Method, apparatus, device and storage medium for avoiding engine stall

Abstract

The application discloses a method, device, equipment and storage medium for avoiding engine stall, and the method comprises the following steps: judging the jamming state of a mixing valve according to a current target opening degree and an actual opening degree; calculating the opening error between the current target opening degree and the actual opening degree by PID control according to the jamming state of the mixing valve; and resetting the integral term of the PID control of the opening error to avoid engine stall when judging that the stable jamming state of the mixing valve is broken. The application aims at solving the problem that the duty cycle overshoot is formed when the mixing valve of the low-pressure EGR system in the prior art is broken due to jamming, which leads to full closing, so that external air cannot enter the cylinder, resulting in engine stall or shaking. The method of the application can effectively identify that the mixing valve enters the jamming break state from the jamming state, and PID control adjustment is performed on the mixing valve, so that the problem of engine stall and shaking caused by the overshoot of the mixing valve is avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of vehicle engine, and particularly relates to a method, device and equipment for avoiding engine stall and a storage medium. BACKGROUND

[0002] The EGR system, i.e. the Exhaust Gas Recirculation system, is an effective technology for reducing the content of nitrogen oxides (NOx) in the exhaust emission of an internal combustion engine. Although the existing low-pressure EGR system technology has significant advantages in reducing nitrogen oxide emission and improving fuel economy compared with the high-pressure EGR system, there are still some deficiencies, which will have certain influence on the engine performance, reliability and vehicle driving safety.

[0003] Due to the relatively long exhaust gas recirculation path in a low-pressure EGR system, the exhaust gas may experience increased resistance during transmission, leading to a decrease in intake pressure. When the exhaust gas pressure is insufficient to overcome the pressure within the cylinder, the exhaust gas will not enter the cylinder smoothly, affecting the normal operation of the EGR system. This problem requires precise control of the mixing valve to solve, but increases the complexity and cost of the system. The mixing valve plays a crucial role in the low-pressure EGR system, and precise control of its opening is essential to ensure that exhaust gas can enter the cylinder smoothly. PID controller: In control systems, the PID controller is a common method used to control the mixing valve of a low-pressure EGR system. The PID controller adjusts the control input by calculating the proportional (P), integral (I), and derivative (D) terms of the deviation (i.e., the difference between the actual output and the desired output), thereby reducing the deviation and maintaining the desired output. However, the control of the mixing valve involves multiple factors such as engine operating conditions, exhaust gas temperature and pressure, etc., making the control system complex and difficult to adjust accurately. If not properly controlled, it may cause the mixing valve to be fully open or fully closed, affecting the normal operation of the engine. Due to the long gas path and complex control system involved in the low-pressure EGR system, its response speed may be relatively slow. When the engine operating conditions change, the EGR system needs some time to adjust the exhaust gas recirculation amount to adapt to the new operating conditions. This delay may cause temporary performance degradation or emission exceedance of the engine. Due to the involvement of multiple components and complex control systems in the low-pressure EGR system, its maintenance cost may be relatively high. In particular, key components such as the mixing valve may need to be replaced or repaired if they fail or wear out, increasing the cost of using the vehicle. The complex control system and long gas path may increase the risk of system failure. For example, failure of the mixing valve may cause exhaust gas to fail to enter the cylinder or outside air to fail to enter the engine, affecting the normal operation of the engine. In addition, impurities and particulate matter in the exhaust gas may also cause blockage or wear of the EGR system, reducing the reliability of the system. SUMMARY

[0004] The main purpose of the present application is to provide a method, device, equipment and storage medium for avoiding engine stall, which aims to solve the problem of engine stall or shaking caused by the duty cycle overshoot of the mixing valve of the low-pressure EGR system in the prior art due to the stuck open state. The method of the present application can effectively identify the transition of the mixing valve from the stuck state to the stuck open state, and timely adjust the PID control strategy when the stuck state is opened, thereby avoiding the problem of engine stall and shaking caused by the overshoot of the mixing valve.

[0005] To achieve the above object, the application provides a method for avoiding engine stall, which comprises the following steps:

[0006] judging the sticking state of the hybrid valve according to the current target opening degree and the actual opening degree;

[0007] calculating the PID control of the opening degree error between the current target opening degree and the actual opening degree according to the sticking state of the hybrid valve;

[0008] resetting the integral term of the PID control of the opening degree error to avoid engine stall when judging that the stable sticking state of the hybrid valve is broken.

[0009] In an embodiment, the step of judging the sticking state of the hybrid valve according to the current target opening degree and the actual opening degree further comprises:

[0010] judging whether the actual opening degree of the hybrid valve is stable at the preset opening degree position;

[0011] calculating the opening degree error according to the current target opening degree and the actual opening degree;

[0012] judging whether the actual opening degree of the hybrid valve is in the stable sticking state according to the calculated current opening degree error.

[0013] In an embodiment, the step of judging whether the actual opening degree of the hybrid valve is in the stable sticking state according to the calculated current opening degree error further comprises:

[0014] recording the time when the actual opening degree of the hybrid valve remains in the stable state;

[0015] when the opening degree error of the hybrid valve meets the requirement of the closed-loop control and the actual opening degree remains in the stable state for a certain time, determining that the hybrid valve is in the state of non-target opening degree sticking and the position is stable.

[0016] In an embodiment, the step of calculating the PID control of the opening degree error according to the sticking state of the hybrid valve further comprises:

[0017] calculating the differential term of the PID control of the opening degree error according to the sticking state of the hybrid valve;

[0018] calculating the integral term of the PID control of the opening degree error according to the sticking state of the hybrid valve;

[0019] calculating the proportional term of the PID control of the opening degree error according to the sticking state of the hybrid valve;

[0020] The PID control result of the hybrid valve is obtained by accumulating the derivative term, the integral term and the proportional term of the PID control.

[0021] In an embodiment, the step of resetting the integral term of the PID control of the opening error to avoid engine stall when the stable sticking state of the hybrid valve is broken, further comprises:

[0022] When the actual opening of the hybrid valve is monitored to change and the change amplitude exceeds a preset threshold, it is determined that the sticking state of the hybrid valve is broken;

[0023] After confirming that the sticking state of the hybrid valve is broken, the integral term in the PID control is reset and the PID control result of the hybrid valve is updated to avoid engine stall.

[0024] In an embodiment, the step of determining that the sticking state of the hybrid valve is broken when the actual opening of the hybrid valve is monitored to suddenly change and the change amplitude exceeds a preset threshold, comprises:

[0025] According to the sticking state of the hybrid valve, a sticking flag bit of the hybrid valve at each moment is recorded;

[0026] When the sticking flag bit at the last moment is a first preset value, the flag bit at the current moment is a second preset value and the change amplitude exceeds a preset threshold, it is determined that the hybrid valve is broken from the sticking state.

[0027] In an embodiment, the step of resetting the integral term in the PID control and updating the PID control result of the hybrid valve to avoid engine stall after confirming that the sticking state of the hybrid valve is broken, further comprises:

[0028] The working state of the hybrid valve is detected;

[0029] After the integral term of the hybrid valve is reset, the hybrid valve moves in the opposite direction of the target opening, and the feedforward provides the duty cycle at this moment;

[0030] The responsiveness provided by the feedforward friction compensation is used to keep the hybrid valve stable after the sticking state is broken.

[0031] In addition, to achieve the above object, the application further provides an engine stall avoiding device, which comprises:

[0032] A judging module is configured to judge the sticking state of the hybrid valve according to the current target opening and the actual opening;

[0033] The adjusting module performs PID control on the opening error between the current target opening and the actual opening according to the sticking state of the mixing valve.

[0034] The resetting module resets the integral term of the PID control of the opening error to avoid engine stall when judging that the stable sticking state of the mixing valve is broken.

[0035] In addition, to achieve the above object, the present application further provides an engine stall avoiding device, which comprises a memory, a processor and a computer program stored in the memory and executable on the processor, and the computer program is configured to implement the steps of the engine stall avoiding method as described above.

[0036] In addition, to achieve the above object, the present application further provides a computer storage medium, which stores a computer program, and the computer program is executed by a processor to implement the steps of the engine stall avoiding method as described above.

[0037] The one or more technical solutions provided by the application can have the following advantages or at least achieve the following technical effects: The application relates to the technical field of automobile engines, and in particular to the control of a mixing valve in a low-pressure EGR (exhaust gas recirculation) system. An innovative method, device, equipment and storage medium are proposed to solve the problem of engine stall or shaking caused by the mixing valve being opened after being stuck. The core of the method is to accurately determine the stuck state of the mixing valve and adjust the PID control strategy when the stuck state is opened to avoid engine stall or shaking caused by the mixing valve overshooting. The system first determines whether the mixing valve is in a stuck state according to the difference between the current target opening and the actual opening, and the response characteristics of the mixing valve. If the actual opening of the mixing valve stays at a fixed value for a long time and deviates significantly from the target opening, the system determines that the mixing valve is in a stuck state. After determining that the mixing valve is in a stuck state, the system calculates the PID control according to the opening error between the current target opening and the actual opening. The PID controller outputs the corresponding control signal according to the error, the rate of change and the cumulative error to adjust the opening of the mixing valve. The system continuously monitors the opening change of the mixing valve, and when it detects that the opening of the mixing valve suddenly increases and the change amplitude exceeds the preset threshold, it determines that the stuck state of the mixing valve is opened. After confirming that the stuck state of the mixing valve is opened, the system immediately resets the integral term of the PID control. The reset of the integral term is to eliminate the excessive control signal caused by the integral accumulation, and to avoid the mixing valve moving in the wrong direction due to the effect of the integral term after being opened, resulting in overshoot. After resetting the integral term, the system recalculates the output signal of the PID controller according to the new opening error. At the same time, the system also combines strategies such as feedforward control to ensure that the opening of the mixing valve is stable near the opening position. After the reset of the I term, the total duty cycle is too small, causing the spring to pull the valve body to rotate. Through the method proposed in the application, the system can accurately determine the stuck state of the mixing valve and adjust the PID control strategy in time when the stuck state is opened, effectively avoiding the problem of engine stall and shaking caused by the overshoot of the mixing valve. This not only improves the reliability and stability of the automobile engine, but also reduces the maintenance cost and safety hazards caused by faults. The method is applicable to all automobile engines using low-pressure EGR systems, especially those with high requirements for air flow control. By integrating the method into the engine control system, the performance and safety of the engine can be significantly improved. BRIEF DESCRIPTION OF DRAWINGS

[0038] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required by the embodiments or prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from the structures shown in these drawings without creative labor.

[0039] Figure 1 Flowchart of the first embodiment of the method for avoiding engine stall of the present application;

[0040] Figure 2 Flowchart of the second embodiment of the method for avoiding engine stall of the present application;

[0041] Figure 3 Flowchart of the third embodiment of the method for avoiding engine stall of the present application;

[0042] Figure 4 Flowchart of the fourth embodiment of the method for avoiding engine stall of the present application.

[0043] The implementation, functional features and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION

[0044] The technical solutions in the embodiments of the present application will be described clearly and completely with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0045] It should be noted that if the embodiments of the present application involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement condition, etc. between the components in a certain posture, and if the certain posture changes, the directional indications will also change accordingly.

[0046] In addition, if the description of "first", "second" and the like is involved in the embodiments of the present application, the description of "first", "second" and the like is only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can be explicitly or implicitly included at least one of the features. In addition, "and / or" or "and / or" appearing throughout the text means that the three parallel schemes are included, for example, "A and / or B" includes A scheme, or B scheme, or A and B scheme. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the realization of the ordinary skilled in the art, when the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, nor within the scope of protection claimed by the present application.

[0047] It should be understood that the specific embodiments described herein are only used to explain the present application, and are not used to limit the present application.

[0048] In the control system of the mixing valve, especially in the air mixing control of the cylinder of the automobile engine, the accurate control of the opening degree of the mixing valve is very important. When the mixing valve is stuck at a small opening degree due to some reasons (such as dirt, mechanical failure, etc.), it may cause insufficient air flow and affect the performance of the engine. In order to deal with this situation, especially when the mixing valve is stuck and finally opened by a larger duty cycle signal, the traditional PID (proportional-integral-derivative) control algorithm may cause overshoot problem, causing the mixing valve to move excessively or even be closed, which is extremely unfavorable for the operation of the engine. In view of the above problems, the present application proposes an innovative mixing valve control strategy optimization method, the specific process is as follows:

[0049] Firstly, the system needs to continuously monitor the difference between the actual opening degree and the target opening degree of the mixing valve, and the response of the mixing valve. When it is found that the opening degree of the mixing valve stays at a certain fixed value (such as below 20%) for a long time, and there is a large deviation from the target opening degree, the system determines that the mixing valve is in a stuck state. By monitoring the sudden change of the opening degree of the mixing valve (such as rapidly increasing from the stuck state), the system identifies that the mixing valve has been opened by a larger duty cycle signal from the stuck state. Once the stuck opening event is identified, the system immediately sets a flag indicating that it is currently in a special control state.

[0050] PID control is a linear control method, which controls according to the deviation between the set value and the actual value. The output of the PID controller is the sum of the proportion (P), integral (I) and derivative (D) of the deviation. The three items represent different aspects of the control effect:

[0051] Proportional control: outputs a control amount based on the size of the error, the larger the error, the larger the control amount. Proportional control can quickly reduce the error, but may avoid overshoot and oscillation.

[0052] Integral control: integrates the error to eliminate the steady-state error of the system. Integral control can ensure that the system eventually stabilizes at the set value, but may increase the response time of the system.

[0053] Derivative control: outputs a control amount based on the rate of change of the error to predict future errors and adjust in advance. Derivative control helps to reduce overshoot and oscillation, and improve the stability of the system.

[0054] PID control algorithm adjustment, after identifying the stuck open, the system immediately clears the integral term in the PID control algorithm. This step is to eliminate the excessive duty cycle caused by the accumulation of the integral term, to avoid overshoot. After clearing, the integral term starts to accumulate again, but this time the accumulation is carried out under more cautious conditions to avoid overshoot again. In the special control state after the stuck open, the feedforward control compensates for the spring force and friction force. Through the above compensation, the system can reduce the sudden change of the valve position at the moment of opening the mixed valve, and try to stabilize the mixed valve at the position opening after opening, to avoid overshoot and the risk of subsequent full closing. The spring force compensation and friction force compensation of the feedforward are obtained by looking up the table according to the opening position of the valve based on the bench test data. The compensation of friction force and spring force not only provides responsiveness, but also provides stability after the stuck open. The control strategy of the duty cycle after identifying the valve body from the stuck state to the stuck open state avoids the problem of engine stall and shaking caused by the overshoot of the mixed valve.

[0055] Through the above method, the application effectively solves the overshoot problem that may occur after the mixed valve is stuck open, and avoids the risk of engine stall or shaking caused thereby. This method not only improves the accuracy and stability of the mixed valve control, but also ensures the reliable operation of the engine under complex working conditions, which is of great significance to improve the vehicle driving safety and overall performance.

[0056] The application proposes a method for avoiding engine stall in the first embodiment, please refer to Figure 1 , the method for avoiding engine stall includes steps S10-S30:

[0057] Step S10, according to the current target opening and the actual opening, the stuck state of the mixed valve is judged;

[0058] Step S20, according to the stuck state of the mixed valve, the opening error between the current target opening and the actual opening is calculated by PID control.

[0059] Step S30: When it is determined that the stable stuck state of the mixing valve has been broken, the integral term of the PID control of the opening error is reset to avoid engine stalling.

[0060] It's important to note that in a car engine's exhaust gas recirculation (EGR) system, the mixing valve is a critical component used to regulate the proportion of exhaust gas entering the cylinders, thereby optimizing combustion efficiency and emissions performance. However, the mixing valve can become stuck in a certain position due to various reasons (such as dirt, wear, or mechanical failure), resulting in inaccurate control of its opening. When the mixing valve is stuck, a significant deviation will occur between its actual opening and the target opening, thus affecting the normal operation of the engine. The following is a detailed description of the above steps:

[0061] Step S10: Determine the jamming state of the mixing valve based on the current target opening and actual opening. The first step of Step S10 is to continuously monitor the target opening and actual opening of the mixing valve. The target opening is usually calculated by the engine management system (EMS) based on the current operating conditions (such as speed, load, temperature, etc.) and sent to the mixing valve controller. The actual opening is the current position of the mixing valve measured by sensors (such as position sensors or pressure sensors). After obtaining the target opening and actual opening, the system needs to calculate the deviation between them. This deviation reflects the difference between the current state of the mixing valve and the target state. The calculation of the opening deviation is usually simple: subtract the actual opening from the target opening. Next, the system will determine whether it is in a jamming state based on the opening deviation and the response characteristics of the mixing valve. The judgment criteria include that if the opening deviation continuously exceeds a preset threshold (such as 5% or 10%), it may indicate that the mixing valve has a jamming problem. The duration of the deviation is also an important indicator. If the deviation remains unchanged or changes very little for a long time (such as a few seconds or minutes), it may mean that the mixing valve is jammed. The system also considers the mixing valve's response speed to control signals. If the mixing valve fails to respond promptly after receiving a control signal (e.g., the response time exceeds a preset threshold), it may indicate jamming or a malfunction. Besides the aforementioned methods based on opening deviation and response characteristics, the system can employ other auxiliary means to improve the accuracy of jamming identification. Temperature monitoring can indirectly determine the presence of jamming by monitoring temperature changes around the mixing valve. If the mixing valve remains in a certain position for an extended period and its temperature rises or falls abnormally, it may indicate jamming. A jammed mixing valve may produce abnormal vibrations or noise. By monitoring these signals, the system can further confirm the jammed state of the mixing valve.

[0062] Determine whether the valve body is currently stable at a certain opening degree. Start accumulating the time when the timer starts. Let the initial value be t. accum(z) = 0, t accum (z) = t accum (z - 1) + T; Timing reset, i.e. t accum (z) = 0. Where, is the current time. The actual opening degree of the mixing valve e stable represents the tolerance of the valve body in the current position to the fluctuation of the position (can be calibrated), i.e. when the actual position fluctuation of the mixing valve is less than the tolerance, it is considered that the mixing valve is temporarily stable at the current opening degree position.

[0063] Calculate the opening degree error according to the current actual opening degree and the target opening degree:

[0064]

[0065] Where, is the current target opening degree, e open (z) is the difference between the current target opening degree and the actual opening degree.

[0066] When and t accum (z) >= t stucksteady , it is determined that the valve body is stuck at a non-target opening degree and remains stable, and the Stucksteady flag is 1. Otherwise, Stucksteady is 0.

[0067] e allowed is the allowable error, i.e. when , it is considered that the actual opening degree meets the requirements of closed-loop control. t stucksteady is the time of position stability, i.e. when the valve opening degree is kept in a stable state for more than t stucksteady , it is considered that the valve body is in a position stable state at this time.

[0068] Step S20: PID control calculation of the opening error between the target opening and the actual opening according to the sticking state of the mixing valve. Once the sticking state of the mixing valve is determined, the system needs to adopt a corresponding control strategy to reduce the opening error and make the actual opening of the mixing valve as close to the target opening as possible. PID control is a commonly used feedback control method that calculates the control signal according to the current error (i.e., the deviation between the target opening and the actual opening) to adjust the output of the controlled object. Proportional control outputs a control signal according to the size of the current error. The larger the error, the stronger the control signal. Proportional control can quickly reduce the error, but may produce overshoot and oscillation. Integral control integrates the error to eliminate the steady-state error of the system. Integral control can ensure that the system eventually stabilizes at the target value, but may increase the response time of the system. Derivative control outputs a control signal according to the rate of change of the error to predict future errors and adjust in advance. Derivative control helps to reduce overshoot and oscillation and improve the stability of the system. Before PID control, the parameters of the PID controller (i.e., the proportional coefficient Kp, the integral coefficient Ki, and the derivative coefficient Kd) need to be set. The selection of these parameters has an important influence on the performance of the system. Generally, these parameters need to be determined through experiments and experience. After the parameters of the PID controller are determined, the system can calculate the control signal according to the current opening error.

[0069] In the case of sticking of the mixing valve, the parameters of the PID controller may need to be adjusted to adapt to this special situation. In the sticking state, too large a proportional coefficient may cause the mixing valve to produce too large an overshoot after being opened. Therefore, Kp can be appropriately reduced to reduce the response speed of the system and avoid overshoot. Although integral control may increase the response time of the system, increasing Ki in the sticking state helps to eliminate the steady-state error caused by sticking. Derivative control can predict future errors and adjust in advance. In the sticking state, introducing derivative control helps to reduce the overshoot and oscillation caused by opening the sticking.

[0070] Step S30: When the stable sticking state of the mixture valve is broken, reset the integral term of the PID control of the opening error to avoid engine stall. When the stable sticking state of the mixture valve is broken by a larger control signal (such as a larger duty cycle), the PID controller may continue to output an excessive control signal due to the effect of the integral term, causing the mixture valve to move excessively and produce overshoot. This overshoot can cause the mixture valve to close completely, preventing outside air from entering the cylinder and causing the engine to stall or shake. To avoid this situation, the system needs to reset the integral term of the PID control when the mixture valve is broken out of the sticking state. The system needs to continuously monitor the opening change of the mixture valve and determine whether it has been broken out of the sticking state. This can usually be achieved by monitoring the change of the opening error. If the opening error rapidly decreases (such as from a larger positive value to a smaller positive value or negative value) in a short period of time, it may indicate that the mixture valve has been broken out of the sticking state. The reset of the integral term is to eliminate the excessive control signal caused by the accumulation of the integral. After the mixture valve is broken out of the sticking state, the system immediately clears the integral term of the PID controller and starts accumulating again. This ensures that after the mixture valve is broken, the PID controller will not continue to output an excessive control signal due to the effect of the integral term, thereby avoiding the risk of overshoot and engine stall. The reset of the integral term can be achieved by software programming. When the system determines that the mixture valve has been broken out of the sticking state, it immediately executes the integral term accumulation restart, but at this time the accumulation process is carried out under more cautious conditions to avoid overshoot again. After the integral term is reset, the system also needs to adjust the output signal of the PID controller according to the new opening error. At this time, the system can combine strategies such as feedforward control to ensure that the opening of the mixture valve can be stabilized around the target opening.

[0071] Based on the first embodiment of the present application, the same or similar contents as the above-mentioned embodiment one can be referred to the above introduction, and will not be described in detail hereinafter. Please refer to Figure 2 In this embodiment, the step of judging the sticking state of the mixture valve according to the current target opening and the actual opening further comprises:

[0072] Step S11, judging whether the actual opening of the mixture valve is stable at the preset opening position;

[0073] Step S12, calculating the opening error according to the current target opening and the actual opening;

[0074] Step S13, judging whether the actual opening of the mixture valve is in a stable sticking state according to the calculated current opening error.

[0075] Specifically, in this embodiment, the mixing valve serves as a key component for regulating exhaust gas flow, and its state has a significant impact on engine performance and emissions. When the mixing valve becomes stuck, it can cause a significant difference between its actual opening and the target opening, which in turn affects the normal operation of the engine. Therefore, accurately determining the stuck state of the mixing valve is crucial to ensure the stability and reliability of the engine. The following is a detailed description of the above steps:

[0076] Step S11: Determine whether the actual opening of the mixing valve is stable at the preset opening position. First, the system needs to continuously monitor the actual opening of the mixing valve. This is usually achieved by installing a position sensor on the mixing valve, which can measure and feedback the opening information of the mixing valve in real time. The preset opening position refers to the opening that the mixing valve should reach under normal working conditions. This value is usually calculated by the engine management system (EMS) according to the current working conditions (such as speed, load, temperature, etc.) and stored in the control unit. After obtaining the actual opening of the mixing valve, the system needs to determine whether it is stable at the preset opening position. This can be achieved by comparing the difference between the actual opening and the preset opening. If the difference between the two is within the preset tolerance range (such as ±1% or ±2%), and this difference remains unchanged for a long time (such as several seconds or minutes), it can be considered that the actual opening of the mixing valve is stable. In addition to the above judgment method based on the difference in opening, the system can also use other auxiliary means to improve the accuracy of judgment. For example, the temperature change or vibration around the mixing valve can be monitored to determine whether it is stuck or faulty.

[0077] Step S12: Calculate the opening error according to the current target opening and actual opening. The target opening refers to the ideal opening that the mixing valve should reach according to the current working conditions calculated by the engine management system. This value is usually stored in the control unit and used for comparison with the actual opening. After obtaining the target opening and the actual opening, the system needs to calculate the error between them. This error reflects the difference between the current state and the target state of the mixing valve, and is an important basis for judging whether the mixing valve is stuck. The calculation of the opening error is usually simple, that is, the difference between the target opening and the actual opening. In order to judge whether the opening error is significant, the system needs to set an error threshold. This threshold is usually determined according to the characteristics of the mixing valve and the requirements of the engine. If the opening error exceeds this threshold, it may indicate that the mixing valve is stuck.

[0078] Step S13: Determine whether the actual opening of the mixing valve is in a stable stuck state based on the calculated current opening error. After obtaining the opening error, the system needs to determine whether this error is stable. If the opening error remains unchanged or changes very little (within a pre-set tolerance range) over a long period of time (such as several seconds or minutes), it can be considered stable. In addition to determining the stability of the opening error, the system also needs to consider the stability of the actual opening of the mixing valve to comprehensively determine whether it is in a stable stuck state. If the actual opening of the mixing valve is stable at a certain position, and the opening error also remains stable and significant (exceeding the pre-set error threshold), it can be considered that the mixing valve is in a stable stuck state. Once it is determined that the mixing valve is in a stable stuck state, the system needs to take appropriate measures to deal with it. This may include adjusting the control strategy, issuing an alarm signal, or taking other necessary measures to ensure the normal operation of the engine.

[0079] It is particularly important to note that in actual application, determining whether the mixing valve is stuck is not a simple matter. Because the state of the mixing valve can be affected by many factors, such as temperature, pressure, vibration, etc. Therefore, the system needs to consider multiple aspects of information to make an accurate judgment. In addition, the judgment of whether the mixing valve is stuck also needs to consider its dynamic characteristics. For example, at the moment when the mixing valve is opened from the stuck state, its actual opening may change rapidly, causing the opening error to suddenly decrease. At this time, the system needs to be able to quickly respond and adjust the control strategy to avoid engine stall or shaking and other problems.

[0080] Further, in the present embodiment, the step of determining whether the actual opening of the mixing valve is in a stable stuck state based on the calculated current opening error further comprises:

[0081] Recording the time when the actual opening of the mixing valve remains in a stable state;

[0082] When the opening error of the mixing valve meets the requirements of closed-loop control and the actual opening remains in a stable state for a certain period of time, it is determined that the mixing valve is in a non-target opening stuck state and the position is stable.

[0083] Specifically, in the present embodiment, accurately determining whether the mixing valve is in a stable non-target opening stuck state is crucial for ensuring the stability and reliability of the engine. The following is a detailed description of the judgment process, including recording the time when the actual opening of the mixing valve remains in a stable state, and determining that the mixing valve is in a non-target opening stuck state and the position is stable when the closed-loop control requirements are met.

[0084] Firstly, the system needs to continuously monitor the actual opening degree variation of the mixing valve. This is usually achieved by installing a position sensor on the mixing valve, which can measure and feedback the opening degree information of the mixing valve in real time. The system needs to record the actual opening degree data at each time point for subsequent analysis. In order to determine whether the actual opening degree of the mixing valve is in a stable state, the system needs to set a standard for the stable state. This standard is usually based on the variation range and time length of the actual opening degree. For example, if the variation range of the actual opening degree within a certain period of time (such as a few seconds or minutes) is less than the pre-set tolerance (such as ±1% or ±2%), it can be considered that the actual opening degree of the mixing valve is in a stable state. Once it is determined that the actual opening degree of the mixing valve is in a stable state, the system needs to start recording this time. This time is calculated from the first time the actual opening degree meets the stable state standard until the actual opening degree no longer meets the stable state standard. This time length is one of the important bases for determining whether the mixing valve is in a stable stuck state.

[0085] Before determining whether the mixing valve is in a non-target opening degree stuck state, the system needs to calculate the opening degree error of the mixing valve. The opening degree error refers to the difference between the actual opening degree and the target opening degree of the mixing valve. This difference reflects the difference between the current state and the target state of the mixing valve, and is an important basis for determining whether the mixing valve is stuck. Closed-loop control refers to the system adjusting the control input (such as control current or voltage) according to the feedback signal (such as actual opening degree) to achieve the desired output (such as target opening degree). When determining whether the mixing valve is in a non-target opening degree stuck state, the system needs to consider the requirements of closed-loop control. If the opening degree error of the mixing valve is within the tolerance range of closed-loop control (i.e. the opening degree error is less than the pre-set threshold), it can be considered that the opening degree of the mixing valve meets the requirements of closed-loop control. Under the premise that the opening degree error of the mixing valve meets the requirements of closed-loop control, the system needs to further determine whether the mixing valve is in a non-target opening degree stuck state. This can be achieved by comparing the actual opening degree with the target opening degree. If there is a significant difference between the actual opening degree and the target opening degree (i.e. the opening degree error exceeds the pre-set threshold), and this difference remains unchanged or changes very little over a long period of time (i.e. the recorded stable state time), it can be considered that the mixing valve is in a non-target opening degree stuck state. In addition to determining whether the mixing valve is in a non-target opening degree stuck state, the system also needs to determine whether the position of the mixing valve is stable. This can be achieved by analyzing the variation of the actual opening degree within the stable state time. If the actual opening degree remains essentially unchanged (i.e. the variation range is less than the pre-set tolerance) within the stable state time, it can be considered that the position of the mixing valve is stable.

[0086] Based on the first embodiment and / or the second embodiment of the present application, in the third embodiment of the present application, the same or similar contents as the above-mentioned embodiments one and two can be referred to the above introduction, and the subsequent will not be described in detail. On this basis, please refer to Figure 3In this embodiment, step S20, the step of calculating the PID control of the opening error between the current target opening and the actual opening according to the sticking state of the mixing valve, further includes:

[0087] Step S21, calculating the derivative term of the PID control of the opening error according to the sticking state of the mixing valve;

[0088] Step S22, calculating the integral term of the PID control of the opening error according to the sticking state of the mixing valve;

[0089] Step S23, calculating the proportional term of the PID control of the opening error according to the sticking state of the mixing valve;

[0090] Step S24, adding the derivative term of the PID control, the integral term of the PID control and the proportional term of the PID control to obtain the PID control result of the mixing valve.

[0091] Specifically, in this embodiment, the step of calculating the PID control of the opening error between the current target opening and the actual opening according to the sticking state of the mixing valve. PID control is a commonly used control algorithm, which adjusts the control input to reduce the error between the target value and the actual value. In the control of the mixing valve, PID control can help us dynamically adjust the control strategy according to the sticking state of the mixing valve to achieve accurate control of the mixing valve. When the mixing valve is stuck, it will cause a significant difference between the actual opening and the target opening, which will affect the normal operation of the engine. In order to deal with this situation, we need to calculate the PID (proportional-integral-derivative) control of the opening error between the target opening and the actual opening according to the sticking state of the mixing valve to achieve accurate control of the mixing valve. The following are the detailed steps and explanations:

[0092] Step S21: Calculate the derivative term of the PID control of the opening error. The derivative term in PID control is mainly used to predict the trend of error change and adjust the control input according to this trend to eliminate potential errors in advance. In the control of the mixing valve, the derivative term can help us adjust the control strategy according to the rate of change of the opening error, so as to achieve fast response of the mixing valve. The calculation of the derivative term is usually based on the rate of change of the opening error. When calculating the derivative term, we need to consider the sticking state of the mixing valve. If the mixing valve is in the sticking state, the rate of change of the opening error may be limited, resulting in inaccurate calculation results of the derivative term. Therefore, we need to adjust the derivative gain according to the sticking state of the mixing valve to ensure that the derivative term can accurately reflect the trend of the opening error change.

[0093] Step S22: Calculate the integral term of the PID control of the opening error. The integral term in PID control is mainly used to eliminate accumulated errors to ensure that the system can reach a steady state. In the control of the mixing valve, the integral term can help us adjust the control input according to the accumulation of the opening error, so as to achieve precise control of the mixing valve. The calculation of the integral term is usually based on the accumulated value of the opening error. When calculating the integral term, we also need to consider the sticking state of the mixing valve. If the mixing valve is in the sticking state, the accumulation speed of the opening error may be limited, resulting in inaccurate calculation results of the integral term. Therefore, we need to adjust the integral gain according to the sticking state of the mixing valve to ensure that the integral term can accurately reflect the accumulation of the opening error.

[0094] Step S23: Calculate the proportional term of the PID control of the opening error. The proportional term in PID control is mainly used to directly reduce the error. In the control of the mixing valve, the proportional term can help us adjust the control input according to the current opening error, so as to achieve fast response of the mixing valve. The calculation of the proportional term is usually based on the current opening error. When calculating the proportional term, we also need to consider the sticking state of the mixing valve. If the mixing valve is in the sticking state, the opening error may persist, resulting in an excessively large calculation result of the proportional term. Therefore, we need to adjust the proportional gain according to the sticking state of the mixing valve to ensure that the proportional term can appropriately reflect the current opening error.

[0095] Step S24: Accumulate the derivative term, integral term and proportional term of the PID control to obtain the PID control result of the mixing valve. After calculating the derivative term, integral term and proportional term of the PID control, we need to accumulate them to obtain the PID control result of the mixing valve. This control result will be used to adjust the control input of the mixing valve to achieve precise control of the mixing valve. When accumulating the PID terms, we need to consider the dynamic characteristics of the mixing valve. For example, the response time, lag effect, etc. of the mixing valve will affect the results of the PID control. Therefore, we need to adjust the parameters of the PID control according to the dynamic characteristics of the mixing valve to ensure that the PID control can achieve precise control of the mixing valve. Finally, the accumulated PID control result is output to the control unit of the mixing valve to adjust the control input of the mixing valve. This control result will directly affect the actual opening of the mixing valve, thereby achieving precise regulation of the engine exhaust gas flow.

[0096] Based on the first embodiment and / or the second embodiment and / or the third embodiment of the present application, in the fourth embodiment of the present application, the same or similar contents as the above-mentioned embodiments one, embodiments two, embodiments three can refer to the above introduction, and the subsequent will not be described in detail. On this basis, please refer to Figure 4In this embodiment, step S30, the step of resetting the integral term of the PID control of the opening error when the stable sticking state of the mixture valve is broken to avoid engine stall, further includes:

[0097] Step S31, when the actual opening of the mixture valve is monitored to change and the change amplitude exceeds the preset threshold, it is determined that the sticking state of the mixture valve is broken;

[0098] Step S32, after confirming that the sticking state of the mixture valve is broken, resetting the integral term of the PID control and updating the PID control result of the mixture valve to avoid engine stall.

[0099] Specifically, in this embodiment, when the stable sticking state of the mixture valve is broken, the integral term of the PID control is reset to avoid engine stall. The purpose of this step is to eliminate the accumulated error by resetting the integral term of the PID control after the sticking state of the mixture valve is broken, so as to avoid engine stall due to improper control of the mixture valve. The following is the detailed steps and explanations:

[0100] Step S31: Monitor the change of the actual opening of the mixture valve and determine that the sticking state is broken. To determine whether the stable sticking state of the mixture valve is broken, first, the change of the actual opening of the mixture valve needs to be monitored. This is usually achieved by a position sensor installed on the mixture valve, which can measure and feedback the opening information of the mixture valve in real time. In order to accurately determine whether the sticking state of the mixture valve is broken, we need to set a preset threshold for the change amplitude. This threshold can be determined according to the normal working range of the mixture valve, the running state of the engine and the precision of the control system, etc. After monitoring the change of the actual opening of the mixture valve, we need to determine whether the change amplitude exceeds the preset threshold. If the change amplitude exceeds the threshold, we can consider that the sticking state of the mixture valve has been broken. This is because the actual opening of the mixture valve usually remains unchanged or changes little in the sticking state. When the sticking state is broken, the actual opening of the mixture valve will change significantly, and the change amplitude will usually exceed the preset threshold.

[0101] Step S32: Reset the PID control integral term and update the PID control result. After confirming that the mixed valve sticking state is broken, we need to reset the integral term in the PID control. The integral term is used in the PID control to eliminate accumulated errors, but when the mixed valve is in a sticking state, the integral term may accumulate a large error because it cannot accurately reflect the change in the actual opening. Therefore, after the sticking state is broken, we need to reset the integral term to eliminate these accumulated errors. After resetting the integral term, we need to recalculate the PID control result based on the current opening error. This new control result will be used to adjust the control input of the mixed valve to achieve precise control of the mixed valve. When updating the PID control result, we need to consider factors such as the dynamic characteristics of the mixed valve and the operating state of the engine to ensure the accuracy and stability of the control result. By resetting the integral term and updating the PID control result, we can avoid engine stalling due to improper control of the mixed valve. This is because when the mixed valve sticking state is broken, if the PID control is not properly adjusted, the actual opening of the mixed valve may continue to deviate from the target opening, leading to a decrease in engine performance or even stalling. By resetting the integral term and updating the PID control result, we can make the actual opening of the mixed valve follow the target opening as soon as possible, thereby maintaining the stable operation of the engine.

[0102] In the implementation of step S30, we need to monitor the actual opening degree change of the mixing valve in real time and respond immediately after detecting that the stuck state is broken. This requires the control system to have high real-time performance and response speed to ensure timely adjustment when the mixing valve stuck state is broken. The setting of the preset threshold is crucial for accurately determining whether the mixing valve stuck state is broken. If the threshold is set too low, it may lead to false positives; if the threshold is set too high, it may delay the judgment. Therefore, we need to reasonably set the preset threshold according to the normal working range of the mixing valve, the running state of the engine, and the precision of the control system, etc. When updating the PID control result, we need to consider the dynamic characteristics of the mixing valve, such as response time, hysteresis, etc., which will affect the PID control result. Therefore, we need to adjust the parameters of the PID control (such as proportional gain, integral gain, and derivative gain) according to the dynamic characteristics of the mixing valve to ensure accurate control of the mixing valve. When resetting the integral term, we need to avoid the problem of integral saturation. Integral saturation refers to the phenomenon that the integral term cannot be increased or decreased beyond a certain limit. If the integral term has been saturated before resetting, it may cause the control system to be unable to quickly respond to changes in the actual opening degree after resetting. Therefore, when resetting the integral term, we need to determine whether to attenuate or limit the integral term according to the actual situation. During the implementation of step S30, we also need to continuously monitor the state of the engine. If the engine has abnormal conditions (such as power reduction, emission exceeding, etc.), we need to adjust and handle it in time to ensure the stability and reliability of the engine. The duty cycle control calculation is as follows:

[0103] PWM(z) = PWM PID + PWM FF

[0104] PWM(z) is the calculated duty cycle, PWM PID is the duty cycle controlled by PID feedback, and PWM FF is the duty cycle controlled by feedforward.

[0105] PWM(z) = K P * e open (z) + k d (e open (z) - e open (z-1) / T)

[0106] In the ideal state, the driving force provided by the feedforward control can just overcome the spring tension and friction, avoiding the situation that the valve body moves too much in the opposite direction of the target opening degree due to insufficient duty cycle during the breaking of the stuck state. The driving force is provided by the duty cycle calculated by PWM PID , and when the opening degree is small, eopen (z) not large, then PWM PID The value of PWM is also not large. Therefore, in the moment when the stuck state is broken, the valve body will only move towards the target opening with a small acceleration. There will be no overshoot due to excessive duty cycle.

[0107] Further, in the embodiment, the step of determining that the stuck state of the mixing valve is broken when the actual opening of the mixing valve is monitored to change and the change amplitude exceeds a preset threshold value comprises:

[0108] According to the stuck state of the mixing valve, a stuck flag bit of the mixing valve at each moment is recorded;

[0109] When the stuck flag bit at the last moment is a first preset value, the current flag bit is a second preset value, and the change amplitude exceeds a preset threshold value, it is determined that the mixing valve is broken from the stuck state.

[0110] Specifically, in the embodiment, in order to determine whether the stuck state of the mixing valve is broken in time, a series of monitoring and determining steps need to be taken. This includes recording the stuck flag bit of the mixing valve and determining whether the mixing valve is broken from the stuck state according to the flag bit and the change amplitude. The purpose of this step is to ensure the stable operation of the engine by real-time monitoring and determining in the case of possible stuck of the mixing valve. The following is a detailed description of the above steps:

[0111] In order to track the stuck state of the mixing valve, we need to define a stuck flag bit. This flag bit can be a binary variable, which indicates whether the mixing valve is currently in a stuck state. For example, we can set the flag bit to 0 to indicate that the mixing valve is not stuck, and set it to 1 to indicate that the mixing valve is stuck. In actual operation, we need to update the state of the stuck flag bit in real time according to the actual opening change of the mixing valve and the judgment of the control system. This is usually achieved through the logic judgment inside the control system. When it is detected that the actual opening of the mixing valve remains unchanged for a long time or changes very little, and there is a large deviation from the target opening, it can be considered that the mixing valve is in a stuck state, and the stuck flag bit is set to 1. Conversely, when the mixing valve can normally follow the change of the target opening, the stuck flag bit can be set to 0. When determining whether the mixing valve is broken from the stuck state, we need to consider two conditions: one is the stuck flag bit state at the last moment, and the other is the flag bit state at the current moment and the change amplitude of the actual opening. The stuck flag bit at the last moment is a first preset value (for example, 1): this indicates that the mixing valve was in a stuck state at the last moment.

[0112] The current time flag is a second preset value (for example, 0) and the change amplitude exceeds a preset threshold: this indicates that the current time mixed valve is no longer in the stuck state, and its actual opening degree has changed significantly. The preset threshold of the change amplitude can be determined according to the normal working range of the mixed valve, the running state of the engine, and the accuracy of the control system, and the like. In the actual judgment process, we need to obtain the stuck flag state of the last time and the current time first, and then compare whether the actual opening degree change amplitude exceeds the preset threshold. If the above two conditions are met, we can consider that the mixed valve has been flushed from the stuck state.

[0113] In the judgment process, we need to ensure the real-time and accuracy of the control system to detect the state change of the mixed valve in time. The setting of the preset threshold is crucial for accurately determining whether the mixed valve has been flushed from the stuck state. If the threshold is set too low, it may lead to misjudgment; if the threshold is set too high, it may delay the judgment. Therefore, we need to reasonably set the preset threshold according to the actual situation. In order to realize step S31, we need a real-time monitoring system to continuously track the state of the mixed valve. This system can include sensors, data acquisition modules, logic judgment modules, and the like. The sensor is used to measure the actual opening degree of the mixed valve in real time; the data acquisition module is used to input the sensor data into the control system; the logic judgment module determines whether the mixed valve is in the stuck state and whether it has been flushed from the stuck state according to the preset algorithm and rules. Suppose at a certain time T1, the stuck flag of the mixed valve is 1, indicating that the mixed valve is in the stuck state. At the next time T2, we detect that the actual opening degree of the mixed valve has changed significantly (for example, from 20% to 60%), and the stuck flag has changed to 0. At the same time, the change amplitude exceeds the preset threshold (for example, 30%). In this case, we can consider that the mixed valve has been flushed from the stuck state.

[0114] Other embodiments or specific implementations of the device for avoiding engine stall can refer to the above-mentioned method embodiments, which will not be described here.

[0115] It should be noted that in this paper, the terms "include", "contain" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or system including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or system. Without more limitations, the element defined by the statement "includes a" does not exclude the presence of another identical element in the process, method, article or system including the element.

[0116] The above-mentioned application embodiment serial number is only for description, not representing the pros and cons of the embodiment.

[0117] Through the above description of the embodiments, those skilled in the art can clearly understand that the above-mentioned example method can be realized by means of software and a necessary general hardware platform, and of course, it can also be realized by hardware, but in many cases, the former is a better embodiment. Based on such understanding, the technical solutions of the present application can be embodied in the form of a software product in essence or in the form of a contribution to the prior art. The computer software product is stored in a storage medium (such as a read-only memory / random access memory, a magnetic disk, an optical disk), and includes a plurality of instructions for causing a terminal device (which can be a mobile phone, a computer, a server, an air conditioner, or a network device, etc.) to execute the method described in each embodiment of the present application.

[0118] The above is only a preferred embodiment of the present application, and does not limit the patent scope of the present application, and any equivalent structure or equivalent process transformation using the content of the specification and drawings, or direct or indirect application in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A method for preventing engine stalling, characterized in that, The methods for preventing engine stalling include: The jamming state of the mixing valve is determined based on the current target opening degree and the actual opening degree; Based on the stuck state of the mixing valve, the opening error between the current target opening degree and the actual opening degree is calculated by PID control; When it is determined that the stable stuck state of the mixing valve has been broken, the integral term of the PID control of the opening error is reset to avoid engine stalling; Resetting the integral term in the PID control and updating the PID control results of the mixing valve to prevent engine stalling also includes: Detect the operating status of the mixing valve; After the integral of the mixing valve is reset, the mixing valve moves in the opposite direction to the target opening, and the feedforward provides the duty cycle at this moment; The responsiveness provided by feedforward friction compensation ensures that the mixing valve remains stable after being disengaged from its jammed state.

2. The method as described in claim 1, characterized in that, The step of determining the jamming state of the mixing valve based on the current target opening degree and the actual opening degree further includes: Determine whether the actual opening degree of the mixing valve is stable at the preset opening degree position; Calculate the opening error based on the target opening and the actual opening. Based on the calculated current opening error, it is determined whether the actual opening of the mixing valve is in a stable stuck state.

3. The method as described in claim 2, characterized in that, The step of determining whether the actual opening degree of the mixing valve is in a stable stuck state based on the calculated current opening degree error further includes: Record the time during which the actual opening degree of the mixing valve remains stable; When the opening error of the mixing valve meets the requirements of closed-loop control and the actual opening degree remains stable for a period of time, it is determined that the mixing valve is in a non-target opening degree stuck state and the position is stable.

4. The method as described in claim 3, characterized in that, The step of calculating the opening error between the current target opening and the actual opening based on the stuck state of the mixing valve using PID control further includes: Based on the stuck state of the mixing valve, calculate the differential term of the PID control for the opening error; Based on the stuck state of the mixing valve, calculate the integral term of the PID control for the opening error; Calculate the proportional term of the PID control for the opening error based on the stuck state of the mixing valve; The differential term, integral term, and proportional term of the PID control are summed to obtain the PID control result of the mixing valve.

5. The method as described in claim 4, characterized in that, The step of resetting the integral term of the PID control for the opening error to prevent engine stalling when the stable stuck state of the mixing valve is determined to be broken includes: When the actual opening degree of the mixing valve changes and the change exceeds a preset threshold, it is determined that the jammed state of the mixing valve has been broken. After confirming that the jammed state of the mixing valve has been cleared, the integral term in the PID control is reset and the PID control result of the mixing valve is updated to prevent the engine from stalling.

6. The method as described in claim 5, characterized in that, The step of determining that the jammed state of the mixing valve has been broken when the actual opening degree of the mixing valve is detected to change and the change exceeds a preset threshold includes: Based on the stuck state of the mixing valve, record the stuck flag bit of the mixing valve at each moment; When the stuck flag is at the first preset value at the previous moment, and the flag is at the second preset value at the current moment and the change exceeds the preset threshold, it is determined that the mixing valve is opened from the stuck state.

7. A device for preventing engine stalling, characterized in that, The device for preventing engine stalling includes: The judgment module determines the jamming state of the mixing valve based on the current target opening degree and the actual opening degree. The adjustment module performs PID control calculations on the opening error between the current target opening and the actual opening based on the jamming state of the mixing valve. The reset module resets the integral term of the PID control for the opening error when it determines that the stable stuck state of the mixing valve has been broken to avoid engine stalling. The reset module resets the integral term in the PID control and updates the PID control result of the mixing valve to prevent engine stalling. It is also used to: detect the operating state of the mixing valve; after the integral of the mixing valve is reset, the mixing valve moves in the opposite direction to the target opening, and feedforward provides the duty cycle at this moment; and provide responsiveness through feedforward friction compensation so that the mixing valve remains stable after being forced open.

8. A device for preventing engine stalling, characterized in that, The device for preventing engine stalling includes: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the computer program, when executed by the processor, implements the steps of the method for preventing engine stalling as described in any one of claims 1 to 6.

9. A computer storage medium, characterized in that, The computer storage medium stores a computer program, which, when executed by a processor, implements the steps of the method for preventing engine stalling as described in any one of claims 1 to 6.

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