A vehicle emergency braking condition control method, computer equipment and vehicle

Abstract

The application discloses a control method of a vehicle emergency braking working condition, computer equipment and a vehicle, and relates to the technical field of engine control, wherein the control method comprises the following steps: determining that the vehicle enters the emergency braking working condition, increasing a preset idle speed of the engine to a first speed threshold, activating idle closed-loop control based on the current speed of the engine and the first speed threshold, obtaining an idle fire path torque under the emergency braking working condition based on the idle closed-loop control, and controlling the engine to output the idle fire path torque. The application can identify the emergency braking working condition of the vehicle, increase the preset idle speed of the engine to the first speed threshold, reduce the phenomenon that the load drag torque is large and the engine output torque is insufficient to meet the stable operation of the idle speed under the emergency braking working condition, reduce the probability of engine stall, and improve the user experience.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of engine control, and particularly relates to a control method for vehicle emergency braking condition, computer equipment and vehicle. BACKGROUND

[0002] In the related art, in the emergency braking scene, the vehicle is rapidly reduced from high speed to low speed, which can cause the vehicle to stall and cause customer complaints. SUMMARY

[0003] Therefore, the embodiments of the present application provide a control method for vehicle emergency braking condition, computer equipment and vehicle to solve the problem of engine stall in emergency braking.

[0004] To achieve the above object, the technical scheme of the embodiments of the present application is as follows:

[0005] In a first aspect, the present application provides a control method for vehicle emergency braking condition, comprising:

[0006] determining that the vehicle enters an emergency braking condition;

[0007] increasing a preset idle speed of the engine to a first speed threshold;

[0008] activating idle closed-loop control based on the current speed of the engine and the first speed threshold;

[0009] obtaining an idle fire path torque in the emergency braking condition based on the idle closed-loop control;

[0010] controlling the engine to output the idle fire path torque.

[0011] In some embodiments, determining that the vehicle enters an emergency braking condition comprises:

[0012] obtaining the deceleration of the vehicle, the brake pedal signal, the vehicle speed signal and the brake master cylinder pressure;

[0013] if the deceleration of the vehicle is higher than a first threshold, the brake pedal signal is in a depressed state, the vehicle speed signal is lower than a second threshold, and the brake master cylinder pressure is higher than a third threshold, it is determined that the vehicle enters the emergency braking condition.

[0014] In some embodiments, activating idle closed-loop control based on the current speed of the engine and the first speed threshold comprises:

[0015] obtaining a speed interval, wherein the speed interval is the difference between the current speed of the engine and the first speed threshold;

[0016] if the speed interval is less than a preset interval, the idle closed-loop control is activated.

[0017] In some embodiments, the preset idle speed is between 700-900 rpm, the first speed threshold is between 900-1100 rpm, and the preset interval is between 25-75 rpm.

[0018] In some embodiments, a ratio of the first speed threshold to the preset idle speed is 1.2, and a ratio of the first speed threshold to the preset interval is 35.

[0019] In some embodiments, based on the idle closed-loop control, an idle fire path torque in an emergency braking condition is obtained, including:

[0020] An inertia of rotation, a time coefficient, a time constant coefficient, and a brake pressure are obtained.

[0021] A first reserve torque time constant is calculated according to the time coefficient and the time constant coefficient.

[0022] A second reserve torque time constant is obtained based on the brake pressure and the first reserve torque time constant.

[0023] The idle fire path torque in the emergency braking condition is calculated based on the inertia of rotation and the second reserve torque time constant.

[0024] In some embodiments, the inertia of rotation is obtained, including:

[0025] A connection state of the engine transmission chain, an initial inertia of rotation, and a fixed change rate are obtained.

[0026] The inertia of rotation is obtained based on the connection state of the engine transmission chain, the initial inertia of rotation, and the fixed change rate.

[0027] In some embodiments, the inertia of rotation is obtained based on the connection state of the engine transmission chain, the initial inertia of rotation, and the fixed change rate, including:

[0028] When the transmission chain is in an unconnected state, the inertia of rotation is the initial inertia of rotation.

[0029] When the transmission chain changes from the unconnected state to a connected state, the inertia of rotation increases from the initial inertia of rotation to a first fixed value at the fixed change rate, and the inertia of rotation remains unchanged at the first fixed value after reaching the first fixed value.

[0030] When the transmission chain switches from the connected state to the unconnected state, the inertia of rotation decreases from the first fixed value to the initial inertia of rotation at the fixed change rate, and the inertia of rotation remains unchanged at the initial inertia of rotation after reaching the initial inertia of rotation.

[0031] In some embodiments, the time coefficient is obtained based on the state of the combustion phase of the engine, the speed interval of the engine, and the speed change rate of the engine, wherein the speed interval is a difference between a current speed and the first speed threshold.

[0032] The state of the combustion phase of the engine, the speed interval of the engine, and the speed change rate of the engine are obtained.

[0033] The time coefficient is calibrated based on the state of the combustion phase of the engine, the speed interval of the engine, and the speed change rate of the engine.

[0034] In some embodiments, the time coefficient is calibrated based on the state of the combustion phase of the engine, the speed interval of the engine, and the speed change rate of the engine, comprising:

[0035] In a preset time after the catalytic converter is ignited and exits the ignition, in a test environment where the speed fluctuation of the engine is lower than a first set speed fluctuation range, the time coefficient is calibrated according to the speed interval of the engine and the speed change rate; or,

[0036] After the ignition phase is exited and a preset time is delayed, in a test environment where the speed fluctuation of the engine is lower than a second set speed fluctuation range, the time coefficient is calibrated according to the speed interval of the engine and the speed change rate.

[0037] In some embodiments, the second reserve torque time constant is obtained based on the brake pressure and the first reserve torque time constant, comprising:

[0038] A reserve torque time constant correction coefficient is obtained based on the brake pressure.

[0039] The second reserve torque time constant is calculated according to the first reserve torque time constant and the reserve torque time constant correction coefficient, wherein the second reserve torque time constant is a product of the first reserve torque time constant and the reserve torque time constant correction coefficient.

[0040] In some embodiments, the idle fire path torque in the emergency braking working condition is calculated based on the moment of inertia and the second reserve torque time constant, comprising:

[0041] A P term parameter and an I term parameter of PI control are calculated according to the moment of inertia and the second reserve torque time constant.

[0042] A P term torque and an I term torque of the idle fire path torque are calculated according to the P term parameter and the I term parameter of the PI control.

[0043] The idle fire path torque is calculated according to the P term torque and the I term torque of the idle fire path torque.

[0044] In a second aspect, the present application provides a computer device, comprising one or more processing modules configured to execute computer instructions stored in a storage module to perform any of the control methods described above.

[0045] In a third aspect, the present application provides a vehicle comprising the computer device described above.

[0046] The control method for vehicle emergency braking condition provided by the embodiments of the present application can identify the emergency braking condition of the vehicle, increase the preset idle speed of the engine to the first speed threshold, make the engine enter the idle closed-loop control more quickly, and then control the idle fire path torque, thereby reducing the phenomenon that the load drag torque is large and the engine output torque is insufficient to meet the idle speed stable operation in the emergency braking condition, reducing the probability of engine stall, and improving the user experience. BRIEF DESCRIPTION OF DRAWINGS

[0047] Figure 1 A flowchart of the control method for vehicle emergency braking condition provided by the embodiments of the present application;

[0048] Figure 2 A time coefficient calibration table provided by the embodiments of the present application;

[0049] Figure 3 Another time coefficient calibration table provided by the embodiments of the present application;

[0050] Figure 4 A functional relationship diagram of the reserve torque time constant correction coefficient and the brake master cylinder pressure provided by the embodiments of the present application. DETAILED DESCRIPTION

[0051] It should be noted that the embodiments and technical features in the present application can be combined with each other without conflict, and the detailed description in the specific embodiments should be understood as an explanation and description of the purpose of the present application, and should not be regarded as an improper limitation of the present application.

[0052] The present application will be further described in detail below with reference to the accompanying drawings and specific embodiments. The "first", "second", etc. in the embodiments of the present application are only for the purpose of description, and should not be understood as indicating or implying their relative importance or implicitly including at least one feature. In the description of the embodiments of the present application, the meaning of "multiple" is at least two, for example, two, three, etc., unless otherwise explicitly specified.

[0053] In a first aspect of the embodiments of the present application, a control method for a vehicle emergency braking condition is provided, comprising: Figure 1

[0054] S1, determining that the vehicle enters an emergency braking condition;

[0055] S2, increasing a preset idle speed of the engine to a first speed threshold;

[0056] S3, activating idle closed-loop control based on the current speed of the engine and the first speed threshold;

[0057] S4, obtaining an idle fire path torque under the emergency braking condition based on the idle closed-loop control;

[0058] S5, controlling the engine to output the idle fire path torque.

[0059] In the related art, when the gearbox is reduced from a high vehicle speed and a high gear to a low vehicle speed and a low gear, the engine clutch cannot quickly disengage the gearbox, the engine is coupled with the gearbox, and the load of the gearbox drags the engine to a lower speed because the clutch cannot disengage in time. The load torque of the gearbox is greater than the output torque of the engine idle speed, and the engine output torque is insufficient to overcome the transient load of the gearbox. In this scenario, when the engine output torque is less than the load torque due to the large transient load of the gearbox, the engine is braked, resulting in the problem of engine stall in the emergency braking condition.

[0060] The control method provided by the embodiments of the present application can identify the emergency braking condition of the vehicle, increase the preset idle speed of the engine to the first speed threshold after the vehicle enters the emergency braking condition, make the engine enter the idle closed-loop control faster, and then control the idle fire path torque. This reduces the phenomenon that the load drag torque is large and the engine output torque is insufficient to meet the idle speed stable operation in the emergency braking condition, reduces the probability of stall occurrence, and improves the user experience.

[0061] It should be noted that the fire path torque is the initial fire path torque demand determined by the throttle pedal opening and the engine speed, and after a series of torque coordination, the torque is converted into the target ignition angle, and the final output ignition advance angle. In the activated idle closed-loop control state, the throttle pedal opening demand torque is generally 0 Nm (Newton-metre), and the speed demand torque is determined by the deviation of the current speed and the first speed threshold.

[0062] The design method of the embodiments of the present application will be described in detail in combination with specific embodiments.

[0063] In an embodiment, step S1 comprises:

[0064] ​S11, obtaining the deceleration of the vehicle, the brake pedal signal, the vehicle speed signal and the brake master cylinder pressure;

[0065] S12, if the deceleration of the vehicle is higher than the first threshold value, the brake pedal signal is in the depressed state, the vehicle speed signal is lower than the second threshold value, and the brake master cylinder pressure is lower than the third threshold value, it is determined that the vehicle enters the emergency braking condition.

[0066] In step S11, the brake pedal signal and the brake master cylinder pressure are obtained by processing the brake vacuum pump through the control system. Exemplarily, the control system is a computer device, such as a driving computer or an on-board computer, also known as an Electronic Control Unit (ECU); the deceleration of the vehicle and the brake pedal signal are obtained through the controller. Exemplarily, the controller is an Electronic Stability Controller (ESC).

[0067] In step S12, the first threshold value, the second threshold value and the third threshold value are calibrated through multiple experiments, wherein the second threshold value refers to the lower limit of the vehicle speed during normal driving. It can be understood that the greater the deceleration, the faster the vehicle decelerates, and the greater the probability that the vehicle enters the emergency braking condition; during the emergency braking condition, the brake pedal signal is in the depressed state, and when the brake pedal is depressed, the brake master cylinder oil pressure signal increases and the brake master cylinder pressure increases. Therefore, it is determined that the vehicle enters the emergency braking condition when the deceleration of the vehicle is higher than the first threshold value, the brake pedal signal is in the depressed state, the vehicle speed signal is lower than the second threshold value, and the brake master cylinder pressure is higher than the third threshold value.

[0068] In this way, the emergency braking condition is identified by multiple conditions, and the vehicle is determined to enter the emergency braking condition when all conditions are met, which improves the accuracy of identification, reduces the situation of activating the idle closed-loop control due to inaccurate identification of the emergency braking condition of the vehicle, and improves the reliability of the control system.

[0069] In step S2, the idle state refers to a state in which the current speed deviates from the first speed threshold by a certain value. The preset idle speed refers to the threshold at which the engine enters the idle state. That is, after the vehicle enters the emergency braking condition, the engine is decelerated to the preset idle speed and then enters the idle state. It can be understood that increasing the preset idle speed of the engine to the first speed threshold can make the engine enter the idle state earlier in the emergency braking condition.

[0070] In step S3, the judgment logic for activating the idle closed-loop control is not limited.

[0071] In an embodiment, the step S3 comprises: if the current engine speed is not greater than the first speed threshold, activating the idle closed-loop control. That is, when the engine speed is high, the idle closed-loop control is not needed, and when the engine speed is reduced to the first speed threshold, the idle closed-loop control is activated.

[0072] In another embodiment, the step S3 comprises:

[0073] The speed interval ΔV is obtained, where the speed interval is the difference between the current engine speed V1 and the first speed threshold V2. That is, ΔV = V1-V2, and ΔV is greater than 0.

[0074] If the speed interval is less than the preset interval, the idle closed-loop control is activated.

[0075] That is, the idle closed-loop control can be activated when the engine speed approaches the first speed threshold. The preset interval is obtained through multiple tests. It can be understood that if the idle closed-loop control is activated only when the engine speed is reduced to the first speed threshold, the control system has a certain reaction time, the idle closed-loop control has a certain hysteresis, the deceleration is large in the emergency braking condition, the speed is reduced quickly, and the control accuracy can be affected. In this embodiment, by setting the preset interval, it can be ensured that the control system has activated the idle closed-loop control when the engine speed is reduced to the first speed threshold, and the control accuracy is improved.

[0076] In an embodiment, the preset idle speed is between 700-900 rpm (revolutions per minute), the first speed threshold is between 900-1100 rpm, and the preset interval is between 25-75 rpm.

[0077] Exemplarily, the preset idle speed is determined according to different vehicle models, and can be 700 rpm, 750 rpm, 800 rpm, 850 rpm, or 900 rpm, etc.

[0078] Exemplarily, the first speed threshold can be 900 rpm, 950 rpm, 1000 rpm, 1050 rpm, or 1100 rpm, etc.

[0079] Exemplarily, the preset interval can be 25 rpm, 30 rpm, 40 rpm, 50 rpm, 60 rpm, 70 rpm, or 75 rpm, etc.

[0080] In some embodiments, the preset idle speed of a certain vehicle model is 850 rpm, the first speed threshold is 1050 rpm, and the preset interval is 30 rpm. In this way, the idle closed-loop control can be activated when the engine speed is reduced to 1080 rpm.

[0081] In another embodiment, the ratio of the first rotation speed threshold to the preset idle rotation speed is 1.2, and the ratio of the first rotation speed threshold to the preset interval is 35.

[0082] For example, the preset idle rotation speed is 800 rpm, the first rotation speed threshold is 960 rpm, and the preset interval is 27 rpm. In this way, the idle closed-loop control can be activated when the engine rotation speed is reduced to 987 rpm.

[0083] In step S4, the idle fire path torque is obtained through the idle closed-loop control.

[0084] In one embodiment, step S4 includes:

[0085] S41, obtaining the moment of inertia, the time coefficient, the time constant coefficient, and the brake pressure;

[0086] S42, calculating the first reserve torque time constant according to the time coefficient and the time constant coefficient;

[0087] S43, obtaining the second reserve torque time constant based on the brake pressure and the first reserve torque time constant;

[0088] S44, calculating the idle fire path torque in the emergency braking condition based on the moment of inertia and the second reserve torque time constant.

[0089] In step S41, the brake pressure is obtained by processing the brake vacuum pump through the control system.

[0090] In one embodiment, the step of obtaining the moment of inertia in step S41 includes obtaining the connection state of the engine transmission chain, the initial moment of inertia, and the fixed change rate; and obtaining the moment of inertia based on the connection state of the engine transmission chain, the initial moment of inertia, and the fixed change rate.

[0091] The fixed change rate refers to the change amount of the moment of inertia of the engine per second within the interval time. It can be understood that the connection state of the engine transmission chain is different, and the moment of inertia of the engine is different.

[0092] In one embodiment, obtaining the moment of inertia based on the connection state of the engine transmission chain, the initial moment of inertia, and the fixed change rate includes:

[0093] When the transmission chain is in the unconnected state, the moment of inertia is the initial moment of inertia;

[0094] When the transmission chain changes from the unconnected state to the connected state, the moment of inertia increases from the initial moment of inertia to a first fixed value at a fixed change rate, and the moment of inertia remains unchanged at the first fixed value after reaching the first fixed value;

[0095] When the transmission chain switches from the connected state to the unconnected state, the moment of inertia decreases from the first fixed value to the initial moment of inertia at a fixed change rate, and when the moment of inertia reaches the initial moment of inertia, the initial moment of inertia is maintained unchanged.

[0096] Exemplarily, the initial moment of inertia of a certain vehicle model is 0.1719 kg·m 2 (kilogram·metre·metre, kilogram x square meter), and the fixed change rate is 0.01 kg·m 2 / s. The interval time for the transmission chain to change from the unconnected state to the connected state is 10 s, and the first fixed value is 0.2719 kg·m 2 .

[0097] In an embodiment, the step of obtaining the time coefficient in step S41 comprises obtaining the state of the combustion phase of the engine, the speed interval of the engine and the speed change rate, wherein the speed interval is the difference between the current speed and the first speed threshold; and calibrating the time coefficient based on the state of the combustion phase of the engine, the speed interval of the engine and the speed change rate.

[0098] Wherein, obtaining the state of the combustion phase of the engine means obtaining the combustion phase in which the current engine is located.

[0099] In an embodiment, the step of calibrating the time coefficient based on the state of the combustion phase of the engine, the speed interval of the engine and the speed change rate comprises: in the catalytic converter light-off phase and within a preset time after exiting the light-off phase, calibrating the time coefficient according to the speed interval of the engine and the speed change rate under the test environment that the speed fluctuation of the engine is lower than the first set speed fluctuation range; or, after exiting the light-off phase and delaying for a preset time, calibrating the time coefficient according to the speed interval of the engine and the speed change rate under the test environment that the speed fluctuation of the engine is lower than the second set speed fluctuation range.

[0100] In the embodiment, the first set speed fluctuation range is ±20 r / min (revolutions per minute), and the second set speed fluctuation range is ±15 r / min. All calibrations are based on an overall target set according to the subjective evaluation requirements of drivability. In the catalytic converter light-off phase, regardless of the water temperature, the fan condition, the change of electrical load, and the change of vehicle state, the speed fluctuation is lower than ±20 r / min in the idle speed in the catalytic converter light-off phase, and the speed fluctuation is lower than ±15 r / min in the idle speed in other phases. All calibrations are obtained through tests around this large index.

[0101] Exemplarily, the preset time is 1.2 s, and the calibration table of the time coefficient f within the preset time after the catalytic converter light-off phase or exiting the light-off is as shown in Table 1. Figure 2 ​

[0102] After exiting the light-off phase and delaying for a preset time, a calibration table of the time coefficient f is as shown in Table 1. Figure 3

[0103] In an embodiment, the step of obtaining the time constant coefficient in step S41 comprises:

[0104] obtaining a cooling coefficient k0 according to the water temperature of the engine;

[0105] obtaining a load coefficient k1 according to the load state;

[0106] obtaining a drive chain coefficient k2 according to the connection state of the drive chain;

[0107] The time constant coefficient k = min[k0, k1, k2], that is, k takes the minimum value among k0, k1 and k2.

[0108] Wherein, k0 is obtained according to a calibration table of the water temperature and the cooling coefficient; the load coefficient k1 is a fixed value less than 1 when a high-power electrical appliance such as a fan is activated or an air conditioner clutch is engaged, and the coefficient k1 takes 1 when the fan is not activated and the air conditioner clutch is not engaged; the drive chain coefficient k2 takes a fixed value less than 1 when the drive chain is in the connection process or the connected state, and the drive chain coefficient k2 takes 1 when the drive chain is in the unconnected state.

[0109] Exemplarily, in an embodiment, the electrical appliance load coefficient k1 takes a fixed value of 0.5 when the fan is activated or the air conditioner clutch is engaged, and the drive chain coefficient k2 takes a fixed value of 0.8 when the drive chain is in the connection process or the connected state.

[0110] The calibration table of the water temperature and the cooling coefficient is shown in Table 2:

[0111]

[0112] In step S42, the first reserve torque time constant is the product of the time coefficient and the time constant coefficient.

[0113] In an embodiment, step S43 comprises:

[0114] S431, obtaining a reserve torque time constant correction coefficient based on the brake pressure;

[0115] S432, calculating a second reserve torque time constant according to the first reserve torque time constant and the reserve torque time constant correction coefficient, wherein the second reserve torque time constant is the product of the first reserve torque time constant and the reserve torque time constant correction coefficient.

[0116] Wherein, the brake pressure and the reserve torque time constant correction coefficient are obtained through experiments, Figure 4 ​The graph shows the functional relationship between the reserve torque time constant correction coefficient and the brake master cylinder pressure. It can be understood that under emergency braking conditions, the higher the brake master cylinder oil pressure signal, the smaller the corresponding torque time constant correction coefficient, resulting in a faster adjustment speed. Under non-emergency braking conditions, the lower the brake master cylinder oil pressure signal, the faster the adjustment speed returns to normal, and the correction of the first reserve torque time constant is not activated.

[0117] For example, as the brake master cylinder pressure increases, the torque time constant correction coefficient decreases to a certain value; please refer to... Figure 4 The corresponding time constant correction factor for the reserve torque is approximately 0.5.

[0118] In one embodiment, step S44 includes:

[0119] S441. The P (proportional) and I (integral) parameters of PI control are calculated based on the moment of inertia and the time constant of the second reserve torque.

[0120] S442. Calculate the P-term torque and I-term torque of the idle speed circuit torque based on the P-term parameters and I-term parameters of PI control.

[0121] S443. The idle speed torque is calculated based on the P-term torque and I-term torque of the idle speed torque circuit.

[0122] For example, in step S441, according to the formula and The P-term and I-term parameters of PI control are calculated, where k p For the P-term parameter of PI control, k I Here, I is the parameter of the PI control, J is the moment of inertia, and λ is the time constant of the second reserve torque.

[0123] In step S442, according to formula M P =kp×n rad ×f1(n) determines the torque M of term P. P , where: n rad To convert the engine speed interval into a speed interval in radians, i.e., n is the speed interval, f1(n) is determined according to the calibrated relationship table between the speed interval and f1(n).

[0124] For example, the relationship between the rotational speed interval and f1(n) is shown in the table below:

[0125] n (r / min) -200 -50 -10 0 10 50 200 [f1(n)] 1.1 1.08 1.05 1 1.05 1.09 1.1

[0126] According to formula M I(x+1)=M I (x)+M IIncredent Determine the torque M of item I. I Where: x is the current engine speed, M I (x) refers to the torque M term with the current rotational speed x as the independent variable. I M is a function of the dependent variable. I (0)=M IInitial M IIntial Let I be the initial value of the torque. Where C is a fixed value, dn is the rate of change of rotational speed, and M... IIncredent =Δt×n rad ×k I ×f2(n)-M AntiWindUp Δt is the time period for each accumulation of term I; f2(n) is determined by the relationship table between the calibrated rotational speed interval and f2(n); M AntiWindUp For the previous time period Δt, (M) P +M I ) and M SparkFinal The difference between them, where M SparkFinal This refers to the torque in the fire circuit.

[0127] For example, the relationship between the rotational speed interval and f2(n) is shown in the table below:

[0128] n (r / min) -200 -50 -10 0 10 50 200 [f2(n)] 1.05 1.04 1.02 1 1.01 1.05 1.06

[0129] In this embodiment, C is -300 r / min / s. AntiWindUp For inverse integral saturation torque; M AntiWindUp For the previous time period Δt, (M) P +M I The difference between the torque before and after the limit is used as the inverse integral saturation torque value of term I. Specifically, M AntiWindUp (x+1)=[M P (x)+M I (x)]-M SparkFinal (x).

[0130] In step S443, the final idle torque M SparkFinal The initial value of (x) is M. P (x)+M I (x), but limited to the range of maximum and minimum values, where the maximum fire torque M SparkFinalThe minimum value is the minimum fixed value of the intake torque, which is not more than the air intake torque. For example, the minimum fixed value is -10 Nm. That is, the intake torque in the current sampling period is equal to the torque of the P term plus the torque of the I term in the current sampling period. It should be noted that the air intake torque is the initial air intake torque requirement determined by the accelerator pedal opening and engine speed. After a series of torque coordination processes, the torque is converted into the desired intake air volume and ultimately guides the throttle valve plate's operation.

[0131] Understandably, during emergency braking, the correction coefficient for the reserve torque time constant obtained based on braking pressure remains around 0.5. Correcting the first reserve torque time constant can reduce it to the level of the second reserve torque time constant, thereby leading to K... P and K I The increase in M, under the same rotational speed interval, will lead to P and M I This increases the idle torque, thereby enhancing the engine's load-bearing capacity under emergency braking conditions.

[0132] Meanwhile, this embodiment employs fuzzy PID control, introducing a first reserve torque time constant as a fuzzy filter parameter. In other words, calibration engineers can obtain the first reserve torque time constant by calibrating the time coefficients for different operating time periods. By identifying emergency braking conditions, the first reserve torque time constant is corrected based on braking pressure to obtain a second reserve torque time constant. This effectively reduces the probability of engine stalling during emergency braking, improving the vehicle user experience. Based on the calibrated time coefficients, both the P-term torque and I-term torque in the fire circuit can be automatically adjusted according to M... P and M I The idle torque M was calculated. SparkFinal The calibration work is minimal, the calibration method is simple and reliable, and the use of fuzzy PI control effectively improves the robustness and dynamic stability of the control system.

[0133] A second aspect of this application provides a computer device including one or more processing modules, each processing module configured to execute computer instructions stored in a storage module to perform any of the control methods described above. This computer device can be a control system or controller as described in the above embodiments.

[0134] In one embodiment, this application provides a computer system comprising: a programmable circuit; and software encoded on at least one computer-readable medium, the software being used to program the programmable circuit to implement any of the above-described measurement methods. The computer device described above is equipped with this computer system.

[0135] In one embodiment, this application provides a computer-readable medium having computer-readable instructions that, when executed by a computer, cause the computer to perform all steps of any of the control methods described above. The computer-readable medium may be one or more. The aforementioned computer device is configured with this computer-readable medium.

[0136] A third aspect of this application provides a vehicle that includes the aforementioned computer equipment.

[0137] The above description is merely a preferred embodiment of this application and is not intended to limit the application. Various modifications and variations can be made to this application by those skilled in the art. All modifications, equivalent substitutions, improvements, etc., within the spirit and principles of this application are included within the scope of protection of this application.

Claims

1. A control method for a vehicle in emergency braking condition, characterized in that, include: Determine if the vehicle has entered emergency braking condition; Raise the engine's preset idle speed to the first speed threshold; Based on the engine's current speed and the first speed threshold, activate the idle speed closed-loop control; Based on the aforementioned idle speed closed-loop control, the idle speed torque under the emergency braking condition is obtained. Control the engine output of the idle speed torque.

2. The control method according to claim 1, characterized in that, Determining that the vehicle has entered emergency braking condition includes: Acquire vehicle deceleration, brake pedal signal, vehicle speed signal, and brake master cylinder pressure; If the vehicle's deceleration is higher than a first threshold, the brake pedal signal is in a depressed state, the vehicle speed signal is lower than a second threshold, and the brake master cylinder pressure is higher than a third threshold, then the vehicle is determined to have entered the emergency braking condition.

3. The control method according to claim 1, characterized in that, Based on the engine's current speed and the first speed threshold, activate idle speed closed-loop control, including: Obtain the speed interval, wherein the speed interval is the difference between the current engine speed and the first speed threshold; If the speed interval is less than the preset interval, the idle speed closed-loop control is activated.

4. The control method according to claim 3, characterized in that, The preset idle speed is between 700 and 900 rpm, the first speed threshold is between 900 and 1100 rpm, and the preset interval is between 25 and 75 rpm.

5. The control method according to claim 3, characterized in that, The ratio of the first speed threshold to the preset idle speed is 1.2, and the ratio of the first speed threshold to the preset interval is 35.

6. The control method according to claim 1, characterized in that, Based on the aforementioned idle speed closed-loop control, the idle speed torque under emergency braking conditions is obtained, including: Obtain the moment of inertia, time coefficient, time constant coefficient, and braking pressure; The first reserve torque time constant is calculated based on the time coefficient and the time constant coefficient; The second reserve torque time constant is obtained based on the braking pressure and the first reserve torque time constant. The idle torque under the emergency braking condition is calculated based on the rotational inertia and the second reserve torque time constant.

7. The control method according to claim 6, characterized in that, Obtaining the moment of inertia includes: Obtain the connection state, initial moment of inertia, and fixed rate of change of the engine drivetrain; The moment of inertia is obtained based on the connection state of the engine drivetrain, the initial moment of inertia, and the fixed rate of change.

8. The control method according to claim 7, characterized in that, The moment of inertia is obtained based on the connection state of the engine drivetrain, the initial moment of inertia, and the fixed rate of change, including: When the transmission chain is not connected, the moment of inertia is the initial moment of inertia; During the process of the transmission chain changing from the unconnected state to the connected state, the moment of inertia increases from the initial moment of inertia to a first fixed value at the fixed rate of change, wherein the moment of inertia remains unchanged after reaching the first fixed value; When the transmission chain switches from the connected state to the disconnected state, the moment of inertia decreases from the first fixed value to the initial moment of inertia at the fixed rate of change, wherein the initial moment of inertia is maintained unchanged after the moment of inertia is reached.

9. The control method according to claim 6, characterized in that, Obtain the time coefficient, including: The state of the combustion phase of the engine, the engine speed interval, and the speed change rate are obtained, wherein the speed interval is the difference between the current speed and the first speed threshold; The time coefficient is calibrated based on the state of the engine's combustion phase, the engine's speed interval, and the speed change rate.

10. The control method according to claim 9, characterized in that, The time coefficient is calibrated based on the state of the engine's combustion phase, the engine's speed interval, and the speed change rate, including: During the catalytic converter ignition phase and within a preset time after ignition exit, under test conditions where the engine speed fluctuation is below a first set speed fluctuation range, the time coefficient is calibrated based on the engine speed interval and the speed change rate; or, After exiting the ignition phase and delaying for a preset time, under test conditions where the engine speed fluctuation is lower than the second preset speed fluctuation range, the time coefficient is calibrated based on the engine speed interval and the speed change rate.

11. The control method according to claim 6, characterized in that, Obtaining the second reserve torque time constant based on the braking pressure and the first reserve torque time constant includes: The correction coefficient for the time constant of the reserve torque is obtained based on the braking pressure. The second reserve torque time constant is calculated based on the first reserve torque time constant and the correction coefficient of the reserve torque time constant, wherein the second reserve torque time constant is the product of the first reserve torque time constant and the correction coefficient of the reserve torque time constant.

12. The control method according to claim 11, characterized in that, The idle torque under the emergency braking condition is calculated based on the moment of inertia and the second reserve torque time constant, including: The P-term and I-term parameters of PI control are calculated based on the moment of inertia and the second reserve torque time constant. The P-term torque and I-term torque of the idle speed circuit torque are calculated based on the P-term parameters and I-term parameters of the PI control. The idle speed torque is calculated based on the P-term torque and I-term torque of the idle speed torque circuit.

13. A computer device, characterized in that, It includes one or more processing modules, the processing modules being configured to execute computer instructions stored in a storage module to perform the control method according to any one of claims 1 to 12.

14. A vehicle, characterized in that, Includes the computer device as described in claim 13.

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