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

Abstract

The application discloses a kind of vehicle low-pressure exhaust gas recirculation valve control method, device, controller and medium, by monitoring the wiper state of vehicle, driving speed, engine intake, the combustion cycle angle time length of each cylinder of engine and current intake manifold temperature;Respectively set corresponding preset state and association, to respectively determine first cycle rate, second cycle rate, third cycle rate and fourth cycle rate, and the smallest cycle rate in it is as target cycle rate, to control exhaust gas recirculation valve according to target cycle rate operation.Visibly, the multiple parameters in the process of vehicle driving are comprehensively applied, to reduce the use of environmental humidity sensor and engine cylinder pressure sensor, to reduce hardware cost, according to identifying the possibility of misfire under different conditions, to control the operation of exhaust gas recirculation valve, to dynamically adjust EGR system, to reduce the possibility of misfire, improve the reliability and efficiency of engine.

Description

TECHNICAL FIELD

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

[0002] The low-pressure EGR (Exhaust Gas Recirculation) system is a kind of exhaust gas recirculation technology, which takes gas from the exhaust to recirculate the exhaust, thereby reducing the degree of pollution of the EGR valve by the exhaust. 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, resulting in engine cylinder misfire.

[0003] In the conventional technology, the amount of exhaust drawn by the EGR valve is adjusted according to the detection data of the environmental humidity sensor and the engine cylinder pressure sensor, so as to reduce the possibility of engine cylinder misfire. However, this method has a high cost due to the addition of sensors. Therefore, how to reduce the possibility of misfire at a low cost is a technical problem to be solved at present. SUMMARY

[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 misfire 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] monitoring the wiper state, the driving speed, the engine intake amount, the combustion cycle angle duration of each cylinder of the engine, and the current intake manifold temperature of the vehicle;

[0007] when the wiper state meets the 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;

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

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

[0010] When the length of the combustion cycle angle corresponding to any cylinder meets the preset state of the cylinder, a fourth cycle rate is determined according to a fourth correlation between the intake manifold temperature and the cycle rate and the current intake manifold temperature when the length of the combustion cycle angle corresponding to any cylinder meets the preset state of the cylinder;

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

[0012] In some embodiments of the present application, based on the foregoing scheme, when the wiper state meets the wiper preset state, a first cycle rate is determined according to a first correlation between the intake manifold temperature and the cycle rate and the current intake manifold temperature, including:

[0013] After the wiper state is in the open state, the continuous opening time of the wiper is monitored;

[0014] When the continuous opening time of the wiper reaches a first preset time, it is determined that the wiper state meets the wiper preset state;

[0015] The first cycle 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 foregoing scheme, when the driving speed meets the high-speed preset state, a second cycle rate is determined according to a second correlation between the intake manifold temperature and the cycle rate and the current intake manifold temperature, including:

[0017] After the driving speed exceeds the preset speed threshold, the continuous high-speed time of the driving speed exceeding the preset speed threshold is monitored;

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

[0019] The second cycle 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 foregoing scheme, when the engine intake amount meets the load preset state, a third cycle rate is determined according to a third correlation between the intake manifold temperature and the cycle rate and the current intake manifold temperature, including:

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

[0022] The third cycle 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 foregoing scheme, the length of the combustion cycle angle of each cylinder of the engine is monitored, including:

[0024] monitoring a start angle and an end angle of the crankshaft in rotation with respect to a top dead center of combustion for each cylinder in each combustion cycle;

[0025] determining a combustion cycle angle duration of each cylinder in each combustion cycle according to the start angle, the end angle and the engine speed corresponding to each cylinder in each combustion cycle;

[0026] when the combustion cycle angle duration corresponding to any cylinder meets the cylinder preset state, determining a fourth cycle rate according to a fourth correlation between the intake manifold temperature and the cycle rate and the current intake manifold temperature, including:

[0027] determining a misfire parameter corresponding to each cylinder according to a change between the combustion cycle angle durations corresponding to the adjacent N combustion cycles; N is a positive integer;

[0028] when the misfire parameter corresponding to any cylinder exceeds a target misfire threshold, determining that the combustion cycle angle duration meets the cylinder preset state;

[0029] determining the fourth cycle rate according to the fourth correlation and the current intake manifold temperature.

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

[0031] determining the target misfire threshold according to a fifth correlation between the engine speed, the engine intake amount and the misfire threshold, and the actual speed of the engine and the actual intake amount of the engine.

[0032] In some embodiments of the present application, based on the foregoing scheme, the method for determining the misfire parameter corresponding to each cylinder according to the change between the combustion cycle angle durations corresponding to the adjacent N combustion cycles includes:

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

[0034] 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 combustion cycle before the previous combustion cycle of each cylinder; wherein the combustion cycle before the previous combustion cycle, the previous combustion cycle and the current combustion cycle are adjacent combustion cycles occurring in turn;

[0035] determining a target time difference of each cylinder according to the first time difference and the 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 application provides a vehicle low-pressure exhaust gas recirculation valve control device, comprising:

[0038] A monitoring module is configured to monitor a wiper state, a driving speed, an engine intake air amount, a combustion cycle angle duration of each cylinder of the engine, and a current intake manifold temperature of the vehicle.

[0039] A first circulation rate determination module is configured to determine 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 wiper state meets a wiper preset state.

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

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

[0042] A fourth circulation rate determination module is configured to determine a fourth circulation rate according to a fourth correlation between the intake manifold temperature and the circulation rate and the current intake manifold temperature when the combustion cycle angle duration of any cylinder meets a cylinder preset state.

[0043] An exhaust gas recirculation valve control module is configured 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 a 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 application provides a vehicle controller, comprising:

[0045] A processor;

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

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

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

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

[0050] The embodiments of the present application monitor the wiper state, the driving speed, the engine intake amount, the combustion cycle angle duration of each cylinder of the engine, and the current intake manifold temperature of the vehicle; when the wiper state meets the preset state of the wiper, a 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 preset state of the high speed, a 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 amount meets the preset state of the load, a 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 preset state of the cylinder, a 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 taken 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 embodiments of the present application comprehensively consider multiple parameters in the driving process of the vehicle, reduce the use of the environmental humidity sensor and the engine cylinder pressure sensor, reduce the hardware cost, control the operation of the exhaust gas recirculation valve according to the identification of the possible misfire under different conditions, dynamically adjust the EGR system, thereby reducing the possibility of misfire, and improving the reliability and efficiency of the engine. BRIEF DESCRIPTION OF DRAWINGS

[0051] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments description. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0052] Figure 1 A structural principle schematic diagram of a low-pressure EGR system is provided for the embodiments of the present application.

[0053] Figure 2 A flowchart schematic diagram of a vehicle low-pressure exhaust gas recirculation valve control method is provided for the embodiments of the present application.

[0054] Figure 3 A structural schematic diagram of a vehicle low-pressure exhaust gas recirculation valve control device is provided for the embodiments of the present application.

[0055] Figure 4 A structural schematic diagram of a vehicle controller is provided for the embodiments of the present application. DETAILED DESCRIPTION

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

[0057] To solve the above technical problems, the technical scheme of the embodiment of the present application is as follows:

[0058] The embodiment of the present application monitors the wiper state, the driving speed, the engine intake air amount, the combustion cycle angle time length of each cylinder of the engine and the current intake manifold temperature of the vehicle; when the wiper state meets the preset wiper state, the first cycle rate is determined according to the first correlation between the intake manifold temperature and the cycle rate and the current intake manifold temperature; when the driving speed meets the high-speed preset state, the second cycle rate is determined according to the second correlation between the intake manifold temperature and the cycle rate and the current intake manifold temperature; when the engine intake air amount meets the load preset state, the third cycle rate is determined according to the third correlation between the intake manifold temperature and the cycle rate and the current intake manifold temperature; when the combustion cycle angle time length corresponding to any cylinder meets the cylinder preset state, the fourth cycle rate is determined according to the fourth correlation between the intake manifold temperature and the cycle rate and the current intake manifold temperature; the minimum cycle rate in the first cycle rate, the second cycle rate, the third cycle rate and the fourth cycle rate is taken as the target cycle rate, and the exhaust gas recirculation valve is controlled to operate according to the target cycle rate. It can be seen that the embodiment of the present application comprehensively considers multiple parameters in the driving process of the vehicle, reduces the use of the environmental humidity sensor and the engine cylinder pressure sensor, reduces the hardware cost, controls the operation of the exhaust gas recirculation valve according to the identification of the possible misfire under different conditions, dynamically adjusts the EGR system, reduces the possibility of misfire, and improves the reliability and efficiency of the engine.

[0059] In order to better understand the above technical solutions, the above technical solutions will be described in detail in combination with the description of the drawings and the specific embodiments.

[0060] Firstly, the term "and / or" appearing in the present document is only to describe the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B can represent the three cases of existence of A alone, existence of A and B simultaneously, and existence of B alone. In addition, the character " / " in the present document generally represents an "or" relationship between the front and rear associated objects.

[0061] First, this application will describe the structure and principle of a low-pressure EGR (Exhaust Gas Recirculation) system. Low-pressure EGR is a type of EGR system, which includes an exhaust gas recirculation valve, i.e., an EGR valve. For simplicity, this application will refer to the exhaust gas recirculation valve as EGR valve. The difference between a low-pressure EGR system and a high-pressure EGR system lies in their placement and operating pressure within the turbocharged engine.

[0062] like Figure 1 The diagram shown is a schematic representation of the structural principle of a low-pressure EGR system provided in this application embodiment. The EGR valve draws air from the outlet of the GPF (Gasoline Particulate Filter), where the exhaust gas is purified, resulting in less contamination of the EGR valve. The exhaust gas drawn by the EGR valve mixes with fresh air collected by the air filter at the mixing valve, then passes through the compressor and enters the intercooler. The intake air volume is controlled by the throttle valve to enter the engine. Compared to high-pressure EGR, the mixing point is before the compressor, resulting in a more uniform mixture entering the engine. The turbine uses the exhaust gas from the engine to drive the turbine to rotate, which in turn drives the compressor to compress air, achieving a turbocharging effect. The TWC (Three-Way Catalyst) converts carbon monoxide, hydrocarbons, and nitrogen oxides emitted by the engine into relatively harmless carbon dioxide, water, and nitrogen, which are then sent to the GPF to capture and reduce particulate matter in the exhaust gas, thereby meeting the vehicle's exhaust emission 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 it passes through the intercooler, affecting the combustion in the engine cylinder and causing misfire, which has an adverse effect on driving.

[0064] To address the aforementioned issues, this application provides a method for controlling a vehicle low-pressure exhaust gas recirculation valve, comprising steps S21-S26.

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

[0066] Step S22: When the wiper state meets the wiper preset state, determine the first circulation rate based on the first correlation 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 a second cycle rate according to the second correlation between the intake manifold temperature and the cycle rate and the current intake manifold temperature;

[0068] Step S24, when the engine intake amount meets the load preset state, determining a third cycle rate according to the third correlation between the intake manifold temperature and the cycle rate and the current intake manifold temperature;

[0069] Step S25, when the combustion cycle angle time length corresponding to any cylinder meets the cylinder preset state, determining a fourth cycle rate according to the fourth correlation between the intake manifold temperature and the cycle rate and the current intake manifold temperature;

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

[0071] Regarding step S21, the wiper state, the driving speed, the engine intake amount, the combustion cycle angle time length of each cylinder of the engine and the current intake manifold temperature of the vehicle are monitored.

[0072] The wiper state includes the opening state, the closing state and other states of the wiper, which can be monitored by directly collecting the signals triggered by the corresponding states of the wiper, or by receiving the state signals of the wiper transmitted by other modules. When the wiper is in the opening state, it means that the vehicle is in the driving condition of rainy weather, and the humidity in the exhaust gas increases. By monitoring the wiper state, the use of the environmental humidity sensor is reduced.

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

[0074] The combustion cycle angle time length of each cylinder of the engine is monitored, including steps S211-S212.

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

[0076] Step S212, determining the combustion cycle angle time length of each cylinder in each combustion cycle according to the start angle, the end angle corresponding to each cylinder in each combustion cycle and the engine speed.

[0077] Regarding step S211, in the working cycle of the engine, the start angle and the end angle of the crankshaft in the rotation process of each cylinder relative to the top dead center of 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. For example, the start angle is 90°, and the end angle is 180°. A positive value of the start angle and the end angle indicates that it is after the top dead center, and a negative value indicates that it is before the top dead center.

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

[0079]

[0080] Wherein, T_SegTime is the combustion cycle angle time length, PHI_StartAngle is the start angle, PHI_EndAngle is the end angle, and RPM_Eng is the engine speed (unit: revolutions / second).

[0081] Since the vehicle is in different use scenarios, the influence of environmental temperature and humidity on condensed water is different, therefore, the embodiment of the application sets corresponding control strategies for the vehicle in three actual scenarios and after detecting misfire.

[0082] Scenario one, corresponding to the vehicle in a rainy day scenario.

[0083] Since the humidity in the exhaust gas of the vehicle on a rainy day is large, the mixed gas is more likely to condense in the intercooler, therefore, the control strategy corresponding to the rainy day scenario is as follows.

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

[0085] Step S221, after the wiper state is in an open state, the continuous opening time of the wiper is monitored;

[0086] Step S222, when the continuous opening time of the wiper reaches a first preset time, it is determined that the wiper state meets the wiper preset state;

[0087] Step S223, according to the first correlation and the current intake manifold temperature, a first cycle rate is determined.

[0088] Regarding step S221, the continuous opening time of the wiper can be realized by accumulating the calculation period length of the controller. The longer the continuous opening time of the wiper, the more likely it is that the vehicle is in a rainy day scenario.

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

[0090] The control strategy of scenario one is described in detail below by 01 program language.

[0091] The controller receives the wiper activation signal B_FrontWiperSwitch, and when the state of the wiper is an open state, i.e., B_FrontWiperSwitch is not equal to 0, the continuous opening time T_FrontWiperSwitchTime of the wiper is monitored by accumulating the calculation period length of the controller.

[0092] That is, T_FrontWiperSwitchTime = ∑T_10ms, where T_ represents the length of each calculation period of the controller, which is 10 ms in this embodiment.

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

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

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

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

[0097] Table 1 First correlation between intake manifold temperature and cycle rate

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

[0099] Scenario two, corresponding to the vehicle being in a high-speed scenario.

[0100] When the vehicle is driving at medium and high speeds, and the vehicle speed is relatively stable, the engine is in the working condition of the EGR valve being opened, and the intercooler temperature is low. When the driving time is relatively long, it is easy to form condensed water, so the control strategy corresponding to the high-speed scenario is as follows.

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

[0102] Step S231, after the driving speed exceeds the preset speed threshold, the driving speed exceeding the preset speed threshold is monitored for a continuous high-speed time;

[0103] Step S232, when the continuous high-speed time reaches a second preset time, it is determined that the driving speed meets the high-speed preset condition;

[0104] Step S233, the second cycle rate is determined according to the second correlation and the current intake manifold temperature.

[0105] As to step S231, the continuous high-speed time can be monitored by accumulating the length of the controller's calculation period, where the controller is the controller described above for monitoring the continuous wiper opening time.

[0106] As to step S232, the second preset time is greater than the first preset time, because the humidity is large on rainy days, the influence on the intercooler is large, and in the case of only high-speed scene, the condensation speed of the condensed water is slower than the case of only rainy scene, 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 correlation are obtained according to the designer's multiple experiments or calibrated according to the actual situation.

[0108] The control strategy of scenario two is described in detail below in 01 program 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 length of each calculation period of the controller, which is 10ms in this embodiment.

[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] A second preset time T_VehSpdHighCheckTime is set to 300s. When the condition T_VehSpdHigTime≥T_VehSpdHighCheckTime is met, i.e., the driving speed meets the high-speed preset state, 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 between the intake manifold temperature and the circulation rate shown in Table 2 and the current intake manifold temperature.

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

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

[0117] Scenario three corresponds to a medium-heavy load scenario of the vehicle.

[0118] According to the power mode of the vehicle, it can be divided into traditional fuel vehicles, electric vehicles and hybrid vehicles. For hybrid vehicles, the engine state cannot be determined according to the driving speed of the vehicle when the vehicle is running. The engine may be stopped or running. When the actual load of the engine is large, the EGR valve is opened, and there is a condition to form condensate water. Therefore, the control strategy corresponding to the medium-heavy load scenario is as follows.

[0119] Regarding step S24, when the engine intake amount 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, including steps S241-S242.

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

[0121] Step S242, the third circulation rate is determined according to the third correlation and the current intake manifold temperature.

[0122] Regarding steps S241-S242, the engine intake amount is obtained through a sensor or other modules, and the preset intake threshold and the third correlation are obtained according to the designer's multiple experiments or are calibrated according to the actual situation.

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

[0124] A preset intake air threshold DM_MaxAirFlowForWaterLimit is set to 100 g / s, and when the engine intake air amount exceeds 100 g / s, the high load state in the vehicle B_EnableHighload is activated to 1.

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

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

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

[0128] Further, as can be seen from Table 1, Table 2 and Table 3, at some same intake manifold temperature, the second circulation rate obtained by the second correlation and the first circulation rate obtained by the first correlation are both less than the third circulation rate obtained by the third correlation. This is because the probability of misfire under scenario three is lower than that under scenario one and scenario two, so a larger circulation rate can be used to make the EGR system work more efficiently.

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

[0130] Regarding step S25, when the combustion period angle duration of any cylinder meets the preset cylinder 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, including steps S251-S253.

[0131] Step S251, according to the change between the combustion period angle durations corresponding to the adjacent N combustion periods, determine the misfire parameter corresponding to each cylinder; 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 period angle duration meets the preset cylinder state;

[0133] Step S253, according to the fourth correlation and the current intake manifold temperature, determine the fourth circulation rate.

[0134] Regarding step S251, according to the change between the combustion period angle durations corresponding to the adjacent N combustion periods, determine the misfire parameter corresponding to each cylinder, including steps S2511-S2514.

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

[0136] Step S2512, determining a second time difference corresponding to each cylinder according to the combustion cycle angle time length corresponding to the previous combustion cycle of each cylinder and a combustion cycle angle time length corresponding to a combustion cycle before the previous combustion cycle; wherein the combustion cycle before the previous combustion cycle, the previous combustion cycle and the current combustion cycle are combustion cycles occurring in turn and being adjacent;

[0137] Step S2513, determining a target time difference of 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, determining the target time difference as a misfire parameter.

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

[0140] The determination process of the second time difference is similar to that of the first time difference, which will not be described here.

[0141] The 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 target time difference corresponding to any cylinder is determined as a misfire parameter.

[0143] Regarding step S252, the determination method of the target misfire threshold value includes:

[0144] According to a fifth correlation relationship between the engine speed, the engine intake amount and the misfire threshold value, and the actual speed of the engine and the actual intake amount of the engine, the target misfire threshold value is determined.

[0145] The fifth correlation relationship is obtained according to the design personnel multiple experiments or according to the actual situation calibration. For example, as shown in Table 4.

[0146] Table 4: fifth correlation relationship between engine speed, engine intake amount and misfire threshold value

[0147]

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

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

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

[0151] As to 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 taken as the target circulation rate, and the EGR valve is controlled to operate according to the target circulation rate.

[0152] It should be noted that in the same period, the actual situation of the vehicle can conform to multiple scenarios, can conform to only one scenario, or can not conform to any scenario, i.e., the circulation rate determined in the same period can include one or more of the first circulation rate, the second circulation rate, the third circulation rate and the fourth circulation rate.

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

[0154] The first circulation rate, the second circulation rate, the third circulation rate and the fourth circulation rate are all EGR rates, i.e., the ratio of the recirculated exhaust gas amount in the EGR system to the total amount of intake air into the cylinder. The target circulation rate is the EGR rate finally determined under multiple scenarios. Under the same working condition, the greater the EGR rate, the greater the opening degree of the EGR valve.

[0155] In summary, the embodiment of the 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 preset wiper state, determines a first circulation rate 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, determines a second circulation rate 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, determines a third circulation rate 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 of any cylinder meets the cylinder preset state, determines a fourth circulation rate according to the fourth correlation between the intake manifold temperature and the circulation rate and the current intake manifold temperature; takes the minimum circulation rate among the first circulation rate, the second circulation rate, the third circulation rate, and the fourth circulation rate as a target circulation rate, and controls the exhaust gas recirculation valve to operate according to the target circulation rate. It can be seen that the embodiment of the application comprehensively considers multiple parameters in the driving process of the vehicle, reduces the use of the environmental humidity sensor and the engine cylinder pressure sensor, reduces the hardware cost, controls the operation of the exhaust gas recirculation valve according to the identification of the possible misfire under different conditions, dynamically adjusts the EGR system, thereby reduces the possibility of misfire, and improves the reliability and efficiency of the engine.

[0156] Based on the same inventive concept, the application provides a vehicle low-pressure exhaust gas recirculation valve control device as shown in Figure 3 The application provides a vehicle low-pressure exhaust gas recirculation valve control device, which comprises:

[0157] The monitoring module 31 is configured to monitor 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.

[0158] The first circulation rate determination module 32 is configured to, when the wiper state meets the preset wiper state, determine a first circulation rate according to the first correlation between the intake manifold temperature and the circulation rate and the current intake manifold temperature.

[0159] The second circulation rate determination module 33 is configured to, when the driving speed meets the high-speed preset state, determine a second circulation rate according to the second correlation between the intake manifold temperature and the circulation rate and the current intake manifold temperature.

[0160] The third circulation rate determination module 34 is configured to, when the engine intake volume meets the load preset state, determine a third circulation rate according to the third correlation between the intake manifold temperature and the circulation rate and the current intake manifold temperature.

[0161] The fourth cycle rate determination module 35 is configured to determine a fourth cycle rate according to a fourth correlation between the intake manifold temperature and the cycle rate and the current intake manifold temperature when the length of the combustion cycle angle corresponding to any cylinder meets the preset state of the cylinder.

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

[0163] Based on the same inventive concept, the present application provides a vehicle controller as shown in Figure 4 The vehicle controller comprises:

[0164] a processor 41;

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

[0166] The processor 41 is configured to execute to implement the vehicle low-pressure exhaust gas recirculation valve control method provided in the foregoing.

[0167] Based on the same inventive concept, the present application provides a non-transitory computer-readable storage medium, when the instructions in the storage medium are executed by the processor 41 of the vehicle controller, the vehicle controller can execute to implement the vehicle low-pressure exhaust gas recirculation valve control method provided in the foregoing.

[0168] Since the vehicle controller introduced in the embodiment is the vehicle controller used to implement the method of information processing in the embodiment, based on the method of information processing introduced in the embodiment, those skilled in the art can understand the specific implementation of the vehicle controller in the embodiment and its various forms, so the vehicle controller how to implement the method in the embodiment will not be introduced in detail. As long as the vehicle controller used to implement the method of information processing in the embodiment is implemented by those skilled in the art, it belongs to the scope of the present application.

[0169] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system or a computer program product. Therefore, the present application can be in the form of a complete hardware embodiment, a complete software embodiment or an embodiment combining software and hardware aspects. Moreover, the present application can be in the form of a computer program product implemented on one or more computer usable storage media containing computer usable program code (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.).

[0170] The present application is described in reference to the flowchart illustrations and / or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the application. It will 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, create means for implementing the functions specified in the flowchart illustrations and / or block diagrams. Figure 1 one or more functions specified in the flowchart illustrations and / or block diagrams. Figure 1 one or more functions specified in the flowchart illustrations and / or block diagrams.

[0171] These computer program instructions can also be stored in a computer- readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instructions which implement the functions specified in the flowchart illustrations and / or block diagrams. Figure 1 one or more functions specified in the flowchart illustrations and / or block diagrams. Figure 1 one or more functions specified in the flowchart illustrations and / or block diagrams.

[0172] These computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart illustrations and / or block diagrams. Figure 1 one or more functions specified in the flowchart illustrations and / or block diagrams. Figure 1 one or more functions specified in the flowchart illustrations and / or block diagrams.

[0173] While the preferred embodiments of the application have been described, additional variations and modifications can be made to the embodiments by those of skill in the art once they have the benefit of the present disclosure without departing from the spirit and scope of the application. Accordingly, the attached claims are intended to embrace all such variations and modifications as fall within the scope of the present application.

[0174] Obviously, numerous modifications and variations of the present application are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims and their equivalents, the application can be practiced otherwise than as specifically described.

Claims

1. A method for controlling a low-pressure exhaust gas recirculation valve in a vehicle, characterized in that, include: Monitor the vehicle's windshield wiper status, driving speed, engine intake air volume, combustion cycle angle duration of each cylinder of the engine, and current intake manifold temperature; When the wiper state meets the wiper preset state, the first circulation rate is determined based on 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 based on the second correlation between the intake manifold temperature and the circulation rate and the current intake manifold temperature. When the engine intake air volume meets the load preset state, the third circulation rate is determined based on the third correlation between intake manifold temperature and circulation rate and the current intake manifold temperature. When the combustion cycle angle duration corresponding to any of the cylinders meets the cylinder preset state, the fourth cycle rate is determined based on the fourth correlation between intake manifold temperature and cycle 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 the 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 as described in claim 1, characterized in that, When the wiper state meets the preset wiper state, the first circulation rate is determined based on the first correlation between the intake manifold temperature and the circulation rate, and the current intake manifold temperature, including: After the windshield wipers are in the on state, monitor the duration of the windshield wipers being on. When the continuous on time of the wiper reaches a first preset time, it is determined that the wiper state meets the preset wiper state. The first circulation rate is determined based on the first correlation and the current intake manifold temperature.

3. The vehicle low-pressure exhaust gas recirculation valve control method as described in claim 1, characterized in that, When the driving speed meets the high-speed preset state, the second circulation rate is determined based on the second correlation between the intake manifold temperature and the circulation rate, and the current intake manifold temperature, including: After the driving speed exceeds a preset speed threshold, monitor the duration of the high-speed driving speed exceeding the preset speed threshold. When the sustained high-speed time reaches the second preset time, it is determined that the driving speed meets the high-speed preset state; The second circulation rate is determined based on the second correlation and the current intake manifold temperature.

4. The vehicle low-pressure exhaust gas recirculation valve control method as described in claim 1, characterized in that, When the engine intake air volume meets the preset load condition, the third circulation rate is determined based on the third correlation between intake manifold temperature and circulation rate, and the current intake manifold temperature, including: When the engine intake air volume exceeds the preset intake air threshold, it is determined that the engine intake air volume meets the preset load state; The third cycle rate is determined based on the third correlation and the current intake manifold temperature.

5. The vehicle low-pressure exhaust gas recirculation valve control method as described in claim 1, characterized in that, The monitoring of the combustion cycle angle duration of each cylinder of the engine includes: Monitor the start and end angles of each cylinder relative to the top dead center of combustion during crankshaft rotation in each combustion cycle; Based on the starting angle, the ending angle, and the engine speed of each cylinder in each combustion cycle, the combustion cycle angle duration corresponding to each cylinder in each combustion cycle is determined. When the combustion cycle angle duration corresponding to any of the cylinders meets the cylinder preset state, the fourth cycle rate is determined based on the fourth correlation between intake manifold temperature and cycle rate and the current intake manifold temperature, including: The misfire parameter for each cylinder is determined based on the change in the combustion cycle angle duration corresponding to each of the 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 cycle rate is determined based on the fourth correlation and the current intake manifold temperature.

6. The vehicle low-pressure exhaust gas recirculation valve control method as described in claim 5, characterized in that, The method for determining the target fire threshold includes: The target misfire threshold is determined based on the fifth correlation between the engine speed, the engine intake air volume and the misfire threshold, as well as the actual engine speed and the actual engine intake air volume.

7. The vehicle low-pressure exhaust gas recirculation valve control method as described in claim 5, characterized in that, The step of determining the misfire parameters for each cylinder based on the changes in the combustion cycle angle duration corresponding to N adjacent combustion cycles includes: The first time difference for each cylinder is determined based on the combustion cycle angle duration corresponding to the current combustion cycle and the combustion cycle angle duration corresponding to the previous combustion cycle. The second time difference for each cylinder is determined based on the combustion cycle angle duration corresponding to the previous combustion cycle 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 sequentially and are adjacent to each other. The target time difference for each cylinder is determined based on 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 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: The monitoring module is used to monitor the vehicle's windshield wiper status, driving speed, engine intake air volume, combustion cycle angle duration of each cylinder of the engine, and current intake manifold temperature. The first cycle rate determination module is used to determine the first cycle rate based on the first correlation between the intake manifold temperature and the cycle rate and the current intake manifold temperature when the wiper state meets the wiper preset state. The second circulation rate determination module is used to determine the second circulation rate based on the second 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 third circulation rate determination module is used to determine the third circulation rate based on the third correlation between the intake manifold temperature and the circulation rate and the current intake manifold temperature when the engine intake air volume meets the load preset state. The fourth cycle rate determination module is used to determine the fourth cycle rate based on the fourth correlation between intake manifold temperature and cycle rate and the current intake manifold temperature when the combustion cycle angle duration corresponding to any of the cylinders meets the cylinder preset state. The exhaust gas recirculation valve control module is used to take the minimum of the first recirculation rate, the second recirculation rate, the third recirculation rate and the fourth recirculation rate as the target recirculation rate, and control the exhaust gas recirculation valve of the vehicle to operate according to the target recirculation rate.

9. A vehicle controller, characterized in that, include: processor; Memory used to store the processor's executable instructions; The processor is configured to execute 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 the processor of the vehicle controller, the vehicle controller is able to perform a vehicle low-pressure exhaust gas recirculation valve control method as described in any one of claims 1-7.

Images