Vehicle torque control method and device

Abstract

The present invention provides a method and device for controlling vehicle torque, belonging to the technical field of vehicle anti-skid, the method comprising: determining a vehicle speed target control value based on a target vehicle speed limit value of the vehicle at the current moment and a maximum allowable vehicle speed of tires of a middle and rear axle; the target vehicle speed limit value is obtained by conversion according to the gearbox gear position and the main reduction ratio at the current moment; the maximum allowable vehicle speed is calculated according to the average vehicle speed of the front wheels of the vehicle and a target proportional coefficient; determining the actual maximum vehicle speed at the current moment based on the wheel speed of the middle axle wheel, the wheel speed of the left wheel of the rear axle, and the wheel speed of the right wheel of the rear axle; the wheel speed of the middle axle wheel is obtained by conversion of the output shaft speed of the middle axle and the main reduction ratio; calculating the speed difference between the vehicle speed target control value and the actual maximum vehicle speed, and controlling the torque based on a correction coefficient when the speed difference meets the torque control condition. The vehicle torque control method of the present invention can improve the vehicle torque control effect.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle anti-skid, and in particular to a method and device for controlling vehicle torque. Background Art

[0002] The maximum difference in mass between an empty and loaded new energy heavy-duty truck can reach more than one hundred tons. When it is heavy-loaded, the motor needs to respond quickly to a large torque, while when it is empty, it needs to respond slowly to a small torque. However, when starting empty on a low-adhesion road, the tires on the middle and rear axles can easily slip quickly, causing tire wear. When climbing a slope with a heavy load, it is easy to shift up and cause power loss. When passing through bumpy roads or when one side of the tire is buried in a mining area, a large wheel difference is likely to occur, causing damage to the differential. Since ineffective work is generated during slipping, energy consumption will also increase.

[0003] The driving anti-skid control in the prior art is to send a speed limit request, and the motor control unit (MCU) limits the motor speed through PID and then performs anti-skid intervention to achieve the purpose of anti-skid and torque reduction.

[0004] Due to the large difference in mass between the empty and fully loaded masses of new energy heavy-duty trucks, it is difficult for PID to take both operating conditions into consideration at the same time when performing torque control. TSC control has a delay and poor control response efficiency. PID control has poor stability, and the empty and fully loaded mass parameters are difficult to adjust. The torque of the entire vehicle will cause unevenness, resulting in poor torque control effects. Summary of the invention

[0005] In view of the problems existing in the prior art, the present invention provides a method and device for controlling vehicle torque.

[0006] The present invention provides a method for controlling vehicle torque, comprising:

[0007] Determine a vehicle speed target control value based on a target vehicle speed limit value of the vehicle at the current moment and a maximum permissible vehicle speed of the tires of the middle and rear axles; the target vehicle speed limit value is obtained by conversion based on the gear position of the transmission and the final reduction ratio at the current moment; the maximum permissible vehicle speed is obtained by calculation based on the average vehicle speed of the front wheels of the vehicle and a target proportional coefficient;

[0008] Determining the actual maximum vehicle speed at the current moment based on the wheel speed of the middle axle wheel, the wheel speed of the left wheel of the rear axle, and the wheel speed of the right wheel of the rear axle; the wheel speed of the middle axle wheel is obtained by converting the output shaft speed of the middle axle and the main reduction ratio;

[0009] A speed difference between the vehicle speed target control value and the actual maximum vehicle speed is calculated, and when the speed difference satisfies a torque control condition, the torque is controlled based on a correction coefficient.

[0010] According to a vehicle torque control method provided by the present invention, the + value includes:

[0011] Obtaining the motor speed protection threshold of the vehicle, the gear position of the gearbox at the current moment and the main reduction ratio, and converting them using formula (1) to obtain the target vehicle speed limit;

[0012]

[0013] Among them, V Limreq is the target speed limit, K is the proportional constant, Speed M is the motor speed protection threshold of the vehicle, i g is the gearbox gear position at the current moment, i o is the main reduction ratio;

[0014] Collecting the average speed of the front wheels of the vehicle, converting it using formula (2) to obtain the maximum allowable speed;

[0015] V maxreq =V mean ×S+C (2)

[0016] Among them, V maxreq is the maximum permissible vehicle speed, V mean is the average speed of the front wheels, S is the target proportional coefficient, and C is an empirical value.

[0017] The target vehicle speed control value is determined based on a minimum value of the target vehicle speed limit value and the maximum allowable vehicle speed.

[0018] According to a vehicle torque control method provided by the present invention, the actual maximum vehicle speed at the current moment is determined based on the wheel speed of the middle axle wheel, the wheel speed of the rear axle left wheel and the wheel speed of the rear axle right wheel of the vehicle, including:

[0019] Based on the output shaft speed of the middle bridge, the wheel speed of the middle bridge is determined using formula (3):

[0020]

[0021] Among them, V sim is the wheel speed of the middle bridge, Speed trm is the output shaft wheel speed of the middle bridge;

[0022] The actual maximum vehicle speed at the current moment is determined based on the maximum value among the wheel speed of the middle axle wheel, the wheel speed of the rear axle left wheel and the wheel speed of the rear axle right wheel.

[0023] According to a vehicle torque control method provided by the present invention, the speed difference between the vehicle speed target control value and the actual maximum vehicle speed is calculated, and when the speed difference satisfies the torque control condition, the torque is controlled based on a correction coefficient, including:

[0024] When the speed difference is less than or equal to a first preset threshold value, and the output shaft wheel speed acceleration or the rear axle wheel speed acceleration is greater than a second preset threshold value, searching in a mapping table of speed difference and correction coefficient based on the speed difference to determine the correction coefficient of the requested torque at the current moment;

[0025] Filtering is performed based on the correction coefficient of the requested torque and a control algorithm, the size and slope of the correction coefficient are determined, and the size and slope of the requested torque are controlled.

[0026] According to a vehicle torque control method provided by the present invention, the method further includes:

[0027] When the torque control condition is not satisfied, the torque at the current moment is kept unchanged.

[0028] According to a vehicle torque control method provided by the present invention, the transfer function of the control algorithm is determined by formula (4):

[0029]

[0030] Wherein, G(s) is the transfer function, fac0 is the correction coefficient of the requested torque at the current moment, and fac final is the correction coefficient after filtering, s is the Laplace operator, TI and K P The preset calibration amount.

[0031] The present invention also provides a vehicle torque control method and device, comprising:

[0032] A first determination module is used to determine a vehicle speed target control value based on a target vehicle speed limit value of the vehicle at the current moment and a maximum allowable vehicle speed of the tires of the middle and rear axles; the target vehicle speed limit value is obtained by conversion according to the gear position of the transmission and the main reduction ratio at the current moment; the maximum allowable vehicle speed is obtained by calculation according to the average vehicle speed of the front wheels of the vehicle and a target proportional coefficient;

[0033] A second determination module is used to determine the actual maximum vehicle speed at the current moment based on the wheel speed of the middle bridge wheel, the wheel speed of the left wheel of the rear bridge, and the wheel speed of the right wheel of the rear bridge; the wheel speed of the middle bridge wheel is obtained by converting the output shaft speed of the middle bridge and the main reduction ratio;

[0034] The control module is used to calculate the speed difference between the vehicle speed target control value and the actual maximum vehicle speed, and control the torque based on the correction coefficient when the speed difference meets the torque control condition.

[0035] The present invention also provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, a vehicle torque control method as described in any one of the above is implemented.

[0036] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the vehicle torque control method as described in any one of the above is implemented.

[0037] The present invention also provides a computer program product, comprising a computer program, wherein when the computer program is executed by a processor, the vehicle torque control method as described in any one of the above is implemented.

[0038] The present invention provides a vehicle torque control method and device, which determines a vehicle speed target control value based on a target vehicle speed limit value of the vehicle at the current moment and a maximum allowable vehicle speed of tires on a middle and rear axles; the target vehicle speed limit value is obtained by conversion according to the gear position of the gearbox and the main reduction ratio at the current moment; the maximum allowable vehicle speed is obtained by calculation according to the average vehicle speed of the front wheels of the vehicle and a target proportional coefficient; then, based on the wheel speed of the middle axle wheels, the wheel speed of the left wheel of the rear axle and the wheel speed of the right wheel of the rear axle, the actual maximum vehicle speed at the current moment is determined; the wheel speed of the middle axle wheels is obtained by conversion of the output shaft speed of the middle axle and the main reduction ratio; finally, the speed difference between the vehicle speed target control value and the actual maximum vehicle speed is calculated, and when the speed difference meets the torque control condition, the torque is controlled based on the correction coefficient. The vehicle torque control method of the present invention performs logical judgment to determine whether to adjust the torque based on the speed difference between the vehicle speed target control value and the actual maximum vehicle speed at the current moment, and takes into account the wheel speeds of the front wheels and the middle and rear axles. When the torque control conditions are met, the torque is actively adjusted to suppress motor overspeed, protect the differential, prevent tire slippage, and improve the torque control adjustment effect of the vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0040] Figure 1 This is one of the flow charts of the vehicle torque control method provided by the present invention;

[0041] Figure 2 This is the second flow chart of the vehicle torque control method provided by the present invention;

[0042] Figure 3 This is the third flow chart of the vehicle torque control method provided by the present invention;

[0043] Figure 4 This is a fourth flow chart of the vehicle torque control method provided by the present invention;

[0044] Figure 5 This is the fifth flow chart of the vehicle torque control method provided by the present invention;

[0045] Figure 6 is a schematic diagram of a filtering algorithm of a vehicle torque control method provided by the present invention;

[0046] Figure 7 It is a schematic diagram of a device of a vehicle torque control method provided by the present invention;

[0047] Figure 8 It is a structural schematic diagram of the electronic device provided by the present invention. DETAILED DESCRIPTION

[0048] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0049] Combine the following Figure 1-Figure 7 The vehicle torque control method and device of the present invention are described.

[0050] Figure 1 FIG. 1 is one of the flow charts of the vehicle torque control method provided by the present invention, such as Figure 1 As shown, the vehicle torque control method provided by the embodiment of the present invention includes:

[0051] Step 110: Determine a vehicle speed target control value based on a target vehicle speed limit value of the vehicle at the current moment and a maximum allowable vehicle speed of the tires of the middle and rear axles; the target vehicle speed limit value is obtained by converting the current gearbox gear and the final reduction ratio; the maximum allowable vehicle speed is obtained by calculating the average vehicle speed of the front wheels of the vehicle and a target proportional coefficient;

[0052] Specifically, in the specific implementation, the application object of the technical solution of the embodiment of the present invention is a new energy heavy-duty truck, and the executors of the technical solution of the embodiment are all electric vehicle control units (VCU) of new energy heavy-duty trucks. VCU is the core system component in the whole vehicle control of new energy heavy-duty trucks in the embodiment of the present invention, and is responsible for the key tasks of controlling the whole vehicle. VCU generally receives the driver's operating ideas by collecting signals such as the accelerator pedal, brake pedal and gear position. It can also calculate the required torque of the electric vehicle by monitoring the relevant information of the battery management system (BMS) and the motor control system (MCU) on the powertrain system, and then sends instructions to the MCU through the CAN line to control the output of the motor, thereby realizing the driving / braking / energy recovery of the whole vehicle to control the whole vehicle.

[0053] It should also be noted that, in the embodiment of the present invention, the control of vehicle torque may include driving torque control and electric braking torque control.

[0054] The technical solution of the embodiment of the present invention is actively executed by the VCU. At a certain moment, the VCU obtains different data for conversion processing and logical judgment, and finally determines whether the current torque needs to be controlled and adjusted.

[0055] Specifically, in this step, the vehicle speed target control value V is first determined. req The specific determination method is to first convert the motor speed protection threshold value preset by the VCU, the gearbox gear position and the main reduction ratio of the vehicle at the current moment, and obtain the target speed limit value V of the new energy heavy truck at the current moment. Limreq It should be noted that the gearbox gear can be the first gear, the second gear, or the third gear, depending on the specific conditions of the vehicle, and is not specifically limited here.

[0056] Furthermore, the main reduction ratio refers to the gear ratio of the main reducer in the vehicle drive axle of the new energy heavy-duty truck, which is equal to the ratio of the rotational angular velocity of the drive shaft to the rotational angular velocity of the upper axle half shaft, and is also equal to the ratio of their rotational speeds. Generally speaking, the larger the main reduction ratio, the stronger the acceleration performance and climbing ability of the car, but the fuel economy is relatively poor; if the main reduction ratio is too large, the full power of the engine may not be effectively exerted, and it is difficult to reach a suitable speed. On the contrary, the smaller the main reduction ratio, the higher the maximum vehicle speed may be, but the acceleration and climbing ability are poor. In an embodiment of the present invention, the main reduction ratio can be directly obtained through the VCU.

[0057] In this step, it is also necessary to determine the maximum permissible speed of the tires of the middle and rear axles. The specific determination method is to calculate the maximum permissible speed of the tires of the middle and rear axles according to the average front wheel speed V of the new energy heavy truck. mean , VCU is corrected according to the target proportional coefficient S and some auxiliary signals.

[0058] In the specific implementation of the embodiment of the present invention, the auxiliary signal is some empirical marking values ​​C, which may include a steering wheel angle signal and a throttle opening signal. Based on the above three values, the maximum allowable vehicle speed V of the middle and rear axle tires at the current moment is obtained. maxrqe The specific calculation formula is V maxrqe =V mean ×S+C, thus obtaining the maximum permissible speed of the tires on the middle and rear axles at the current moment.

[0059] Based on the target vehicle speed limit V obtained through the above conversion Limreq and the maximum permissible speed V of the tires on the middle and rear axles maxrqe , select the smaller value between the two to determine the current moment, the new energy heavy truck vehicle speed target control value V req .

[0060] Step 120: determining the actual maximum vehicle speed at the current moment based on the wheel speed of the middle axle wheel, the wheel speed of the left wheel of the rear axle, and the wheel speed of the right wheel of the rear axle; the wheel speed of the middle axle wheel is obtained by converting the output shaft speed of the middle axle and the main reduction ratio;

[0061] Specifically, in this step, it is necessary to determine the actual maximum speed of the new energy heavy truck at the current moment. This feedback value is determined based on the wheel speed of the middle bridge, the wheel speed of the left wheel of the rear bridge, and the wheel speed of the right wheel of the rear bridge. The specific determination method is to first convert the wheel speed of the middle bridge V based on the output shaft speed of the middle bridge of the vehicle and the main reduction ratio. sim The output shaft speed of the middle bridge can be obtained through the output shaft speed sensor; at the same time, the left and right wheel speeds of the rear axle of the vehicle are obtained, and the left wheel speed of the rear axle is V Rleft , the rear axle right wheel speed is V Rright , which is also obtained through the wheel speed sensor of the rear axle of the vehicle. The above three values ​​are compared and the maximum value of the three values ​​is selected as the actual maximum vehicle speed V at the current moment. max .

[0062] Furthermore, it should be noted that after determining V max Afterwards, the actual maximum vehicle speed value needs to be low-pass filtered to denoise the signal value.

[0063] Step 130: Calculate the speed difference between the vehicle speed target control value and the actual maximum vehicle speed, and control the torque based on the correction coefficient when the speed difference satisfies the torque control condition.

[0064] Specifically, in this step, the speed difference V between the vehicle speed target control value and the actual maximum vehicle speed value needs to be calculated first, that is, V = V req -V max, and then make a logical judgment based on the quick-check value, that is, whether the torque control conditions are met.

[0065] In a specific implementation, the torque needs to be adjusted and controlled under the condition that the speed difference is less than or equal to the first preset threshold, that is, V≤B1, and at the same time, the wheel speed acceleration of the vehicle output shaft or the rear axle wheel speed acceleration is greater than the second preset threshold B2.

[0066] When these two conditions are met at the same time, it means that the torque needs to be adjusted at the current moment. The specific torque control algorithm is to look up the table based on the quick-lookup value. In the specific implementation, there is a mapping relationship table between the speed difference value and the correction coefficient, that is, different speed difference values ​​correspond to different correction coefficients. The corresponding correction coefficient is queried in the mapping table based on the speed difference value, and then the filtering algorithm is used to filter the current correction coefficient. The torque requested by the VCU is controlled and adjusted according to the filtered correction coefficient, and finally the size and slope of the torque requested by the VCU are obtained.

[0067] The vehicle torque control method provided by the present invention is actively executed by VCU, that is, an active torque reduction strategy, which can automatically adapt to the torque control of different adhesion roads, and determine the vehicle speed target control value through the current target speed limit of the vehicle and the maximum allowable speed of the tires of the middle and rear axles; then determine the actual maximum vehicle speed at the current moment based on the wheel speed of the middle axle, the wheel speed of the left wheel of the rear axle, and the wheel speed of the right wheel of the rear axle; further calculate the speed difference between the vehicle speed target control value and the actual maximum vehicle speed, and control the torque adjustment based on the correction coefficient when the speed difference meets the torque control condition. The vehicle torque control method of the embodiment of the present invention performs logical judgment to determine whether to adjust the torque based on the speed difference between the vehicle speed target control value and the actual maximum vehicle speed at the current moment, and takes into account the wheel speeds of the front wheels, the middle and rear axles, and actively adjusts the torque when the torque control condition is met, suppresses motor overspeed, protects the differential, prevents tire slippage, and improves the torque control adjustment effect of new energy heavy trucks.

[0068] Optionally, according to a vehicle torque control method provided by an embodiment of the present invention, the above step 110 specifically includes the following steps: Figure 2 FIG. 2 is a flow chart of the vehicle torque control method provided by the present invention. Figure 2 As shown, based on the current target vehicle speed limit and the maximum permissible vehicle speed of the middle and rear axle tires, the target vehicle speed control value is determined, including:

[0069] Step 210: Obtain the motor speed protection threshold of the vehicle, the gearbox gear at the current moment and the main reduction ratio, and convert them using formula (1) to obtain the target vehicle speed limit;

[0070] Specifically, in this step, the VCU will pre-set a motor speed protection threshold, which can be directly obtained through the VCU, and then obtain the gearbox gear at the current moment, combined with the main reduction ratio obtained by the VCU, and convert it to obtain the target vehicle speed limit V at the current moment. Limreq .

[0071] In the specific implementation, formula (1) is used for conversion:

[0072]

[0073] Among them, V Limreq is the target speed limit, K is the proportional constant, Speed M is the motor speed protection threshold of the vehicle, i g is the gearbox gear position at the current moment, i o is the main reduction ratio;

[0074] Step 220, collecting the average front wheel speed of the vehicle, the steering wheel angle signal value, and the target proportional coefficient, and converting them using formula (2) to obtain the maximum allowable vehicle speed;

[0075] Specifically, in this step, the average front wheel speed V of the vehicle at the current moment is collected. mean , and the vehicle steering wheel angle signal value, the steering wheel angle signal value is also directly obtained through the VCU, and then combined with the target proportional coefficient S and the anti-skid speed judgment threshold C, V is calculated according to the calculation formula maxrqe =V mean ×S+C, we can get the maximum allowed speed V at the current moment. maxrqe .

[0076] In a specific implementation, the target proportionality coefficient is an empirical control value, and the anti-skid vehicle speed judgment threshold C is an empirical marking value. In the embodiment of the present invention, C is related to the steering wheel angle signal value and the throttle opening of the vehicle.

[0077] And, the target scale factor is defined as follows:

[0078]

[0079] Among them, V rear is the rear wheel speed of the vehicle.

[0080] Step 230: Determine the target vehicle speed control value based on the minimum value of the target vehicle speed limit and the maximum allowable vehicle speed.

[0081] Specifically, based on the above steps, two key values ​​are obtained, namely, the target vehicle speed limit V Limreq and the maximum permissible vehicle speed V maxrqe, compare the two values ​​and select the minimum value as the current target vehicle speed control value V req , that is, V req =Min{V Limreq , V maxrqe}.

[0082] Optionally, according to a vehicle torque control method provided by an embodiment of the present invention, the above step 120 is specifically implemented as follows: Figure 3 FIG. 3 is a flow chart of the vehicle torque control method provided by the present invention. Figure 3 As shown, based on the wheel speed of the middle bridge wheel, the wheel speed of the left rear bridge wheel and the wheel speed of the right rear bridge wheel, the actual maximum vehicle speed at the current moment is determined, including:

[0083] Step 310: Based on the output shaft speed of the middle bridge, determine the wheel speed of the middle bridge using formula (3);

[0084] Specifically, in this step, the output shaft speed of the middle bridge at the current moment is obtained through the shaft speed sensor, and the wheel speed V of the middle bridge is obtained by conversion in combination with the main reduction ratio. sim .

[0085] Based on the output shaft speed of the middle bridge, the wheel speed of the middle bridge is determined using formula (3):

[0086]

[0087] Among them, V sim is the wheel speed of the middle bridge, Speed trm is the output shaft wheel speed of the middle bridge;

[0088] Step 320: Determine the actual maximum vehicle speed at the current moment based on the maximum value among the wheel speed of the middle axle wheel, the wheel speed of the rear axle left wheel, and the wheel speed of the rear axle right wheel.

[0089] Specifically, in this step, the wheel speeds of the left and right wheels of the rear axle are first obtained through the speed sensors of the left and right wheels of the rear axle, which are V and V respectively. Rleft , V Rright Then compare the wheel speeds of the left and right wheels of the rear axle with the wheel speed of the middle axle wheel, and select the maximum value of the three values ​​as the actual maximum vehicle speed V at the current moment max , that is, V max =max{V sim , V Rleft , V Rrigh}.

[0090] The vehicle torque control method provided by the present invention can automatically adapt to the torque control of different adhesion roads through the active execution of the VCU, and determine the vehicle speed target control value through the current target speed limit of the vehicle and the maximum allowable speed of the tires of the middle and rear axles; then determine the actual maximum vehicle speed at the current moment based on the wheel speed of the middle axle, the wheel speed of the left wheel of the rear axle, and the wheel speed of the right wheel of the rear axle; further calculate the speed difference between the vehicle speed target control value and the actual maximum vehicle speed, and control the torque adjustment based on the correction coefficient when the speed difference meets the torque control condition. The vehicle driving torque control method of the embodiment of the present invention performs logical judgment to determine whether to adjust the torque based on the speed difference between the vehicle speed target control value and the actual maximum vehicle speed at the current moment, and takes into account the wheel speeds of the front wheels, the middle and rear axles, and actively adjusts the torque when the torque control condition is met, suppresses motor overspeed, protects the differential, prevents tire slippage, and improves the torque control adjustment effect of new energy heavy trucks.

[0091] Optionally, according to a vehicle torque control method provided by an embodiment of the present invention, the specific implementation of the above step 130 is as follows, that is, calculating the speed difference between the vehicle speed target control value and the actual maximum vehicle speed, and controlling the torque based on the correction coefficient when the speed difference satisfies the torque control condition, including:

[0092] When the speed difference is less than or equal to a first preset threshold value, and the output shaft wheel speed acceleration or the rear axle wheel speed acceleration is greater than a second preset threshold value, searching in a mapping table of speed difference and correction coefficient based on the speed difference to determine the correction coefficient of the requested torque at the current moment;

[0093] Filtering is performed based on the correction coefficient of the requested torque and a control algorithm, the size and slope of the correction coefficient are determined, and the size and slope of the requested torque are controlled.

[0094] Specifically, in this step, the speed difference V between the vehicle speed target control value and the actual maximum vehicle speed value needs to be calculated first, that is, V = V req -V max , and then make a logical judgment based on the quick-check value, that is, whether the torque control conditions are met.

[0095] In a specific implementation, the torque needs to be adjusted and controlled under the condition that the speed difference is less than or equal to the first preset threshold, that is, V≤B1, and at the same time, the wheel speed acceleration of the vehicle output shaft or the rear axle wheel speed acceleration is greater than the second preset threshold B2.

[0096] When these two conditions are met at the same time, it means that the torque needs to be adjusted at the current moment. The specific torque control algorithm is to look up the table based on the quick-lookup value. In the specific implementation, there is a mapping relationship table between the speed difference value and the correction coefficient, that is, different speed difference values ​​correspond to different correction coefficients. The corresponding correction coefficient is queried in the mapping table based on the speed difference value, and then the filtering algorithm is used to filter the current correction coefficient. The torque requested by the VCU is controlled and adjusted according to the filtered correction coefficient, and finally the size and slope of the torque requested by the VCU are obtained.

[0097] The vehicle torque control method provided by the present invention is actively executed by VCU, that is, an active torque reduction strategy, which can automatically adapt to the torque control of different adhesion roads, and determine the vehicle speed target control value through the current target speed limit of the vehicle and the maximum allowable speed of the tires of the middle and rear axles; then determine the actual maximum vehicle speed at the current moment based on the wheel speed of the middle axle, the wheel speed of the left wheel of the rear axle, and the wheel speed of the right wheel of the rear axle; further calculate the speed difference between the vehicle speed target control value and the actual maximum vehicle speed, and control the torque adjustment based on the correction coefficient when the speed difference meets the torque control condition. The vehicle torque control method of the embodiment of the present invention performs logical judgment to determine whether to adjust the torque based on the speed difference between the vehicle speed target control value and the actual maximum vehicle speed at the current moment, and takes into account the wheel speeds of the front wheels, the middle and rear axles, and actively adjusts the torque when the torque control condition is met, suppresses motor overspeed, protects the differential, prevents tire slippage, and improves the torque control adjustment effect of new energy heavy trucks.

[0098] Furthermore, the vehicle torque control method of the embodiment of the present invention determines whether to perform torque control by actively acquiring, converting and logically judging by the VCU at the current moment, thereby further improving the real-time performance and effect of torque control of new energy heavy-duty trucks.

[0099] Optionally, according to a vehicle torque control method provided by an embodiment of the present invention, the method further includes: when the torque control condition is not met, keeping the torque at the current moment unchanged.

[0100] Figure 4 FIG. 4 is a flow chart of the vehicle torque control method provided by the present invention. Figure 4 As shown, the logical judgment of the torque control of the embodiment of the present invention is as follows:

[0101] Step 410, calculating the speed difference V between the vehicle speed target control value and the actual maximum vehicle speed value;

[0102] Step 420, determining whether the torque adjustment condition is met;

[0103] Specifically, the torque adjustment condition is V≤B1&&a>B2;

[0104] Wherein, B1 is the first preset threshold, B2 is the second preset threshold, and a is the wheel speed acceleration of the vehicle output shaft or the rear axle wheel speed acceleration;

[0105] When the torque adjustment condition is met, step 430 is executed to obtain the correction coefficient fac corresponding to V based on a table lookup;

[0106] Then, step 440 is executed to filter the correction coefficient fac;

[0107] Step 450: VCU requests torque reduction or torque increase;

[0108] Specifically, the magnitude and slope of the torque requested by the VCU can be obtained, and after the torque is adjusted, the MCU responds to the torque request of the VCU and performs closed-loop control.

[0109] If the torque adjustment is not satisfied, step 460 is executed and the VCU requests the torque to remain unchanged.

[0110] Figure 5 FIG. 5 is a flow chart of the vehicle torque control method provided by the present invention. Figure 5 As shown, the overall logic of the vehicle torque control method of the embodiment of the present invention is that based on the transmission controller TCU, the vehicle's gear signal and output shaft speed signal are obtained, and based on the chassis controller ABS, the front axle and rear axle wheel speed signals, steering wheel angle signal, ABS working status signal, and throttle signal obtained from the ADC signal can be obtained. The above signals are input into the vehicle controller VCU of the vehicle. After the conversion and logical judgment of the above steps, when it is determined that torque control is required, the motor controller MCU is requested for torque, and the MCU drives the vehicle after responding to the torque.

[0111] Optionally, according to a vehicle torque control method provided by the present invention,

[0112] The transfer function of the control algorithm is determined using formula (4):

[0113]

[0114] Wherein, G(s) is the transfer function, fac0 is the correction coefficient of the requested torque at the current moment, and fac final is the correction coefficient after filtering, s is the Laplace operator, TI and K P The preset calibration amount.

[0115] Specifically, in the embodiment of the present invention, the control algorithm is an algorithm that performs supplementary adjustment based on the filtering algorithm, which may be referred to as a Ramp PDTI filtering algorithm.

[0116] Figure 6 FIG. 1 is a schematic diagram of a filtering algorithm of a vehicle torque control method provided by the present invention, such as Figure 6 As shown, the fac obtained by searching the mapping table and the slope parameter setting obtained by slope calculation are combined with the time step dt and input into the slope function Ramp_fun, and then PTI low-pass filtering is performed, where TI is the calibration quantity and Kp is the proportional coefficient, which can be understood as the quantity set according to the empirical value. After low-pass filtering, the filtered fac is obtained, and then multiplied by the driver's requested torque to obtain the final VCU requested MCU torque.

[0117] The vehicle torque control method of the embodiment of the present invention further filters the correction system and combines the new Ramp PDTI filtering algorithm to stably adjust the torque, adapt to no-load and heavy-load conditions, smooth the rate of change of the correction coefficient, prevent sudden changes or jitters in the coefficient, and further ensure the availability of torque control.

[0118] The vehicle torque control device provided by the present invention is described below. The vehicle torque control device described below and the vehicle torque control method described above can be referenced to each other.

[0119] Figure 7 Schematic diagram of the structure of the vehicle torque control device provided by the present invention, such as Figure 7 As shown, the control device for the torque of a truck provided by the embodiment of the present invention comprises:

[0120] A first determination module is used to determine a vehicle speed target control value based on a target vehicle speed limit value of the vehicle at the current moment and a maximum allowable vehicle speed of the tires of the middle and rear axles; the target vehicle speed limit value is obtained by conversion according to the gear position of the transmission and the main reduction ratio at the current moment; the maximum allowable vehicle speed is obtained by calculation according to the average vehicle speed of the front wheels of the vehicle and a target proportional coefficient;

[0121] A second determination module is used to determine the actual maximum vehicle speed at the current moment based on the wheel speed of the middle bridge wheel, the wheel speed of the left wheel of the rear bridge, and the wheel speed of the right wheel of the rear bridge; the wheel speed of the middle bridge wheel is obtained by converting the output shaft speed of the middle bridge and the main reduction ratio;

[0122] The control module is used to calculate the speed difference between the vehicle speed target control value and the actual maximum vehicle speed, and control the torque based on the correction coefficient when the speed difference meets the torque control condition.

[0123] The vehicle torque control device provided by the present invention realizes torque control of new energy heavy-duty trucks through the mutual cooperation of various modules. Through the active execution of VCU, that is, the active torque reduction strategy, it can automatically adapt to the torque control of different adhesion roads. The vehicle speed target control value is determined by the target speed limit of the vehicle at the current moment and the maximum allowable speed of the tires of the middle and rear axles; then the actual maximum speed at the current moment is determined based on the wheel speed of the middle axle, the wheel speed of the left wheel of the rear axle, and the wheel speed of the right wheel of the rear axle; the speed difference between the vehicle speed target control value and the actual maximum speed is further calculated, and the torque adjustment is controlled based on the correction coefficient when the speed difference meets the torque control condition. The vehicle torque control method of the embodiment of the present invention performs logical judgment to determine whether to adjust the torque based on the speed difference between the vehicle speed target control value and the actual maximum speed at the current moment, and takes into account the wheel speeds of the front wheels, the middle and rear axles, and actively adjusts the torque when the torque control condition is met, suppresses motor overspeed, protects the differential, prevents tire slippage, and improves the torque control adjustment effect of new energy heavy-duty trucks.

[0124] Figure 8 It is a structural schematic diagram of the electronic device provided by the present invention. Figure 8 An example of a physical structure diagram of an electronic device is shown in FIG. Figure 8 As shown, the electronic device may include: a processor 810, a communication interface 820, a memory 830 and a communication bus 840, wherein the processor 810, the communication interface 820 and the memory 830 communicate with each other through the communication bus 840. The processor 810 may call the logic instructions in the memory 830 to execute the above-mentioned vehicle torque control method, which includes:

[0125] Determine a vehicle speed target control value based on a target vehicle speed limit value of the vehicle at the current moment and a maximum permissible vehicle speed of the tires of the middle and rear axles; the target vehicle speed limit value is obtained by conversion based on the gear position of the transmission and the final reduction ratio at the current moment; the maximum permissible vehicle speed is obtained by calculation based on the average vehicle speed of the front wheels of the vehicle and a target proportional coefficient;

[0126] Determining the actual maximum vehicle speed at the current moment based on the wheel speed of the middle axle wheel, the wheel speed of the left wheel of the rear axle, and the wheel speed of the right wheel of the rear axle; the wheel speed of the middle axle wheel is obtained by converting the output shaft speed of the middle axle and the main reduction ratio;

[0127] A speed difference between the vehicle speed target control value and the actual maximum vehicle speed is calculated, and when the speed difference satisfies a torque control condition, the torque is controlled based on a correction coefficient.

[0128] In addition, the logic instructions in the above-mentioned memory 830 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when it is sold or used as an independent product. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program codes.

[0129] On the other hand, the present invention further provides a computer program product, the computer program product includes a computer program, the computer program can be stored in a non-transitory computer-readable storage medium, when the computer program is executed by a processor, the computer can execute the vehicle torque control method provided by the above methods, the method includes:

[0130] Determine a vehicle speed target control value based on a target vehicle speed limit value of the vehicle at the current moment and a maximum permissible vehicle speed of the tires of the middle and rear axles; the target vehicle speed limit value is obtained by conversion based on the gear position of the transmission and the final reduction ratio at the current moment; the maximum permissible vehicle speed is obtained by calculation based on the average vehicle speed of the front wheels of the vehicle and a target proportional coefficient;

[0131] Determining the actual maximum vehicle speed at the current moment based on the wheel speed of the middle axle wheel, the wheel speed of the left wheel of the rear axle, and the wheel speed of the right wheel of the rear axle; the wheel speed of the middle axle wheel is obtained by converting the output shaft speed of the middle axle and the main reduction ratio;

[0132] A speed difference between the vehicle speed target control value and the actual maximum vehicle speed is calculated, and when the speed difference satisfies a torque control condition, the torque is controlled based on a correction coefficient.

[0133] In another aspect, the present invention further provides a non-transitory computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the vehicle torque control method provided by the above methods is implemented, and the method includes:

[0134] Determine a vehicle speed target control value based on a target vehicle speed limit value of the vehicle at the current moment and a maximum permissible vehicle speed of the tires of the middle and rear axles; the target vehicle speed limit value is obtained by conversion based on the gear position of the transmission and the final reduction ratio at the current moment; the maximum permissible vehicle speed is obtained by calculation based on the average vehicle speed of the front wheels of the vehicle and a target proportional coefficient;

[0135] Determining the actual maximum vehicle speed at the current moment based on the wheel speed of the middle axle wheel, the wheel speed of the left wheel of the rear axle, and the wheel speed of the right wheel of the rear axle; the wheel speed of the middle axle wheel is obtained by converting the output shaft speed of the middle axle and the main reduction ratio;

[0136] A speed difference between the vehicle speed target control value and the actual maximum vehicle speed is calculated, and when the speed difference satisfies a torque control condition, the torque is controlled based on a correction coefficient.

[0137] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.

[0138] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0139] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for controlling vehicle torque, characterized in that: include: Determining a vehicle speed target control value based on a target vehicle speed limit value of the vehicle at the current moment and a maximum permissible vehicle speed of the tires of the middle and rear axles; The target speed limit is calculated based on the gear position and the main reduction ratio of the current gearbox; the maximum allowable speed is calculated based on the average speed of the front wheels of the vehicle and the target proportionality coefficient; Determining the actual maximum vehicle speed at the current moment based on the wheel speed of the middle axle wheel, the wheel speed of the left wheel of the rear axle, and the wheel speed of the right wheel of the rear axle; the wheel speed of the middle axle wheel is obtained by converting the output shaft speed of the middle axle and the main reduction ratio; calculating a speed difference between the vehicle speed target control value and the actual maximum vehicle speed, and controlling the torque based on a correction coefficient when the speed difference satisfies a torque control condition; The determining of the target vehicle speed control value based on the target vehicle speed limit value of the vehicle at the current moment and the maximum permissible vehicle speed of the tires of the middle and rear axles includes: Obtaining the motor speed protection threshold of the vehicle, the gear position of the gearbox at the current moment and the main reduction ratio, and converting them using formula (1) to obtain the target vehicle speed limit; Among them, V Limreq is the target speed limit, K is the proportional constant, Speed M is the motor speed protection threshold of the vehicle, i g is the gearbox gear position at the current moment, i o is the main reduction ratio; Collecting the average speed of the front wheels of the vehicle, converting it using formula (2) to obtain the maximum allowable speed; In maxreq =V mean ×S+C (2) Among them, V maxreq is the maximum permissible vehicle speed, V mean is the average speed of the front wheels, S is the target proportionality coefficient, and C is an empirical value; The target vehicle speed control value is determined based on a minimum value of the target vehicle speed limit value and the maximum allowable vehicle speed.

2. The vehicle torque control method according to claim 1, characterized in that: The determining the actual maximum vehicle speed at the current moment based on the wheel speed of the middle axle wheel, the wheel speed of the left wheel of the rear axle, and the wheel speed of the right wheel of the rear axle comprises: Based on the output shaft speed of the middle bridge, the wheel speed of the middle bridge is determined using formula (3): Among them, V sim is the wheel speed of the middle bridge, Speed trm is the output shaft wheel speed of the middle bridge; The actual maximum vehicle speed at the current moment is determined based on the maximum value among the wheel speed of the middle axle wheel, the wheel speed of the rear axle left wheel and the wheel speed of the rear axle right wheel.

3. The vehicle torque control method according to claim 1, characterized in that: The calculating the speed difference between the vehicle speed target control value and the actual maximum vehicle speed, and controlling the torque based on a correction coefficient when the speed difference satisfies a torque control condition, comprises: When the speed difference is less than or equal to a first preset threshold value, and the output shaft wheel speed acceleration or the rear axle wheel speed acceleration is greater than a second preset threshold value, searching in a mapping table of speed difference and correction coefficient based on the speed difference to determine the correction coefficient of the requested torque at the current moment; Filtering is performed based on the correction coefficient of the requested torque and a control algorithm, the size and slope of the correction coefficient are determined, and the size and slope of the requested torque are controlled.

4. The vehicle torque control method according to claim 3, characterized in that: The method further comprises: When the torque control condition is not satisfied, the torque at the current moment is kept unchanged.

5. The vehicle torque control method according to claim 3, characterized in that: The transfer function of the control algorithm is determined using formula (4): Wherein, G(s) is the transfer function, fac0 is the correction coefficient of the requested torque at the current moment, and fac final is the correction coefficient after filtering, s is the Laplace operator, TI and K P The preset calibration amount.

6. A method and device for controlling vehicle torque, characterized in that: include: A first determination module is used to determine a vehicle speed target control value based on a target vehicle speed limit value of the vehicle at a current moment and a maximum permissible vehicle speed of tires of the middle and rear axles; The target speed limit is calculated based on the gear position and the main reduction ratio of the current gearbox; the maximum allowable speed is calculated based on the average speed of the front wheels of the vehicle and the target proportionality coefficient; A second determination module is used to determine the actual maximum vehicle speed at the current moment based on the wheel speed of the middle bridge wheel, the wheel speed of the left wheel of the rear bridge, and the wheel speed of the right wheel of the rear bridge; the wheel speed of the middle bridge wheel is obtained by converting the output shaft speed of the middle bridge and the main reduction ratio; a control module, configured to calculate a speed difference between the vehicle speed target control value and the actual maximum vehicle speed, and control the torque based on a correction coefficient when the speed difference satisfies a torque control condition; The first determining module is specifically configured to: Obtaining the motor speed protection threshold of the vehicle, the gear position of the gearbox at the current moment and the main reduction ratio, and converting them using formula (1) to obtain the target vehicle speed limit; Among them, V Limreq is the target speed limit, K is the proportional constant, Speed M is the motor speed protection threshold of the vehicle, i g is the gearbox gear position at the current moment, i o is the main reduction ratio; Collecting the average speed of the front wheels of the vehicle, converting it using formula (2) to obtain the maximum allowable speed; In maxreq =V mean ×S+C (2) Among them, V maxreq is the maximum permissible vehicle speed, V mean is the average speed of the front wheels, S is the target proportionality coefficient, and C is an empirical value; The target vehicle speed control value is determined based on a minimum value of the target vehicle speed limit value and the maximum allowable vehicle speed.

7. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, the vehicle torque control method according to any one of claims 1 to 5 is implemented.

8. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the vehicle torque control method according to any one of claims 1 to 5 is implemented.

9. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the vehicle torque control method according to any one of claims 1 to 5 is implemented.

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