A control method and device for an engine under transient operating conditions

Abstract

The application discloses a control method and device for an engine under transient operating conditions, comprising: acquiring a throttle pedal opening degree sequence, an engine speed sequence, a transient misfire rate sequence and an exhaust temperature sequence in a current time window, determining a throttle change rate sequence based on the throttle pedal opening degree sequence, and determining a combustion stability index of the current time window based on the transient misfire rate sequence. If the continuous N throttle change rates in the throttle change rate sequence exceed the operating condition threshold, and the combustion stability index and / or the exhaust temperature in the exhaust temperature sequence exceed the threshold, then the first air-fuel ratio actual value and the first exhaust gas recirculation demand value required by the engine are determined according to the throttle pedal opening degree sequence and the engine speed sequence, respectively, and air-fuel ratio control instructions and exhaust gas recirculation control instructions are generated and output. The method can achieve fast response to transient operating conditions, improve combustion stability, and avoid misfire and high temperature risks.

Description

Technical Field

[0001] This invention relates to the field of engine control, and more particularly to a method and apparatus for controlling an engine under transient operating conditions. Background Technology

[0002] For natural gas engines that employ premixed combustion and stoichiometric combustion, their stable operation is highly dependent on the precise control of the air-fuel ratio.

[0003] Currently, air-fuel ratio control generally employs Lambda closed-loop feedback control based on oxygen sensors, which ensures good control performance under steady-state or gradually changing operating conditions. However, in actual operation, especially in congested urban traffic or specific work scenarios, frequent throttle input by the driver can cause rapid changes in engine speed and load, leading to transient operating conditions. Under transient operating conditions, problems such as sluggish response, increased risk of misfire, and high exhaust temperature arise.

[0004] Therefore, how to respond quickly under transient conditions and avoid the risks of fire and high temperature is an urgent problem to be solved. Summary of the Invention

[0005] This invention provides a method and apparatus for controlling an engine under transient operating conditions. By monitoring the throttle change rate, combustion stability index, and exhaust temperature within a time window, it enables rapid identification of transient operating conditions. Furthermore, it controls the air-fuel ratio and exhaust gas recirculation requirement under transient conditions to improve combustion stability and avoid misfire and high-temperature risks.

[0006] In a first aspect, embodiments of the present invention provide a method and apparatus for controlling an engine under transient operating conditions, comprising: The system acquires the accelerator pedal opening sequence, engine speed sequence, instantaneous misfire rate sequence, and exhaust temperature sequence within the current time window. Based on the accelerator pedal opening sequence, it determines the throttle change rate sequence. Based on the instantaneous misfire rate sequence, it determines the combustion stability index for the current time window. The throttle change rate sequence includes the rate of change of accelerator pedal opening at adjacent acquisition times within the current time window. The combustion stability index is used to indicate the stability of engine combustion within the current time window. If N consecutive throttle change rates in the throttle change rate sequence exceed the operating condition threshold, and the combustion stability index and / or the exhaust temperature in the exhaust temperature sequence exceed the threshold, then based on the throttle pedal opening sequence and the engine speed sequence, the actual value of the first air-fuel ratio and the first exhaust gas recirculation requirement value required by the engine are determined respectively based on the correspondence between the throttle pedal opening and engine speed and the air-fuel ratio and exhaust gas recirculation requirement value, where N is a positive integer greater than or equal to 2; An air-fuel ratio control command is generated based on the first actual air-fuel ratio value, and an exhaust gas recirculation control command is generated based on the first exhaust gas recirculation demand value. The air-fuel ratio control command and the exhaust gas recirculation control command are then output to the engine so that the engine can be controlled based on the first actual air-fuel ratio value and the first exhaust gas recirculation demand value.

[0007] In the above technical solution, the vehicle's operating condition is monitored using a sliding time window. For the current time window, the following sequences are first acquired: throttle pedal opening sequence, engine speed sequence, instantaneous misfire rate sequence, and exhaust temperature sequence. The acquired vehicle data is then processed. Based on the throttle pedal opening sequence, the rate of change of throttle pedal opening at adjacent acquisition times within the current time window is calculated to obtain the throttle change rate sequence. Next, the combustion stability index for the current time window is determined based on the instantaneous misfire rate sequence. The combustion stability index indicates the stability of engine combustion within the current time window. A higher combustion stability index indicates a higher instantaneous misfire rate and less stable combustion. When N consecutive throttle change rates in the throttle change rate sequence exceed the operating condition threshold, and the combustion stability index and / or the exhaust temperature in the exhaust temperature sequence exceed the threshold, the vehicle is considered to have entered a transient operating condition. In this case, the engine's air-fuel ratio and exhaust gas recirculation requirement need to be adjusted. First, based on the accelerator pedal opening sequence and engine speed sequence within the current time window, the actual first air-fuel ratio value required by the engine is determined from the correspondence between accelerator pedal opening, engine speed, and air-fuel ratio. Then, based on the same accelerator pedal opening sequence and engine speed sequence within the current time window, the first exhaust gas recirculation (EGR) requirement value is retrieved from the correspondence between accelerator pedal opening, engine speed, and exhaust gas recirculation (EGR) requirement value. Finally, air-fuel ratio control commands and EGR control commands are generated and output based on the actual first air-fuel ratio value and the first EGR requirement value, enabling the engine to be controlled based on these values. This achieves rapid identification and control of transient engine conditions, improving combustion stability and avoiding misfire and high-temperature risks while rapidly responding to transient conditions.

[0008] Optionally, based on the accelerator pedal opening sequence and the engine speed sequence, and based on the correspondence between the accelerator pedal opening and engine speed and the air-fuel ratio and exhaust gas recirculation (EGR) requirements, the actual first air-fuel ratio and the first EGR requirement for the engine are determined, respectively, including: Based on the accelerator pedal opening sequence and the engine speed sequence, the actual first air-fuel ratio and the first exhaust gas recirculation requirement value of the engine are determined according to the air-fuel ratio map and the exhaust gas recirculation map, respectively. The air-fuel ratio map indicates the basic air-fuel ratio value required by the engine under transient conditions at different engine speeds and different engine torques, and the exhaust gas recirculation map indicates the exhaust gas recirculation requirement value required by the engine under transient conditions at different engine speeds and different engine torques.

[0009] In the above technical solutions, the air-fuel ratio diagram and exhaust gas recirculation diagram are determined during the engine development stage. They indicate the basic air-fuel ratio and exhaust gas recirculation requirements of the engine at different engine speeds and torques.

[0010] Optionally, based on the accelerator pedal opening sequence and the engine speed sequence, the actual value of the first air-fuel ratio and the required value of the first exhaust gas recirculation for the engine are determined according to the air-fuel ratio map and the exhaust gas recirculation map, respectively, including: The engine torque sequence is determined based on the accelerator pedal opening sequence; The engine torque sequence and the engine speed sequence are subjected to a second low-pass filter, and a moving average integral is performed based on a preset time window to obtain a smoothed engine torque sequence and engine speed sequence. Based on the smoothed engine torque sequence and engine speed sequence, the air-fuel ratio base value is obtained by querying the air-fuel ratio graph and then fine-tuning it to obtain the first actual air-fuel ratio value required by the engine. The first exhaust gas recirculation (EGR) requirement value is obtained by querying the exhaust gas recirculation (EGR) spectrum based on the smoothed engine torque sequence and engine speed sequence.

[0011] In the above technical solution, when the vehicle is determined to be in transient operating condition, the engine torque sequence is first determined based on the accelerator pedal opening sequence. Then, the engine torque and engine speed sequences are smoothed by performing secondary low-pass filtering and moving average integration to smooth the signals and suppress high-frequency fluctuations from interfering with control. Next, based on the smoothed engine torque and engine speed sequences, the baseline air-fuel ratio value is obtained from the air-fuel ratio graph. A differential correction is then performed, specifically adjusting the baseline air-fuel ratio value based on the vehicle's actual conditions to obtain the first required actual air-fuel ratio value for the engine. Finally, based on the smoothed engine torque and engine speed sequences, the first exhaust gas recirculation (EGR) requirement value is obtained from the exhaust gas recirculation (EGR) graph. This combines the air-fuel ratio and EGR requirement value to improve combustion stability.

[0012] Optionally, the air-fuel ratio control command instructs the engine to adjust the air-fuel ratio to the first actual air-fuel ratio value, and the exhaust gas recirculation control command instructs the engine to reduce the current exhaust gas recirculation demand value by 50%, and then gradually modify it to the first exhaust gas recirculation demand value.

[0013] In the above technical solution, the exhaust gas recirculation control command first instructs the engine to reduce the current exhaust gas recirculation demand value by 50%, and then gradually modifies it to the first exhaust gas recirculation demand value, so as to actively reduce the exhaust gas recirculation rate under transient conditions to improve combustion stability.

[0014] Optionally, the method further includes: If there are no consecutive N throttle change rate exceeding the operating condition threshold in the throttle change rate sequence, or if the combustion stability index and the exhaust temperature in the exhaust temperature sequence do not exceed the threshold, then after the sliding interval, the time window is slid backward to obtain an updated time window, and the throttle pedal opening sequence, engine speed sequence, instantaneous misfire rate sequence and exhaust temperature sequence in the updated time window are obtained for judgment.

[0015] In the above technical solution, when the vehicle does not enter a transient operating condition, the time window will be slid backward and re-evaluated. That is, after the sliding interval has elapsed, the time window will be slid backward to obtain an updated time window, and then it will be determined whether the vehicle in the updated time window is in a transient operating condition, thereby realizing continuous monitoring of the vehicle's condition.

[0016] Optionally, the method further includes: If the combustion stability index and the exhaust temperature in the exhaust temperature sequence do not exceed the threshold in the subsequent time window, the exhaust gas recirculation demand value under steady-state conditions is determined, an exhaust gas recirculation recovery command is generated and output, and the exhaust gas recirculation recovery command instructs the engine to modify the exhaust gas recirculation demand value from the first exhaust gas recirculation demand value to the exhaust gas recirculation demand value under steady-state conditions according to a fixed step size.

[0017] In the above technical solution, once the exhaust temperature and combustion stability index are monitored and stabilized within a safe range, the exhaust gas recirculation demand is slowly increased in fixed increments until it returns to normal. This achieves dynamic adjustment of the exhaust gas recirculation demand under transient operating conditions.

[0018] Secondly, embodiments of the present invention provide a control device for an engine under transient operating conditions, comprising: The acquisition module is used to acquire the accelerator pedal opening sequence, engine speed sequence, instantaneous misfire rate sequence, and exhaust temperature sequence within the current time window, and to determine the accelerator pedal change rate sequence based on the accelerator pedal opening sequence, and to determine the combustion stability index of the current time window based on the instantaneous misfire rate sequence. The accelerator pedal change rate sequence includes the change rate of accelerator pedal opening at adjacent acquisition times within the current time window, and the combustion stability index is used to indicate the stability of engine combustion within the current time window. The processing module is configured to determine the first actual value of the air-fuel ratio and the first exhaust gas recirculation requirement of the engine based on the correspondence between the throttle pedal opening sequence and the engine speed sequence, and the corresponding values ​​of the air-fuel ratio and exhaust gas recirculation requirement, respectively, when N is a positive integer greater than or equal to 2, if N consecutive throttle change rate exceeds the operating condition threshold in the throttle change rate sequence, and the combustion stability index and / or the exhaust temperature in the exhaust temperature sequence exceed the threshold. An air-fuel ratio control command is generated based on the first actual air-fuel ratio value, and an exhaust gas recirculation control command is generated based on the first exhaust gas recirculation demand value. The air-fuel ratio control command and the exhaust gas recirculation control command are then output to the engine so that the engine can be controlled based on the first actual air-fuel ratio value and the first exhaust gas recirculation demand value.

[0019] Optionally, the processing module is specifically used for: Based on the accelerator pedal opening sequence and the engine speed sequence, the actual first air-fuel ratio and the first exhaust gas recirculation requirement value of the engine are determined according to the air-fuel ratio map and the exhaust gas recirculation map, respectively. The air-fuel ratio map indicates the basic air-fuel ratio value required by the engine under transient conditions at different engine speeds and different engine torques, and the exhaust gas recirculation map indicates the exhaust gas recirculation requirement value required by the engine under transient conditions at different engine speeds and different engine torques.

[0020] Optionally, the processing module is specifically used for: The engine torque sequence is determined based on the accelerator pedal opening sequence; The engine torque sequence and the engine speed sequence are subjected to a second low-pass filter, and a moving average integral is performed based on a preset time window to obtain a smoothed engine torque sequence and engine speed sequence. Based on the smoothed engine torque sequence and engine speed sequence, the air-fuel ratio base value is obtained by querying the air-fuel ratio graph and then fine-tuning it to obtain the first actual air-fuel ratio value required by the engine. The first exhaust gas recirculation (EGR) requirement value is obtained by querying the exhaust gas recirculation (EGR) spectrum based on the smoothed engine torque sequence and engine speed sequence.

[0021] Optionally, the air-fuel ratio control command instructs the engine to adjust the air-fuel ratio to the first actual air-fuel ratio value, and the exhaust gas recirculation control command instructs the engine to reduce the current exhaust gas recirculation demand value by 50%, and then gradually modify it to the first exhaust gas recirculation demand value.

[0022] Optionally, the processing module is further configured to: If there are no consecutive N throttle change rate exceeding the operating condition threshold in the throttle change rate sequence, or if the combustion stability index and the exhaust temperature in the exhaust temperature sequence do not exceed the threshold, then after the sliding interval, the time window is slid backward to obtain an updated time window, and the throttle pedal opening sequence, engine speed sequence, instantaneous misfire rate sequence and exhaust temperature sequence in the updated time window are obtained for judgment.

[0023] Optionally, the processing module is further configured to: If the combustion stability index and the exhaust temperature in the exhaust temperature sequence do not exceed the threshold in the subsequent time window, the exhaust gas recirculation demand value under steady-state conditions is determined, an exhaust gas recirculation recovery command is generated and output, and the exhaust gas recirculation recovery command instructs the engine to modify the exhaust gas recirculation demand value from the first exhaust gas recirculation demand value to the exhaust gas recirculation demand value under steady-state conditions according to a fixed step size.

[0024] Thirdly, embodiments of the present invention also provide a computer device, comprising: Memory, used to store program instructions; The processor is used to call the program instructions stored in the memory and execute the engine control method under transient conditions as described above according to the obtained program.

[0025] Fourthly, embodiments of the present invention also provide a computer-readable storage medium storing computer-executable instructions for causing a computer to execute the above-described engine control method under transient operating conditions.

[0026] Fifthly, embodiments of the present invention also provide a computer program product, the computer program product including an executable program, which is executed by a processor to perform the above-described engine control method under transient operating conditions. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 A schematic diagram of an engine architecture provided for an embodiment of the present invention; Figure 2 A schematic diagram of a system architecture provided for an embodiment of the present invention; Figure 3 A flowchart illustrating an engine control method under transient conditions provided by an embodiment of the present invention; Figure 4 This is a schematic diagram of the structure of a control device for an engine under transient operating conditions, provided in an embodiment of the present invention. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0030] The application scenarios described in this application are for the purpose of more clearly illustrating the technical solutions protected by the embodiments of this application, and do not constitute a limitation on the technical solutions provided by the embodiments of this application. Those skilled in the art will understand that with the emergence of new application scenarios, the technical solutions provided by the embodiments of this application are also applicable to similar technical problems. The terms "first" and "second" in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order. In the description of this application, unless otherwise stated, "multiple" means two or more.

[0031] Before introducing the engine control method under transient conditions provided by the embodiments of this application, for ease of understanding, the terms and background technology involved in the embodiments of this application will be introduced below.

[0032] Air-Fuel Ratio (also known as Lambda): The Lambda value describes the mixing ratio of air and fuel in the engine's intake air and is a key indicator for achieving efficient combustion and reducing emissions. By precisely controlling the Lambda value, the engine can achieve optimal performance and emission control under different operating conditions.

[0033] Instantaneous misfire rate: refers to the frequency or proportion of engine cylinder misfires at a specific moment or within a very short period of time (such as within a few crankshaft revolutions). It reflects the instantaneous stability of the engine combustion process and is an important basis for on-board diagnostic (OBD) systems to diagnose misfire faults.

[0034] For natural gas engines employing premixed combustion and stoichiometric combustion, stable operation is highly dependent on precise air-fuel ratio control. Currently, Lambda closed-loop feedback control based on oxygen sensors is commonly used, ensuring good control performance under steady-state or gradually changing conditions. However, in actual operation, especially in congested urban traffic or specific work scenarios, frequent throttle input by the driver can cause rapid changes in engine speed and load, entering transient operating conditions. Under such conditions, existing technologies have the following significant drawbacks: 1. Response hysteresis: Traditional Lambda closed-loop control relies on sensor feedback signals, which has an inherent delay and cannot quickly respond to sudden changes in intake air volume, resulting in an instantaneous air-fuel ratio that is too lean or too rich.

[0035] 2. Misfire and High Exhaust Temperature: An excessively lean air-fuel ratio can lead to ignition difficulties, causing cylinder misfires and resulting in high temperatures in the three-way catalytic converter; an excessively rich air-fuel ratio leads to incomplete combustion, causing a sharp rise in the temperature of the three-way catalytic converter, and even burn-out. These problems not only cause driver complaints but also seriously damage the engine and after-treatment system, increasing maintenance costs.

[0036] 3. Rigid control strategy: The existing feedforward control MAP is based on standard operating condition calibration and cannot adapt to different driving styles of drivers or performance degradation caused by the aging of vehicle parts, resulting in poor individual adaptability.

[0037] Figure 1 An exemplary schematic diagram of an engine architecture applicable to an embodiment of the present invention is shown. The diagram includes multiple engine components, specifically: 1 is the engine control unit (ECM), 2 is the engine speed sensor, 3 is the aftertreatment inlet temperature sensor, 4 is the exhaust gas recirculation control valve (EGR), 5 is the intake air temperature and pressure sensor, 6 is the intake throttle valve, 7 is knock sensor #1, 8 is knock sensor #2, 9 is exhaust pressure sensor #1, 10 is exhaust pressure sensor #2, 11 is the pre-oxygen sensor, 12 is the three-way catalytic converter aftertreatment system, 13 is the post-oxygen sensor, and 14 is the gas cylinder.

[0038] Figure 2 An exemplary system architecture applicable to an embodiment of the present invention is shown. This system architecture includes an engine control unit 200. The control logic of the system of the present invention is implemented by a software algorithm in the engine control unit 200. The engine control unit 200 may include a processor 210, a communication interface 220, and a memory 230.

[0039] The communication interface 220 is used to transmit data with various sensors on the engine.

[0040] The processor 210 is the control center of the engine control unit 200. It connects to various parts of the engine control unit 200 through various interfaces and routes. By running or executing software programs and / or modules stored in the memory 230, and by calling data stored in the memory 230, it performs various functions of the engine control unit 200 and processes data. Optionally, the processor 210 may include one or more processing units.

[0041] The memory 230 can be used to store software programs and modules. The processor 210 executes various functional applications and data processing by running the software programs and modules stored in the memory 230. The memory 230 may mainly include a program storage area and a data storage area. The program storage area may store the operating system, at least one application program required for a function, etc.; the data storage area may store data created according to business processing, etc. In addition, the memory 230 may include high-speed random access memory, and may also include non-volatile memory, such as at least one disk storage device, flash memory device, or other volatile solid-state storage device.

[0042] It should be noted that the above Figure 2 The structure shown is merely an example, and the embodiments of the present invention are not limited thereto.

[0043] Based on the above description Figure 3 An exemplary flowchart of a control method for an engine under transient operating conditions provided by an embodiment of the present invention is shown. This process can be executed by a control device for the engine under transient operating conditions.

[0044] like Figure 3 As shown, the process specifically includes: Step 310: Obtain the throttle pedal opening sequence, engine speed sequence, instantaneous misfire rate sequence, and exhaust temperature sequence within the current time window. Determine the throttle change rate sequence based on the throttle pedal opening sequence and the combustion stability index for the current time window based on the instantaneous misfire rate sequence. The throttle change rate sequence includes the rate of change of throttle pedal opening at adjacent acquisition times within the current time window. The combustion stability index is used to indicate the stability of engine combustion within the current time window.

[0045] In this embodiment of the invention, the vehicle's condition is monitored in real time. To ensure the accuracy of the analysis of the vehicle's condition, it is necessary to obtain vehicle data within a time period for analysis. Therefore, a sliding time window algorithm can be used to set the time window and the sliding interval. For example, the length of the time window can be set to 10 seconds and the sliding interval can be set to 20 ms. That is, the 10-second time window is slid forward once every 20 ms. The length of the time window and the sliding interval are not specifically limited here.

[0046] For the current moment, the first step is to acquire vehicle data within the current time window, monitor the driver's throttle operation, and make a status judgment based on the driver's behavior. Specifically, this involves acquiring the throttle pedal opening sequence, engine speed sequence, instantaneous misfire rate sequence, and exhaust temperature sequence within the current time window. The throttle pedal opening sequence includes the throttle pedal opening at each acquisition moment within the current time window; the engine speed sequence includes the engine speed at each acquisition moment within the current time window; the instantaneous misfire rate sequence includes the instantaneous misfire rate of the engine at each acquisition moment within the current time window; and the exhaust temperature sequence includes the exhaust temperature of the engine at each acquisition moment within the current time window. The elements in the sequences are arranged in the order of acquisition time. In some embodiments, the intake pressure sequence and the current actual air-fuel ratio value are also acquired.

[0047] Then, a throttle change rate sequence is determined based on the throttle pedal opening sequence within the current time window. This throttle change rate sequence includes the rate of change of throttle pedal opening at adjacent acquisition times within the current time window. The interval between acquisition times is an empirically set value, such as 20ms, meaning data is acquired every 20ms. Therefore, it can also be understood as acquiring vehicle data once every time the time window slides; no specific limit is placed on the interval between acquisition times here.

[0048] Next, the combustion stability index for the current time window is determined from the instantaneous misfire rate sequence within the current time window. The combustion stability index indicates the stability of engine combustion within the current time window. For example, the instantaneous misfire rate is collected at fixed intervals. These intervals are the same as the intervals between the collection times mentioned above, and will not be elaborated upon here. Therefore, the instantaneous misfire rates in the resulting instantaneous misfire rate sequence are discrete. Thus, by numerically integrating the instantaneous misfire rates in the instantaneous misfire rate sequence, the combustion stability index for the current time window can be obtained. It can be understood that since the combustion stability index is obtained by integrating multiple instantaneous misfire rates within the time window, that is, by accumulating the instantaneous misfire rates of the engine over a specific time period, the combustion stability index refers to the cumulative amount of engine misfires within the current time window. In some embodiments, the instantaneous misfire rates in the instantaneous misfire rate sequence can also be directly summed to obtain the combustion stability index for the current time window.

[0049] Step 320: If N consecutive throttle change rates in the throttle change rate sequence exceed the operating condition threshold, and the combustion stability index and / or the exhaust temperature in the exhaust temperature sequence exceed the threshold, then based on the throttle pedal opening sequence and engine speed sequence, determine the actual value of the first air-fuel ratio and the first exhaust gas recirculation requirement value required by the engine, respectively, based on the correspondence between the throttle pedal opening and engine speed and the air-fuel ratio and exhaust gas recirculation requirement value. N is a positive integer greater than or equal to 2.

[0050] In this embodiment of the invention, the driver's operating behavior is judged based on the throttle change rate sequence, combustion stability index, and exhaust temperature sequence. Specifically, it determines whether there are N consecutive throttle change rate sequences exceeding the operating condition threshold, and whether the combustion stability index and / or exhaust temperature sequences exceed the threshold. The operating condition threshold, combustion stability index, and exhaust temperature threshold are empirically set values ​​and are not specifically limited here. N is a positive integer greater than or equal to 2. For example, if N is 10, it means judging whether there are 10 consecutive throttle change rate sequences exceeding the operating condition threshold, i.e., whether there is a rapid change in throttle pedal opening within 2 seconds. The value of N is not specifically limited here.

[0051] In some embodiments, the throttle change frequency is determined based on the throttle pedal opening sequence within the current time window, and it is determined whether the throttle change frequency exceeds the operating condition threshold to determine whether the vehicle has entered a transient operating condition.

[0052] In another embodiment, the exhaust temperature growth rate is determined based on the exhaust temperature sequence within the current time window, and the vehicle is determined to have entered a transient operating condition by judging whether the exhaust temperature growth rate exceeds a threshold.

[0053] When N consecutive throttle change rates in the throttle change rate sequence exceed the operating condition threshold, and the combustion stability index and / or exhaust temperature in the exhaust temperature sequence exceed the threshold, the vehicle is considered to have entered a transient operating condition, requiring adjustments to the air-fuel ratio and exhaust gas recirculation. For example, a trigger signal is sent to the intelligent Lambda controller and the EGR co-controller, and the entire system switches from the conventional control mode to the transient control mode.

[0054] In transient control mode, based on the throttle pedal opening sequence and engine speed sequence, the actual first air-fuel ratio and the required first exhaust gas recirculation (EGR) value for the engine are determined according to the correspondence between throttle pedal opening and engine speed and the air-fuel ratio and EGR demand values, respectively. Specifically, the correspondence between throttle pedal opening and engine speed and the air-fuel ratio and EGR demand values ​​can refer to the air-fuel ratio map and the exhaust gas recirculation map. Therefore, based on the throttle pedal opening sequence and engine speed sequence, the actual first air-fuel ratio and the required first EGR value for the engine can be determined according to the air-fuel ratio map and the exhaust gas recirculation map, respectively. The air-fuel ratio map indicates the basic air-fuel ratio value required by the engine under transient conditions at different engine speeds and different engine torques. For example, a target Lambda MAP for transient conditions can be set. This MAP uses engine speed and torque as index axes to provide a fast, preliminary basic Lambda value. An example MAP is shown below:

[0055] Exhaust Gas Recirculation (EGR) maps indicate the required EGR values ​​for an engine under transient operating conditions at different engine speeds and torques. For example, a transient EGR map can be created. This map, indexed by engine speed and torque, provides a rapid EGR requirement. An example map is shown below:

[0056] The specific determination process includes: First, determining the engine torque sequence based on the accelerator pedal opening sequence. Different accelerator pedal openings correspond to different engine torques, thus allowing the determination of the engine torque sequence. Then, performing a second low-pass filter on the engine torque and engine speed sequences, and performing a moving average integration based on a preset time window to obtain smoothed engine torque and engine speed sequences. The preset time window is a value set empirically, for example, 80ms; the specific preset time window length is not specified here. It can be understood that smoothing the engine torque and engine speed sequences allows the smoothed signal to suppress high-frequency fluctuations from interfering with control.

[0057] In some embodiments, after the transient control mode is triggered, the intake manifold pressure fluctuates drastically, making the sensor signals unreliable. Therefore, an intake pressure estimate based on an engine model is used instead of the actual intake pressure sensor signal for the control logic, thereby improving computational stability. The engine model is developed during engine development, involving extensive DOE (Design of Engines) and data acquisition. Regression processing is performed on the acquired data to obtain a three-dimensional map with engine speed and load as coordinate axes, serving as the engine model. This allows the determination of the corresponding manifold pressure values ​​under different operating conditions.

[0058] Then, after obtaining the smoothed engine torque and engine speed sequences, the air-fuel ratio is queried in the air-fuel ratio map based on these sequences to obtain the basic air-fuel ratio value. This value is then fine-tuned to obtain the first actual air-fuel ratio value required by the engine. For example, if the smoothed engine torque sequence is 130 and the engine speed sequence is 1050, based on the Lambda target MAP diagram in the example above, it can be seen that there is no speed of 1050 in the table. Therefore, the air-fuel ratios of 1.01:1 and 1.03:1 at torques of 130 and speeds of 1000 and 1100 are selected as the basic air-fuel ratio values. Based on the smoothed engine torque sequence of 130 and engine speed sequence of 1050, the initial values ​​are differentially corrected. That is, the engine speed sequence of 1050 is the average of speeds of 1000 and 1100. Therefore, the average of the air-fuel ratios 1.01:1 and 1.03:1 is calculated to obtain the first actual air-fuel ratio value of 1.02:1.

[0059] In some embodiments, the base air-fuel ratio value is differentially corrected based on the vehicle's operating data at the time, making the air-fuel ratio more adaptable to the vehicle's actual conditions.

[0060] The first exhaust gas recirculation (EGR) requirement value is then obtained by querying the exhaust gas recirculation (EGR) map based on the smoothed engine torque sequence and engine speed sequence.

[0061] In one possible implementation, if there are no consecutive N throttle change rate sequences exceeding the operating condition threshold in the throttle change rate sequence, or if the exhaust temperature in the combustion stability index and exhaust temperature sequences does not exceed the threshold, then the vehicle is considered not to have entered a transient operating condition. Therefore, the time window needs to be shifted backward to continue monitoring the vehicle. That is, after a shift interval, the time window is shifted backward to obtain an updated time window. For example, after 20ms, the time window is shifted backward by 20ms to obtain an updated time window. The throttle pedal opening sequence, engine speed sequence, instantaneous misfire rate sequence, and exhaust temperature sequence within the updated time window are then acquired, and the driver's operating behavior is judged accordingly.

[0062] Step 330: Generate an air-fuel ratio control command based on the first actual air-fuel ratio value, generate an exhaust gas recirculation control command based on the first exhaust gas recirculation demand value, and output the air-fuel ratio control command and the exhaust gas recirculation control command to the engine so that the engine can be controlled based on the first actual air-fuel ratio value and the first exhaust gas recirculation demand value.

[0063] In this embodiment of the invention, an air-fuel ratio control command and an exhaust gas recirculation control command are generated based on the actual first air-fuel ratio value and the first exhaust gas recirculation demand value, respectively, and output to the engine so that the engine can be controlled based on the actual first air-fuel ratio value and the first exhaust gas recirculation demand value. The air-fuel ratio control command is output to the fuel injection rail, and the exhaust gas recirculation control command is output to the exhaust gas recirculation control valve.

[0064] In one possible implementation, the air-fuel ratio control command is used to instruct the engine to adjust the air-fuel ratio to a first actual air-fuel ratio value.

[0065] The exhaust gas recirculation (EGR) control command instructs the engine to reduce the current EGR requirement by 50%, and then gradually adjust it back to the first EGR requirement. That is, when the transient control mode is triggered, the EGR requirement is immediately halved, and then increased or decreased to a new EGR requirement based on the moving average of the engine speed and load. This operation significantly reduces the EGR rate under transient conditions, improving combustion limits. In some embodiments, the EGR control command can also instruct the engine to directly adjust the current EGR requirement to the first EGR requirement.

[0066] In another possible implementation, if the combustion stability index and exhaust temperature in the subsequent time window do not exceed the threshold, the exhaust gas recirculation (EGR) demand value under steady-state conditions is determined, an EGR recovery command is generated, and output. This command instructs the engine to modify the EGR demand value from the initial EGR demand value to the steady-state EGR demand value using a fixed step size. For example, once the exhaust temperature and combustion stability index are detected to be stable within a safe range, the EGR demand is slowly increased in fixed steps (e.g., increasing the EGR rate by 1% every 100 cycles) until normal operation is restored. This achieves dynamic adjustment of EGR under transient conditions.

[0067] In another possible implementation, key data from the transient event, such as the average throttle change rate and the actual value after Lambda feedback correction (i.e., the actual value of the first air-fuel ratio), are recorded during and after the entire transient control process. This data is temporarily stored in the non-volatile memory of the ECM. In subsequent vehicle operation (such as in the next driving cycle), when similar conditions are encountered, the module compares and analyzes the new data with historical data. If a systematic deviation is found, the corresponding grid points in the Lambda target MAP are fine-tuned and updated using methods such as weighted averaging, achieving online and adaptive updates to the MAP. This adaptive intelligent iterative method allows the control system to adapt increasingly accurately to the characteristics of the vehicle, achieving customized control. It can be understood that, based on the above method, the embodiments of the present invention possess online self-learning capabilities, continuously optimizing the feedforward MAP based on actual operating data, enabling the control strategy to have personalized adaptability, maintaining the engine's efficient and stable operation over the long term, and reducing the impact of performance degradation caused by component aging.

[0068] In this embodiment of the invention, transient operating conditions are actively identified by detecting operational behavior and setting thresholds. Enhanced feedforward control significantly shortens the response time of Lambda control, fundamentally avoiding misfires and excessive exhaust temperature caused by control delays. Simultaneously, when adjusting the air-fuel ratio and exhaust gas recirculation (EGR) requirements, key signals (throttle, engine speed) undergo secondary filtering and moving average integration processing. Model values ​​are used to replace drastically fluctuating intake pressure signals, effectively suppressing signal noise and improving the stability and robustness of the control system. Furthermore, this embodiment innovatively dynamically couples Lambda control with EGR control, proactively reducing the EGR rate under transient conditions to improve combustion stability, and then gradually restoring it once the operating conditions stabilize, achieving coordinated optimization between subsystems.

[0069] Based on the same technological concept Figure 4 An exemplary schematic diagram of a control device for an engine under transient operating conditions provided by an embodiment of the present invention is shown. This device can execute the flow of a control method for an engine under transient operating conditions.

[0070] like Figure 4 As shown, the device specifically includes: The acquisition module 410 is used to acquire the accelerator pedal opening sequence, engine speed sequence, instantaneous misfire rate sequence and exhaust temperature sequence within the current time window, and to determine the accelerator pedal change rate sequence based on the accelerator pedal opening sequence, and to determine the combustion stability index of the current time window based on the instantaneous misfire rate sequence. The accelerator pedal change rate sequence includes the change rate of accelerator pedal opening at adjacent acquisition times within the current time window, and the combustion stability index is used to indicate the stability of engine combustion within the current time window. The processing module 420 is used to determine the first actual value of the air-fuel ratio and the first exhaust gas recirculation requirement of the engine based on the correspondence between the throttle pedal opening sequence and the engine speed sequence, and the corresponding values ​​of the air-fuel ratio and exhaust gas recirculation requirement, respectively, when N is a positive integer greater than or equal to 2; if N consecutive throttle change rates in the throttle change rate sequence exceed the operating condition threshold, and the combustion stability index and / or the exhaust temperature in the exhaust temperature sequence exceed the threshold, then N is used to determine the first actual value of the air-fuel ratio and the first exhaust gas recirculation requirement of the engine, respectively, based on the correspondence between the throttle pedal opening and the engine speed and the air-fuel ratio and exhaust gas recirculation requirement values. An air-fuel ratio control command is generated based on the first actual air-fuel ratio value, and an exhaust gas recirculation control command is generated based on the first exhaust gas recirculation demand value. The air-fuel ratio control command and the exhaust gas recirculation control command are then output to the engine so that the engine can be controlled based on the first actual air-fuel ratio value and the first exhaust gas recirculation demand value.

[0071] Optionally, the processing module 420 is specifically used for: Based on the accelerator pedal opening sequence and the engine speed sequence, the actual first air-fuel ratio and the first exhaust gas recirculation requirement value of the engine are determined according to the air-fuel ratio map and the exhaust gas recirculation map, respectively. The air-fuel ratio map indicates the basic air-fuel ratio value required by the engine under transient conditions at different engine speeds and different engine torques, and the exhaust gas recirculation map indicates the exhaust gas recirculation requirement value required by the engine under transient conditions at different engine speeds and different engine torques.

[0072] Optionally, the processing module 420 is specifically used for: The engine torque sequence is determined based on the accelerator pedal opening sequence; The engine torque sequence and the engine speed sequence are subjected to a second low-pass filter, and a moving average integral is performed based on a preset time window to obtain a smoothed engine torque sequence and engine speed sequence. Based on the smoothed engine torque sequence and engine speed sequence, the air-fuel ratio base value is obtained by querying the air-fuel ratio graph and then fine-tuning it to obtain the first actual air-fuel ratio value required by the engine. The first exhaust gas recirculation (EGR) requirement value is obtained by querying the exhaust gas recirculation (EGR) spectrum based on the smoothed engine torque sequence and engine speed sequence.

[0073] Optionally, the air-fuel ratio control command instructs the engine to adjust the air-fuel ratio to the first actual air-fuel ratio value, and the exhaust gas recirculation control command instructs the engine to reduce the current exhaust gas recirculation demand value by 50%, and then gradually modify it to the first exhaust gas recirculation demand value.

[0074] Optionally, the processing module 420 is further configured to: If there are no consecutive N throttle change rate exceeding the operating condition threshold in the throttle change rate sequence, or if the combustion stability index and the exhaust temperature in the exhaust temperature sequence do not exceed the threshold, then after the sliding interval, the time window is slid backward to obtain an updated time window, and the throttle pedal opening sequence, engine speed sequence, instantaneous misfire rate sequence and exhaust temperature sequence in the updated time window are obtained for judgment.

[0075] Optionally, the processing module 420 is further configured to: If the combustion stability index and the exhaust temperature in the exhaust temperature sequence do not exceed the threshold in the subsequent time window, the exhaust gas recirculation demand value under steady-state conditions is determined, an exhaust gas recirculation recovery command is generated and output, and the exhaust gas recirculation recovery command instructs the engine to modify the exhaust gas recirculation demand value from the first exhaust gas recirculation demand value to the exhaust gas recirculation demand value under steady-state conditions according to a fixed step size.

[0076] Based on the same technical concept, embodiments of the present invention also provide a computer device, including: Memory, used to store program instructions; The processor is used to call the program instructions stored in the memory and execute the engine control method under transient conditions as described above according to the obtained program.

[0077] Based on the same technical concept, embodiments of the present invention also provide a computer-readable storage medium storing computer-executable instructions for causing a computer to execute the above-described engine control method under transient operating conditions.

[0078] Based on the same technical concept, embodiments of the present invention also provide a computer program product, the computer program product including an executable program, which is executed by a processor to perform the above-described engine control method under transient operating conditions.

[0079] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0080] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to this application. It should be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0081] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0082] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0083] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A control method for an engine under transient operating conditions, characterized in that, include: The system acquires the accelerator pedal opening sequence, engine speed sequence, instantaneous misfire rate sequence, and exhaust temperature sequence within the current time window. Based on the accelerator pedal opening sequence, it determines the throttle change rate sequence. Based on the instantaneous misfire rate sequence, it determines the combustion stability index for the current time window. The throttle change rate sequence includes the rate of change of accelerator pedal opening at adjacent acquisition times within the current time window. The combustion stability index is used to indicate the stability of engine combustion within the current time window. If N consecutive throttle change rates in the throttle change rate sequence exceed the operating condition threshold, and the combustion stability index and / or the exhaust temperature in the exhaust temperature sequence exceed the threshold, then based on the throttle pedal opening sequence and the engine speed sequence, the actual value of the first air-fuel ratio and the first exhaust gas recirculation requirement value required by the engine are determined respectively based on the correspondence between the throttle pedal opening and engine speed and the air-fuel ratio and exhaust gas recirculation requirement value, where N is a positive integer greater than or equal to 2; An air-fuel ratio control command is generated based on the first actual air-fuel ratio value, and an exhaust gas recirculation control command is generated based on the first exhaust gas recirculation demand value. The air-fuel ratio control command and the exhaust gas recirculation control command are then output to the engine so that the engine can be controlled based on the first actual air-fuel ratio value and the first exhaust gas recirculation demand value.

2. The method as described in claim 1, characterized in that, Based on the accelerator pedal opening sequence and the engine speed sequence, the actual first air-fuel ratio and the first exhaust gas recirculation (EGR) requirement of the engine are determined according to the correspondence between the accelerator pedal opening and engine speed and the air-fuel ratio and exhaust gas recirculation (EGR) requirements, including: Based on the accelerator pedal opening sequence and the engine speed sequence, the actual first air-fuel ratio and the first exhaust gas recirculation requirement value of the engine are determined according to the air-fuel ratio map and the exhaust gas recirculation map, respectively. The air-fuel ratio map indicates the basic air-fuel ratio value required by the engine under transient conditions at different engine speeds and different engine torques, and the exhaust gas recirculation map indicates the exhaust gas recirculation requirement value required by the engine under transient conditions at different engine speeds and different engine torques.

3. The method as described in claim 2, characterized in that, Based on the accelerator pedal opening sequence and the engine speed sequence, the actual value of the first air-fuel ratio and the required value of the first exhaust gas recirculation (EGR) for the engine are determined according to the air-fuel ratio map and the exhaust gas recirculation map, respectively, including: The engine torque sequence is determined based on the accelerator pedal opening sequence; The engine torque sequence and the engine speed sequence are subjected to a second low-pass filter, and a moving average integral is performed based on a preset time window to obtain a smoothed engine torque sequence and engine speed sequence. Based on the smoothed engine torque sequence and engine speed sequence, the air-fuel ratio base value is obtained by querying the air-fuel ratio graph and then fine-tuning it to obtain the first actual air-fuel ratio value required by the engine. The first exhaust gas recirculation (EGR) requirement value is obtained by querying the exhaust gas recirculation (EGR) spectrum based on the smoothed engine torque sequence and engine speed sequence.

4. The method as described in claim 1, characterized in that, The air-fuel ratio control command instructs the engine to adjust the air-fuel ratio to the first actual air-fuel ratio value, and the exhaust gas recirculation control command instructs the engine to reduce the current exhaust gas recirculation demand value by 50%, and then gradually modify it to the first exhaust gas recirculation demand value.

5. The method as described in claim 1, characterized in that, The method further includes: If there are no consecutive N throttle change rate exceeding the operating condition threshold in the throttle change rate sequence, or if the combustion stability index and the exhaust temperature in the exhaust temperature sequence do not exceed the threshold, then after the sliding interval, the time window is slid backward to obtain an updated time window, and the throttle pedal opening sequence, engine speed sequence, instantaneous misfire rate sequence and exhaust temperature sequence in the updated time window are obtained for judgment.

6. The method as described in claim 1, characterized in that, The method further includes: If the combustion stability index and the exhaust temperature in the exhaust temperature sequence do not exceed the threshold in the subsequent time window, the exhaust gas recirculation demand value under steady-state conditions is determined, an exhaust gas recirculation recovery command is generated and output, and the exhaust gas recirculation recovery command instructs the engine to modify the exhaust gas recirculation demand value from the first exhaust gas recirculation demand value to the exhaust gas recirculation demand value under steady-state conditions according to a fixed step size.

7. A control device for an engine under transient operating conditions, characterized in that, include: The acquisition module is used to acquire the accelerator pedal opening sequence, engine speed sequence, instantaneous misfire rate sequence, and exhaust temperature sequence within the current time window, and to determine the accelerator pedal change rate sequence based on the accelerator pedal opening sequence, and to determine the combustion stability index of the current time window based on the instantaneous misfire rate sequence. The accelerator pedal change rate sequence includes the change rate of accelerator pedal opening at adjacent acquisition times within the current time window, and the combustion stability index is used to indicate the stability of engine combustion within the current time window. The processing module is configured to determine the first actual value of the air-fuel ratio and the first exhaust gas recirculation requirement of the engine based on the correspondence between the throttle pedal opening sequence and the engine speed sequence, and the corresponding values ​​of the air-fuel ratio and exhaust gas recirculation requirement, respectively, when N is a positive integer greater than or equal to 2, if N consecutive throttle change rate exceeds the operating condition threshold in the throttle change rate sequence, and the combustion stability index and / or the exhaust temperature in the exhaust temperature sequence exceed the threshold. An air-fuel ratio control command is generated based on the first actual air-fuel ratio value, and an exhaust gas recirculation control command is generated based on the first exhaust gas recirculation demand value. The air-fuel ratio control command and the exhaust gas recirculation control command are then output to the engine so that the engine can be controlled based on the first actual air-fuel ratio value and the first exhaust gas recirculation demand value.

8. A computer device, characterized in that, include: Memory, used to store program instructions; A processor is configured to invoke program instructions stored in the memory and execute the method according to any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer-executable instructions for causing a computer to perform the method according to any one of claims 1 to 6.

10. A computer program product, characterized in that, The computer program product includes an executable program that is executed by a processor to implement the method of any one of claims 1 to 6.

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