Vehicle recovery slip control method and device and electronic equipment

Abstract

The invention relates to a vehicle recycling slip control method and device and electronic equipment. The vehicle recycling slip control method comprises the steps that the vehicle speed, the longitudinal acceleration, the whole vehicle mass, the road slope information and the requested recycling torque of a vehicle are obtained; determining a vehicle estimated acceleration and a real acceleration of the vehicle; predicting a vehicle target acceleration after the driving motor responds to the request to recover the torque according to the vehicle estimated acceleration and the real acceleration; determining the real-time minimum rotating speed boundary of the target motor according to the vehicle target acceleration and the like; if it is determined that the recovery antiskid state is the activated state, the rotating speed of the driving motor is controlled to be larger than or equal to the real-time minimum rotating speed boundary of the target motor. Vehicle slipping can be greatly reduced, the deceleration driving intention of a driver can be better responded, it is guaranteed that the vehicle braking performance is not attenuated, and the vehicle stability is improved; in addition, through the method of limiting the rotating speed of the motor, the motor can respond faster and more stably, and the control precision is improved.

Description

Technical Field

[0001] The present application relates to the field of automotive technology, and in particular to a vehicle recovery skid control method, device, and electronic equipment. Background Art

[0002] In existing technology, anti-slip control for four-wheel-drive electric vehicles (4WDs) relies on identifying the wheel speeds and accelerator pedal depth of the vehicle's four wheels, estimating the vehicle's true speed based on the wheel speeds, and determining the required torque based on a target difference between the true and wheel speeds and the accelerator pedal depth. Anti-slip control is then applied to the wheel torque based on the wheel speeds, true vehicle speed, target difference, and required torque. This stabilizes the difference between the wheel speed and true vehicle speed within the corresponding target difference range to maintain an appropriate slip ratio, eliminating the need to identify the road surface adhesion coefficient and minimizing the impact of varying road surfaces on control accuracy.

[0003] However, the existing technology only considers anti-skid in driving and anti-skid through torque control, and still cannot accurately predict the driver's intention, resulting in the problem of affected braking performance of the entire vehicle. Summary of the Invention

[0004] In order to solve the above technical problems or at least partially solve the above technical problems, the present application provides a vehicle recovery slip control method, device and electronic equipment.

[0005] In a first aspect, the present application provides a vehicle recovery skid control method, comprising:

[0006] Obtain vehicle speed, longitudinal acceleration, vehicle mass, road slope information, and requested recovery torque;

[0007] determining an estimated vehicle acceleration and an actual acceleration of the vehicle according to the vehicle speed, the longitudinal acceleration, the vehicle mass, the road gradient information, and the requested regenerative torque;

[0008] predicting a target vehicle acceleration after the drive motor responds to the requested recovery torque based on the estimated vehicle acceleration and the actual acceleration;

[0009] Determining a target motor real-time minimum speed boundary according to the vehicle speed, the vehicle target acceleration, and the actual acceleration;

[0010] determining whether a regenerative anti-skid state of the vehicle is active according to the vehicle speed and the requested regenerative torque;

[0011] If it is determined that the recovery anti-skid state is activated, the rotation speed of the drive motor is controlled to be greater than or equal to the target motor real-time minimum rotation speed limit.

[0012] Optionally, determining the estimated vehicle acceleration and the actual acceleration of the vehicle according to the vehicle speed, the longitudinal acceleration, the vehicle mass, the road gradient information, and the requested regenerative torque includes:

[0013] determining an estimated vehicle acceleration of the vehicle according to the vehicle speed, the vehicle mass, the road gradient information, and the requested regenerative torque;

[0014] A real acceleration of the vehicle is determined based on the vehicle speed and the longitudinal acceleration.

[0015] Optionally, determining the estimated vehicle acceleration of the vehicle according to the vehicle speed, the vehicle mass, the road gradient information, and the requested regenerative torque includes:

[0016] determining a first vehicle driving resistance according to the vehicle speed and a preset vehicle driving resistance formula;

[0017] obtaining a slope-corrected resistance according to the vehicle speed and the road slope information;

[0018] Obtaining a brake master cylinder pressure, and obtaining a brake correction resistance according to the brake master cylinder pressure and the vehicle speed;

[0019] Correcting the first vehicle running resistance by using the slope correction resistance and the brake correction resistance to obtain a second vehicle running resistance;

[0020] The estimated vehicle acceleration is determined according to the requested recovery torque, a second vehicle driving resistance, and the vehicle mass.

[0021] Optionally, determining the actual acceleration of the vehicle according to the vehicle speed and the longitudinal acceleration includes:

[0022] determining a reference acceleration of the vehicle over a plurality of time periods based on the vehicle speed;

[0023] Obtaining an acceleration weight factor according to the vehicle speed and the road slope information;

[0024] The longitudinal acceleration and the reference acceleration are weighted by using the acceleration weight factor to obtain the true acceleration.

[0025] Optionally, determining whether the vehicle's regenerative anti-skid state is active according to the vehicle speed and the requested regenerative torque includes:

[0026] Obtaining the accelerator pedal depth of the vehicle;

[0027] obtaining a regenerative anti-skid activation accelerator pedal depth threshold according to the vehicle speed;

[0028] determining whether the accelerator pedal depth is less than the regenerative anti-skid activation accelerator pedal depth threshold, and determining whether the requested regenerative torque is less than the regenerative anti-skid activation torque threshold;

[0029] If the accelerator pedal depth is less than the regenerative anti-skid activation accelerator pedal depth threshold, and the requested regenerative torque is less than the regenerative anti-skid activation torque threshold, it is determined that the regenerative anti-skid state of the vehicle is an activated state.

[0030] Optionally, predicting a target vehicle acceleration after the drive motor responds to the requested recovery torque based on the estimated vehicle acceleration and the actual acceleration includes:

[0031] Obtaining a brake master cylinder stroke of the vehicle;

[0032] obtaining a vehicle estimated acceleration amplification factor according to the vehicle speed and the brake master cylinder stroke;

[0033] The target vehicle acceleration at the current moment is determined according to the vehicle estimated acceleration at the previous moment, the actual acceleration at the previous moment, the actual acceleration at the current moment, and the vehicle estimated acceleration amplification factor.

[0034] Optionally, determining the target vehicle acceleration at the current moment according to the vehicle estimated acceleration at the previous moment, the actual acceleration at the previous moment, the actual acceleration at the current moment, and the vehicle estimated acceleration amplification factor includes:

[0035] Calculating the difference between the vehicle's estimated acceleration at the previous moment and the actual acceleration at the previous moment to obtain an acceleration change;

[0036] Calculating the sum of the acceleration change and the actual acceleration at the current moment to obtain a corrected acceleration;

[0037] The product of the corrected acceleration and the vehicle estimated acceleration amplification factor is calculated to obtain the vehicle target acceleration.

[0038] Optionally, determining the target motor real-time minimum speed limit according to the vehicle speed, the vehicle target acceleration, and the actual acceleration includes:

[0039] determining a slip boundary lower limit curve and a slip boundary upper limit curve of the vehicle according to the vehicle speed;

[0040] Determining the original motor real-time minimum speed boundary according to the current vehicle speed, the current vehicle target acceleration, and the real-time minimum speed boundary offset of the drive motor;

[0041] The target motor real-time minimum speed boundary is determined according to the original motor real-time minimum speed boundary, the slip boundary lower limit curve, and the slip boundary upper limit curve.

[0042] Optionally, determining a lower slip boundary curve and an upper slip boundary curve of the vehicle according to the vehicle speed includes:

[0043] Obtaining an actual regenerative torque and a minimum slip coefficient of the vehicle;

[0044] determining a real-time minimum speed boundary offset of the drive motor according to the vehicle speed and the actual recovery torque;

[0045] determining the slip boundary upper limit curve according to the vehicle speed and the minimum slip rate coefficient;

[0046] The slip boundary lower limit curve is determined according to the vehicle speed, the minimum slip ratio coefficient, and the real-time minimum speed boundary offset.

[0047] Optionally, determining the original motor real-time minimum speed boundary according to the current vehicle speed, the current vehicle target acceleration, and the real-time minimum speed boundary offset of the drive motor includes:

[0048] Calculating the product of the vehicle target acceleration and a preset time period to obtain a speed change;

[0049] The original motor real-time minimum speed boundary is determined according to the vehicle speed, the speed change and the real-time minimum speed boundary offset.

[0050] Optionally, determining the target motor real-time minimum speed boundary according to the original motor real-time minimum speed boundary, the slip boundary lower limit curve, and the slip boundary upper limit curve includes:

[0051] determining a first rotational speed value corresponding to a current moment in the slip boundary lower limit curve;

[0052] determining a second rotational speed value corresponding to a current moment in the slip limit upper limit curve;

[0053] Determine the maximum value between the original motor real-time minimum speed boundary and the first speed value as a third speed value;

[0054] determining a minimum value between the third speed value and the second speed value as a fourth speed value;

[0055] The fourth speed value is filtered to obtain the real-time minimum speed limit of the target motor.

[0056] Optionally, the method further includes:

[0057] determining whether the recovery anti-skid state of the vehicle is a recovery state when the recovery anti-skid state of the vehicle is not a fault state;

[0058] If it is determined that the regeneration anti-skid state of the vehicle is not in the recovery state, a step of determining whether the regeneration anti-skid state of the vehicle is in the active state according to the vehicle speed and the requested regeneration torque is performed.

[0059] Optionally, determining whether the recovery anti-skid state of the vehicle is a recovery state includes:

[0060] If it is determined that the vehicle speed is greater than the recovery anti-skid control speed threshold and the motor feedback state is not responding to real-time speed control, the recovery anti-skid state is determined to be a recovery state; or, when the vehicle is on a low-adhesion road surface and the intelligent driving is not enabled, if the brake master cylinder stroke is greater than the recovery anti-skid control brake master cylinder stroke threshold, the recovery anti-skid state is determined to be a recovery state; or, when the vehicle is on a low-adhesion road surface and the intelligent driving is enabled, the vehicle deceleration is obtained based on the road slope information and the vehicle speed, and if the longitudinal acceleration is less than the deceleration, the recovery anti-skid state is determined to be a recovery state;

[0061] Otherwise, it is determined that the recovery anti-skid state of the vehicle is not a recovery state.

[0062] In a second aspect, the present application provides a vehicle recovery skid control device, comprising:

[0063] An acquisition module is used to obtain vehicle speed, longitudinal acceleration, vehicle mass, road slope information and requested recovery torque;

[0064] a first determining module, configured to determine an estimated vehicle acceleration and an actual acceleration of the vehicle according to the vehicle speed, the longitudinal acceleration, the vehicle mass, the road gradient information, and the requested regenerative torque;

[0065] a second determining module, configured to predict a target vehicle acceleration after the drive motor responds to the requested recovery torque based on the estimated vehicle acceleration and the actual acceleration;

[0066] a third determining module, configured to determine a target motor real-time minimum speed boundary according to the vehicle speed, the vehicle target acceleration, and the actual acceleration;

[0067] a fourth determining module, configured to determine whether a regenerative anti-skid state of the vehicle is activated according to the vehicle speed and the requested regenerative torque;

[0068] The control module is configured to control the rotation speed of the drive motor to be greater than or equal to the target motor real-time minimum rotation speed limit if it is determined that the recovery anti-skid state is activated.

[0069] In a third aspect, the present application provides an electronic device, comprising a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other via the communication bus;

[0070] Memory for storing computer programs;

[0071] The processor is configured to implement any vehicle recovery slip control method described in the first aspect when executing a program stored in the memory.

[0072] Beneficial effects of the present invention:

[0073] The embodiment of the present application predicts the vehicle's future acceleration state by predicting the vehicle's target acceleration after the drive motor responds to the requested recovery torque based on the vehicle's estimated acceleration and actual acceleration. Since the vehicle's acceleration will change when the driver controls the vehicle to decelerate, the prediction of the future acceleration state can reflect the driver's future deceleration driving intention. The target motor's real-time minimum speed boundary is then determined based on the vehicle speed, the actual acceleration, and the vehicle's target acceleration that reflects the driver's future deceleration driving intention. The target motor's real-time minimum speed boundary is used to represent the critical threshold at which the vehicle will experience increased slippage under the driver's deceleration driving intention. Therefore, when the vehicle's recovery anti-skid state is activated, the vehicle's Active control of the motor speed through the target motor real-time minimum speed boundary can avoid the motor speed being less than the target motor real-time minimum speed boundary during future vehicle deceleration, so that the motor speed is always within the range that will not aggravate vehicle slippage. Compared with passive control, the timing of anti-skid control is earlier, which can greatly reduce the vehicle slippage caused by future vehicle deceleration, and thus better respond to the driver's deceleration driving intention, fully utilize the longitudinal adhesion of the road to the wheels, ensure that the vehicle braking performance is not attenuated, and fully utilize the lateral adhesion of the road to the wheels to improve vehicle stability. In addition, by limiting the motor speed, the motor can respond faster and more stably, thereby improving control accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0074] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0075] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0076] Figure 1A flow chart of a vehicle recovery skid control method provided in an embodiment of the present application;

[0077] Figure 2 for Figure 1 Flowchart of step S104;

[0078] Figure 3 A diagram showing the relationship between a real-time minimum speed boundary curve, a slip boundary upper limit curve, and a slip boundary lower limit curve of a motor during a recycling process provided by an embodiment of the present application;

[0079] Figure 4 A flowchart of another vehicle recovery skid control method provided in an embodiment of the present application;

[0080] Figure 5 A schematic diagram of a state machine for recovering an anti-slip state provided in an embodiment of the present application;

[0081] Figure 6 A structural diagram of a vehicle recovery skid control device provided in an embodiment of the present application;

[0082] Figure 7 A structural diagram of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0083] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0084] Because existing anti-skid control for four-wheel-drive electric vehicles only considers anti-skid driving and anti-skid through torque control, it cannot accurately predict the driver's intention, which affects the braking performance of the entire vehicle. To this end, the embodiments of the present application provide a vehicle recovery skid control method, device, and electronic device to meet the driver's desired deceleration during braking and coasting on low-adhesion roads such as ice and snow, while reducing wheel slip and ensuring vehicle stability.

[0085] The embodiment of the present application provides a vehicle recovery skid control method, such as Figure 1 Shown, including:

[0086] Step S101, obtaining vehicle speed, longitudinal acceleration, vehicle mass, road slope information, and requested regenerative torque;

[0087] In an embodiment of the present application, the vehicle speed can be estimated based on parameters such as the wheel speed, the actual recovery torque and the brake master cylinder pressure. The longitudinal acceleration data can be directly collected using an on-board acceleration sensor (such as an inertial measurement unit IMU). The vehicle mass can be pre-set. The road slope information can be calculated by measuring the component of the gravity acceleration in the vehicle coordinate system using the accelerometer in the IMU. The requested recovery torque can be calculated based on parameters such as the maximum power limit, motor efficiency, vehicle speed, brake pedal position and battery status. The acquisition of the above parameters is existing technology and will not be repeated here.

[0088] Step S102, determining an estimated vehicle acceleration and an actual vehicle acceleration of the vehicle according to the vehicle speed, the longitudinal acceleration, the vehicle mass, the road gradient information, and the requested regenerative torque;

[0089] In the embodiment of the present application, the vehicle estimated acceleration is a preliminary estimate of the vehicle acceleration based on the vehicle speed, vehicle mass, road slope information and requested recovery torque. The vehicle estimated acceleration is an advance estimate of the vehicle's future acceleration state based on the current vehicle speed, road slope information and requested recovery torque. The actual acceleration is the real-time acceleration of the vehicle estimated based on the vehicle speed and longitudinal acceleration.

[0090] In this step, the estimated vehicle acceleration of the vehicle can be determined based on the vehicle speed, the vehicle mass, the road slope information and the requested recovery torque; and the actual vehicle acceleration can be determined based on the vehicle speed and the longitudinal acceleration.

[0091] Among them, the vehicle estimated acceleration of the vehicle is determined according to the vehicle speed, the vehicle mass, the road slope information and the requested recovery torque, including: determining the first vehicle driving resistance according to the vehicle speed and a preset vehicle driving resistance formula; obtaining the slope correction resistance according to the vehicle speed and the road slope information; obtaining the brake master cylinder pressure, and obtaining the brake correction resistance according to the brake master cylinder pressure and the vehicle speed; using the slope correction resistance and the brake correction resistance to correct the first vehicle driving resistance to obtain the second vehicle driving resistance; determining the vehicle estimated acceleration according to the requested recovery torque, the second vehicle driving resistance and the vehicle mass.

[0092] In the embodiment of the present application, the vehicle driving resistance formula is F tRaw =A+BV+CV 2 , where F tRaw is the vehicle's running resistance, A, B and C are fixed parameters, and V is the vehicle's speed.

[0093] In practical applications, the vehicle speed can be input into the vehicle driving resistance formula to calculate the first vehicle driving resistance, and the slope correction resistance F can be obtained by looking up the table based on the road slope information and vehicle speed. isv , based on the brake master cylinder pressure and vehicle speed, the brake correction resistance F is obtained by looking up the table bv , the second vehicle running resistance F ft =F tRaw +F isv +F bv , the requested recovery torque T w Divide by the tire radius R w , minus the second vehicle's driving resistance F ft Get the vehicle deceleration resistance F w =T w ÷R w -F ft , divide the vehicle deceleration resistance by the vehicle mass M kg Get the estimated vehicle acceleration a expR =F w ÷M kg .

[0094] Determining the true acceleration of the vehicle based on the vehicle speed and the longitudinal acceleration includes: determining a reference acceleration of the vehicle over multiple time periods based on the vehicle speed; obtaining an acceleration weighting factor based on the vehicle speed and the road slope information; and weighting the longitudinal acceleration and the reference acceleration using the acceleration weighting factor to obtain the true acceleration.

[0095] In practical applications, the reference acceleration a within multiple time periods can be calculated based on the vehicle speed. Ref For specific working conditions such as uphill and starting, the vehicle longitudinal acceleration cannot truly reflect the actual vehicle acceleration. Therefore, according to the vehicle speed and road slope information, the acceleration weight factor r is obtained from Table 1. The acceleration weight factor is used to respectively calculate the vehicle longitudinal acceleration a and the reference acceleration a. Ref According to the following formula a Real =a·(1-r)+a Ref r is weighted to obtain the true acceleration. Table 1 below shows an example of an optimal weight distribution acceleration weight factor.

[0096] Table 1 Acceleration weight factor table

[0097]

[0098] Step S103, predicting a target vehicle acceleration after the drive motor responds to the requested recovery torque based on the estimated vehicle acceleration and the actual acceleration;

[0099] In this step, the brake master cylinder stroke of the vehicle can be obtained; the vehicle estimated acceleration amplification factor can be obtained based on the vehicle speed and the brake master cylinder stroke; the vehicle target acceleration at the current moment can be determined based on the vehicle estimated acceleration at the previous moment, the actual acceleration at the previous moment, the actual acceleration at the current moment and the vehicle estimated acceleration amplification factor.

[0100] Determining a target vehicle acceleration at a current moment based on the vehicle's estimated acceleration at a previous moment, the actual acceleration at a previous moment, the actual acceleration at a current moment, and the vehicle's estimated acceleration amplification factor includes: calculating the difference between the vehicle's estimated acceleration at a previous moment and the actual acceleration at a previous moment to obtain an acceleration change; calculating the sum of the acceleration change and the actual acceleration at the current moment to obtain a corrected acceleration; and calculating the product of the corrected acceleration and the vehicle's estimated acceleration amplification factor to obtain the vehicle's target acceleration.

[0101] In practical applications, the vehicle estimated acceleration amplification factor k is first obtained by looking up the table based on the vehicle speed and brake master cylinder stroke. fac ; Using the vehicle's estimated acceleration a expR Subtract the vehicle's actual acceleration a at the previous moment Real Plus the actual acceleration a of the vehicle at the current moment Real , and then multiply the obtained acceleration value by the vehicle estimated acceleration amplification factor k fac Calculate the vehicle target acceleration a exp , wherein the following Table 2 is an example of a vehicle estimated acceleration amplification factor.

[0102] Table 2 Vehicle estimated acceleration amplification factor table

[0103]

[0104] Step S104, determining a target motor real-time minimum speed boundary according to the vehicle speed, the vehicle target acceleration, and the actual acceleration;

[0105] In this step, when controlling the real-time speed of the drive motor, it is necessary to first calculate a control target, ie, a target motor real-time minimum speed boundary, based on the vehicle speed, the vehicle target acceleration, and the actual acceleration.

[0106] In one embodiment of the present application, step S104 determines the target motor real-time minimum speed limit according to the vehicle speed, the vehicle target acceleration and the actual acceleration, such as Figure 2 Shown, including:

[0107] Step S201, determining a slip boundary lower limit curve and a slip boundary upper limit curve of the vehicle according to the vehicle speed;

[0108] In order to ensure that the vehicle slip rate is controlled within the set range and there is no excessive slip or too little slip to affect the stability of the vehicle, it is necessary to control the maximum slip rate and the minimum slip rate of the vehicle. The slip boundary upper limit curve and the slip boundary lower limit curve can be obtained as follows: first, obtain the actual recovery torque and the minimum slip rate coefficient of the vehicle; determine the real-time minimum speed boundary offset of the drive motor according to the vehicle speed and the actual recovery torque; determine the slip boundary upper limit curve according to the vehicle speed and the minimum slip rate coefficient; determine the slip boundary lower limit curve according to the vehicle speed, the minimum slip rate coefficient and the real-time minimum speed boundary offset.

[0109] In practical applications, the motor real-time minimum speed boundary offset n can be obtained by first looking up Table 3 (Table 3 is an example of a motor real-time minimum speed offset table) based on the vehicle speed and the actual recovery torque. offs To meet the requirements of vehicle braking performance and stability, the vehicle's minimum slip coefficient r is obtained by querying Table 4 (Table 4 is an example of a minimum slip coefficient table during vehicle recovery) at vehicle speed. rat ; By subtracting 1 from the minimum slip coefficient r rat The difference is multiplied by the vehicle speed v, and then the upper limit of the motor's real-time minimum speed during vehicle recovery is calculated based on the wheel radius R and unit conversion. maxrat =25·v·(1-r rat ) / 3πR, the upper limit of the motor's real-time minimum speed boundary n is calculated based on the vehicle speed at multiple moments maxrat The line connecting the two is determined as the upper limit curve of the slip boundary (such as Figure 3 As shown); through the motor real-time minimum speed limit n maxrat Subtract the real-time minimum speed boundary offset n of the above motor offs The lower limit of the motor's real-time minimum speed during vehicle recovery is calculated as n minrat =n maxrat -n offs The lower limit of the motor's real-time minimum speed n is calculated based on the vehicle speed at multiple moments. minrat The line connecting the two is determined as the lower limit curve of the slip boundary (such as Figure 3 As shown), Figure 3 As shown, the vertical axis speed is the speed of the three curves at the motor end. Figure 3The reason for the negative speed values ​​is that when the motor speed is near 0 r / min, the motor's low-speed control precision is insufficient, making it impossible to accurately control the motor speed to 0 r / min. To prevent the motor from misresponding to the target motor real-time minimum speed boundary, the target motor real-time minimum speed boundary is calculated as a negative value by subtracting the motor real-time minimum speed boundary offset from the original motor real-time minimum speed boundary. This process essentially compensates for the low-speed control precision defects and ensures that the boundary settings are more closely aligned with actual control requirements.

[0110] Table 3 Motor real-time minimum speed deviation table

[0111]

[0112] Table 4 Minimum slip coefficient table

[0113]

[0114] Step S202 : determining the original motor real-time minimum speed boundary according to the current vehicle speed, the current vehicle target acceleration, and the real-time minimum speed boundary offset of the drive motor.

[0115] Furthermore, the real-time minimum speed boundary of the original motor is determined based on the vehicle speed at the current moment, the vehicle target acceleration at the current moment and the real-time minimum speed boundary offset of the drive motor, including: calculating the product of the vehicle target acceleration and the preset time period to obtain the speed change; determining the real-time minimum speed boundary of the original motor based on the vehicle speed, the speed change and the real-time minimum speed boundary offset.

[0116] The vehicle's vehicle speed V plus the vehicle's target acceleration a exp The sum is obtained by multiplying the sum by the preset time period, and then the unit of the sum is converted according to the wheel radius R (from km / h to r / min), and then the motor real-time minimum speed boundary offset n is subtracted from the converted value. offs Calculate the original motor's real-time minimum speed boundary n expR Step S203 , determining the target motor real-time minimum speed boundary according to the original motor real-time minimum speed boundary, the slip boundary lower limit curve, and the slip boundary upper limit curve;

[0117] In this step, a first speed value corresponding to the current moment can be determined in the slip boundary lower limit curve; a second speed value corresponding to the current moment can be determined in the slip boundary upper limit curve; the maximum value between the original motor real-time minimum speed boundary and the first speed value is determined as a third speed value; the minimum value between the third speed value and the second speed value is determined as a fourth speed value; and the fourth speed value is filtered to obtain the target motor real-time minimum speed boundary.

[0118] In practical applications, the original motor real-time minimum speed boundary n expR The first speed value corresponding to the current moment in the slip boundary lower limit curve is maximized, and the third speed value obtained is minimized with the second speed value corresponding to the current moment in the slip boundary upper limit curve, and the fourth speed value obtained is filtered and calculated to obtain the target motor real-time minimum speed boundary n exp , the connection line of the target motor real-time minimum speed boundary corresponding to multiple moments is determined as the motor real-time minimum speed boundary curve (such as Figure 3 shown).

[0119] Step S105 , determining whether the vehicle's regenerative anti-skid state is activated according to the vehicle speed and the requested regenerative torque;

[0120] When the real-time speed control of the driving motor is performed, it is necessary to respond according to whether the recovery anti-skid state is activated. Only when the recovery anti-skid state is activated, step S106 is triggered to control the speed of the driving motor to be greater than or equal to the real-time minimum speed boundary of the target motor.

[0121] In this step, the determination of whether the recovery anti-skid state is active can be made by obtaining the vehicle's accelerator pedal depth; obtaining a recovery anti-skid activation accelerator pedal depth threshold based on the vehicle speed; determining whether the accelerator pedal depth is less than the recovery anti-skid activation accelerator pedal depth threshold, and determining whether the requested recovery torque is less than the recovery anti-skid activation torque threshold; if the accelerator pedal depth is less than the recovery anti-skid activation accelerator pedal depth threshold, and the requested recovery torque is less than the recovery anti-skid activation torque threshold, determining that the vehicle's recovery anti-skid state is active.

[0122] In the embodiment of the present application, the vehicle's recovery anti-skid state is determined to be activated only when the accelerator pedal depth is less than the recovery anti-skid activation accelerator pedal depth threshold and the requested recovery torque is less than the recovery anti-skid activation control torque threshold, thereby avoiding wheel slip and vehicle instability caused by excessive braking recovery and coasting recovery torque.

[0123] Step S106 : If it is determined that the recovery anti-skid state is activated, the speed of the drive motor is controlled to be greater than or equal to the target motor real-time minimum speed limit.

[0124] In this step, the rotation speed of the driving motor can be controlled to always be greater than or equal to the target motor's real-time minimum rotation speed boundary.

[0125] The embodiment of the present application predicts the vehicle's future acceleration state by predicting the vehicle's target acceleration after the drive motor responds to the requested recovery torque based on the vehicle's estimated acceleration and actual acceleration. Since the vehicle's acceleration will change when the driver controls the vehicle to decelerate, the prediction of the future acceleration state can reflect the driver's future deceleration driving intention. The target motor's real-time minimum speed boundary is then determined based on the vehicle speed, the actual acceleration, and the vehicle's target acceleration that reflects the driver's future deceleration driving intention. The target motor's real-time minimum speed boundary is used to represent the critical threshold at which the vehicle will experience increased slippage under the driver's deceleration driving intention. Therefore, when the vehicle's recovery anti-skid state is activated, the vehicle's Active control of the motor speed through the target motor real-time minimum speed boundary can avoid the motor speed being less than the target motor real-time minimum speed boundary during future vehicle deceleration, so that the motor speed is always within the range that will not aggravate vehicle slippage. Compared with passive control, the timing of anti-skid control is earlier, which can greatly reduce the vehicle slippage caused by future vehicle deceleration, and thus better respond to the driver's deceleration driving intention, fully utilize the longitudinal adhesion of the road to the wheels, ensure that the vehicle braking performance is not attenuated, and fully utilize the lateral adhesion of the road to the wheels to improve vehicle stability. In addition, by limiting the motor speed, the motor can respond faster and more stably, thereby improving control accuracy.

[0126] In another embodiment of the present application, Figure 4 As shown, the method further includes:

[0127] Step S301, when the recovery anti-skid state of the vehicle is not in a fault state, determining whether the recovery anti-skid state of the vehicle is in a recovery state;

[0128] When the motor has a high-level fault and cannot respond to the motor's real-time minimum speed in time, the recovery anti-skid state is determined to be a fault. Otherwise, the vehicle's recovery anti-skid state is determined not to be a fault state.

[0129] In the embodiment of this application, Figure 5 The schematic diagram of the state machine for recovering the anti-skid state is as follows: Figure 5 As shown, the recovery anti-skid state includes three states: activation state, recovery state and fault state. The conversion of the three states can be triggered by corresponding trigger conditions. The priority of the fault state is higher than that of the recovery state, which is higher than that of the activation state.

[0130] In one embodiment of the present application, determining whether the recovery anti-skid state of the vehicle is a recovery state includes:

[0131] If it is determined that the vehicle speed is greater than the recovery anti-skid control speed threshold and the motor feedback state is not responding to real-time speed control, the recovery anti-skid state is determined to be a recovery state; or, when the vehicle is on a low-adhesion road surface and the intelligent driving is not enabled, if the brake master cylinder stroke is greater than the recovery anti-skid control brake master cylinder stroke threshold, the recovery anti-skid state is determined to be a recovery state; or, when the vehicle is on a low-adhesion road surface and the intelligent driving is enabled, the vehicle deceleration is obtained based on the road slope information and the vehicle speed, and if the longitudinal acceleration is less than the deceleration, the recovery anti-skid state is determined to be a recovery state;

[0132] Otherwise, it is determined that the recovery anti-skid state of the vehicle is not a recovery state.

[0133] The embodiments of the present application can be individually controlled for the following specific working conditions to ensure that the vehicle's braking performance remains unchanged, reduce vehicle slippage, and improve vehicle stability. First, when the vehicle is on a low-adhesion road and the intelligent driving is not turned on, in order to prevent the driver from stepping on the brake deeply and the current motor is executing the real-time minimum speed limit of the motor, causing the entire vehicle to shake, when the brake master cylinder stroke is greater than the recovery recovery anti-skid control brake master cylinder stroke threshold, the recovery anti-skid state is controlled to be restored; secondly, when the vehicle is on a low-adhesion road and the intelligent driving is turned on, hydraulic braking and recovery braking work together to achieve braking during the vehicle's driving process. Therefore, it is necessary to obtain the vehicle deceleration in real time based on the current slope information and the vehicle's actual vehicle speed. When the vehicle's longitudinal acceleration is less than the real-time obtained vehicle deceleration, the recovery anti-skid state is controlled to be restored.

[0134] Compared with existing control technologies, the above-mentioned specific working conditions are identified and precisely controlled, which greatly reduces the risk of false triggering of functions. The applicable working conditions are more comprehensive, and all working conditions can be achieved. The control is more precise, and the stability performance of the vehicle is improved.

[0135] Step S302 : If it is determined that the vehicle's regenerative anti-skid state is not in the recovery state, a step of determining whether the vehicle's regenerative anti-skid state is in the active state according to the vehicle speed and the requested regenerative torque is executed.

[0136] In the embodiment of the present application, whether the vehicle's recovery anti-skid state is in the activated state is determined only when the vehicle's recovery anti-skid state is neither in the fault state nor in the recovery state, thereby avoiding conflicts caused by performing the same anti-skid control in different states.

[0137] In another embodiment of the present application, a vehicle recovery skid control device is also provided, such as Figure 6 Shown, including:

[0138] An acquisition module 11 is used to obtain vehicle speed, longitudinal acceleration, vehicle mass, road slope information, and requested recovery torque;

[0139] a first determining module 12, configured to determine an estimated vehicle acceleration and an actual vehicle acceleration of the vehicle according to the vehicle speed, the longitudinal acceleration, the vehicle mass, the road gradient information, and the requested regenerative torque;

[0140] a second determining module 13, configured to predict a target vehicle acceleration after the drive motor responds to the requested recovery torque based on the estimated vehicle acceleration and the actual acceleration;

[0141] A third determining module 14 is configured to determine a target motor real-time minimum speed limit according to the vehicle speed, the vehicle target acceleration, and the actual acceleration;

[0142] a fourth determining module 15, configured to determine whether the regenerative anti-skid state of the vehicle is activated according to the vehicle speed and the requested regenerative torque;

[0143] The control module 16 is configured to control the rotation speed of the drive motor to be greater than or equal to the target motor real-time minimum rotation speed limit if it is determined that the recovery anti-skid state is activated.

[0144] In another embodiment of the present application, an electronic device is provided, including a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other via the communication bus;

[0145] Memory for storing computer programs;

[0146] The processor is configured to implement the vehicle recovery slip control method described in any of the aforementioned method embodiments when executing the program stored in the memory.

[0147] In the electronic device provided by the embodiment of the present invention, the processor can predict the vehicle's future acceleration state by executing the program stored in the memory through predicting the vehicle's target acceleration after the drive motor responds to the request to recover the torque based on the vehicle's estimated acceleration and actual acceleration. Since the vehicle acceleration will change when the driver controls the vehicle to decelerate, the prediction of the future acceleration state can reflect the driver's future deceleration driving intention. The target motor's real-time minimum speed boundary is then determined based on the vehicle speed, the actual acceleration and the vehicle's target acceleration reflecting the driver's future deceleration driving intention. The target motor's real-time minimum speed boundary is used to represent a critical threshold value at which the vehicle slip will intensify under the driver's deceleration driving intention. Therefore, when the vehicle's When the recovery anti-skid state is activated, the motor speed is actively controlled through the target motor real-time minimum speed boundary, which can avoid the motor speed being less than the target motor real-time minimum speed boundary during future vehicle deceleration, so that the motor speed is always within the range that will not aggravate vehicle slippage. Compared with passive control, the timing of anti-skid control is earlier, which can greatly reduce the vehicle slippage caused by future vehicle deceleration, and thus better respond to the driver's deceleration driving intention, fully utilize the longitudinal adhesion of the road to the wheels, ensure that the vehicle braking performance is not attenuated, and fully utilize the lateral adhesion of the road to the wheels to improve vehicle stability; in addition, by limiting the motor speed, the motor can respond faster and more stably, thereby improving control accuracy.

[0148] The communication bus 1140 mentioned in the above electronic device can be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus. The communication bus 1140 can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 7 Only one thick line is used in the diagram, but this does not mean that there is only one bus or one type of bus.

[0149] The communication interface 1120 is used for communication between the electronic device and other devices.

[0150] The memory 1130 may include a random access memory (RAM) or a non-volatile memory, such as at least one disk storage. Alternatively, the memory may be at least one storage device located away from the processor.

[0151] The above-mentioned processor 1110 can be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it can also be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components.

[0152] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus comprising the element.

[0153] The foregoing description is intended only to provide specific embodiments of the present invention, which will enable those skilled in the art to understand and implement the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not intended to be limited to the embodiments shown herein, but is intended to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A vehicle recovery skid control method, characterized in that: include: Obtain vehicle speed, longitudinal acceleration, vehicle mass, road slope information, and requested recovery torque; determining an estimated vehicle acceleration and an actual acceleration of the vehicle according to the vehicle speed, the longitudinal acceleration, the vehicle mass, the road gradient information, and the requested regenerative torque; predicting a target vehicle acceleration after the drive motor responds to the requested recovery torque based on the estimated vehicle acceleration and the actual acceleration; Determining a target motor real-time minimum speed boundary according to the vehicle speed, the vehicle target acceleration, and the actual acceleration; determining whether a regenerative anti-skid state of the vehicle is active according to the vehicle speed and the requested regenerative torque; If it is determined that the recovery anti-skid state is activated, the rotation speed of the drive motor is controlled to be greater than or equal to the target motor real-time minimum rotation speed limit.

2. The vehicle recovery slip control method according to claim 1, characterized in that: Determining the estimated vehicle acceleration and the actual acceleration of the vehicle according to the vehicle speed, the longitudinal acceleration, the vehicle mass, the road gradient information, and the requested regenerative torque includes: determining an estimated vehicle acceleration of the vehicle according to the vehicle speed, the vehicle mass, the road gradient information, and the requested regenerative torque; A real acceleration of the vehicle is determined based on the vehicle speed and the longitudinal acceleration.

3. The vehicle recovery slip control method according to claim 2, characterized in that: Determining an estimated vehicle acceleration of the vehicle according to the vehicle speed, the vehicle mass, the road gradient information, and the requested regenerative torque includes: determining a first vehicle driving resistance according to the vehicle speed and a preset vehicle driving resistance formula; obtaining a slope-corrected resistance according to the vehicle speed and the road slope information; Obtaining a brake master cylinder pressure, and obtaining a brake correction resistance according to the brake master cylinder pressure and the vehicle speed; Correcting the first vehicle running resistance by using the slope correction resistance and the brake correction resistance to obtain a second vehicle running resistance; The estimated vehicle acceleration is determined according to the requested recovery torque, a second vehicle driving resistance, and the vehicle mass.

4. The vehicle recovery slip control method according to claim 2, characterized in that: Determining the actual acceleration of the vehicle according to the vehicle speed and the longitudinal acceleration includes: determining a reference acceleration of the vehicle over a plurality of time periods based on the vehicle speed; Obtaining an acceleration weight factor according to the vehicle speed and the road slope information; The longitudinal acceleration and the reference acceleration are weighted by using the acceleration weight factor to obtain the true acceleration.

5. The vehicle recovery slip control method according to claim 1, characterized in that: Determining whether the vehicle's regenerative anti-skid state is active according to the vehicle speed and the requested regenerative torque includes: Obtaining the accelerator pedal depth of the vehicle; obtaining a regenerative anti-skid activation accelerator pedal depth threshold according to the vehicle speed; determining whether the accelerator pedal depth is less than the regenerative anti-skid activation accelerator pedal depth threshold, and determining whether the requested regenerative torque is less than the regenerative anti-skid activation torque threshold; If the accelerator pedal depth is less than the regenerative anti-skid activation accelerator pedal depth threshold, and the requested regenerative torque is less than the regenerative anti-skid activation torque threshold, it is determined that the regenerative anti-skid state of the vehicle is an activated state.

6. The vehicle recovery slip control method according to claim 1, characterized in that: Predicting a target vehicle acceleration after the drive motor responds to the requested recovery torque based on the estimated vehicle acceleration and the actual acceleration includes: Obtaining a brake master cylinder stroke of the vehicle; obtaining a vehicle estimated acceleration amplification factor according to the vehicle speed and the brake master cylinder stroke; The target vehicle acceleration at the current moment is determined according to the vehicle estimated acceleration at the previous moment, the actual acceleration at the previous moment, the actual acceleration at the current moment, and the vehicle estimated acceleration amplification factor.

7. The vehicle recovery slip control method according to claim 6, characterized in that: Determining a target vehicle acceleration at a current moment based on the vehicle's estimated acceleration at a previous moment, the actual acceleration at a previous moment, the actual acceleration at a current moment, and the vehicle's estimated acceleration amplification factor, including: Calculating the difference between the vehicle's estimated acceleration at the previous moment and the actual acceleration at the previous moment to obtain an acceleration change; Calculating the sum of the acceleration change and the actual acceleration at the current moment to obtain a corrected acceleration; The product of the corrected acceleration and the vehicle estimated acceleration amplification factor is calculated to obtain the vehicle target acceleration.

8. The vehicle recovery slip control method according to claim 1, characterized in that: Determining a target motor real-time minimum speed limit according to the vehicle speed, the vehicle target acceleration, and the actual acceleration includes: determining a slip boundary lower limit curve and a slip boundary upper limit curve of the vehicle according to the vehicle speed; Determining the original motor real-time minimum speed boundary according to the current vehicle speed, the current vehicle target acceleration, and the real-time minimum speed boundary offset of the drive motor; The target motor real-time minimum speed boundary is determined according to the original motor real-time minimum speed boundary, the slip boundary lower limit curve, and the slip boundary upper limit curve.

9. The vehicle recovery slip control method according to claim 8, characterized in that: Determining a slip boundary lower limit curve and a slip boundary upper limit curve of the vehicle according to the vehicle speed includes: Obtaining an actual regenerative torque and a minimum slip coefficient of the vehicle; determining a real-time minimum speed boundary offset of the drive motor according to the vehicle speed and the actual recovery torque; determining the slip boundary upper limit curve according to the vehicle speed and the minimum slip rate coefficient; The slip boundary lower limit curve is determined according to the vehicle speed, the minimum slip ratio coefficient, and the real-time minimum speed boundary offset.

10. The vehicle recovery slip control method according to claim 8, characterized in that: The original motor real-time minimum speed boundary is determined according to the current vehicle speed, the current vehicle target acceleration, and the real-time minimum speed boundary offset of the drive motor, including: Calculating the product of the vehicle target acceleration and a preset time period to obtain a speed change; The original motor real-time minimum speed boundary is determined according to the vehicle speed, the speed change and the real-time minimum speed boundary offset.

11. The vehicle recovery slip control method according to claim 8, characterized in that: Determining a target motor real-time minimum speed boundary according to the original motor real-time minimum speed boundary, the slip boundary lower limit curve, and the slip boundary upper limit curve includes: determining a first rotational speed value corresponding to a current moment in the slip boundary lower limit curve; determining a second rotational speed value corresponding to a current moment in the slip limit upper limit curve; Determine the maximum value between the original motor real-time minimum speed boundary and the first speed value as a third speed value; determining a minimum value between the third speed value and the second speed value as a fourth speed value; The fourth speed value is filtered to obtain the real-time minimum speed limit of the target motor.

12. The vehicle recovery slip control method according to claim 1, characterized in that: The method further comprises: determining whether the recovery anti-skid state of the vehicle is a recovery state when the recovery anti-skid state of the vehicle is not a fault state; If it is determined that the regeneration anti-skid state of the vehicle is not in the recovery state, a step of determining whether the regeneration anti-skid state of the vehicle is in the active state according to the vehicle speed and the requested regeneration torque is performed.

13. The vehicle recovery slip control method according to claim 12, characterized in that: Determining whether the recovery anti-skid state of the vehicle is a recovery state includes: If it is determined that the vehicle speed is greater than the recovery anti-skid control speed threshold and the motor feedback state is not responding to real-time speed control, the recovery anti-skid state is determined to be a recovery state; or, when the vehicle is on a low-adhesion road surface and the intelligent driving is not enabled, if the brake master cylinder stroke is greater than the recovery anti-skid control brake master cylinder stroke threshold, the recovery anti-skid state is determined to be a recovery state; or, when the vehicle is on a low-adhesion road surface and the intelligent driving is enabled, the vehicle deceleration is obtained based on the road slope information and the vehicle speed, and if the longitudinal acceleration is less than the deceleration, the recovery anti-skid state is determined to be a recovery state; Otherwise, it is determined that the recovery anti-skid state of the vehicle is not a recovery state.

14. A vehicle recovery skid control device, characterized in that: include: An acquisition module is used to obtain vehicle speed, longitudinal acceleration, vehicle mass, road slope information and requested recovery torque; a first determining module, configured to determine an estimated vehicle acceleration and an actual acceleration of the vehicle according to the vehicle speed, the longitudinal acceleration, the vehicle mass, the road gradient information, and the requested regenerative torque; a second determining module, configured to predict a target vehicle acceleration after the drive motor responds to the requested recovery torque based on the estimated vehicle acceleration and the actual acceleration; a third determining module, configured to determine a target motor real-time minimum speed boundary according to the vehicle speed, the vehicle target acceleration, and the actual acceleration; a fourth determining module, configured to determine whether a regenerative anti-skid state of the vehicle is activated according to the vehicle speed and the requested regenerative torque; The control module is configured to control the rotation speed of the drive motor to be greater than or equal to the target motor real-time minimum rotation speed limit if it is determined that the recovery anti-skid state is activated.

15. An electronic device, characterized in that: It includes a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory communicate with each other via the communication bus; Memory for storing computer programs; The processor is configured to implement the vehicle recovery slip control method according to any one of claims 1 to 13 when executing a program stored in the memory.

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