or more programs 142 contained in memory 134, and thereby generally controls the general operation of controller 130 and the computer system of controller 130 during the execution of the processes described herein, for example, in conjunction with the following... Figure 2 Further discussion process 200.

[0042] Memory 134 can be any suitable type of memory. For example, memory 134 may include various types of dynamic random access memory (DRAM), such as SDRAM, various types of static RAM (SRAM), and various types of non-volatile memory (PROM, EPROM, and flash memory). In some examples, memory 134 is located and / or co-located on the same computer chip as processor 132. In the illustrated embodiment, memory 134 stores the program 142 described above, as well as one or more stored values ​​144 (e.g., in various embodiments, including predetermined thresholds for controlling the emissions of the drive system).

[0043] Bus 140 is used to transfer programs, data, status, and other information or signals between various components of the computer system of controller 130. Interface 136 allows communication, for example, from system drivers and / or another computer system to the computer system of controller 130, and can be implemented using any suitable methods and devices. In one embodiment, interface 136 obtains various data from sensor array 120, drive system 104, drive system 104, and / or one or more other components and / or systems of vehicle 100. Interface 136 may include one or more network interfaces for communicating with other systems or components. Interface 136 may also include one or more network interfaces for communicating with technicians, and / or one or more storage interfaces for connecting to storage devices, such as storage device 138.

[0044] Storage device 138 may be any suitable type of storage device, including various types of direct access memory and / or other storage devices. In one exemplary embodiment, storage device 138 includes a program product from which memory 134 can receive program 142, which program 152 executes one or more embodiments of one or more processes of this disclosure, such as those described below. Figure 2 The steps of process 200 are discussed further. In another exemplary embodiment, the program product may be directly stored in memory 134 and / or one or more other disks 146 and / or other storage devices and / or otherwise accessed therefrom.

[0045] Bus 140 can be any suitable physical or logical device for connecting computer systems and components. This includes, but is not limited to, direct hardwired connections, fiber optic, infrared, and wireless bus technologies. During operation, program 142 is stored in memory 134 and executed by processor 132.

[0046] It should be understood that although this exemplary embodiment has been described in the context of a full-featured computer system, those skilled in the art will recognize that the mechanisms of the present invention can be distributed as a program product, with one or more types of non-transitory computer-readable signal-bearing media used to store the program and its instructions and to perform its distribution, such as a non-transitory computer-readable medium carrying the program and containing computer instructions stored therein for causing a computer processor (e.g., processor 132) to execute and run the program. Such a program product can take many forms, and this disclosure applies equally to whatever specific type of computer-readable signal-bearing medium is used to perform the distribution. Examples of signal-bearing media include: recordable media, such as floppy disks, hard disks, memory cards, and optical disks; and transmission system media, such as digital and analog communication links. It should be understood that cloud-based storage and / or other technologies may also be utilized in some embodiments. Similarly, it should be understood that the computer system of controller 130 may also differ from... Figure 1 In the illustrated embodiments, for example, the computer system of controller 130 may be coupled to or may utilize one or more remote computer systems and / or other control systems.

[0047] For reference Figure 2 The flowchart illustrates the control according to an exemplary embodiment. Figure 1 The process 200 illustrates the regeneration of the particulate filter 74 in the engine system 150 shown. In various embodiments, process 200 may be combined with... Figure 1 The vehicle 100 is implemented, including its control system 102 and drive system 104.

[0048] like Figure 2As shown, process 200 may begin at 202. In some embodiments, process 200 begins when one or more events occur to indicate that vehicle driving is taking place or is about to take place, such as when a driver, operator, or passenger enters vehicle 100, the engine or motor of vehicle 100 is turned on, the transmission of vehicle 100 is placed in "driving" mode, etc. In various embodiments, the events(s) that trigger the start of process 200 are based on... Figure 1 The determination is made using sensor data from one or more other sensors 124 (e.g., from an ignition sensor in some embodiments). Also in some embodiments, as part of step 202, the control system 102 is turned on or "wake up".

[0049] Then, at 204, process 200 monitors for requests to regenerate the particulate filter. When a request for particulate filter regeneration is received at 204, the compression ratio and expansion ratio are optimized at 206, for example, by generating control signals to actuator 76. For example, the compression ratio can be increased to increase the exhaust temperature. In another example, the expansion ratio is decreased to increase the exhaust temperature. In various embodiments, the control signals are generated by one or more proportional-integral-derivative (PID) controllers or model predictive controllers (MPCs) that utilize a trained model to achieve the desired exhaust temperature. For a particular engine system 150, the compression ratio and expansion ratio for the desired exhaust temperature are learned.

[0050] Essentially simultaneously, at point 208, engine system 150 is further controlled to optimize torque output by generating a control signal that is a function of desired exhaust temperature, engine speed, and desired engine load. For example, the control signal controls other actuators of engine system 150, such as valve timing, ignition timing, injection timing, and compression or expansion ratio mechanisms, to maintain the required engine output while providing sufficient exhaust enthalpy to achieve the desired exhaust temperature. In various embodiments, the control signal is generated by one or more proportional-integral-derivative (PID) controllers or model predictive controllers (MPCs) that utilize a trained model to achieve optimized torque output. Optimized torque output is learned for a specific engine system 150.

[0051] Once the exhaust temperature reaches the target temperature to initiate regeneration at 210, it is determined at 212 whether regeneration is complete (e.g., regeneration has occurred for a specified period of time, etc.). Once regeneration is complete at 212, process 200 can end at 214.

[0052] Therefore, the system and method provide a mechanism for regenerating particulate filters based on a reduced compression ratio while still optimizing torque output. While at least one exemplary embodiment has been presented in the foregoing detailed description, it should be understood that numerous variations exist. It should also be understood that one or more exemplary embodiments are merely examples and are not intended to limit the scope, applicability, or construction of this disclosure in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient roadmap for implementing one or more exemplary embodiments. It should be understood that various changes can be made to the function and arrangement of the elements without departing from the scope of this disclosure as set forth in the appended claims and their legal equivalents.

Claims

1. A method for enabling the regeneration of a particulate filter in an engine system, the method comprising: The processor receives a request to regenerate the particulate filter; In response to the request, the processor determines at least one of the compression ratio and the expansion ratio; The processor generates a control signal to the actuator of the engine system to adjust at least one of the compression ratio and expansion ratio, thereby achieving the desired exhaust temperature. The processor generates control signals to the actuators of the engine system to optimize torque output based on desired exhaust temperature, engine speed, and desired engine load. and The processor initiates the regeneration of the particulate filter based on a command signal.

2. The method according to claim 1, wherein, Increase the compression ratio to raise the exhaust temperature.

3. The method according to claim 1, wherein, Reduce the expansion ratio to increase the exhaust temperature.

4. The method according to claim 1, wherein, The actuators of an engine system used to optimize torque are associated with valve timing.

5. The method according to claim 1, wherein, The actuators of an engine system used to optimize torque are associated with ignition timing.

6. The method according to claim 1, wherein, The actuators of the engine system used to optimize torque are associated with injection timing.

7. The method according to claim 1, wherein, The actuators in an engine system used to optimize torque are associated with the compression ratio or expansion ratio.

8. The method of claim 1, further comprising determining a control signal based on at least one of a model predictive control model and a proportional-integral-derivative (PID) model to adjust at least one of the compression ratio and the expansion ratio.

9. The method of claim 1, further comprising determining a control signal to optimize torque output based on at least one of a model predictive control model and a proportional-integral-derivative (PID) model.

10. A system for regenerating a particulate filter, the system comprising: The engine system is configured to change at least one of the compression ratio and the expansion ratio; and The processor communicates with the engine system and is configured to: Receive a request for particulate filter regeneration; In response to the request, at least one of the compression ratio and the expansion ratio is determined; A control signal is generated to the actuator of the engine system to adjust at least one of the compression ratio and expansion ratio, thereby achieving the desired exhaust temperature. Based on the desired exhaust temperature, engine speed, and desired engine load, control signals are generated to the actuators of the engine system to optimize torque output. and The regeneration of the particulate filter is initiated based on a command signal.

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