Vehicle low-pressure exhaust gas recirculation valve control method and device, controller and medium

Abstract

The invention discloses a vehicle low-pressure exhaust gas recirculation valve control method and device, a controller and a medium. The vehicle low-pressure exhaust gas recirculation valve control method comprises the steps that the state of a windscreen wiper of a vehicle, the running speed, the air inflow of an engine, the combustion cycle angle duration of each air cylinder of the engine and the current inlet manifold temperature are monitored; and respectively setting corresponding preset states and association relationships to respectively determine a first circulation rate, a second circulation rate, a third circulation rate and a fourth circulation rate, and taking the minimum circulation rate as a target circulation rate to control the exhaust gas recirculation valve to operate according to the target circulation rate. It can be seen that the multiple parameters in the vehicle running process are integrated, use of an environment humidity sensor and an engine air cylinder pressure sensor is reduced, so that the hardware cost is reduced, operation of the EGR valve is controlled according to the situation that fire possibly happens under different conditions, the EGR system is dynamically adjusted, and the reliability of the system is improved. Therefore, the possibility of fire occurrence is reduced, and the reliability and efficiency of the engine are improved.

Description

Technical Field

[0001] The present invention relates to the field of vehicle control technology, and in particular to a vehicle low-pressure exhaust gas recirculation valve control method, device, controller and medium. Background Art

[0002] The low-pressure EGR (Exhaust Gas Recirculation) system is a type of exhaust gas recirculation technology. The low-pressure EGR system takes air from the tail exhaust to recirculate the exhaust gas, which can reduce the degree of pollution of the EGR valve by the exhaust gas. However, since the exhaust gas entering the low-pressure EGR contains a large amount of water vapor, it is easy to condense into the engine cylinder when passing through the intercooler, causing the engine cylinder to misfire.

[0003] In the traditional technology, the amount of exhaust gas absorbed by the EGR valve is adjusted mainly according to the detection data of the ambient humidity sensor and the engine cylinder pressure sensor to reduce the possibility of misfire in the engine cylinder. However, this method is more expensive due to the addition of sensors. Therefore, how to reduce the possibility of misfire at a low cost is a technical problem that needs to be solved urgently. Summary of the invention

[0004] The embodiments of the present application provide a vehicle low-pressure exhaust gas recirculation valve control method, device, controller and medium, which solve the technical problem of adding sensors in the prior art and achieve the technical effect of reducing the possibility of fire at a low cost.

[0005] In a first aspect, the present application provides a vehicle low-pressure exhaust gas recirculation valve control method, comprising:

[0006] Monitor the vehicle's wiper status, driving speed, engine air intake, combustion cycle angle duration of each cylinder of the engine, and current intake manifold temperature;

[0007] When the wiper state satisfies the wiper preset state, determining a first circulation rate according to a first correlation between the intake manifold temperature and the circulation rate and the current intake manifold temperature;

[0008] When the driving speed meets the high speed preset state, determining the second circulation rate according to the second correlation relationship between the intake manifold temperature and the circulation rate and the current intake manifold temperature;

[0009] When the engine intake volume meets the preset load state, determining the third circulation rate according to the third correlation relationship between the intake manifold temperature and the circulation rate and the current intake manifold temperature;

[0010] When the combustion cycle angle duration corresponding to any cylinder satisfies the preset cylinder state, a fourth circulation rate is determined according to a fourth correlation relationship between the intake manifold temperature and the circulation rate and the current intake manifold temperature;

[0011] The minimum circulation rate among the first circulation rate, the second circulation rate, the third circulation rate and the fourth circulation rate is taken as the target circulation rate, and the exhaust gas recirculation valve is controlled to operate according to the target circulation rate.

[0012] In some embodiments of the present application, based on the above solution, when the wiper state satisfies the preset wiper state, the first circulation rate is determined according to the first correlation between the intake manifold temperature and the circulation rate and the current intake manifold temperature, including:

[0013] After the wiper state is turned on, monitoring the continuous on time of the wiper;

[0014] When the continuous opening time of the wiper reaches a first preset time, determining that the wiper state satisfies the wiper preset state;

[0015] A first circulation rate is determined according to the first correlation and the current intake manifold temperature.

[0016] In some embodiments of the present application, based on the above solution, when the driving speed meets the high speed preset state, the second circulation rate is determined according to the second correlation relationship between the intake manifold temperature and the circulation rate and the current intake manifold temperature, including:

[0017] After the driving speed exceeds the preset speed threshold, monitoring the continuous high-speed time that the driving speed exceeds the preset speed threshold;

[0018] When the continuous high-speed time reaches a second preset time, determining that the driving speed meets the high-speed preset state;

[0019] A second circulation rate is determined according to the second correlation and the current intake manifold temperature.

[0020] In some embodiments of the present application, based on the above scheme, when the engine intake air volume meets the preset load state, the third circulation rate is determined according to the third correlation relationship between the intake manifold temperature and the circulation rate and the current intake manifold temperature, including:

[0021] When the engine air intake exceeds the preset air intake threshold, it is determined that the engine air intake meets the preset load state;

[0022] A third circulation rate is determined according to the third correlation and the current intake manifold temperature.

[0023] In some embodiments of the present application, based on the above scheme, monitoring the combustion cycle angle duration of each cylinder of the engine includes:

[0024] Monitor the starting and ending angles of each cylinder relative to the top dead center of combustion during the rotation of the crankshaft in each combustion cycle;

[0025] Determine the combustion cycle angle duration corresponding to each cylinder in each combustion cycle according to the starting angle, ending angle and engine speed of each cylinder in each combustion cycle;

[0026] When the combustion cycle angle duration corresponding to any cylinder satisfies the preset state of the cylinder, a fourth circulation rate is determined according to a fourth correlation relationship between the intake manifold temperature and the circulation rate and the current intake manifold temperature, including:

[0027] According to the changes between the combustion cycle angle durations corresponding to N adjacent combustion cycles, the misfire parameter corresponding to each cylinder is determined; N is a positive integer;

[0028] When the misfire parameter corresponding to any cylinder exceeds the target misfire threshold, it is determined that the combustion cycle angle duration satisfies the preset state of the cylinder;

[0029] A fourth circulation rate is determined according to the fourth correlation relationship and the current intake manifold temperature.

[0030] In some embodiments of the present application, based on the above scheme, a method for determining a target misfire threshold includes:

[0031] The target misfire threshold is determined based on a fifth correlation between the engine speed, the engine air intake volume and the misfire threshold, as well as the actual engine speed and the actual engine air intake volume.

[0032] In some embodiments of the present application, based on the above scheme, the misfire parameter corresponding to each cylinder is determined according to the change between the combustion cycle angle durations corresponding to N adjacent combustion cycles, including:

[0033] Determine a first time difference corresponding to each cylinder according to a combustion cycle angle duration corresponding to a current combustion cycle of each cylinder and a combustion cycle angle duration corresponding to a previous combustion cycle;

[0034] Determine the second time difference corresponding to each cylinder according to the combustion cycle angle duration corresponding to the previous combustion cycle of each cylinder and the combustion cycle angle duration corresponding to the previous combustion cycle; wherein the previous combustion cycle, the previous combustion cycle and the current combustion cycle are combustion cycles that occur successively and are adjacent;

[0035] Determine a target time difference for each cylinder according to a first time difference and a second time difference corresponding to each cylinder;

[0036] When the first time difference, the second time difference and the target time difference corresponding to any cylinder are all greater than 0, the corresponding target time difference is determined as the misfire parameter.

[0037] In a second aspect, the present application provides a vehicle low-pressure exhaust gas recirculation valve control device, comprising:

[0038] A monitoring module is used to monitor the vehicle's wiper status, driving speed, engine air intake, combustion cycle angle duration of each cylinder of the engine, and current intake manifold temperature;

[0039] a first circulation rate determination module, configured to determine a first circulation rate according to a first correlation between the intake manifold temperature and the circulation rate and a current intake manifold temperature when the wiper state satisfies a preset wiper state;

[0040] a second circulation rate determination module, configured to determine a second circulation rate according to a second correlation between the intake manifold temperature and the circulation rate and a current intake manifold temperature when the driving speed satisfies a high-speed preset state;

[0041] A third circulation rate determination module, configured to determine a third circulation rate according to a third correlation between the intake manifold temperature and the circulation rate and a current intake manifold temperature when the engine intake air volume meets a preset load state;

[0042] a fourth circulation rate determination module, configured to determine a fourth circulation rate according to a fourth correlation relationship between the intake manifold temperature and the circulation rate and a current intake manifold temperature when the combustion cycle angle duration corresponding to any cylinder satisfies a preset cylinder state;

[0043] The exhaust gas recirculation valve control module is used to take the minimum circulation rate among the first circulation rate, the second circulation rate, the third circulation rate and the fourth circulation rate as the target circulation rate, and control the exhaust gas recirculation valve of the vehicle to operate according to the target circulation rate.

[0044] In a third aspect, the present application provides a vehicle controller, comprising:

[0045] processor;

[0046] a memory for storing processor-executable instructions;

[0047] The processor is configured to execute to implement a vehicle low-pressure exhaust gas recirculation valve control method as provided in the first aspect.

[0048] In a fourth aspect, the present application provides a non-temporary computer-readable storage medium, characterized in that when the instructions in the storage medium are executed by a processor of a vehicle controller, the vehicle controller is enabled to execute a vehicle low-pressure exhaust gas recirculation valve control method as provided in the first aspect.

[0049] One or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages:

[0050] The embodiment of the present application monitors the wiper status, driving speed, engine intake volume, combustion cycle angle duration of each cylinder of the engine and current intake manifold temperature of the vehicle; when the wiper status meets the wiper preset state, the first circulation rate is determined according to the first correlation between the intake manifold temperature and the circulation rate and the current intake manifold temperature; when the driving speed meets the high-speed preset state, the second circulation rate is determined according to the second correlation between the intake manifold temperature and the circulation rate and the current intake manifold temperature; when the engine intake volume meets the load preset state, the third circulation rate is determined according to the third correlation between the intake manifold temperature and the circulation rate and the current intake manifold temperature; when the combustion cycle angle duration corresponding to any cylinder meets the cylinder preset state, the fourth circulation rate is determined according to the fourth correlation between the intake manifold temperature and the circulation rate and the current intake manifold temperature; the minimum circulation rate among the first circulation rate, the second circulation rate, the third circulation rate and the fourth circulation rate is used as the target circulation rate, and the exhaust gas recirculation valve is controlled to operate according to the target circulation rate. It can be seen that the embodiment of the present application integrates multiple parameters during vehicle driving, reduces the use of ambient humidity sensors and engine cylinder pressure sensors to reduce hardware costs, and controls the operation of the exhaust gas recirculation valve based on the identification of possible misfires under different conditions to dynamically adjust the EGR system, thereby reducing the possibility of misfires and improving the reliability and efficiency of the engine. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0052] Figure 1 A schematic diagram of the structural principle of a low-pressure EGR system provided in an embodiment of the present application;

[0053] Figure 2 A schematic flow chart of a vehicle low-pressure exhaust gas recirculation valve control method provided in an embodiment of the present application;

[0054] Figure 3 A schematic structural diagram of a vehicle low-pressure exhaust gas recirculation valve control device provided in an embodiment of the present application;

[0055] Figure 4 A schematic diagram of the structure of a vehicle controller provided in an embodiment of the present application. DETAILED DESCRIPTION

[0056] The embodiment of the present application solves the technical problem of adding a sensor in the prior art by providing a vehicle low-pressure exhaust gas recirculation valve control method.

[0057] The technical solution of the embodiment of the present application is to solve the above technical problems, and the overall idea is as follows:

[0058] The embodiment of the present application monitors the wiper status, driving speed, engine intake volume, combustion cycle angle duration of each cylinder of the engine and current intake manifold temperature of the vehicle; when the wiper status meets the wiper preset state, the first circulation rate is determined according to the first correlation between the intake manifold temperature and the circulation rate and the current intake manifold temperature; when the driving speed meets the high-speed preset state, the second circulation rate is determined according to the second correlation between the intake manifold temperature and the circulation rate and the current intake manifold temperature; when the engine intake volume meets the load preset state, the third circulation rate is determined according to the third correlation between the intake manifold temperature and the circulation rate and the current intake manifold temperature; when the combustion cycle angle duration corresponding to any cylinder meets the cylinder preset state, the fourth circulation rate is determined according to the fourth correlation between the intake manifold temperature and the circulation rate and the current intake manifold temperature; the minimum circulation rate among the first circulation rate, the second circulation rate, the third circulation rate and the fourth circulation rate is used as the target circulation rate, and the exhaust gas recirculation valve is controlled to operate according to the target circulation rate. It can be seen that the embodiment of the present application integrates multiple parameters during vehicle driving, reduces the use of ambient humidity sensors and engine cylinder pressure sensors to reduce hardware costs, and controls the operation of the exhaust gas recirculation valve based on the identification of possible misfires under different conditions to dynamically adjust the EGR system, thereby reducing the possibility of misfires and improving the reliability and efficiency of the engine.

[0059] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0060] First of all, the term "and / or" in this article is only a description of the association relationship of the associated objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0061] First, the embodiment of the present application first describes the structure and principle of the low-pressure EGR (Exhaust Gas Recirculation) system. Low-pressure EGR is a type of EGR system. The low-pressure EGR system includes an exhaust gas recirculation valve, namely, an EGR valve. To simplify the description, the EGR valve is used to represent the exhaust gas recirculation valve in the embodiment of the present application. The difference between the low-pressure EGR system and the high-pressure EGR system lies in the different layout positions and working pressures in the turbocharged engine.

[0062] like Figure 1 As shown, it is a schematic diagram of the structural principle of a low-pressure EGR system provided by an embodiment of the present application. The EGR valve takes air from the outlet of the GPF (Gasoline Particulate Filter), where the tail gas is purified and has less pollution to the EGR valve. The tail gas taken by the EGR valve is mixed with the fresh gas collected by the air filter (air cleaner) at the mixing valve, and then enters the intercooler through the compressor, and the intake volume is controlled by the throttle to enter the engine. Compared with high-pressure EGR, since the mixing point is before the compressor, the mixed gas entering the engine is more uniform. The turbine drives the turbine to rotate by utilizing the exhaust gas discharged by the engine, and then drives the compressor to compress the air to achieve the supercharging effect. TWC (Three-Way Catalyst) converts the carbon monoxide, hydrocarbons and nitrogen oxides emitted by the engine into relatively harmless carbon dioxide, water and nitrogen, and then sends them to the GPF to capture and reduce the particulate matter in the exhaust gas to meet the vehicle's exhaust standards.

[0063] However, since the exhaust gas taken by the EGR valve contains a certain amount of water vapor, it is easy to condense and enter the engine when passing through the intercooler, affecting the combustion in the engine cylinder, causing engine cylinder misfire, and causing adverse effects on driving.

[0064] In order to solve the above problems, an embodiment of the present application provides a vehicle low-pressure exhaust gas recirculation valve control method, including steps S21-S26.

[0065] Step S21, monitoring the vehicle's wiper status, driving speed, engine air intake, combustion cycle angle duration of each cylinder of the engine, and current intake manifold temperature;

[0066] Step S22, when the wiper state satisfies the wiper preset state, determining a first circulation rate according to a first correlation relationship between the intake manifold temperature and the circulation rate and the current intake manifold temperature;

[0067] Step S23, when the driving speed meets the high speed preset state, determining the second circulation rate according to the second correlation relationship between the intake manifold temperature and the circulation rate and the current intake manifold temperature;

[0068] Step S24, when the engine intake air volume meets the preset load state, determining the third circulation rate according to the third correlation relationship between the intake manifold temperature and the circulation rate and the current intake manifold temperature;

[0069] Step S25, when the combustion cycle angle duration corresponding to any cylinder satisfies the preset state of the cylinder, a fourth circulation rate is determined according to a fourth correlation relationship between the intake manifold temperature and the circulation rate and the current intake manifold temperature;

[0070] Step S26, taking the minimum circulation rate among the first circulation rate, the second circulation rate, the third circulation rate and the fourth circulation rate as the target circulation rate, and controlling the exhaust gas recirculation valve to operate according to the target circulation rate.

[0071] Regarding step S21, the wiper status, driving speed, engine air intake, combustion cycle angle duration of each cylinder of the engine, and current intake manifold temperature of the vehicle are monitored.

[0072] The wiper status includes the on state, off state and other states of the wiper. The wiper status can be monitored by directly collecting the signal triggered by the corresponding state of the wiper, or by receiving the wiper status signal transmitted by other modules. When the wiper is in the on state, it means that the vehicle is driving on a rainy road, and the humidity in the tail exhaust gas increases. By monitoring the wiper status, the use of the ambient humidity sensor can be reduced.

[0073] The driving speed, the engine air intake volume and the current intake manifold temperature are obtained through sensors arranged at corresponding positions or can be obtained from other modules.

[0074] Monitoring the combustion cycle angle duration of each cylinder of the engine includes steps S211-S212.

[0075] Step S211, monitoring the starting angle and ending angle of each cylinder relative to the combustion top dead center during the rotation of the crankshaft in each combustion cycle;

[0076] Step S212, determining the combustion cycle angle duration corresponding to each cylinder in each combustion cycle according to the starting angle, the ending angle and the engine speed corresponding to each cylinder in each combustion cycle.

[0077] Regarding step S211, in the working cycle of the engine, the starting angle and ending angle of each cylinder relative to the top dead center of combustion during the rotation of the crankshaft in the combustion cycle refer to the angle from the top dead center to the start of combustion and the angle from the top dead center to the end of combustion when the piston moves in the cylinder. Exemplarily, the starting angle is 90° and the ending angle is 180°, and the positive values ​​of the starting angle and the ending angle indicate that they are after the top dead center, and the negative values ​​indicate that they are before the top dead center.

[0078] Regarding step S212, the combustion cycle angle duration is realized by the following formula:

[0079]

[0080] Among them, T_SegTime is the angular duration of the combustion cycle, PHI_StartAngle is the starting angle, PHI_EndAngle is the ending angle, and RPM_Eng is the engine speed (unit: revolutions per second).

[0081] Since the ambient temperature and humidity have different effects on condensed water when the vehicle is in different usage scenarios, the embodiments of the present application respectively set corresponding control strategies for the vehicle in three actual scenarios and after a fire is detected.

[0082] Scene 1: The vehicle is in a rainy day scene.

[0083] Since the humidity in the tail gas of vehicles is higher on rainy days, the mixed gas is more likely to condense in the intercooler, so the control strategy corresponding to the rainy day scene is as follows.

[0084] Regarding step S22, when the wiper state meets the wiper preset state, the first circulation rate is determined according to the first correlation between the intake manifold temperature and the circulation rate and the current intake manifold temperature, including steps S221-S223.

[0085] Step S221, after the wiper is in the on state, monitoring the continuous on time of the wiper;

[0086] Step S222, when the continuous opening time of the wiper reaches a first preset time, determining that the wiper state satisfies the wiper preset state;

[0087] Step S223, determining a first circulation rate according to the first correlation relationship and the current intake manifold temperature.

[0088] Regarding step S221, monitoring the continuous opening time of the wiper can be achieved by accumulating the calculation cycle time of the controller. The longer the continuous opening time of the wiper is, the more likely the vehicle is in a rainy day.

[0089] Regarding step S222 and step S223, the first preset time and the first association relationship are obtained according to multiple experiments or calibrated according to actual conditions.

[0090] The control strategy of scenario 1 is described in detail below using 01 programming language.

[0091] The controller receives a wiper activation signal B_FrontWiperSwitch. When the wiper is in an on state, that is, B_FrontWiperSwitch is not equal to 0, the controller monitors the continuous on time T_FrontWiperSwitchTime of the wiper by accumulating the calculation cycle time of the controller.

[0092] That is, T_FrontWiperSwitchTime=∑T_10ms, where T_ represents the duration of each calculation cycle of the controller. In this embodiment, the duration of each calculation cycle is 10ms.

[0093] In the above accumulation process, when the wiper activation signal is equal to 0, the wiper continuous on time T_FrontWiperSwitchTime is reset to 0.

[0094] The first preset time T_FrontWiperSwitchCheckTime is set to 120 seconds. When the condition T_FrontWiperSwitchTime≥T_FrontWiperSwitchCheckTime is met, it is determined that the wiper state meets the wiper preset state, and the rainy day state B_FrontWiperWork=1 is activated.

[0095] When the engine stops running, the rain state B_FrontWiperWork is reset to 0.

[0096] When the rainy day state is activated, the first circulation rate is determined according to the first correlation relationship between the intake manifold temperature and the circulation rate shown in Table 1 and the current intake manifold temperature.

[0097] Table 1 The first correlation between intake manifold temperature and circulation rate

[0098] Intake manifold temperature / ℃ 10 20 25 30 32 34 35 43 45 50 Cycle rate 0 0 0 0.05 0.1 0.15 0.15 0.2 0.2 0.2

[0099] Scenario 2: The vehicle is in a high-speed scenario.

[0100] When the vehicle is traveling at medium to high speed and the speed is relatively stable, the engine is in the condition where the EGR valve is open and the intercooler temperature is low. When the driving time is long, condensation water is easy to form. Therefore, the control strategy corresponding to the high-speed scenario is as follows.

[0101] Regarding step S23, when the driving speed meets the high-speed preset state, the second circulation rate is determined according to the second correlation between the intake manifold temperature and the circulation rate and the current intake manifold temperature, including steps S231-S233.

[0102] Step S231, after the driving speed exceeds the preset speed threshold, monitoring the continuous high-speed time that the driving speed exceeds the preset speed threshold;

[0103] Step S232, when the high-speed duration reaches a second preset time, determining that the driving speed meets the high-speed preset state;

[0104] Step S233, determining a second circulation rate according to the second association relationship and the current intake manifold temperature.

[0105] Regarding step S231, monitoring the continuous high-speed time can be achieved by accumulating the calculation cycle time of the controller, and the controller here is the above-mentioned controller for monitoring the continuous opening time of the wiper.

[0106] Regarding step S232, the second preset time is greater than the first preset time because the humidity is high on rainy days and has a greater impact on the intercooler. In the case of only high-speed scenes, the condensation speed of condensed water is slower than in the case of only rainy scenes, so the second preset time is set to be greater than the first preset time.

[0107] The preset speed threshold, the second preset time and the second association relationship are obtained by designers through multiple experiments or calibrated according to actual conditions.

[0108] The control strategy of scenario 2 is described in detail below using 01 programming language.

[0109] The preset speed threshold V_VehSpdForEMFCLimit is set to 60km / h. When the vehicle speed exceeds 60km / h, the high-speed signal B_EnableVehSpdSteadyCheckTime=1 is activated, and the continuous high-speed time T_VehSpdHigTime is monitored.

[0110] T_VehSpdHigTime=∑T_10ms, where T_ represents the duration of each calculation cycle of the controller. In this embodiment, the duration of each calculation cycle is 10ms.

[0111] In the above accumulation process, when the high-speed signal is equal to 0, the continuous high-speed time T_VehSpdHigTime is reset to 0.

[0112] The second preset time T_VehSpdHighCheckTime is set to 300s. When the condition T_VehSpdHigTime≥T_VehSpdHighCheckTime is met, it is determined that the driving speed meets the high-speed preset state, and the high-speed state B_VehSpdHighLastLong=1 is activated.

[0113] When the engine stops running, T_VehSpdHigTime is reset to 0.

[0114] When the high speed state is activated, the second circulation rate is determined according to the second correlation relationship between the intake manifold temperature and the circulation rate shown in Table 2 and the current intake manifold temperature.

[0115] Table 2 The second correlation between intake manifold temperature and circulation rate

[0116] Intake manifold temperature / ℃ 10 20 25 30 32 34 35 43 45 50 Cycle rate 0 0 0 0.05 0.05 0.05 0.05 0.1 0.1 0.15

[0117] Scenario three: The vehicle is in a medium to heavy load scenario.

[0118] According to the vehicle's power mode, it can be divided into traditional fuel vehicles, electric vehicles and hybrid vehicles. For hybrid vehicles, when the vehicle is running, the engine status cannot be judged based on the vehicle's driving speed. The engine may be shut down or running. When the actual engine load is large, the EGR valve opens and there are conditions for the formation of condensed water. Therefore, the control strategies corresponding to medium and large load scenarios are as follows.

[0119] Regarding step S24, when the engine intake volume meets the preset load state, the third circulation rate is determined according to the third correlation relationship between the intake manifold temperature and the circulation rate and the current intake manifold temperature, including steps S241-S242.

[0120] Step S241, when the engine air intake exceeds the preset air intake threshold, it is determined that the engine air intake meets the preset load state;

[0121] Step S242, determining a third circulation rate according to the third association relationship and the current intake manifold temperature.

[0122] Regarding steps S241-S242, the engine intake volume is obtained through sensors or other modules, and the preset intake threshold value and the third correlation relationship are obtained based on multiple experiments by designers or calibrated based on actual conditions.

[0123] The control strategy of scenario three is described in detail below using 01 programming language.

[0124] The preset intake threshold DM_MaxAirFlowForWaterLimit is set to 100g / s. When the engine intake volume exceeds 100g / s, the vehicle medium and high load state B_EnableHighload=1 is activated.

[0125] When the medium-to-high load state of the vehicle is activated, the third circulation rate is determined according to the third correlation relationship between the intake manifold temperature and the circulation rate shown in Table 3 and the current intake manifold temperature.

[0126] Table 3 The third correlation between intake manifold temperature and circulation rate

[0127] Intake manifold temperature / ℃ 10 20 25 30 32 34 35 36 38 40 Cycle rate 0.05 0.06 0.08 0.1 0.12 0.14 0.16 0.18 0.2 0.22

[0128] Furthermore, it can be seen from Tables 1, 2 and 3 that at certain same intake manifold temperatures, the second cycle rate obtained by the second correlation relationship and the first cycle rate obtained by the first correlation relationship are both less than the third cycle rate obtained by the third correlation relationship. This is because the probability of misfire in the vehicle under scenario 3 is lower than that of misfire in scenarios 1 and 2, so a larger cycle rate can be used to achieve better working efficiency of the EGR system.

[0129] In addition to the three actual scenarios, the vehicle low-pressure exhaust gas recirculation valve control method provided in the present application also detects misfire conditions and sets corresponding control strategies.

[0130] Regarding step S25, when the combustion cycle angle duration corresponding to any cylinder meets the preset state of the cylinder, the fourth circulation rate is determined according to the fourth correlation between the intake manifold temperature and the circulation rate and the current intake manifold temperature, including steps S251-S253.

[0131] Step S251, determining the misfire parameter corresponding to each cylinder according to the change between the combustion cycle angle durations corresponding to N adjacent combustion cycles; N is a positive integer;

[0132] Step S252, when the misfire parameter corresponding to any cylinder exceeds the target misfire threshold, it is determined that the combustion cycle angle duration meets the preset state of the cylinder;

[0133] Step S253, determining a fourth circulation rate according to the fourth association relationship and the current intake manifold temperature.

[0134] Regarding step S251, the misfire parameter corresponding to each cylinder is determined according to the changes between the combustion cycle angle durations corresponding to N adjacent combustion cycles, including steps S2511 to S2514.

[0135] Step S2511, determining a first time difference corresponding to each cylinder according to the combustion cycle angle duration corresponding to the current combustion cycle of each cylinder and the combustion cycle angle duration corresponding to the previous combustion cycle;

[0136] Step S2512, determining a second time difference corresponding to each cylinder according to the combustion cycle angle duration corresponding to the previous combustion cycle and the combustion cycle angle duration corresponding to the previous combustion cycle of each cylinder; wherein the previous combustion cycle, the previous combustion cycle and the current combustion cycle are combustion cycles that occur successively and are adjacent;

[0137] Step S2513, determining a target time difference for each cylinder according to the first time difference and the second time difference corresponding to each cylinder;

[0138] Step S2514: when the first time difference, the second time difference and the target time difference corresponding to any cylinder are all greater than 0, the corresponding target time difference is determined as the misfire parameter.

[0139] Exemplarily, the first time difference T_Delt_Time=T_SegTime-T_SegTime_z; wherein T_SegTime is the combustion cycle angle duration corresponding to the current combustion cycle, and T_SegTime_z is the combustion cycle angle duration corresponding to the previous combustion cycle.

[0140] The process of determining the second time difference is similar to that of the first time difference, and will not be described in detail here.

[0141] Target time difference T_Delt_Misfire=T_Delt_Time-T_Delt_Time_z; wherein T_Delt_Time_z is the second time difference.

[0142] When T_Delt_Time_z>0, T_Delt_Time>0, and T_Delt_Misfire>0 are satisfied at the same time, the corresponding target time difference is determined as the misfire parameter.

[0143] Regarding step S252, the method for determining the target misfire threshold includes:

[0144] The target misfire threshold is determined based on a fifth correlation between the engine speed, the engine air intake volume and the misfire threshold, as well as the actual engine speed and the actual engine air intake volume.

[0145] The fifth association relationship is obtained through multiple experiments by designers or calibrated according to actual conditions. For example, as shown in Table 4.

[0146] Table 4 The fifth correlation between engine speed, engine intake volume and misfire threshold

[0147]

[0148] Regarding step S253, the fourth circulation rate is determined according to the fourth association relationship and the current intake manifold temperature. Exemplarily, the fourth association relationship is shown in Table 5.

[0149] Table 5 The fourth correlation between intake manifold temperature and circulation rate

[0150] Intake manifold temperature / ℃ 10 20 25 30 32 34 35 43 45 50 Cycle rate 0 0 0 0 0 0 0 0 0.1 0.15

[0151] Regarding step S26, the minimum circulation rate among the first circulation rate, the second circulation rate, the third circulation rate and the fourth circulation rate is set as the target circulation rate, and the exhaust gas recirculation valve is controlled to operate according to the target circulation rate.

[0152] It should be noted that, within the same time period, the actual situation of the vehicle may conform to multiple scenarios, or may conform to only one scenario, or may not conform to any scenario, that is, the cycle rate determined within the same time period may include one or more of the first cycle rate, the second cycle rate, the third cycle rate and the fourth cycle rate.

[0153] The control of the EGR valve is a dynamic adjustment process. The minimum circulation rate among the circulation rates determined in the current period is used as the target circulation rate and the EGR valve is controlled to operate according to the target circulation rate in the current period. When the next period is reached, the first circulation rate, the second circulation rate, the third circulation rate and the fourth circulation rate are re-determined, and then the target circulation rate corresponding to the next period is re-determined.

[0154] The first circulation rate, the second circulation rate, the third circulation rate, and the fourth circulation rate are all EGR rates, that is, the ratio of the amount of exhaust gas recirculated in the EGR system to the total amount of air sucked into the cylinder. The target circulation rate is the final EGR rate determined under multiple scenarios at the same time. Under the same operating conditions, the larger the EGR rate, the larger the opening of the EGR valve.

[0155] In summary, the embodiment of the present application monitors the wiper state, driving speed, engine intake volume, combustion cycle angle duration of each cylinder of the engine, and current intake manifold temperature of the vehicle; when the wiper state meets the wiper preset state, the first circulation rate is determined according to the first correlation between the intake manifold temperature and the circulation rate and the current intake manifold temperature; when the driving speed meets the high-speed preset state, the second circulation rate is determined according to the second correlation between the intake manifold temperature and the circulation rate and the current intake manifold temperature; when the engine intake volume meets the load preset state, the third circulation rate is determined according to the third correlation between the intake manifold temperature and the circulation rate and the current intake manifold temperature; when the combustion cycle angle duration corresponding to any cylinder meets the cylinder preset state, the fourth circulation rate is determined according to the fourth correlation between the intake manifold temperature and the circulation rate and the current intake manifold temperature; the minimum circulation rate among the first circulation rate, the second circulation rate, the third circulation rate and the fourth circulation rate is used as the target circulation rate, and the exhaust gas recirculation valve is controlled to operate according to the target circulation rate. It can be seen that the embodiment of the present application integrates multiple parameters during vehicle driving, reduces the use of ambient humidity sensors and engine cylinder pressure sensors to reduce hardware costs, and controls the operation of the exhaust gas recirculation valve based on the identification of possible misfires under different conditions to dynamically adjust the EGR system, thereby reducing the possibility of misfires and improving the reliability and efficiency of the engine.

[0156] Based on the same inventive concept, the present application provides Figure 3 A vehicle low-pressure exhaust gas recirculation valve control device shown includes:

[0157] A monitoring module 31 is used to monitor the wiper status, driving speed, engine air intake, combustion cycle angle duration of each cylinder of the engine, and current intake manifold temperature of the vehicle;

[0158] A first circulation rate determination module 32, configured to determine a first circulation rate according to a first correlation between the intake manifold temperature and the circulation rate and a current intake manifold temperature when the wiper state satisfies a preset wiper state;

[0159] A second circulation rate determination module 33, for determining a second circulation rate according to a second correlation relationship between the intake manifold temperature and the circulation rate and a current intake manifold temperature when the driving speed meets a high speed preset state;

[0160] A third circulation rate determination module 34 is used to determine the third circulation rate according to the third correlation relationship between the intake manifold temperature and the circulation rate and the current intake manifold temperature when the engine intake air volume meets the preset load state;

[0161] A fourth circulation rate determination module 35, configured to determine a fourth circulation rate according to a fourth correlation relationship between the intake manifold temperature and the circulation rate and a current intake manifold temperature when the combustion cycle angle duration corresponding to any cylinder satisfies a preset cylinder state;

[0162] The exhaust gas recirculation valve control module 36 is used to take the minimum circulation rate among the first circulation rate, the second circulation rate, the third circulation rate and the fourth circulation rate as the target circulation rate, and control the exhaust gas recirculation valve of the vehicle to operate according to the target circulation rate.

[0163] Based on the same inventive concept, the present application provides Figure 4 A vehicle controller is shown, comprising:

[0164] Processor 41;

[0165] A memory 42 for storing instructions executable by the processor 41;

[0166] The processor 41 is configured to execute to implement a vehicle low-pressure exhaust gas recirculation valve control method as provided above.

[0167] Based on the same inventive concept, the present application provides a non-temporary computer-readable storage medium. When the instructions in the storage medium are executed by the processor 41 of the vehicle controller, the vehicle controller is able to execute a vehicle low-pressure exhaust gas recirculation valve control method as provided above.

[0168] Since the vehicle controller introduced in this embodiment is a vehicle controller used to implement the information processing method in the embodiment of the present application, based on the information processing method introduced in the embodiment of the present application, a person skilled in the art can understand the specific implementation of the vehicle controller of the present embodiment and its various variations, so how the vehicle controller implements the method in the embodiment of the present application is not described in detail here. As long as a person skilled in the art implements the vehicle controller used by the information processing method in the embodiment of the present application, it belongs to the scope of protection of this application.

[0169] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented 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.

[0170] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0171] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0172] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0173] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0174] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A vehicle low-pressure exhaust gas recirculation valve control method, characterized in that: include: Monitoring the wiper status, driving speed, engine air intake, combustion cycle angle duration of each cylinder of the engine, and current intake manifold temperature of the vehicle; When the wiper state satisfies a preset wiper state, determining a first circulation rate according to a first correlation between the intake manifold temperature and the circulation rate and the current intake manifold temperature; When the driving speed satisfies a high speed preset state, determining a second circulation rate according to a second correlation relationship between the intake manifold temperature and the circulation rate and the current intake manifold temperature; When the engine intake air volume meets the preset load state, determining a third circulation rate according to a third correlation relationship between the intake manifold temperature and the circulation rate and the current intake manifold temperature; When the combustion cycle angle duration corresponding to any of the cylinders satisfies a preset cylinder state, determining a fourth circulation rate according to a fourth correlation relationship between the intake manifold temperature and the circulation rate and the current intake manifold temperature; The minimum circulation rate among the first circulation rate, the second circulation rate, the third circulation rate and the fourth circulation rate is taken as a target circulation rate, and the exhaust gas recirculation valve is controlled to operate according to the target circulation rate.

2. The vehicle low-pressure exhaust gas recirculation valve control method according to claim 1, characterized in that: When the wiper state satisfies the wiper preset state, determining the first circulation rate according to the first correlation relationship between the intake manifold temperature and the circulation rate and the current intake manifold temperature includes: After the wiper is in the on state, monitoring the continuous on time of the wiper; When the continuous opening time of the wiper reaches a first preset time, determining that the wiper state satisfies the wiper preset state; The first circulation rate is determined according to the first correlation and the current intake manifold temperature.

3. The vehicle low-pressure exhaust gas recirculation valve control method according to claim 1, characterized in that: When the driving speed satisfies the high speed preset state, determining the second circulation rate according to the second correlation relationship between the intake manifold temperature and the circulation rate and the current intake manifold temperature includes: After the driving speed exceeds a preset speed threshold, monitoring the continuous high-speed time during which the driving speed exceeds the preset speed threshold; When the continuous high-speed time reaches a second preset time, determining that the driving speed meets the high-speed preset state; The second circulation rate is determined according to the second association relationship and the current intake manifold temperature.

4. The vehicle low-pressure exhaust gas recirculation valve control method according to claim 1, characterized in that: When the engine intake air volume meets the preset load state, determining the third circulation rate according to the third correlation relationship between the intake manifold temperature and the circulation rate and the current intake manifold temperature includes: When the engine air intake exceeds a preset air intake threshold, it is determined that the engine air intake meets the preset load state; The third circulation rate is determined according to the third correlation relationship and the current intake manifold temperature.

5. The vehicle low-pressure exhaust gas recirculation valve control method according to claim 1, characterized in that: The monitoring of the combustion cycle angle duration of each cylinder of the engine includes: Monitoring the starting angle and ending angle of each cylinder relative to the combustion top dead center during the rotation of the crankshaft in each combustion cycle; Determine the combustion cycle angle duration corresponding to each cylinder in each combustion cycle according to the starting angle, the ending angle and the engine speed corresponding to each cylinder in each combustion cycle; When the combustion cycle angle duration corresponding to any of the cylinders satisfies a preset cylinder state, determining a fourth circulation rate according to a fourth correlation relationship between the intake manifold temperature and the circulation rate and the current intake manifold temperature includes: Determine the misfire parameter corresponding to each cylinder according to the change between the combustion cycle angle durations corresponding to N adjacent combustion cycles; N is a positive integer; When the misfire parameter corresponding to any of the cylinders exceeds the target misfire threshold, it is determined that the combustion cycle angle duration satisfies the preset state of the cylinder; The fourth circulation rate is determined according to the fourth correlation relationship and the current intake manifold temperature.

6. The vehicle low-pressure exhaust gas recirculation valve control method according to claim 5, characterized in that: The method for determining the target misfire threshold comprises: The target misfire threshold is determined according to a fifth correlation relationship between the engine speed, the engine air intake amount and the misfire threshold, and the actual engine speed and the actual engine air intake amount.

7. The vehicle low-pressure exhaust gas recirculation valve control method according to claim 5, characterized in that: Determining the misfire parameter corresponding to each cylinder according to the change between the combustion cycle angle durations corresponding to N adjacent combustion cycles includes: Determine a first time difference corresponding to each cylinder according to the combustion cycle angle duration corresponding to the current combustion cycle of each cylinder and the combustion cycle angle duration corresponding to the previous combustion cycle; Determine the second time difference corresponding to each cylinder according to the combustion cycle angle duration corresponding to the previous combustion cycle and the combustion cycle angle duration corresponding to the previous combustion cycle of each cylinder; wherein the previous combustion cycle, the previous combustion cycle and the current combustion cycle are combustion cycles that occur successively and are adjacent; determining a target time difference for each cylinder according to the first time difference and the second time difference corresponding to each cylinder; When the first time difference, the second time difference and the target time difference corresponding to any one of the cylinders are all greater than 0, the corresponding target time difference is determined as the misfire parameter.

8. A vehicle low-pressure exhaust gas recirculation valve control device, characterized in that: include: A monitoring module, used to monitor the wiper status, driving speed, engine air intake, combustion cycle angle duration of each cylinder of the engine, and current intake manifold temperature of the vehicle; a first circulation rate determination module, configured to determine a first circulation rate according to a first correlation between an intake manifold temperature and a circulation rate and the current intake manifold temperature when the wiper state satisfies a preset wiper state; a second circulation rate determination module, configured to determine a second circulation rate according to a second correlation relationship between the intake manifold temperature and the circulation rate and the current intake manifold temperature when the driving speed satisfies a high speed preset state; a third circulation rate determination module, configured to determine a third circulation rate according to a third correlation relationship between the intake manifold temperature and the circulation rate and the current intake manifold temperature when the engine intake air volume meets a preset load state; a fourth circulation rate determination module, configured to determine a fourth circulation rate according to a fourth correlation relationship between the intake manifold temperature and the circulation rate and the current intake manifold temperature when the combustion cycle angle duration corresponding to any of the cylinders satisfies a preset cylinder state; The exhaust gas recirculation valve control module is used to take the minimum circulation rate among the first circulation rate, the second circulation rate, the third circulation rate and the fourth circulation rate as the target circulation rate, and control the exhaust gas recirculation valve of the vehicle to operate according to the target circulation rate.

9. A vehicle controller, characterized in that: include: processor; a memory for storing instructions executable by the processor; The processor is configured to execute to implement a vehicle low-pressure exhaust gas recirculation valve control method as described in any one of claims 1-7.

10. A non-transitory computer-readable storage medium, characterized in that: When the instructions in the storage medium are executed by a processor of a vehicle controller, the vehicle controller is enabled to implement a vehicle low-pressure exhaust gas recirculation valve control method as described in any one of claims 1-7.

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