Vehicle control method, control device and vehicle

Abstract

The present application provides a vehicle control method, a control device and a vehicle. The vehicle includes an engine and a fuel system for providing methanol fuel to the engine; the control method includes: when the engine is in operation, obtaining the fuel correction coefficient of the fuel system in real time, and adjusting the fuel injection amount of the fuel system so that the actual excess air coefficient of the engine approaches the target excess air coefficient; wherein the fuel correction coefficient is positively correlated with the difference between the actual excess air coefficient and the target excess air coefficient; according to the fuel correction coefficient, determining whether the fuel system is operating abnormally. In the process of adjusting the fuel injection amount of the fuel system, different fuel qualities will have different effects on the change of the fuel correction coefficient. Judging whether the fuel correction coefficient is operating abnormally can realize real-time monitoring of the vehicle operation, thereby monitoring the operation abnormality caused by methanol fuel quality problems, which is conducive to optimizing the safety performance of the vehicle.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicles, and in particular to a vehicle control method, a vehicle control device and a vehicle. Background Art

[0002] Methanol fuel, as a carrier of hydrogen, is a green fuel with a wide range of applications. At present, the quality assurance measures and quality inspection technologies for methanol fuel in production, transportation, and refueling are still in the process of continuous improvement, and the quality of methanol fuel cannot be strictly guaranteed, resulting in uneven quality of methanol fuel on the market. The risk of vehicle failures such as engine cylinder poking, cylinder pulling, valve wear or erosion, cylinder gasket wear, and post-processing ablation caused by methanol fuel quality problems cannot be ignored. The safety risks of vehicle driving also hinder the promotion and application of methanol fuel.

[0003] To solve the above problems, the related technology marks the location of methanol filling stations with qualified quality and obtains the vehicle location in real time to determine whether the vehicle is filled with methanol within the specified location range, so as to basically control the methanol instructions filled by the vehicle. However, the related technology cannot realize real-time monitoring of the quality of methanol fuel that has been filled in the vehicle, and cannot accurately determine whether the vehicle will have a fault caused by methanol fuel quality problems during operation. Summary of the invention

[0004] The present application provides a vehicle control method, a control device and a vehicle, so as to timely monitor the operation abnormality caused by the quality problem of methanol fuel, thereby optimizing the safety of vehicles using methanol fuel.

[0005] The present application provides a control method for a vehicle, the vehicle comprising an engine and a fuel system for providing methanol fuel to the engine; the control method comprises: when the engine is in operation, obtaining a fuel correction coefficient of the fuel system in real time, and adjusting the fuel injection amount of the fuel system so that the actual excess air coefficient of the engine approaches a target excess air coefficient; wherein the fuel correction coefficient is positively correlated with the difference between the actual excess air coefficient and the target excess air coefficient; and determining whether the fuel system is operating abnormally based on the fuel correction coefficient.

[0006] Optionally, determining whether the fuel system is operating abnormally is based on the fuel correction coefficient, including: when the absolute value of the fuel correction coefficient is less than or equal to a first coefficient threshold, determining that the fuel system is operating normally; when the absolute value of the fuel correction coefficient is greater than the first coefficient threshold, obtaining a first operating parameter of the fuel system, and determining whether the fuel system is operating abnormally based on the first operating parameter.

[0007] Optionally, the first operating parameter includes the cumulative oxygen consumption of the fuel system when the absolute value of the fuel correction coefficient is maintained greater than the first coefficient threshold value; determining whether the fuel system is operating abnormally based on the first operating parameter includes: when the cumulative oxygen consumption is greater than or equal to the first consumption threshold value, determining that the fuel system is operating abnormally; when the cumulative oxygen consumption is less than the first consumption threshold value, determining that the fuel system is operating normally.

[0008] Optionally, the first operating parameter includes a duration during which the absolute value of the fuel correction coefficient is greater than a first coefficient threshold; determining whether the fuel system is operating abnormally based on the first operating parameter includes: when the duration is greater than or equal to the first duration threshold, determining that the fuel system is operating abnormally; when the duration is less than the first duration threshold, determining that the fuel system is operating normally.

[0009] Optionally, after determining whether the fuel system is operating abnormally according to the fuel correction coefficient, the method further includes: when it is determined that the fuel system is operating abnormally, determining an engine protection strategy according to the fuel correction coefficient; the engine protection strategy includes controlling the engine to reduce output power or controlling the engine to shut down.

[0010] Optionally, an engine protection strategy is determined based on a fuel correction coefficient, including: when the absolute value of the fuel correction coefficient is less than a second coefficient threshold, determining that the engine protection strategy is to control the engine to reduce output power; when the absolute value of the fuel correction coefficient is greater than or equal to the second coefficient threshold, obtaining a second operating parameter of the fuel system, and based on the second operating parameter, determining that the engine protection strategy is to control the engine to reduce output power or to control the engine to shut down; wherein the second coefficient threshold is greater than the first coefficient threshold.

[0011] Optionally, the second operating parameter includes the cumulative oxygen consumption of the fuel system when the absolute value of the fuel correction coefficient is maintained greater than or equal to a second coefficient threshold value; based on the second operating parameter, the engine protection strategy is determined to be controlling the engine to reduce output power or controlling the engine to shut down, including: when the cumulative oxygen consumption is less than the second consumption threshold value, determining the engine protection strategy is to control the engine to reduce output power; when the cumulative oxygen consumption is greater than or equal to the second consumption threshold value, determining the engine protection strategy is to control the engine to shut down.

[0012] Optionally, the second operating parameter includes the duration during which the absolute value of the fuel correction coefficient is greater than a second coefficient threshold; based on the second operating parameter, the engine protection strategy is determined to be controlling the engine to reduce output power or controlling the engine to shut down, including: when the duration is less than the second duration threshold, determining the engine protection strategy is to control the engine to reduce output power; when the duration is greater than or equal to the second duration threshold, determining the engine protection strategy is to control the engine to shut down.

[0013] Optionally, when the engine protection strategy is determined to control the engine to reduce the output power, after determining the engine protection strategy according to the fuel correction coefficient, it also includes: determining the engine's torque limit coefficient according to the fuel correction coefficient; taking the product of the torque limit coefficient and the current maximum torque of the engine as the target torque; taking the target torque as the maximum torque allowed for the engine to run; wherein the torque limit coefficient is less than 1 and greater than or equal to 0, and the torque limit coefficient is negatively correlated with the absolute value of the fuel correction coefficient.

[0014] Optionally, after determining whether the fuel system is operating abnormally according to the fuel correction coefficient, the method further includes: if it is determined that the fuel system is operating abnormally, determining a fault condition of the fuel system according to the fuel correction coefficient; and providing a fault prompt according to the fault condition.

[0015] Optionally, the vehicle includes an oxygen sensor, which is used to obtain the actual excess air coefficient of the engine; adjust the fuel injection amount of the fuel system, including: obtaining the exhaust temperature of the engine; when the exhaust temperature is greater than or equal to the dew point temperature, controlling the heating of the oxygen sensor; after the oxygen sensor is heated to the target temperature, adjusting the fuel injection amount of the fuel system.

[0016] Optionally, adjusting the fuel injection amount of the fuel system includes: reducing the fuel injection amount of the fuel system when the fuel correction coefficient indicates that the difference between the actual excess air coefficient and the target excess air coefficient is less than 0; and increasing the fuel injection amount of the fuel system when the fuel correction coefficient indicates that the difference between the actual excess air coefficient and the target excess air coefficient is greater than 0.

[0017] Optionally, after adjusting the fuel injection amount of the fuel system, it also includes: when the fuel correction coefficient reaches the upper threshold or the lower threshold, and the absolute value of the difference between the actual excess air coefficient of the engine and the target excess air coefficient is greater than the difference threshold, determining that the fuel system is abnormal. Optionally, it also includes: detecting whether the vehicle currently has other faults other than the abnormal operation of the fuel system; if there are other faults, controlling the engine to reduce output power or control the engine to stop according to the fault type of the other fault.

[0018] The present application provides a vehicle control device, including one or more processors, for implementing the above-mentioned vehicle control method.

[0019] The present application provides a vehicle, comprising the above-mentioned vehicle control device, an engine electrically connected to the control device, and a fuel system for providing methanol fuel to the engine.

[0020] The vehicle control method, control device and vehicle provided in the present application adjust the fuel injection amount of the fuel system when the engine is in operation so that the actual excess air parameter of the engine approaches the target excess air parameter. In this process, the fuel correction coefficient of the fuel system is monitored in real time, and a judgment is made as to whether the fuel system is operating abnormally based on the fuel correction coefficient. In the process of adjusting the fuel system, different fuel qualities will have different effects on the change of the fuel correction coefficient during the adjustment process. Judging based on whether the fuel correction coefficient is operating abnormally can achieve real-time monitoring of the vehicle's operating conditions, thereby monitoring operating abnormalities caused by methanol fuel quality problems, which is conducive to avoiding safety risks and optimizing the safety performance of vehicles using methanol fuel. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a schematic diagram of a vehicle provided by an embodiment of the present application;

[0022] Figure 2 is a schematic diagram of a vehicle control method provided by an embodiment of the present application;

[0023] Figure 3 is a schematic diagram of a vehicle control method provided by another embodiment of the present application;

[0024] Figure 4 is a schematic diagram of a vehicle control method provided by another embodiment of the present application;

[0025] Figure 5 is a schematic diagram of a vehicle control method provided by another embodiment of the present application;

[0026] Figure 6 It is a schematic diagram of a vehicle control method provided by another embodiment of the present application.

[0027] Reference numerals:

[0028] 10: vehicle controller; 201: generator; 202: engine; 203: fuel system; 211: generator controller; 212: engine management system; 301: power battery; 311: battery management system; 401: drive motor; 411: drive motor controller; 50: public CAN. DETAILED DESCRIPTION

[0029] Reference will now be made in detail to exemplary embodiments, examples of which are illustrated in the accompanying drawings.

[0030] The embodiment of the present application provides a vehicle, including an engine powered by methanol fuel. The vehicle may be a methanol range-extended vehicle or a pure methanol fuel vehicle.

[0031] Combination Figure 1 As shown, a methanol range-extended vehicle is used as an example for explanation. The vehicle includes a vehicle controller 10, a range extender system, a power battery system, and a drive motor system. The range extender system, the power battery system, and the drive motor system are all electrically connected to the vehicle controller 10, and the range extender system and the power battery system are used to control and supply energy to the drive motor system.

[0032] Specifically, the range extender system includes a range extender and a range extender control system. The range extender includes a generator 201, an engine 202, and a fuel system for providing methanol fuel to the engine 202; the range extender control system is electrically connected to the vehicle controller 10, and includes a generator controller 211 and an engine management system 212. The generator controller 211 is used to control the generator 201, and the engine management system 212 is used to control the engine 202 and the fuel system. The power battery system includes a power battery 301 and a battery management system 311, and the battery management system 311 is connected to the vehicle controller 10. The drive motor system includes a drive motor 401 and a drive motor controller 411, and the drive motor controller 411 is connected to the vehicle controller 10.

[0033] In some embodiments, the vehicle controller 10 communicates with the battery management system 311 through the public CAN (Controller Area Network) 50, and communicates with the engine management system 212 and the generator controller 211 through the internal CAN. The vehicle controller 10 receives hard-wired signals such as the remaining power, remaining fuel, vehicle fault signal, generator fault signal, engine fault signal, and accelerator pedal on the external public CAN 50 and the internal CAN, and determines whether the range extender needs to be started through at least part of these signals, and realizes the power generation control of the range extender.

[0034] The embodiment of the present application provides a control device for a vehicle, comprising one or more processors for implementing a control method for a vehicle. The control device is configured to adjust the fuel injection amount of the fuel system when the engine 202 is in operation so that the actual excess air coefficient of the engine is equivalent to the target excess air coefficient; obtain the fuel correction coefficient of the fuel system when the actual excess air coefficient is equivalent to the target excess air coefficient; and determine whether the fuel system is operating abnormally based on the fuel correction coefficient. The control device may be an engine management system 212 in a range extender. In some embodiments, the control device of the vehicle is another controller of the vehicle connected to the range extender, such as a vehicle controller 10 of the vehicle.

[0035] Combination Figure 2 As shown, an embodiment of the present application provides a control method for the above-mentioned vehicle, and the control method includes steps S11 to S13.

[0036] Step S11, when the engine is in operation, the fuel correction coefficient of the fuel system is obtained in real time, and the fuel injection amount of the fuel system is adjusted so that the actual excess air coefficient of the engine approaches the target excess air coefficient. The fuel correction coefficient is positively correlated with the difference between the actual excess air coefficient and the target excess air coefficient.

[0037] In the actual operation of the vehicle, the engine is often intermittently operated. Limiting the execution conditions of the vehicle control method to the stage when the engine is in the running state can avoid unnecessary control and judgment processes.

[0038] Specifically, in the process of adjusting the fuel injection amount of the fuel system, the adjustment control of the fuel injection amount is achieved based on the continuous comparison between the actual excess air coefficient and the target excess air coefficient. Further, in some embodiments, the actual excess air coefficient and the target excess air coefficient can be compared through the fuel correction coefficient. Adjusting the fuel injection amount of the fuel system includes: when the fuel correction coefficient indicates that the difference between the actual excess air coefficient and the target excess air coefficient is less than 0, reducing the fuel injection amount of the fuel system. When the fuel correction coefficient indicates that the difference between the actual excess air coefficient and the target excess air coefficient is greater than 0, increasing the fuel injection amount of the fuel system. In this way, the actual excess air coefficient can be adjusted in the direction of approaching the target excess air coefficient, thereby approaching the ideal state of finally making the two equal.

[0039] The fuel injection amount of the fuel system is adjusted by controlling the injection pulse width. The longer the injection pulse width, the greater the injection amount, and vice versa.

[0040] Step S12: determining whether the fuel system is operating abnormally according to the fuel correction coefficient.

[0041] Using the vehicle control method provided in the embodiment of the present application, when the engine is in operation, the fuel injection amount of the fuel system is adjusted so that the actual excess parameter of the engine approaches the target excess air parameter. In this process, the fuel correction coefficient of the fuel system is monitored in real time, and a judgment is made as to whether the fuel system is operating abnormally based on the fuel correction coefficient. In the process of adjusting the fuel injection amount of the fuel system, different fuel qualities will have different effects on the change of the fuel correction coefficient during the adjustment process. Judging based on whether the fuel correction coefficient is operating abnormally can achieve real-time monitoring of the vehicle's operating conditions, thereby monitoring operating abnormalities caused by methanol fuel quality problems, which is conducive to avoiding safety risks and optimizing the safety performance of vehicles using methanol fuel.

[0042] The aforementioned vehicle includes an oxygen sensor for obtaining the actual excess air coefficient of the engine. In some embodiments, adjusting the injection amount of the fuel system includes: obtaining the exhaust temperature of the engine; when the exhaust temperature is greater than or equal to the dew point temperature, controlling the oxygen sensor to heat; after the oxygen sensor is heated to the target temperature, adjusting the injection amount of the fuel system. Here, the exhaust temperature of the engine is detected by a temperature sensor in the vehicle. In some embodiments, the exhaust temperature of the engine can be calculated by an exhaust temperature model. In the process of adjusting the injection amount of the fuel system so that the actual excess air coefficient of the engine approaches the target excess air coefficient, it is necessary to obtain the actual excess air coefficient of the current engine in real time multiple times, and the actual excess air coefficient is detected by the oxygen sensor set in the vehicle. The oxygen sensor needs to be heated before it can achieve an accurate detection process during use. After the exhaust temperature is greater than or equal to the dew point temperature, the oxygen sensor is controlled to heat, and the actual excess air coefficient is monitored after heating, which is conducive to ensuring the accuracy of monitoring. The target temperatures corresponding to different types of oxygen sensors may be different. For example, the LSU4.9 model oxygen sensor needs to be heated and maintained at a target temperature of 780°C; the LUS5.2 model oxygen sensor needs to be heated and maintained at a target temperature of 800°C. Setting the exhaust temperature to be greater than or equal to the dew point temperature can avoid starting the oxygen sensor heating at low temperatures or even detecting the actual excess air coefficient through the oxygen sensor at low temperatures, which may result in inaccurate actual excess air coefficient or even damage to the oxygen sensor.

[0043] Here, the process of determining whether the fuel system is operating abnormally based on the fuel correction factor is further explained. Figure 3 As shown, in some embodiments, the aforementioned step S12, determining whether the fuel system is operating abnormally according to the fuel correction coefficient, includes steps S121 to S124.

[0044] Step S121, determining whether the absolute value of the fuel correction coefficient is less than or equal to a first coefficient threshold.

[0045] If the absolute value of the fuel correction coefficient is less than or equal to the first coefficient threshold, execute step S122; if the absolute value of the fuel correction coefficient is greater than the first coefficient threshold, execute step S123.

[0046] Step S122, determining whether the fuel system operates normally.

[0047] Step S123, obtaining a first operating parameter of the fuel system.

[0048] Step S124, determining whether the fuel system operates abnormally according to the first operating parameter.

[0049] The worse the quality of methanol fuel, that is, the more serious the abnormal operation of the fuel system, the more likely the fuel correction coefficient will be offset for a long time during the adjustment of the engine fuel injection amount. At the same time, a fuel correction coefficient that is too large or too small indicates that there is a quality problem with the current methanol fuel. Therefore, the absolute value of the fuel correction coefficient is used as the basis for judgment here to simplify the judgment logic. If the absolute value of the fuel correction coefficient currently monitored is within a range less than or equal to the first coefficient threshold, it means that the actual excess air coefficient is close to the target excess air coefficient, and the current fuel system is operating normally. In this way, based on the comparison of the fuel correction coefficient with the first coefficient threshold, an accurate judgment can be made as to whether the current fuel system is operating abnormally.

[0050] Furthermore, in the actual operation of the vehicle, the various parameters of the vehicle are not completely stable. Even if the fuel system operates normally, the fuel correction coefficient may fluctuate in a short period of time and become greater than the first coefficient threshold. Therefore, on the basis of judging the size of the fuel correction coefficient, a secondary judgment based on the first operating parameter of the fuel system can further distinguish between the two different situations of fuel correction coefficient fluctuation and fuel system operation abnormality, reduce misjudgment, and improve the accuracy of judgment on fuel system operation abnormality.

[0051] It should be noted here that Figure 3 The judgment process in the illustrated embodiment is only an example in the execution process, and the implementation method is not limited to this example. It is sufficient to distinguish between the case where the absolute value of the fuel correction coefficient is less than or equal to the first coefficient threshold and the case where the fuel correction coefficient is greater than the first correction threshold.

[0052] It can be understood that the first operating parameter is used to reflect the degree of continuity of the situation that the absolute value of the fuel correction factor is greater than the first coefficient threshold. In some embodiments, the first operating parameter includes the cumulative oxygen consumption of the fuel system when the absolute value of the fuel correction factor is maintained greater than the first coefficient threshold. In some embodiments, the first operating parameter includes the duration of the absolute value of the fuel correction factor being greater than the first coefficient threshold.

[0053] Specifically, in some embodiments, the first operating parameter includes the cumulative oxygen consumption of the fuel system when the absolute value of the fuel correction coefficient is maintained at a value greater than the first coefficient threshold value, and determining whether the fuel system is operating abnormally according to the first operating parameter includes: determining that the fuel system is operating abnormally when the cumulative oxygen consumption is greater than or equal to the first consumption threshold value; and determining that the fuel system is operating normally when the cumulative oxygen consumption is less than the first consumption threshold value. It should be noted here that the cumulative oxygen consumption is measured during the process in which the absolute value of the fuel correction coefficient is continuously greater than the first coefficient threshold value. That is, when it is detected that the absolute value of the fuel correction coefficient is greater than the first coefficient threshold value, the cumulative oxygen consumption is detected. If the absolute value of the fuel correction coefficient decreases to less than or equal to the first coefficient threshold value and the cumulative oxygen consumption at this time does not reach the first consumption threshold value, the cumulative oxygen consumption is cleared to zero, and the count is restarted when the absolute value of the fuel correction coefficient is greater than the first coefficient threshold value again. The accumulated oxygen consumption here can accurately reflect the degree to which the fuel correction coefficient of the fuel system is continuously greater than the first coefficient threshold. Using the accumulated oxygen consumption as the basis for judgment can accurately determine whether the current fuel correction coefficient is a fluctuation in normal operation or an abnormal operation of the fuel system, which is conducive to improving the accuracy of the judgment process of abnormal operation of the fuel system.

[0054] The first coefficient threshold and the first consumption threshold here can be calibrated in advance by simulation. That is, the operation of the engine under different methanol fuel qualities is simulated to determine the critical value between the fuel correction coefficient under the two conditions of qualified methanol quality and unqualified methanol quality, as the first coefficient threshold. The cumulative oxygen consumption under the condition of fuel correction coefficient fluctuation when the methanol quality is qualified and the cumulative oxygen consumption when the methanol quality is unqualified are compared to determine the cumulative oxygen consumption threshold for distinguishing the two conditions as the first consumption threshold. As an example, in some embodiments, the first coefficient threshold can be 25%, and the first consumption threshold can be set to 150g.

[0055] In some embodiments, the first operating parameter includes the duration of time that the absolute value of the fuel correction coefficient is greater than the first coefficient threshold. Determining whether the fuel system is operating abnormally according to the first operating parameter includes: determining that the fuel system is operating abnormally when the duration is greater than or equal to the first duration threshold; determining that the fuel system is operating normally when the duration is less than the first duration threshold. The duration here is the duration of time that the fuel correction coefficient is continuously greater than the first coefficient threshold. When the absolute value of the fuel correction coefficient decreases to less than or equal to the first coefficient threshold, the timing of the duration is stopped and reset to zero, and the timing is restarted when the absolute value of the fuel correction coefficient is greater than the first coefficient threshold. In this way, through the duration of time that the absolute value of the fuel correction coefficient is greater than the first coefficient threshold, it is possible to accurately distinguish between the fluctuation of the fuel correction coefficient and the abnormality of the fuel system during normal operation, reduce misjudgment, and improve the accuracy of detecting abnormal operation of the fuel system. Similar to the value-taking method of the first coefficient threshold and the first consumption threshold mentioned above, the first duration threshold here can also be calibrated by simulation, which will not be repeated here.

[0056] In some embodiments, after adjusting the fuel injection amount of the fuel system, the control method of the vehicle further includes: when the fuel correction coefficient reaches an upper threshold or a lower threshold, and the absolute value of the difference between the actual excess air coefficient of the engine and the target excess air coefficient is greater than the difference threshold, determining that the fuel system is abnormal. The adjustable range of the fuel correction coefficient is limited in advance, and after the fuel injection amount of the fuel system is adjusted, if the current fuel correction coefficient has reached the upper threshold or the lower threshold of the adjustable range, and the absolute value of the difference between the actual excess air coefficient of the engine and the target excess air coefficient is still large, it means that the ideal state in which the actual excess air coefficient is equivalent to the target excess air coefficient cannot be achieved by adjusting the fuel injection amount under the current operating state, and the fuel system is seriously abnormal. Furthermore, in order to avoid damage to the engine caused by the abnormal situation, the engine is controlled to shut down.

[0057] Combination Figure 4 As shown, the embodiment of the present application provides another control method, including steps S21 to S23.

[0058] Step S21, when the engine is in operation, the fuel correction coefficient of the fuel system is obtained in real time, and the fuel injection amount of the fuel system is adjusted so that the actual excess air coefficient of the engine approaches the target excess air coefficient. The fuel correction coefficient is positively correlated with the difference between the actual excess air coefficient and the target excess air coefficient.

[0059] Step S22: determining whether the fuel system is operating abnormally based on the fuel correction coefficient.

[0060] Step S23, when it is determined that the fuel system is operating abnormally, an engine protection strategy is determined according to the fuel correction coefficient. The engine protection strategy here includes controlling the engine to reduce output power or controlling the engine to stop.

[0061] The current fuel correction factor can more accurately reflect the abnormal conditions of the fuel system. Determining the engine protection strategy based on this is conducive to ensuring the accuracy of the engine protection strategy, allowing the engine protection strategy to change with the actual fault conditions, which is conducive to achieving accurate engine protection and reducing the risk of engine failure.

[0062] Combination Figure 5 As shown, in some embodiments, the aforementioned step S23, determining the engine protection strategy according to the fuel correction coefficient, includes steps S231 to S234.

[0063] Step S231, determining whether the absolute value of the fuel correction coefficient is less than a second coefficient threshold value. The second coefficient threshold value here is greater than the first coefficient threshold value.

[0064] When the absolute value of the fuel correction coefficient is less than the second coefficient threshold, step S232 is executed; when the absolute value of the fuel correction coefficient is greater than or equal to the second coefficient threshold, step S233 is executed.

[0065] Step S232, determining that the engine protection strategy is to control the engine to reduce output power.

[0066] Step S233, obtaining a second operating parameter of the fuel system.

[0067] Step S234: According to the second operating parameter, the engine protection strategy is determined to be controlling the engine to reduce output power or controlling the engine to stop. Controlling the engine to reduce output power can be achieved by limiting the maximum torque of the engine, controlling the engine idle speed, and the like.

[0068] That is, on the basis of determining that the fuel system is operating abnormally, the degree of the operating abnormality is distinguished, and different engine protection strategies are determined accordingly. On the basis that the fuel correction coefficient is greater than the first coefficient threshold, the greater the absolute value of the fuel correction coefficient, the more serious the deviation from the normal operating condition at this time. If the absolute value of the fuel correction coefficient is within the interval less than the second coefficient threshold, it means that the actual excess air coefficient and the target excess air coefficient at this time are relatively close, the degree of the fault is relatively light, and it will not cause serious damage to the engine in a short time. Therefore, the engine protection strategy is determined to control the engine to reduce the output power to reduce the damage intensity to the engine. If the absolute value of the fuel correction coefficient is greater than or equal to the second coefficient threshold, it means that on the basis of the abnormal operation of the fuel system, the fuel system may be seriously abnormal in operation, so that the engine is seriously damaged in a short time. At this time, considering that the fuel correction coefficient will fluctuate during the operation, the current fault condition is further judged according to the actual operation condition of the fuel system, that is, the second operation parameter. In this way, the fault condition of the fuel system is determined in combination with the fuel correction coefficient and the second operation parameter of the fuel system, which is conducive to ensuring the accuracy of the judgment of the current fault condition.

[0069] It should be noted that Figure 5 The judgment process in the illustrated embodiment is only an example in the execution process, and the implementation method is not limited to this example. It is sufficient to distinguish between the case where the fuel correction coefficient is less than the second coefficient threshold and the case where it is greater than or equal to the second coefficient threshold.

[0070] The second coefficient threshold here can be calibrated in advance by simulation. Different degrees of abnormal conditions in the operation of the fuel system are simulated respectively, specifically, a situation where an abnormality occurs but no serious damage to the engine occurs in a short period of time and a situation where an abnormality occurs and serious damage to the engine occurs in a short period of time are simulated, and the second coefficient threshold that can be used as a critical value is determined according to the value range of the fuel correction coefficient in the two different situations. As an example, in some embodiments, the second coefficient threshold is set to 40%.

[0071] Similar to the first operating parameter, the second operating parameter is used to reflect the degree of continuity of the situation that the absolute value of the fuel correction factor is greater than the second coefficient threshold. In some embodiments, the second fuel operating parameter includes the cumulative oxygen consumption of the fuel system when the absolute value of the fuel correction factor is maintained greater than or equal to the second coefficient threshold. In some embodiments, the second operating parameter includes the duration of the absolute value of the fuel correction factor being greater than the second coefficient threshold.

[0072] Specifically, in some embodiments, the second operating parameter includes the cumulative oxygen consumption of the fuel system when the absolute value of the fuel correction coefficient is maintained at greater than or equal to the second coefficient threshold value. According to the second operating parameter, the engine protection strategy is determined to be controlling the engine to reduce output power or controlling the engine to shut down, including: when the cumulative oxygen consumption is less than the second consumption threshold value, determining the engine protection strategy is to control the engine to reduce output power; when the cumulative oxygen consumption is greater than or equal to the second consumption threshold value, determining the engine protection strategy is to control the engine to shut down.

[0073] Similar to the cumulative oxygen consumption of the fuel system included in the aforementioned first operating parameter when the absolute value of the fuel correction coefficient is maintained at a value greater than the first coefficient threshold, the cumulative oxygen consumption here is detected only when the absolute value of the fuel correction coefficient is maintained at a value greater than or equal to the second coefficient threshold. If the absolute value of the fuel correction coefficient decreases to be less than the second coefficient threshold, the recorded cumulative oxygen consumption is cleared until the absolute value of the fuel correction coefficient is greater than or equal to the second coefficient threshold, and the oxygen consumption is re-recorded. The cumulative oxygen consumption here can accurately reflect the continuous situation that the absolute value of the current fuel correction coefficient is greater than the second coefficient threshold, thereby achieving accurate judgment of whether the absolute value of the current fuel correction coefficient is greater than the second coefficient threshold is a short-term fluctuation or a serious abnormality in the operation of the fuel system, which is conducive to achieving an accurate judgment of the degree of abnormality of the fuel system, thereby improving the accuracy of the engine protection strategy finally determined. At least in some embodiments, the second consumption threshold is greater than the first consumption threshold. As an example, the second consumption threshold can be set to 200g.

[0074] In some embodiments, when the second operating parameter includes the duration of the absolute value of the fuel correction coefficient being greater than the second coefficient threshold, the engine protection strategy is determined to be to control the engine to reduce the output power or to control the engine to stop according to the second operating parameter, including: when the duration is less than the second duration threshold, the engine protection strategy is determined to be to control the engine to reduce the output power; when the duration is greater than or equal to the second duration threshold, the engine protection strategy is determined to be to control the engine to stop. When the absolute value of the fuel correction coefficient is greater than the second coefficient threshold, the timing is started as the duration. When the absolute value of the fuel correction coefficient decreases to less than or equal to the second coefficient threshold, the timing is stopped, and when the absolute value of the fuel correction coefficient returns to greater than the second coefficient threshold, the timing is restarted from zero. In this way, the duration of the absolute value of the fuel correction coefficient being greater than the second coefficient threshold can be accurately determined, thereby realizing accurate judgment of whether the current absolute value of the fuel correction coefficient being greater than the second coefficient threshold is a short-term fluctuation or a serious abnormality in the operation of the fuel system, which is conducive to accurate judgment of the degree of abnormality of the fuel system, thereby improving the accuracy of the engine protection strategy finally determined. At least in some embodiments, the second duration threshold is greater than the first duration threshold.

[0075] Similar to the determination method of the first consumption threshold and the first duration threshold mentioned above, the second consumption threshold and the second duration threshold here can also be determined in advance by simulation. The abnormal conditions of different degrees of the fuel system are simulated to determine the critical value of the accumulated oxygen consumption that can be used to distinguish different conditions as the second consumption threshold; and the critical value of the duration that can be used to distinguish different conditions is determined as the second duration threshold.

[0076] Here, the process of controlling the engine to reduce the output power is further described in detail. In the case where the engine protection strategy is determined to control the engine to reduce the output power, after the engine protection strategy is determined according to the fuel correction coefficient, the control method also includes: determining the engine torque limit coefficient according to the fuel correction coefficient; taking the product of the torque limit coefficient and the current maximum torque of the engine as the target torque; taking the target torque as the maximum torque allowed for the engine to run. Among them, the torque limit coefficient is less than 1 and greater than or equal to 0, and the torque limit coefficient and the absolute value of the fuel correction coefficient are negatively correlated. In this way, different degrees of torque limit are performed corresponding to different sizes of fuel correction coefficients in the actual implementation process, thereby realizing the detailed control of the process of controlling the engine to reduce the output power. In the implementation process, the relationship between the fuel correction coefficient and the torque limit coefficient is pre-set, and the torque limit coefficient corresponding to the current fuel correction coefficient is determined according to the relationship. For example, as shown in Table 1, in some embodiments, the relationship between the fuel correction coefficient and the torque limit coefficient can be directly reflected in a one-to-one corresponding numerical value, and the torque limit coefficient corresponding to the current fuel correction coefficient is determined by looking up the table. For values ​​that are not directly disclosed in the existing data table, they can be determined by interpolation calculation based on the disclosed values.

[0077] Table 1

[0078]

[0079] In some embodiments, the relationship between the fuel correction factor and the torque limit coefficient can also be expressed in the form of a formula. The formula uses the fuel correction factor as an independent variable and the torque limit coefficient as a dependent variable. According to the formula, the torque limit coefficient corresponding to the current fuel correction factor can be determined.

[0080] Combination Figure 6 As shown, an embodiment of the present application provides another vehicle control method, including steps S31 to S36.

[0081] Step S31, when the engine is in operation, the fuel correction coefficient of the fuel system is obtained in real time, and the fuel injection amount of the fuel system is adjusted so that the actual excess air coefficient of the engine approaches the target excess air coefficient. The fuel correction coefficient is positively correlated with the difference between the actual excess air coefficient and the target excess air coefficient.

[0082] Step S32, determining whether the fuel system is operating abnormally according to the fuel correction coefficient.

[0083] Step S33, when it is determined that the fuel system is operating abnormally, determine the fault condition of the fuel system according to the fuel correction coefficient.

[0084] Step S34, giving a fault prompt according to the fault condition of the fuel system.

[0085] Step S35, determining an engine protection strategy according to the fault condition of the fuel system. The engine protection strategy includes controlling the engine to reduce output power or controlling the engine to stop.

[0086] The above-mentioned step of determining the engine protection strategy according to the fuel correction coefficient when it is determined that the fuel system is operating abnormally can be divided into step S33 and step S35 here, that is, determining the fault condition of the fuel system according to the fuel correction coefficient, and determining the engine protection strategy according to the fault condition.

[0087] Specifically, determining the fault condition of the fuel system according to the fuel correction coefficient includes: determining that the fault condition of the fuel system is a primary fault when the absolute value of the fuel correction coefficient is less than the second coefficient threshold, or when the cumulative oxygen consumption of the fuel system when the absolute value of the fuel correction coefficient is maintained at or above the second coefficient threshold is less than the second consumption threshold, or when the duration of the fuel system when the absolute value of the fuel correction coefficient is maintained at or above the second coefficient threshold is less than the second duration threshold. Determining that the fault condition of the fuel system is a secondary fault when the cumulative oxygen consumption of the fuel system when the absolute value of the fuel correction coefficient is maintained at or above the second coefficient threshold is greater than or equal to the second consumption threshold, or when the duration of the fuel correction system when the absolute value of the fuel correction coefficient is maintained at or above the second coefficient threshold is greater than or equal to the second duration threshold. The degree of the secondary fault here is more serious, and the risk of engine damage is higher.

[0088] Determining the engine protection strategy according to the fuel system fault condition includes: when the fuel system fault condition is a primary fault, determining the engine protection strategy is to control the engine to reduce output power. When the fuel system fault condition is a secondary fault, determining the engine protection strategy is to control the engine to stop.

[0089] Corresponding to the fault condition, a fault prompt is given according to the fault condition of the fuel system, and different fault prompts are issued corresponding to the primary fault and the secondary fault. This can be achieved by displaying a fault prompt message or issuing a fault prompt sound through an information display device such as an instrument in the vehicle, and can distinguish between primary faults and secondary faults. For example, when the fault condition is a primary fault, a message "The fuel system needs maintenance and inspection" pops up; when the fault condition is a secondary fault, a message "The fuel system continues to be maintained and inspected" pops up. The specific fault prompt method can be set according to actual needs. In addition, in some embodiments, only the above-mentioned steps S31 to S36 may be executed, and the engine protection strategy is not automatically executed, and the subsequent vehicle control is performed by the user or relevant staff.

[0090] In some embodiments, the control method of the vehicle further includes: detecting whether the vehicle currently has other faults other than abnormal operation of the fuel system; in the case of other faults, controlling the engine to reduce output power or controlling the engine to shut down according to the fault type of the other fault. The fault types of other faults other than the fuel system are classified to determine the target fault type that has a damaging effect on the engine, and controlling the engine to reduce output power or controlling the engine to shut down when the current fault type is the target fault type. In some embodiments, the target fault type is further divided according to the degree of damage to the engine, corresponding to two different control strategies of controlling the engine to reduce output power and controlling the engine to shut down.

[0091] Here, further, in some embodiments, only when the current fuel system is normal, it is detected whether the vehicle currently has other faults other than the fuel system operation abnormality, or only when the engine protection strategy corresponding to the current fuel system operation abnormality is to control the engine to reduce the output power, it is detected whether the vehicle currently has other faults other than the fuel system operation abnormality. This is conducive to ensuring that the fuel system abnormality identification is performed first, so as to prevent the fuel system abnormality from damaging the engine in time.

[0092] In the description of the present disclosure, it should be understood that the terms "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first", "second", etc. may explicitly or implicitly include at least one of the features. In the description of the present disclosure, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

Claims

1. A vehicle control method, characterized in that: The vehicle includes an engine and a fuel system for providing methanol fuel to the engine; the control method includes: When the engine is in operation, a fuel correction coefficient of a fuel system is obtained in real time, and a fuel injection amount of the fuel system is adjusted so that an actual excess air coefficient of the engine approaches a target excess air coefficient; wherein the fuel correction coefficient is positively correlated with a difference between the actual excess air coefficient and the target excess air coefficient; determining, based on the fuel correction factor, whether the fuel system operates abnormally; In the case where it is determined that the fuel system is operating abnormally, determining an engine protection strategy according to the fuel correction coefficient; the engine protection strategy includes controlling the engine to reduce output power or controlling the engine to stop; Wherein, determining whether the fuel system operates abnormally according to the fuel correction coefficient includes: When the absolute value of the fuel correction coefficient is less than or equal to a first coefficient threshold, determining that the fuel system operates normally; When the absolute value of the fuel correction coefficient is greater than the first coefficient threshold, obtaining a first operating parameter of the fuel system, and determining whether the fuel system operates abnormally according to the first operating parameter; Determining the engine protection strategy according to the fuel correction factor includes: When the absolute value of the fuel correction coefficient is less than the second coefficient threshold, determining the engine protection strategy is to control the engine to reduce output power; When the absolute value of the fuel correction coefficient is greater than or equal to the second coefficient threshold, obtaining a second operating parameter of the fuel system, and determining, based on the second operating parameter, that the engine protection strategy is to control the engine to reduce output power or to control the engine to stop; The second coefficient threshold is greater than the first coefficient threshold.

2. The control method according to claim 1, characterized in that: The first operating parameter includes the accumulated oxygen consumption of the fuel system when the absolute value of the fuel correction factor is maintained greater than the first factor threshold; Determining whether the fuel system operates abnormally according to the first operating parameter includes: When the accumulated oxygen consumption is greater than or equal to a first consumption threshold, determining that the fuel system is operating abnormally; When the accumulated oxygen consumption is less than the first consumption threshold, it is determined that the fuel system operates normally.

3. The control method according to claim 1, characterized in that: The first operating parameter includes a duration during which the absolute value of the fuel correction coefficient is greater than the first coefficient threshold; Determining whether the fuel system operates abnormally according to the first operating parameter includes: When the duration is greater than or equal to a first duration threshold, determining that the fuel system is operating abnormally; When the duration is less than the first duration threshold, it is determined that the fuel system operates normally.

4. The control method according to claim 1, characterized in that: The second operating parameter includes the accumulated oxygen consumption of the fuel system when the absolute value of the fuel correction factor is maintained greater than or equal to the second factor threshold; According to the second operating parameter, determining the engine protection strategy is to control the engine to reduce output power or control the engine to stop, including: When the accumulated oxygen consumption is less than a second consumption threshold, determining the engine protection strategy is to control the engine to reduce output power; When the accumulated oxygen consumption is greater than or equal to the second consumption threshold, the engine protection strategy is determined to control the engine to shut down.

5. The control method according to claim 1, characterized in that: The second operating parameter includes a duration during which the absolute value of the fuel correction factor is greater than the second factor threshold; According to the second operating parameter, determining the engine protection strategy is to control the engine to reduce output power or control the engine to stop, including: When the duration is less than a second duration threshold, determining that the engine protection strategy is to control the engine to reduce output power; When the duration is greater than or equal to the second duration threshold, the engine protection strategy is determined to be controlling the engine to stop.

6. The control method according to claim 1, characterized in that: In the case where the engine protection strategy is determined to control the engine to reduce output power, after determining the engine protection strategy according to the fuel correction coefficient, the method further includes: determining a torque limit coefficient of the engine according to the fuel correction coefficient; The product of the torque limit coefficient and the current maximum torque of the engine is used as the target torque; Taking the target torque as the maximum torque allowed for the engine to run; The torque limit coefficient is less than 1 and greater than or equal to 0, and the torque limit coefficient is negatively correlated with the fuel correction coefficient.

7. The control method according to claim 1, characterized in that: After determining whether the fuel system is operating abnormally according to the fuel correction coefficient, the method further includes: In the case where it is determined that the fuel system is operating abnormally, determining a fault condition of the fuel system according to the fuel correction coefficient; A fault prompt is given according to the fault condition.

8. The control method according to claim 1, characterized in that: The vehicle includes an oxygen sensor, wherein the oxygen sensor is used to obtain an actual excess air coefficient of the engine; The step of adjusting the fuel injection amount of the fuel system comprises: obtaining an exhaust temperature of the engine; When the exhaust temperature is greater than or equal to the dew point temperature, controlling the oxygen sensor to heat; After the oxygen sensor is heated to the target temperature, the fuel injection amount of the fuel system is adjusted.

9. The control method according to claim 1, characterized in that: Adjusting the fuel injection amount of the fuel system includes: When the fuel correction coefficient indicates that the difference between the actual excess air coefficient and the target excess air coefficient is less than 0, reducing the fuel injection amount of the fuel system; When the fuel correction coefficient indicates that the difference between the actual excess air ratio and the target excess air ratio is greater than 0, the fuel injection amount of the fuel system is increased.

10. The control method according to claim 9, characterized in that: After adjusting the fuel injection amount of the fuel system, the method further includes: When the fuel correction factor reaches an upper threshold or a lower threshold and the absolute value of the difference between the actual excess air factor of the engine and the target excess air factor is greater than the difference threshold, it is determined that the fuel system is abnormal.

11. The control method according to claim 1, characterized in that: Also includes: Detecting whether the vehicle currently has other faults other than abnormal operation of the fuel system; In the case of other faults, the engine is controlled to reduce output power or to stop according to the fault type of the other faults.

12. A vehicle control device, characterized in that: The method comprises one or more processors for implementing the vehicle control method as claimed in any one of claims 1 to 11.

13. A vehicle, characterized in that: The invention comprises a control device for a vehicle as claimed in claim 12, an engine electrically connected to the control device, and a fuel system for providing methanol fuel to the engine.

Images