A hybrid vehicle engine starting control method, device and computer system

Abstract

The application discloses a kind of hybrid vehicle engine starting control methods, comprising the following steps: S1, determine starting air quantity optimization condition, ensure the whole vehicle ensure the whole vehicle completely stops for a long time, do not affect the next starting performance of engine;S2, if meeting starting air quantity optimization condition, then record and determine starting optimization control condition;S3, whether starting optimization control condition is in preset range is judged, if meeting starting air quantity control condition, then do not adjust air quantity control in starting process;S4, determine that starting air quantity needs to be corrected, and make correction to starting air quantity value according to each condition.The application also discloses a kind of hybrid vehicle engine starting control device and computer system, the application can optimize control to starting process when the abnormality of engine starting performance appears, and can be widely applied in engine control field.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of engine control, in particular to a hybrid vehicle engine starting control method, device and computer system. BACKGROUND

[0002] Studies have shown that the engine emission is extremely large during the starting process. The starting time needs to be controlled within a specified range during the starting process, while ensuring the smoothness of the speed during the starting process, and taking into account the emission and reducing the impact on the environment.

[0003] Therefore, many manufacturers have made their own attempts in this regard, and typical cases are as follows:

[0004] 1. An invention application with the publication number CN108757196A and the invention name of "a starting control system and method of vehicle engine", which improves the NVH of starting by determining the set speed of starting injection. However, the deficiency is also obvious throughout the text. The invention does not comprehensively consider the starting time, and the consideration of starting performance indicators may cause the starting time to be too long, and the customers may complain about the starting time. Moreover, it does not specifically propose how to determine the set speed of starting injection.

[0005] 2. An invention patent with the publication number CN111946474B and the invention name of "direct injection gasoline engine starting control method", which records real-time monitoring of engine starting condition parameters. From the perspective of improving NVH, it determines the starting injection cylinder according to different conditions and system capacity, and sets the injection amount and angle of the intake and compression strokes, and the control of ignition timing after determining the starting injection cylinder, which improves the PN and COV of the starting process. However, the patent does not consider the smoothness of the engine speed and intelligent optimization control during the engine starting process. There are still deficiencies in the comprehensive control and management of the engine.

[0006] Based on the above situation, the industry urgently needs to invent a hybrid vehicle engine starting control method and device. SUMMARY

[0007] The purpose of the present application is to overcome the deficiencies of the above background art, and to provide a hybrid vehicle engine starting control method, device and computer system, which monitors the performance of the engine starting process under different conditions, judges whether the engine starting performance is abnormal according to the performance, and optimizes the control of the starting process when the performance is abnormal.

[0008] The present invention provides a starting control method for a hybrid electric vehicle engine, comprising the following steps: S1, determining the starting air volume optimization conditions to ensure that the vehicle can be completely stopped for a relatively long period of time without affecting the engine's starting performance next time; S2, if the starting air volume optimization conditions are met, recording and determining the starting optimization control condition; S3, determining whether the starting optimization control condition is within the preset range, and if the starting air volume control conditions are met, not adjusting the air volume control during the starting process; S4, determining that the starting air volume needs to be corrected, and correcting the starting air volume value according to various situations.

[0009] In the above technical solution, the specific process of step S1 is as follows: S11, the vehicle immersion time exceeds the preset immersion time threshold, but the vehicle immersion time is not greater than the maximum preset immersion time; S12, the temperature deviation between all temperature sensors on the vehicle and the ambient temperature is less than the preset temperature value; S13, before the previous engine stopped, the EGR did not exceed the first preset activation time, ensuring that there is no residual exhaust gas in the cylinder when the engine stops, so as not to affect the engine's starting performance next time;

[0010] S14. Before the previous engine was stopped, the carbon canister did not exceed the second activation preset time to ensure that there is less fuel vapor in the cylinder when the engine is stopped, so as not to affect the engine’s starting performance next time.

[0011] S15. The engine fuel octane rating was not updated in the previous driving cycle to avoid the impact of fuel octane rating updates on the optimization of starting parameters in this cycle; S16. When the engine speed was lower than the preset engine speed in the previous driving cycle, the engine long-term fuel correction coefficient was not updated to avoid the impact of long-term fuel correction on the optimization of starting parameters in this cycle; S17. The time interval t1 from the start of engine fuel injection to the starter motor disengagement exceeds the first preset value to ensure that the starter motor provides sufficient starting assistance during engine starting.

[0012] In the above technical solution, the specific process of step S2 is as follows: S21, under the premise that the starting air volume optimization conditions are met, record the engine starting water temperature T. CoolantStart Atmospheric pressure p during startup Ambient Record the moment the engine starts injecting fuel, record the moment the starter motor disengages, and record the cylinder number (Cnt) of the engine's first fuel injection. CylinderID Record the battery voltage V1 and SOC1 at the moment the engine starts injecting fuel; read the time interval t1 from the moment the engine starts injecting fuel to the moment the starter disengages; and read the change in engine speed Δn from the moment the engine starts injecting fuel to the moment the starter disengages. Starter 1. Read the time t2 from when the engine starts injecting fuel until the speed rises to the preset speed; 2. Read the engine speed n at the moment the engine and starter disengage. StarterDisengaged1. Read the number of times the rate of change of speed (Cnt) is lower than the preset rate of change from the moment the starter disengages until the preset speed is reached; 2. Read the maximum speed surge (n) during the starting process. StartMax S22. Read parameters such as the time t3 from when the engine speed reaches its maximum speed until it drops back down; CoolantStart p Ambient Battery voltage V1 at the moment the engine starts fuel injection; Battery SOC1 at the moment the engine starts fuel injection; Cnt of the cylinder for the first fuel injection. CylinderID Time interval t1, and change in engine speed Δn Starter As the starting optimization control condition; S23, record t2, t3, Cnt, and n under the starting optimization control condition respectively. StarterDisengaged and n StartMax t2, t3, Cnt, n under the same working condition StarterDisengaged and n StartMax Store it, and record the number of times it is recorded.

[0013] In the above technical solution, in step S22, when determining the stability of the operating condition parameters, parameter T... CoolantStart When the fluctuation is within ±0.5℃, the parameter T is considered to be... CoolantStart Same; p Ambient Fluctuations within ±0.3 kPa are considered the same parameter; fluctuations within ±1 V in battery voltage V1 are considered the same parameter; fluctuations within ±2% in battery SOC1 are considered the same parameter; fluctuations within ±0.08 s in time interval t1 are considered the same parameter; and changes in engine speed Δn are also considered the same parameter. Starter The parameter is considered to be the same when the fluctuation is within ±15 rpm.

[0014] In the above technical solution, the specific process of step S3 is as follows: S31, if Cnt equals 0, and n StarterDisengaged and n StartMax All are within a preset range, which is determined by the starting water temperature T. CoolantStart and starting atmospheric pressure p Ambient Together, we decide that, based on the aforementioned conditions, we record the values ​​of t2 and t3. If the conditions are met multiple times, we take the average value to obtain t2. Avg_m and t3 Avg_m Where m is the cylinder number, t2 Avg_m and t3 Avg_m Stored as a standard time and continuously updated, the gas volume control during startup is not adjusted in this case; S32, if Cnt equals 0, and n StarterDisengaged and n StartMax None of them are affected by the starting water temperature T CoolantStart and starting atmospheric pressure pAmbient If the preset range is not met, the air amount control during the starting process is not adjusted, and the average value t2 is not calculated Avg_m and t3 Avg_m .

[0015] In the above technical solution, the specific process of step S4 is as follows: S41, when Cnt is equal to 1 and the number of occurrences of Cnt exceeds a preset number of times, during the next starting process, attempt to delay fuel injection, and check whether it can improve Cnt to 0; if Cnt can be improved to 0 after delaying fuel injection, then in the subsequent working conditions corresponding to the starting optimization control, the cylinder number that delays fuel injection is used for the first fuel injection; if Cnt cannot be improved to 0 after delaying fuel injection, then in the subsequent working conditions corresponding to the starting optimization control, the original fuel injection cylinder number is used for the first fuel injection, and fuel injection is delayed once in each working condition; S42, when Cnt is equal to 2, and |t2-t2 Avg_m |<k1×Δc1, and |t3 Avg_m -t3|<k2×Δc2, and |n StartMaxNominal -n StartMax |<k3×Δc3, where Δc1 and Δc2 are time parameters, Δc3 is an engine speed parameter, k1, k2, and k3 are positive real number parameters, and the air amount during the starting process is controlled as follows: rho DsrdStart =rho DsrdStartRaw ×f1(Cnt CombStart ,T Coolant ), where rho DsrdStartRaw is the starting air amount updated last time or the starting air amount of the existing prior art without updating for the first time, Cnt CombStart is the number of engine starting combustion, T Coolant is the real-time water temperature of the engine; S43, when Cnt is greater than 2, and t2-t2 Avg_m >Δc1, and t3 Avg_m -t3>Δc2, and n StartMaxNominal -n StartMax >Δc3, at this time, the starting air amount control during the starting process is not adjusted, and the starting air amount control during the starting process is further optimized, and the optimization method is as follows: rho DsrdStart =rho DsrdStartRaw ×f2(Cnt CombStart ,T Coolant ), where f2(Cnt CombStart ,T Coolant ) is not less than f1(Cnt CombStart ,T Coolant ); S44, when Cnt is greater than 2, and t2-t2 Avg_m <-Δc1, and t3 Avg_m -t3<-Δc2, and n StartMaxNominal-n StartMax <-Δc3, at this time, the air amount control in the starting process is not adjusted, the air amount control in the starting process will be further optimized, and the optimization method is as follows: rho DsrdStart =rho DsrdStartRaw ×f3(Cnt CombStart ,T Coolant ), wherein f3(Cnt CombStart ,T Coolant ) is not greater than f1(Cnt CombStart ,T Coolant ).

[0016] In the above technical solution, in step S41, the method of delaying fuel injection is as follows: assuming that the current first fuel injection cylinder number is m, the next time the fuel injection cylinder number is the cylinder number of the second fuel injection, that is, the cylinder number of the first fuel injection is interrupted, and the cylinder number of the second fuel injection is used as the cylinder number of the first fuel injection for fuel injection.

[0017] The application further provides a hybrid vehicle engine starting control device comprising a computer program, wherein the computer program can execute the hybrid vehicle engine starting control method.

[0018] The application further provides a computer system comprising the hybrid vehicle engine starting control device.

[0019] The hybrid vehicle engine starting control method, device and computer system have the following beneficial effects: during the engine starting process, the engine characteristic parameters are monitored in real time, the starting air amount is optimized according to the abnormal engine speed, and the starting performance, emission and NVH effect are improved. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 It is a whole flowchart of the hybrid vehicle engine starting control method of the application;

[0021] Figure 2 It is a flowchart of step S1 in the hybrid vehicle engine starting control method of the application;

[0022] Figure 3 It is a flowchart of step S2 in the hybrid vehicle engine starting control method of the application;

[0023] Figure 4 It is a flowchart of step S3 in the hybrid vehicle engine starting control method of the application;

[0024] Figure 5 It is a flowchart of step S4 in the hybrid vehicle engine starting control method of the application;

[0025] Figure 6 Structure diagram of the hybrid vehicle engine start control device of the present application;

[0026] Figure 7 Structure diagram of the computer system of the present application;

[0027] Figure 8 Technical principle diagram of the hybrid vehicle engine start control method, device and computer system of the present application. DETAILED DESCRIPTION

[0028] The present application will be further described in detail below in conjunction with the accompanying drawings and embodiments, but the embodiments should not be understood as limiting the present application.

[0029] Referring to Figure 1 The hybrid vehicle engine start control method of the present application comprises the following steps:

[0030] S1, determining a start air quantity optimization condition to ensure that the vehicle is completely stopped for a long time without affecting the next engine start performance, and the specific process of the step S1 is as follows:

[0031] This is a condition judgment to ensure that the vehicle is completely stopped for a long time, and the cylinder is relatively clean, i.e.:

[0032] Referring to Figure 2 S11, the vehicle immersion time exceeds a preset time threshold, and the present example takes 8 hours, but the vehicle immersion time is not longer than the longest immersion preset time, and the present example takes 120 hours;

[0033] S12, all temperature sensors (such as intake temperature, engine water temperature, oil temperature, etc.) on the vehicle are less than a temperature preset value from the atmospheric temperature deviation, and the present example takes 0.5℃;

[0034] S13, before the last engine stop, the EGR does not exceed a first activation preset time, and the first activation preset time of the present example is less than 2s, to ensure that there is no residual exhaust gas in the cylinder when the engine is stopped, and the next engine start performance is not affected;

[0035] S14, before the last engine stop, the carbon tank does not exceed a second activation preset time, and the second activation preset time of the present example is less than 0.5s, to ensure that there is less fuel vapor in the cylinder when the engine is stopped, and the next engine start performance is not affected;

[0036] S15, within the last driving cycle, the engine fuel octane rating is not updated; to avoid the influence of the update of the octane rating of the fuel on the optimization of the start parameters this time;

[0037] S16, in the last driving cycle, the engine long-term fuel correction coefficient is not updated when the engine speed is lower than the preset engine speed. The preset engine speed is not more than 2000 rpm. Since the engine speed during starting is not more than 2000 rpm, it is only necessary to ensure that the long-term fuel correction is not updated at low speed, thereby avoiding the influence of the long-term fuel correction on the optimization of the starting parameters this time;

[0038] S17, the time interval t1 from the time when the engine starts to inject fuel to the time when the starter is disengaged is greater than the first preset time value. In this example, the first preset time value is 0.5 s. That is, it is necessary to ensure that the starter provides sufficient starting assistance during the engine starting process.

[0039] S2, if the starting air quantity optimization condition is met, record and determine the starting optimization control condition. The specific process of step S2 is as follows:

[0040] Referring to Figure 3 , S21, under the premise that the above conditions of step S1 are met, record the engine starting water temperature T CoolantStart , the atmospheric pressure p Ambient during starting, record the time when the engine starts to inject fuel, record the time when the starter is disengaged, record the cylinder number Cnt CylinderID of the first fuel injection of the engine, record the battery voltage V1 and SOC1 at the time when the engine starts to inject fuel, read the time interval t1 from the time when the engine starts to inject fuel to the time when the starter is disengaged, read the engine speed rising change amount Δn Starter from the time when the engine starts to inject fuel to the time when the engine speed rises to the preset speed (750 rpm in this example), read the engine speed n StarterDisengaged at the time when the starter is disengaged, read the number Cnt of times when the speed change rate is lower than the preset change rate (15 rpm / s in this example) during the process from the time when the starter is disengaged to the time when the speed rises to the preset speed (750 rpm in this example), read the maximum speed n StartMax during starting, read the time t3 from the time when the engine speed rises to the maximum speed to the time when the speed falls (the speed falling can be monitored by the speed change rate, that is, the speed change rate is negative, and the absolute value exceeds the preset value, which is -100 rpm / s in this example);

[0041] S22, the parameters T CoolantStart , p Ambient , the battery voltage V1 at the time when the engine starts to inject fuel, the battery SOC1 at the time when the engine starts to inject fuel, the cylinder number Cnt CylinderID of the first fuel injection of the engine, the time interval t1, the engine speed rising change amount Δn StarterThis is the operating condition for optimized starting control. It should be noted that, since the operating condition parameters cannot be exactly the same, parameter T will be adjusted during the engineering development process. CoolantStart When the fluctuation is within ±0.5℃, the parameter T is considered to be... CoolantStart Same; p Ambient Fluctuations within ±0.3 kPa are considered the same parameter; fluctuations within ±1 V in battery voltage V1 are considered the same parameter; fluctuations within ±2% in battery SOC1 are considered the same parameter; fluctuations within ±0.08 s in time interval t1 are considered the same parameter; and changes in engine speed Δn are also considered the same parameter. Starter When the fluctuation is within ±15 rpm, the parameter is considered to be the same;

[0042] S23. Record the operating conditions of the start-up optimization control (T) CoolantStart p Ambient Cnt CylinderID V1, SOC1, t1, Δn Starter ) under t2, t3, Cnt, n StarterDisengaged and n StartMax Under the same working condition (T) CoolantStart p Ambient Cnt CylinderID V1, SOC1, t1, Δn Starter ) under t2, t3, Cnt, n StarterDisengaged and n StartMax Store it, and record the number of times it is recorded.

[0043] S3. Determine whether the start-up optimized control condition is within the preset range. If the start-up air volume control condition is met, then the air volume control during the start-up process is not adjusted. The specific process of step S3 is as follows:

[0044] See Figure 4 S31. If Cnt equals 0, and n StarterDisengaged Within the preset range (290 rpm and 310 rpm in this example), and n StartMax Within a preset range, the preset range is determined by the starting water temperature T. CoolantStart and starting atmospheric pressure p Ambient In this embodiment, S311, based on the starting water temperature T, is determined jointly. CoolantStart and starting atmospheric pressure p Ambient Together, determine the standard value n for the speed surge to the maximum speed during its starting process. StartMaxNo minal The final preset range is within the standard value n. StartMaxNominal Within ±100 rpm, see the table below for details:

[0045]

[0046] S312, after the above conditions are met, the values of t2 and t3 are recorded, and if the conditions are met for multiple times (the number of times exceeds a preset number, in this example, the number of times exceeds 50; if the number of times is less than 50, the start control optimization is not performed), the average value of t2 is obtained Avg_m and t3 Avg_m (m is the cylinder number of the cylinder), which is stored as a standard time and is constantly updated;

[0047] S3121, in particular, assuming that the number of cylinders of the engine is N, t2 and t3 of the cylinder far from the center axis of the engine are greater than t2 and t3 of the cylinder close to the center axis of the cylinder, if an individual abnormal situation occurs, t2 and t3 in the abnormal situation are removed. For example, assuming that the number of cylinders of the engine is 4, two cylinders are on one side of the center axis of the engine, and two cylinders are on the other side of the center axis of the engine, the cylinders on one side can be defined as cylinder 1 and cylinder 2 (and cylinder 1 is farther from the center axis of the engine), and the cylinders on the other side can be defined as cylinder 3 and cylinder 4 (and cylinder 4 is farther from the center axis of the engine), then cylinders 2 and 3 are closest to the center axis of the cylinder, and cylinders 1 and 4 are farther from the center axis of the cylinder, then either t2 and t3 corresponding to cylinders 1 and 4 are greater than t2 and t3 corresponding to cylinders 2 and 3, or t2 and t3 corresponding to cylinders 1 and 4 are less than t2 and t3 corresponding to cylinders 2 and 3, t2 and t3 that do not meet the rules are removed and are not used for average calculation;

[0048] In this case, the air amount control in the starting process is not adjusted at this time;

[0049] S32, if Cnt is equal to 0, but other conditions do not meet the first condition, the air amount control in the starting process is not adjusted, and the average value t2 is not calculated Avg_m and t3 Avg_m .

[0050] S4, it is determined that the starting air amount needs to be corrected, and the starting air amount value is corrected according to different situations, and the specific process of the step S4 is as follows:

[0051] Referring to Figure 5, S41, once Cnt equals 1, and the number of times Cnt exceeds the preset number (3 times in this example), the next time the process is started, the fuel injection is delayed, and it is checked whether it can be improved to Cnt = 0; the method of delaying fuel injection is: assuming that the current first fuel injection cylinder number is m, the next time the fuel injection cylinder number is the cylinder number that should be the second fuel injection, that is, the cylinder number that should be the first fuel injection is treated as fuel cut, and the cylinder number that should be the second fuel injection is used as the cylinder number for the first fuel injection; if the fuel injection is delayed and Cnt can be improved to 0, then in the subsequent start-up optimization control conditions (T CoolantStart , p Ambient , Cnt CylinderID , V1, SOC1, t1, Δn Starter ) the cylinder number for the first fuel injection is delayed, if the fuel injection is delayed and Cnt cannot be improved to 0, then in the subsequent start-up optimization control conditions (T CoolantStart , p Ambient , Cnt CylinderID , V1, SOC1, t1, Δn Starter ) the original fuel injection cylinder number is used for the first fuel injection, the fuel injection is delayed to allow one attempt in each condition, regardless of whether the attempt can improve Cnt to 0, only one fuel injection is delayed, and the fuel injection delay time is too long, which will cause the engine start-up time to be prolonged, resulting in high start-up emissions;

[0052] S42, when Cnt equals 2, and |t2-t2 Avg_m | < k1 x Δc1, and |t3 Avg_m -t3| < k2 x Δc2, and |n StartMaxNominal -n StartMax | < k3 x Δc3, where Δc1 is 0.8s, Δc2 is 0.5s, Δc3 is 200rpm, k1 is 0.5, k2 is 0.5, and k3 is 0.5, which indicates that at this time, the speed abnormal fluctuation occurs twice during the speed start-up process, but other parameters are relatively stable and normal, at this time the air volume is not sufficient, the air volume during the start-up process is optimized and controlled, and the optimization method is as follows:

[0053] rho DsrdStart = rho DsrdStartRaw x f1(Cnt CombStart , T Coolant ),

[0054] The example is shown in the following table:

[0055]

[0056] f1(Cnt C o mbStart , T C oo lant) parameters will be saved after the vehicle power off,

[0057] wherein rho DsrdStartRaw is the starting air quantity of the last optimization update (the first time is the existing prior art starting air quantity), Cnt CombStart is the number of engine starting combustion, T Coolant is the real-time water temperature of the engine;

[0058] S43, when Cnt is greater than 2, and t2-t2 Avg_m >Δc1, and t3 Avg_m -t3>Δc2, and n StartMaxNominal -n StartMax >Δc3, it means that the speed abnormal fluctuation occurs twice during the speed starting process, but the speed overshoot performance during the starting process is also poor, at this time, the air quantity control during the starting process is not adjusted, and the air quantity control during the starting process is further optimized, and the optimization method is as follows:

[0059] rho DsrdStart = rho DsrdStartRaw ×f2(Cnt CombStart ,T Coolant ),

[0060] and f2(Cnt CombStart ,T Coolant ) is not less than f1(Cnt CombStart ,T Coolant ),

[0061] See the following table for example:

[0062]

[0063] f2(Cnt CombStart ,T Coolant ) parameters will be saved after the vehicle power off,

[0064] S44, when Cnt is greater than 2, and t2-t2 Avg_m <-Δc1, and t3 Avg_m -t3<-Δc2, and n StartMaxNominal -n StartMax <-Δc3, it means that the speed abnormal fluctuation occurs twice during the speed starting process, but the speed overshoot performance during the starting process is also poor, at this time, the air quantity control during the starting process is not adjusted, and the air quantity control during the starting process is further optimized, and the optimization method is as follows:

[0065] rho DsrdStart = rho DsrdStartRaw ×f3(Cnt CombStart ,T Coolant )

[0066] And f3(Cnt) CombStart ,T Coolant ) is not greater than f1(Cnt) CombStart ,T Coolant ),

[0067] See the table below for examples:

[0068]

[0069]

[0070] f3(Cnt CombStart ,T Coolant The parameters will be saved after the vehicle is powered off.

[0071] The above f1(Cnt) CombStart ,T Coolant f2(Cnt) CombStart ,T Coolant ) and f3(Cnt CombStart ,T Coolant The system saves the data after power-down. If the engine mileage under start-up control optimization exceeds the preset mileage (30,000 km in this example), or if the engine downtime exceeds 240 hours, all three parameters will be reset to 1. After the reset, the engine mileage under start-up control optimization will be 0, and the calculation will start again.

[0072] The above is a complete description of the engine starting control method for hybrid electric vehicles.

[0073] See Figure 6 The present invention relates to a hybrid electric vehicle engine starting control device, comprising the following parts:

[0074] Air volume optimization determination module: Determines the start-up air volume optimization conditions to ensure that the engine's start-up performance is not affected even if the entire vehicle is completely stopped for a long period of time.

[0075] Start-up optimization determination module: If the start-up air volume optimization conditions are met, the start-up optimization control conditions are recorded and determined.

[0076] Start-up optimization judgment module: Determines whether the start-up optimization control conditions are within the preset range. If the start-up air volume control conditions are met, the air volume control during the start-up process will not be adjusted.

[0077] Starting air volume correction module: Determines whether the starting air volume needs correction and corrects the starting air volume value according to various situations.

[0078] See Figure 7 The present invention relates to a computer system, which includes a hybrid vehicle engine start control device.

[0079] Referring to Figure 8 The technical key points and technical principles of the present application are as follows:

[0080] Start-up optimization condition determination;

[0081] Start-up air volume optimization specific implementation method.

[0082] The beneficial effects brought by the technical scheme of the present application are as follows:

[0083] During the engine starting process, the engine characteristic parameters are monitored in real time, and the starting air volume is optimized according to the abnormal situation of the engine speed, so as to improve the starting performance, emission and NVH effect.

[0084] Obviously, those skilled in the art can make various modifications and variations to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application belong to the scope of the claims of the present application and their equivalent technologies, the present application also intends to include these modifications and variations.

[0085] The contents not described in detail in the specification belong to the prior art known to those skilled in the art.

Claims

1. A hybrid vehicle engine start control method characterized by: The method comprises the following steps: S1, determining a starting air volume optimization condition to ensure that the vehicle is completely stopped for a long time without affecting the performance of the next engine start; S2, if the starting air volume optimization condition is met, recording and determining a starting optimization control condition, and the specific process of step S2 is as follows: S21, record engine start water temperature T CoolantStart , atmospheric pressure p Ambient , record engine start fuel injection time, record starter disengagement time, record engine first fuel injection cylinder number Cnt CylinderID , record battery voltage V1 and SOC1 at engine start fuel injection time, read time interval t1 from engine start fuel injection to starter disengagement, read engine speed rise change amount Δn from engine start fuel injection time to starter disengagement Starter , read time t2 from engine start fuel injection until speed rises to preset speed, read engine speed n at engine and starter disengagement time StarterDisengaged , read number Cnt of times speed change rate is below preset change rate during speed rise from starter disengagement time to preset speed, read maximum speed n of speed overshoot during starting StartMax , read time t3 from engine speed overshoot to maximum speed time to speed fall back S22, the parameter T CoolantStart , p Ambient , the battery voltage V1 at the engine start injection time, the battery SOC1 at the engine start injection time, the cylinder number Cnt of the first engine injection CylinderID , the time interval t1, the engine speed rise change Δn Starter as a starting optimization control condition; S23, record t2, t3, Cnt, n respectively under the working condition of starting optimization control StarterDisengaged and n StartMax Store t2, t3, Cnt, n under the same working condition StarterDisengaged and n StartMax and store the number of records thereof; S3, determining whether the starting optimization control condition is within a preset range, if the starting air volume control condition is met, the air volume control in the starting process is not adjusted, and the specific process of step S3 is as follows: S31, if Cnt equals 0, and n StarterDisengaged and n StartMax are within a preset range, which is determined by the starting water temperature T CoolantStart and the starting atmospheric pressure p Ambient , on the basis of meeting the aforementioned conditions, the values of t2 and t3 are recorded, and if the conditions are met multiple times, the average value is taken to obtain t2 Avg_m and t3 Avg_m , where m is the cylinder number, t2 Avg_m and t3 StarterDisengaged are stored as standard times and are constantly updated, and in this case the air quantity control during starting is not adjusted; S32, if Cnt is equal to 0, and n StarterDisengaged and n StartMax are not both within a preset range determined by the start water temperature T CoolantStart and the start atmospheric pressure p Ambient , then the air amount control during the start process is not adjusted, and the average values t2 Avg_m and t3 Avg_m are not calculated. S4, determining that the starting air volume needs to be corrected, and correcting the starting air volume value according to various conditions, and the specific process of step S4 is as follows: S41, when Cnt is equal to 1 and the number of times that Cnt appears exceeds a preset number of times, in the next starting process, the oil injection is delayed, and it is checked whether Cnt can be improved to 0; if the oil injection is delayed, Cnt can be improved to 0, then in the subsequent starting optimization control condition, the cylinder number of the delayed oil injection is used for the first oil injection, if the oil injection is delayed, Cnt cannot be improved to 0, then in the subsequent starting optimization control condition, the original oil injection cylinder number is used for the first oil injection, and the oil injection delay is tried once in each condition; S42, when Cnt is equal to 2, and |t2-t2 Avg_m |<k1 x Δc1, and |t3 Avg_m -t3|<k2 x Δc2, and |n StartMaxNominal -n StartMax |<k3 x Δc3, wherein Δc1 and Δc2 are time parameters, Δc3 is an engine speed parameter, k1, k2 and k3 are positive real parameters, the air quantity during the starting process is controlled as follows: rho DsrdStart = rho DsrdStartRaw × f1(Cnt CombStart , T Coolant ), wherein, rho DsrdStartRaw is the start air amount of the last optimization update or the start air amount of the existing known technology that is not updated for the first time, Cnt CombStart is the number of engine start combustion, T Coolant is the real-time water temperature of the engine; S43, when Cnt is greater than 2, and t2-t2 Avg_m >Δc1, and t3 Avg_m -t3>Δc2, and n StartMaxNominal - n StartMax >Δc3, at this time, the air quantity control in the starting process is not adjusted, the air quantity control in the starting process will be further optimized, and the optimization method is as follows: rho DsrdStart = rho DsrdStartRaw × f2(Cnt CombStart , T Coolant ), wherein f2(Cnt CombStart ,T Coolant ) is not less than f1(Cnt CombStart ,T Coolant ). S44, when Cnt is greater than 2, and t2-t2 Avg_m <-Δc1, and t3 Avg_m -t3<-Δc2, and n StartMaxNominal -n StartMax <-Δc3, at this time, the air quantity control in the starting process is not adjusted, the air quantity control in the starting process will be further optimized, and the optimization method is as follows: rho DsrdStart = rho DsrdStartRaw × f3(Cnt CombStart , T Coolant ), wherein f3(Cnt CombStart ,T Coolant ) is not greater than f1(Cnt CombStart ,T Coolant ).

2. The hybrid vehicle engine start control method according to claim 1, characterized by: The specific process of step S1 is as follows: S11, the vehicle immersion time exceeds a preset immersion time threshold, but the vehicle immersion time is not greater than a longest preset immersion time; S12, all temperature sensors on the vehicle have a temperature deviation from the atmospheric temperature less than a preset temperature value; S13, before the last engine stop, the EGR does not exceed a first activation preset time, ensuring that there is no residual exhaust gas in the cylinder when the engine is stopped, and the performance of the next engine start is not affected; S14, before the last engine stop, the carbon canister does not exceed a second activation preset time, ensuring that there is less fuel vapor in the cylinder when the engine is stopped, and the performance of the next engine start is not affected; S15, in the last driving cycle, the engine fuel product octane number is not updated, avoiding the influence of the update of the fuel product octane number on the optimization of the starting parameters this time; S16, in the last driving cycle, when the engine speed is lower than a preset engine speed, the engine long-term fuel correction coefficient is not updated, avoiding the influence of the long-term fuel correction on the optimization of the starting parameters this time; S17, the time interval t1 from the start of the engine oil injection to the moment when the starter is disconnected exceeds a first time preset value, ensuring that the starter fully provides starting assistance during the engine starting process.

3. The hybrid vehicle engine start control method according to claim 2, characterized by: In step S22, when determining the stability of the operating condition parameters, parameter T... CoolantStart When the fluctuation is within ±0.5℃, the parameter T is considered to be... CoolantStart Same; p Ambient Fluctuations within ±0.3 kPa are considered the same parameter; fluctuations within ±1 V in battery voltage V1 are considered the same parameter; fluctuations within ±2% in battery SOC1 are considered the same parameter; fluctuations within ±0.08 s in time interval t1 are considered the same parameter; and changes in engine speed Δn are also considered the same parameter. Starter The parameter is considered to be the same when the fluctuation is within ±15 rpm.

4. The hybrid vehicle engine start control method according to claim 3, characterized by: In step S41, the method of delaying oil injection is as follows: assuming that the current first oil injection cylinder number is m, the next oil injection cylinder number is the cylinder number that should be the second oil injection, that is, the cylinder number that should be the first oil injection is interrupted, and the cylinder number that should be the second oil injection is used as the cylinder number for the first oil injection.

5. A hybrid vehicle engine start control device characterized by comprising: The computer program can execute the hybrid vehicle engine starting control method according to any one of claims 1-4.

6. A computer system, characterized by: The computer system comprises the hybrid vehicle engine starting control device according to claim 5.

Images