Torque control method, device, equipment and storage medium

Abstract

The present invention discloses a torque control method, device, equipment, and storage medium, belonging to the field of vehicle control technology. The present invention obtains the current vehicle speed and front wheel angle of a vehicle while it is traveling; when the vehicle is traveling at a low speed, the target wheel speeds of the left and right drive wheels are obtained based on the current vehicle speed and the front wheel angle; torque is distributed according to the target wheel speeds of the left and right drive wheels; when the vehicle is traveling at a high speed, the yaw moment is calculated based on the current vehicle speed and the front wheel angle, and torque is distributed according to the yaw moment. The torque is reasonably and flexibly distributed according to different vehicle speed conditions, thereby improving the vehicle's steering flexibility at low speeds and steering stability at high speeds, thereby enhancing the user experience.

Description

Technical Field

[0001] The present invention relates to the field of vehicle control technology, and in particular to a torque control method, device, equipment and storage medium. Background Art

[0002] Electric vehicles replace traditional fuel-powered vehicles' engines with electric motors, achieving zero emissions and zero pollution. Coupled with strong national policy support, electric vehicle technology has developed rapidly in recent years. Distributed electric drive systems enable precise and independent control of motor torque, making control more flexible. Distributed drive systems also eliminate traditional differentials, resulting in a more compact structure and higher transmission efficiency. Distributed control of distributed drive electric vehicles has become a research hotspot, with motor torque vectoring control in distributed drive systems being a key component of distributed control.

[0003] At present, the control of distributed drive systems is mostly based on yaw torque control, focusing on vehicle stability while ignoring the vehicle's steering flexibility at low speeds, and is not flexible enough in torque distribution.

[0004] The above content is only used to assist in understanding the technical solution of the present invention and does not constitute an admission that the above content is prior art. Summary of the Invention

[0005] The main purpose of the present invention is to provide a torque control method, device, equipment and storage medium, aiming to solve the technical problem of inflexible vehicle torque distribution in the prior art.

[0006] To achieve the above object, the present invention provides a torque control method, which comprises the following steps:

[0007] Get the current speed and front wheel angle of the car while it is driving;

[0008] When the vehicle is traveling at a low speed, obtaining target wheel speeds of the left and right driving wheels based on the current vehicle speed and the front wheel steering angle;

[0009] Distributing torque according to the target wheel speeds of the left and right driving wheels;

[0010] When the vehicle is traveling at high speed, the yaw moment is calculated according to the current vehicle speed and the front wheel angle, and torque distribution is performed according to the yaw moment.

[0011] Optionally, the calculating the target wheel speeds of the left and right driving wheels of the vehicle based on the current vehicle speed and the front wheel steering angle includes:

[0012] Get the car's wheelbase, the car's rear wheel track, and the distance from the car's center of mass to the rear axle;

[0013] The target wheel speeds of the left drive wheel and the right drive wheel of the vehicle are calculated by using the wheelbase, the front wheel turning angle, the rear wheel track, the distance from the center of mass to the rear axle, and the current vehicle speed.

[0014] Optionally, distributing the torque according to the target wheel speeds of the left and right driving wheels includes:

[0015] calculating a compensation torque based on the target wheel speeds of the left and right drive wheels, the current vehicle speed, and the front wheel steering angle;

[0016] A target torque is obtained by using the compensation torque, and torque distribution is performed according to the target torque.

[0017] Optionally, the calculating the compensation torque based on the target wheel speed, the current vehicle speed, and the front wheel steering angle includes:

[0018] Obtaining actual wheel speeds of the left and right driving wheels of the vehicle and a first feedforward control coefficient;

[0019] Calculating a first difference between the target wheel speeds of the left and right driving wheels and the actual wheel speeds of the left and right driving wheels;

[0020] obtaining a first feedback control coefficient according to the current vehicle speed and the first difference;

[0021] obtaining a first feedforward term according to the current vehicle speed and the front wheel steering angle;

[0022] The compensation torque is calculated by using the first feedforward control coefficient, the first feedback control coefficient, the first difference, and the first feedforward term.

[0023] Optionally, obtaining the target torque through the compensation torque includes:

[0024] obtaining gear lever information and requested torque of the vehicle;

[0025] When the gear lever information of the vehicle is the first gear, the sum of the compensation torque and the request torque is used as the target torque;

[0026] When the shift lever information of the vehicle indicates the second gear, the difference between the requested torque and the compensation torque is used as the target torque.

[0027] Optionally, when the vehicle is traveling at high speed, calculating the yaw moment by using the current vehicle speed and the front wheel angle, and performing torque distribution according to the yaw moment, includes:

[0028] Obtaining the wheelbase, longitudinal acceleration, and lateral acceleration of the vehicle;

[0029] Obtaining a stability coefficient of the vehicle according to the longitudinal acceleration and the lateral acceleration;

[0030] Calculating a target yaw rate using the current vehicle speed, the front wheel steering angle, the wheelbase, and the stability coefficient;

[0031] obtaining an additional yaw moment according to the target yaw angular velocity and the current vehicle speed;

[0032] The target torque is obtained by using the additional yaw moment to achieve torque distribution for the vehicle.

[0033] Optionally, obtaining the additional yaw moment according to the target yaw angular velocity and the current vehicle speed includes:

[0034] Obtaining an actual yaw rate of the vehicle, a steering state of the vehicle, and a second feedforward control coefficient;

[0035] calculating a second difference between the target yaw rate and the actual yaw rate;

[0036] obtaining a second feedback control coefficient by using the second difference and the current vehicle speed;

[0037] obtaining a second feedforward term by using the current vehicle speed, the target yaw rate, and the steering state;

[0038] The additional yaw moment is obtained by calculation through the second feedforward control coefficient, the second feedback control coefficient, the second feedforward term, and the second difference.

[0039] In addition, to achieve the above-mentioned object, the present invention further provides a torque control device, comprising:

[0040] The acquisition module is used to obtain the current speed and front wheel angle of the car while it is driving;

[0041] an allocation module, configured to obtain target wheel speeds of left and right driving wheels based on the current vehicle speed and the front wheel steering angle when the vehicle is traveling at a low speed;

[0042] The distribution module is further configured to distribute torque according to the target wheel speeds of the left and right driving wheels;

[0043] The distribution module is further configured to calculate the yaw moment according to the current vehicle speed and the front wheel angle when the vehicle is traveling at high speed, and perform torque distribution according to the yaw moment.

[0044] In addition, to achieve the above-mentioned purpose, the present invention also proposes a torque control device, which includes: a memory, a processor, and a torque control program stored in the memory and executable on the processor, wherein the torque control program is configured to implement the steps of the torque control method described above.

[0045] In addition, to achieve the above-mentioned purpose, the present invention further proposes a storage medium, on which a torque control program is stored. When the torque control program is executed by a processor, the steps of the torque control method described above are implemented.

[0046] The present invention obtains the current vehicle speed and the front wheel steering angle of a vehicle when it is traveling; when the vehicle is traveling at a low speed, obtains the target wheel speeds of the left and right driving wheels based on the current vehicle speed and the front wheel steering angle, and distributes torque according to the target wheel speeds of the left and right driving wheels; when the vehicle is traveling at a high speed, calculates the yaw moment according to the current vehicle speed and the front wheel steering angle, distributes torque according to the yaw moment, and reasonably and flexibly distributes the torque according to different speed conditions of the vehicle, thereby improving the steering flexibility of the vehicle when traveling at a low speed and the steering stability when traveling at a high speed, thereby enhancing the user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 Schematic diagram of the structure of the torque control device in the hardware operating environment involved in the embodiment of the present invention;

[0048] Figure 2 This is a flow chart of a first embodiment of a torque control method according to the present invention;

[0049] Figure 3 This is a flow chart of a second embodiment of a torque control method according to the present invention;

[0050] Figure 4 1 is a flow chart of a third embodiment of a torque control method according to the present invention;

[0051] Figure 5 Schematic diagram of torque control under low-speed conditions in one embodiment of the torque control method of the present invention;

[0052] Figure 6 This is a flow chart of a fourth embodiment of a torque control method according to the present invention;

[0053] Figure 7 1. A schematic flow chart of a fifth embodiment of a torque control method according to the present invention;

[0054] Figure 8 A schematic diagram of torque control under high-speed conditions in an embodiment of a torque control method of the present invention;

[0055] Figure 9This is a structural block diagram of the first embodiment of the torque control device of the present invention.

[0056] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0057] It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0058] Reference Figure 1 , Figure 1 This is a schematic diagram of the torque control device structure in the hardware operating environment involved in the embodiment of the present invention.

[0059] like Figure 1 As shown, the torque control device may include: a processor 1001, such as a central processing unit (CPU), a communication bus 1002, a user interface 1003, a network interface 1004, and a memory 1005. The communication bus 1002 is used to implement communication between these components. The user interface 1003 may include a display screen and an input unit such as a keyboard. Optionally, the user interface 1003 may also include a standard wired interface or a wireless interface. The network interface 1004 may optionally include a standard wired interface or a wireless interface (such as a wireless fidelity (Wi-Fi) interface). The memory 1005 may be a high-speed random access memory (RAM) memory or a stable non-volatile memory (NVM), such as a disk storage. The memory 1005 may also be a storage device independent of the aforementioned processor 1001.

[0060] Those skilled in the art will understand that Figure 1 The structure shown in the figure does not constitute a limitation to the torque control device, and may include more or less components than shown in the figure, or combine certain components, or arrange the components differently.

[0061] like Figure 1 As shown, the memory 1005 as a storage medium may include an operating system, a network communication module, a user interface module, and a torque control program.

[0062] exist Figure 1In the torque control device shown, the network interface 1004 is mainly used for data communication with the network server; the user interface 1003 is mainly used for data interaction with the user; the processor 1001 and the memory 1005 in the torque control device of the present invention can be set in the torque control device, and the torque control device calls the torque control program stored in the memory 1005 through the processor 1001 and executes the torque control method provided by the embodiment of the present invention.

[0063] The embodiment of the present invention provides a torque control method, referring to Figure 2 , Figure 2 Schematic diagram of the flow chart of the first embodiment of the torque control method of the present invention.

[0064] In this embodiment, the torque control method includes the following steps:

[0065] Step S10: Acquire the current speed and front wheel angle of the vehicle while it is traveling.

[0066] It should be noted that the executor of this embodiment is the controller in the distributed drive system of the vehicle, which is used to control and distribute the torque of the vehicle. It can also be other devices that can achieve the same or similar functions, and this embodiment does not limit this.

[0067] In this embodiment, the torque demand and distribution vary depending on the vehicle's speed. Therefore, it is necessary to rationally distribute the torque based on the vehicle's operating conditions to improve the vehicle's maneuverability and comfort during use. While the vehicle is driving, a speed sensor installed on the vehicle can detect the vehicle's current speed, and a steering angle sensor can detect the front wheel angle.

[0068] Step S20: When the vehicle is traveling at a low speed, the target wheel speeds of the left and right driving wheels are obtained based on the current vehicle speed and the front wheel steering angle.

[0069] Step S30: Distributing torque according to the target wheel speeds of the left and right driving wheels.

[0070] In a specific implementation, the low-speed vehicle can be 30 km / h or 40 km / h, and can be identified based on the vehicle's operating conditions and speed limit signs in the driving environment, which is not limited in this embodiment. The target wheel speeds of the left and right driving wheels of the vehicle can be calculated based on the vehicle's current speed and front wheel angle using the calculation formula of the Ackerman steering model. Target torques are then determined based on the target wheel speeds of the left and right driving wheels of the vehicle, and torque distribution control of the vehicle is achieved using the target torques.

[0071] Step S40: When the vehicle is traveling at high speed, the yaw moment is calculated according to the current vehicle speed and the front wheel angle, and torque is distributed according to the yaw moment.

[0072] It should be understood that when a vehicle is traveling at high speed, torque distribution is necessary to ensure steering stability. When the vehicle's steering wheel angle is below a set angle threshold (which may be 30 degrees or 40 degrees, and is not limited in this embodiment), and the vehicle speed signal is greater than the speed threshold (which may be 100 km / h or 110 km / h, and is not limited in this embodiment), the vehicle is determined to be traveling at high speed when the gear lever signal indicates forward gear D and the vehicle is not slipping.

[0073] When the car is traveling at high speed, the torque control strategy for high-speed conditions can be activated. The yaw moment of the car is calculated by the current speed of the car and the front wheel angle of the car, and the torque distribution control of the car is realized through the yaw moment of the car.

[0074] This embodiment obtains the current vehicle speed and front wheel steering angle of the vehicle while it is traveling; when the vehicle is traveling at a low speed, obtains the target wheel speeds of the left and right drive wheels based on the current vehicle speed and the front wheel steering angle; and distributes torque according to the target wheel speeds of the left and right drive wheels; when the vehicle is traveling at a high speed, calculates the yaw moment based on the current vehicle speed and the front wheel steering angle, and distributes torque according to the yaw moment. The torque is reasonably and flexibly distributed according to different speed conditions of the vehicle, thereby improving the steering flexibility of the vehicle at low speeds and the steering stability at high speeds, thereby enhancing the user experience.

[0075] refer to Figure 3 , Figure 3 FIG. 4 is a flow chart of a second embodiment of a torque control method according to the present invention.

[0076] Based on the first embodiment described above, step S20 of the torque control method of this embodiment specifically includes:

[0077] Step S201: Obtain the wheelbase of the vehicle, the track width of the rear wheels of the vehicle, and the distance from the center of mass of the vehicle to the rear axle.

[0078] In practice, the wheelbase of a car refers to the distance from the center of the front wheels to the center of the rear wheels. The car can be parked on a straight road when it is empty, the center points of the front and rear wheels of the car can be found, and the straight-line distance between the two points can be measured, which is the wheelbase of the car.

[0079] A car's rear wheel track is the distance between the centerlines of the tracks left by the left and right rear tires on the support surface. The track width between the left and right rear tires can be directly measured. The distance from the car's center of mass to the rear axle can be determined by measuring the distance from the center of mass to the rear axle.

[0080] Step S202: Calculate the target wheel speeds of the left drive wheel and the right drive wheel of the vehicle based on the wheelbase, the front wheel turning angle, the rear wheel track, the distance from the center of mass to the rear axle, and the current vehicle speed.

[0081] The target wheel speeds of the left and right driving wheels of the vehicle can be calculated using the wheelbase, front wheel turning angle, rear wheel track, distance from the center of mass to the rear axle, and current vehicle speed. The calculation process is as follows:

[0082]

[0083]

[0084] In Equation 1 and Equation 2, v x is the current speed, l is the wheelbase of the car, δ is the front wheel turning angle of the car; B is the wheelbase of the rear wheel of the car; b is the distance from the center of mass of the car to the rear axle, v w_lr is the target wheel speed of the left drive wheel of the car, v w_rr is the target wheel speed of the right drive wheel of the car.

[0085] This embodiment obtains the vehicle's wheelbase, the vehicle's rear wheel track, and the distance from the vehicle's center of mass to the rear axle; and calculates the target wheel speeds of the vehicle's left and right drive wheels based on the wheelbase, the front wheel turning angle, the rear wheel track, the distance from the vehicle's center of mass to the rear axle, and the current vehicle speed. This allows for rapid and accurate calculation of the vehicle's target wheel speeds, facilitates calculation of the vehicle's target torque based on the vehicle's target wheel speeds, and implements torque distribution control of the vehicle.

[0086] refer to Figure 4 , Figure 4 FIG. 4 is a flow chart of a third embodiment of a torque control method according to the present invention.

[0087] Based on the first embodiment described above, step S30 of the torque control method of this embodiment specifically includes:

[0088] Step S301: Calculating a compensation torque based on the target wheel speeds of the left and right driving wheels, the current vehicle speed, and the front wheel steering angle.

[0089] In a specific implementation, after the target wheel speed of the right driving wheel of the vehicle is obtained, the torque required to be compensated during torque distribution can be calculated using the target wheel speed, the current vehicle speed, and the front wheel angle.

[0090] Furthermore, in order to ensure adaptability to different working conditions when distributing torque, it is necessary to perform PI control on the vehicle. The vehicle is controlled by PI through a feedforward term and an integral term to calculate the compensation torque of the vehicle. When calculating the compensation torque, it is also necessary to obtain the actual wheel speeds of the left and right drive wheels of the vehicle and the first feedforward term control coefficient.

[0091] The target wheel speed of a car is the ideal wheel speed calculated based on the parameters. However, during actual driving, the actual wheel speed of the car is not necessarily the same as the target wheel speed. The actual wheel speed of the car can be detected by a speed sensor installed on the car, and the first feedforward control coefficient of the PI control of the car can be obtained.

[0092] A first difference between the target wheel speeds of the left and right driving wheels and the actual wheel speeds of the left and right driving wheels is calculated; and a first feedback control coefficient is obtained according to the current vehicle speed and the first difference.

[0093] The first difference e(t) is the difference between the actual wheel speed of the vehicle and the target wheel speed of the vehicle.

[0094] e(t)=v des -v real (Formula 3)

[0095] In formula 3, v des is the target wheel speed, v real is the actual wheel speed, and e(t) is the first difference.

[0096] The first feedback control coefficient includes the proportional term P term coefficient K p and the integral term I coefficient K i The first feedback control coefficient is adjusted in real time by the current vehicle speed and the first difference. When the first difference is small, the P coefficient K in the first feedback control coefficient can be appropriately reduced. p and I coefficient K i , improving the vehicle's adaptability in different working conditions.

[0097] In a specific implementation, in order to ensure the adaptability of the motor torque distribution of the vehicle to different working conditions, the first feedforward term is obtained according to the current vehicle speed and the front wheel angle. The corresponding relationship between the first feedforward term and the vehicle speed and the front wheel angle can be established in advance. The first feedforward term T is obtained according to the current vehicle speed and the front wheel angle. FF ;

[0098] In this embodiment, the compensation torque is calculated by using the first feedforward control coefficient, the first feedback control coefficient, the first difference, and the first feedforward term. The calculation process is as follows:

[0099]

[0100] In formula 4, T com To compensate for the torque, P fac is the first feedforward control coefficient, K p is the P term coefficient in the first feedback control coefficient, K i is the I-term coefficient in the first feedback control coefficient, and e(t) is the first difference.

[0101] When the vehicle's PI control begins to activate, the integral term of the I term needs to be reset, the calculation restarted, and the integral term must be constrained to its minimum and maximum values. A threshold for the integral term can be set in advance by the operator to prevent it from exceeding the threshold. The threshold can be set to [0.1-0.5], [0.3-0.6], etc., and can be set according to the operator's specific needs. To improve the vehicle's system response speed, when the P term and the I term in the PI controller have opposite signs and the first difference e(t) exceeds a set threshold, the I term is reset to zero to prevent the I term from being adjusted quickly during commutation. The threshold for the first difference can be set to 10, 20, etc., and this embodiment does not impose any restrictions on this.

[0102] It is understandable that after the compensation torque is obtained, it is also necessary to perform first-order low-pass filtering and limit processing on the compensation torque to control the compensation torque of the vehicle so as not to exceed the requested torque of the vehicle controller motor, thereby improving the user experience.

[0103] Step 302: Obtain a target torque through the compensation torque, and perform torque distribution according to the target torque.

[0104] It should be noted that after the compensation torque of the vehicle is obtained, the torque of the vehicle can be dynamically coordinated according to the compensation torque of the vehicle to obtain the final torque of the vehicle, that is, the target torque, and the torque of the vehicle can be distributed through the target torque to achieve torque control.

[0105] Furthermore, the steps of obtaining the target torque through the compensation torque are: obtaining the gear lever information and the requested torque of the vehicle; when the gear lever information of the vehicle is the first gear, using the sum of the compensation torque and the requested torque as the target torque; when the gear lever information of the vehicle is the second gear, using the difference between the requested torque and the compensation torque as the target torque.

[0106] In a specific implementation, the vehicle's gear lever information includes first gear, second gear, and other gears, and the requested torque is the requested torque of the vehicle's controller motor. The vehicle's target torque can be derived based on the vehicle's gear lever information, the requested torque of the motor, and the compensation torque. Torque distribution is performed based on the target torque, and the vehicle's torque distribution is controlled based on the target torque.

[0107] The first gear of a car is D, the forward gear. When the car is in D, the target torque is output by outputting the sum of the requested torque and the compensation torque of the car controller's motor, which controls the car. The second gear of a car is R, the reverse gear. When the car is in R, the target torque is output by subtracting the compensation torque from the requested torque of the car controller's motor, which controls the car. In addition to first and second gears, cars also have other gears, such as neutral (N) or parking (P). When the car is in other gears, the target torque is output as 0. To prevent unintended acceleration, the motor's target torque must be limited to no more than the requested torque of the car controller's motor to ensure the safety of the car and driver.

[0108] like Figure 5 As shown, Figure 5 The figure is a schematic diagram of torque control under low-speed conditions in the torque control method of the present invention. The target wheel speeds of the left and right rear wheels of the vehicle are calculated by obtaining the current vehicle speed and the front wheel angle. The actual wheel speeds of the left and right rear wheels are then obtained. The compensation torques for the left and right rear motors of the vehicle are calculated based on the actual wheel speeds, target wheel speeds, current vehicle speed, and the front wheel angle. The target torques for the left and right rear motors are then calculated based on the compensation torques, the current gear information, and the requested torques for the left and right rear motors. Torque is then distributed to the left and right rear wheels based on the target torques, achieving dynamic torque distribution of the vehicle.

[0109] This embodiment calculates the compensation torque based on the target wheel speeds of the left and right drive wheels, the current vehicle speed and the front wheel steering angle; obtains the target torque through the compensation torque, and calculates the compensation torque according to the target wheel speeds of the left and right drive wheels of the vehicle, the current vehicle speed and the front wheel steering angle of the vehicle when the vehicle is traveling at a low speed, and dynamically distributes the torque of the vehicle according to the compensation torque of the vehicle, the requested torque and the current gear position of the vehicle, thereby improving the steering flexibility of the vehicle when traveling at a low speed, improving the vehicle's controllability and comfort, and enhancing the user experience.

[0110] refer to Figure 6 , Figure 6 2 is a flow chart of a fourth embodiment of a torque control method according to the present invention.

[0111] Based on the first embodiment, step S40 of the torque control method of this embodiment specifically includes:

[0112] Step S401: Obtain the wheelbase, longitudinal acceleration and lateral acceleration of the vehicle.

[0113] It should be noted that when the steering wheel angle and vehicle speed of the vehicle are greater than the set threshold and the vehicle is in the forward gear D, and the vehicle is not slipping, it means that the vehicle is in a high-speed driving state. In order to ensure the stability of the vehicle when driving at high speed, the torque of the vehicle needs to be calculated and distributed, so the wheelbase of the vehicle, as well as the longitudinal acceleration and lateral acceleration of the vehicle when driving are obtained.

[0114] Step S402: Obtaining the stability coefficient of the vehicle according to the longitudinal acceleration and the lateral acceleration.

[0115] The stability coefficient of a car is related to the longitudinal acceleration and lateral acceleration of the vehicle during driving. The stability coefficient of the car can be adjusted by the longitudinal acceleration and lateral acceleration of the car. Therefore, when the longitudinal acceleration and lateral acceleration are obtained, the corresponding stability coefficient of the car can be obtained.

[0116] Step S403: Calculating a target yaw rate according to the current vehicle speed, the front wheel steering angle, the wheelbase, and the stability coefficient.

[0117] It should be understood that yaw rate refers to the deflection of the vehicle around the vertical axis. The magnitude of the deflection represents the vehicle's stability. Since the stability coefficient decreases with increasing speed and acceleration when the vehicle is driving at high speed, it is necessary to calculate the vehicle's target yaw rate. The target yaw rate refers to the yaw rate that maintains vehicle stability. The calculation process is as follows:

[0118]

[0119] In formula 5, ω des is the target yaw rate, v x is the current vehicle speed, l is the vehicle wheelbase, δ is the front wheel turning angle; K is the vehicle stability coefficient.

[0120] Step S404: obtaining an additional yaw moment according to the target yaw angular velocity and the current vehicle speed.

[0121] Additional yaw moment refers to the compensation torque applied when a vehicle is traveling at high speed. It is divided into feedforward compensation torque and PI control compensation torque. The additional yaw moment can be calculated by obtaining the vehicle's current speed, target yaw angular velocity, and other operating parameters, such as the vehicle's steering state and actual yaw angular velocity.

[0122] Step S405: obtaining a target torque through the additional yaw moment to achieve torque distribution for the vehicle.

[0123] In this embodiment, after the additional yaw moment is obtained, the torque of the vehicle can be distributed and controlled according to the steering state of the vehicle and the requested torques of the left and right wheels.

[0124] When the vehicle understeers left, the additional yaw moment is positive, indicating a torque reduction tendency for the left wheel. The target torque for the left motor is the vehicle motor controller's requested torque minus the additional yaw moment, while the target torque for the right motor is the vehicle motor controller's requested torque plus the additional yaw moment. To ensure vehicle stability, the target torques of the left and right motors are converted so that the torque increase on the torque-increasing side is equal to the torque reduction on the torque-reducing side. This ensures vehicle stability without changing the requested torque values.

[0125] This embodiment obtains the wheelbase, longitudinal acceleration, and lateral acceleration of the vehicle; obtains the stability coefficient of the vehicle based on the longitudinal acceleration and lateral acceleration; calculates a target yaw rate based on the current vehicle speed, the front wheel angle, the wheelbase, and the stability coefficient; obtains an additional yaw moment based on the target yaw rate and the current vehicle speed; and obtains a target torque based on the additional yaw moment to achieve torque distribution for the vehicle. The target yaw rate is calculated when the vehicle is traveling at high speed, and the vehicle torque is distributed based on the target yaw rate to ensure vehicle stability.

[0126] refer to Figure 7 , Figure 7 FIG. 4 is a flow chart of a fifth embodiment of a torque control method according to the present invention.

[0127] Based on the fourth embodiment, step S404 of the torque control method of this embodiment specifically includes:

[0128] Step S414: Acquire the actual yaw rate of the vehicle, the steering state of the vehicle, and the second feedforward control coefficient.

[0129] It should be noted that the actual yaw rate and steering state of the vehicle, including understeering and oversteering, can be measured by sensors, and the second preceding control coefficient can be obtained.

[0130] Step S424: Calculate a second difference between the target yaw rate and the actual yaw rate.

[0131] Step S434: Obtain a second feedback control coefficient through the second difference and the current vehicle speed.

[0132] In a specific implementation, the second difference e(t) is the difference between the target yaw rate and the actual yaw rate of the vehicle. The second feedback control coefficient includes the proportional term P term coefficient K p and the integral term I coefficient K i The second feedback control coefficient is adjusted in real time by the current vehicle speed and the second difference, K p With K i When the second difference e(t) is small, the parameter needs to be appropriately reduced. When the PI control starts to be activated, the integral term needs to be cleared, the calculation starts again, and the maximum and minimum values ​​of the integral term need to be limited.

[0133] Step S444: Obtain a second feedforward term through the current vehicle speed, the target yaw rate, and the steering state.

[0134] In order to ensure that the relevant parameters of the vehicle motor torque control can adapt to different working conditions, the second feedforward term T ff Obtained based on the current vehicle speed, target yaw rate and vehicle steering state.

[0135] Step S454: Calculate the additional yaw moment by using the second feedforward control coefficient, the second feedback control coefficient, the second feedforward term, and the second difference.

[0136] The calculation process of the additional yaw moment is as follows:

[0137]

[0138] In formula 6, T yaw is the additional yaw moment, P fac is the second preceding control coefficient, T ff is the second feedforward term, K p is the P term coefficient in the second feedback control coefficient, K i is the I term coefficient in the second feedback control coefficient, and e(t) is the second difference.

[0139] It should be understood that after the additional yaw moment is obtained, it is necessary to perform a first-order low-pass filtering process on the additional yaw moment.

[0140] In a specific implementation, in order to achieve smooth switching of torque distribution between low-speed and high-speed operating conditions, the calculated target wheel speed is adjusted in real time according to the vehicle speed. Under the condition of a fixed vehicle steering wheel angle, the higher the vehicle speed, the smaller the target wheel speed difference between the left and right wheels of the vehicle. The adjustment coefficient can be obtained based on the current vehicle speed and steering wheel angle, and the target wheel speed can be corrected using the following equations 7 and 8.

[0141]

[0142]

[0143] Among them, v w_lr The target wheel speeds of the left and right driving wheels before the car is corrected, v w_rr The target wheel speed of the right driving wheel before the car is corrected, is the target wheel speed of the left drive wheel after correction, v des_rr is the corrected target wheel speed of the right driving wheel, P fac The adjustment coefficient is calculated based on vehicle speed and steering wheel angle. The corrected target wheel speed enables smooth switching of torque distribution under different speed conditions.

[0144] like Figure 8 As shown, Figure 8 This diagram illustrates the torque control method for high-speed operation. The target yaw rate is calculated based on the vehicle's current speed and front wheel angle. The actual yaw rate is then used to calculate the additional yaw moment. The torque distribution is achieved by calculating the target torques for the left and right motors based on the requested torques and taking into account the actual operating conditions and vehicle steering state.

[0145] This embodiment obtains the actual yaw rate of the vehicle, the steering state of the vehicle, and a second feedforward control coefficient; calculates a second difference between the target yaw rate and the actual yaw rate; obtains a second feedback control coefficient based on the second difference and the current vehicle speed; obtains a second feedforward term based on the current vehicle speed, the target yaw rate, and the steering state; and obtains an additional yaw moment based on the second feedforward control coefficient, the second feedback control coefficient, the second feedforward term, and the second difference. The additional yaw moment is used to rationally and flexibly distribute torque, thereby achieving steering stability of the vehicle during high-speed driving.

[0146] Reference Figure 9 , Figure 9 This is a structural block diagram of the first embodiment of the torque control device of the present invention.

[0147] like Figure 9 As shown, the torque control device proposed in the embodiment of the present invention includes:

[0148] The acquisition module 10 is used to acquire the current vehicle speed and front wheel angle of the vehicle while it is traveling.

[0149] The allocation module 20 is configured to obtain target wheel speeds of the left and right driving wheels based on the current vehicle speed and the front wheel steering angle when the vehicle is traveling at a low speed.

[0150] The distribution module 20 is further configured to distribute torque according to the target wheel speeds of the left and right driving wheels.

[0151] The distribution module 20 is further configured to calculate the yaw moment according to the current vehicle speed and the front wheel angle when the vehicle is traveling at high speed, and perform torque distribution according to the yaw moment.

[0152] This embodiment obtains the current vehicle speed and front wheel steering angle of the vehicle while it is traveling; when the vehicle is traveling at a low speed, obtains the target wheel speeds of the left and right drive wheels based on the current vehicle speed and the front wheel steering angle; and distributes torque according to the target wheel speeds of the left and right drive wheels; when the vehicle is traveling at a high speed, calculates the yaw moment based on the current vehicle speed and the front wheel steering angle, and distributes torque according to the yaw moment. The torque is reasonably and flexibly distributed according to different speed conditions of the vehicle, thereby improving the steering flexibility of the vehicle at low speeds and the steering stability at high speeds, thereby enhancing the user experience.

[0153] In one embodiment, the allocation module 20 is further used to obtain the wheelbase of the vehicle, the track width of the rear wheels of the vehicle, and the distance from the center of mass of the vehicle to the rear axle; and calculate the target wheel speed of the left drive wheel and the target wheel speed of the right drive wheel of the vehicle through the wheelbase, the front wheel turning angle, the rear wheel track, the distance from the center of mass to the rear axle and the current vehicle speed.

[0154] In one embodiment, the distribution module 20 is further configured to calculate a compensation torque based on the target wheel speeds of the left and right drive wheels, the current vehicle speed, and the front wheel angle; obtain a target torque through the compensation torque, and perform torque distribution according to the target torque.

[0155] In one embodiment, the distribution module 20 is further used to obtain the actual wheel speeds of the left and right drive wheels of the vehicle and a first feedforward control coefficient; calculate a first difference between the target wheel speeds of the left and right drive wheels and the actual wheel speeds of the left and right drive wheels; obtain a first feedback control coefficient based on the current vehicle speed and the first difference; obtain a first feedforward term based on the current vehicle speed and the front wheel angle; and calculate a compensation torque using the first feedforward control coefficient, the first feedback control coefficient, the first difference, and the first feedforward term.

[0156] In one embodiment, the allocation module 20 is further used to obtain the gear lever information and the requested torque of the vehicle; when the gear lever information of the vehicle is the first gear, the sum of the compensation torque and the requested torque is used as the target torque; when the gear lever information of the vehicle is the second gear, the difference between the requested torque and the compensation torque is used as the target torque.

[0157] In one embodiment, the distribution module 20 is further used to obtain the wheelbase, longitudinal acceleration and lateral acceleration of the vehicle; obtain the stability coefficient of the vehicle based on the longitudinal acceleration and lateral acceleration; calculate the target yaw rate using the current vehicle speed, the front wheel angle, the wheelbase and the stability coefficient; obtain an additional yaw moment based on the target yaw rate and the current vehicle speed; and obtain a target torque using the additional yaw moment to achieve torque distribution for the vehicle.

[0158] In one embodiment, the allocation module 20 is further configured to obtain an actual yaw rate of the vehicle, a steering state of the vehicle, and a second feedforward control coefficient; calculate a second difference between the target yaw rate and the actual yaw rate; obtain a second feedback control coefficient using the second difference and the current vehicle speed; obtain a second feedforward term using the current vehicle speed, the target yaw rate, and the steering state; and obtain an additional yaw moment using the second feedforward control coefficient, the second feedback control coefficient, the second feedforward term, and the second difference.

[0159] In addition, to achieve the above-mentioned purpose, the present invention also proposes a torque control device, which includes: a memory, a processor, and a torque control program stored in the memory and executable on the processor, wherein the torque control program is configured to implement the steps of the torque control method described above.

[0160] Since the torque control device adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought by the technical solutions of the above embodiments, which will not be described one by one here.

[0161] In addition, an embodiment of the present invention further provides a storage medium, on which a torque control program is stored. When the torque control program is executed by a processor, the steps of the torque control method described above are implemented.

[0162] Since the storage medium adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought by the technical solutions of the above embodiments, which will not be described one by one here.

[0163] It should be understood that the above is only an example and does not constitute any limitation to the technical solution of the present invention. In specific applications, those skilled in the art can make settings as needed, and the present invention does not impose any limitation on this.

[0164] It should be noted that the workflow described above is merely illustrative and does not limit the scope of protection of the present invention. In practical applications, technicians in this field can select part or all of it according to actual needs to achieve the purpose of the embodiment scheme, and no limitation is made here.

[0165] In addition, for technical details not fully described in this embodiment, reference can be made to the torque control method provided in any embodiment of the present invention, and will not be repeated here.

[0166] In addition, it should be noted that, in this document, the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or system 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 system. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or system comprising the element.

[0167] The serial numbers of the above embodiments of the present invention are for description only and do not represent the advantages or disadvantages of the embodiments.

[0168] Through the description of the above embodiments, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus the necessary general hardware platform, or of course by hardware, but in many cases the former is a better embodiment. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product. The computer software product is stored in a storage medium (such as a read-only memory (ROM) / RAM, a magnetic disk, or an optical disk), and includes a number of instructions for enabling a terminal device (which can be a mobile phone, a computer, a server, or a network device, etc.) to execute the methods described in each embodiment of the present invention.

[0169] The above are only preferred embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention description and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A torque control method, characterized in that: The torque control method comprises: Get the current speed and front wheel angle of the car while it is driving; When the vehicle is traveling at a low speed, obtaining target wheel speeds of the left and right driving wheels based on the current vehicle speed and the front wheel steering angle; Obtaining actual wheel speeds of the left and right driving wheels of the vehicle and a first feedforward control coefficient; Calculating a first difference between the target wheel speeds of the left and right driving wheels and the actual wheel speeds of the left and right driving wheels; obtaining a first feedback control coefficient according to the current vehicle speed and the first difference; obtaining a first feedforward term according to the current vehicle speed and the front wheel steering angle; The compensation torque is calculated by using the first feedforward control coefficient, the first feedback control coefficient, the first difference and the first feedforward term; obtaining gear lever information and requested torque of the vehicle; When the gear lever information of the vehicle is the first gear, the sum of the compensation torque and the request torque is used as the target torque; When the gear lever information of the vehicle is the second gear, a difference between the requested torque and the compensation torque is used as a target torque; When the vehicle is traveling at high speed, the yaw moment is calculated according to the current vehicle speed and the front wheel angle, and torque distribution is performed according to the yaw moment.

2. The torque control method according to claim 1, wherein: Calculating target wheel speeds of left and right driving wheels of the vehicle based on the current vehicle speed and the front wheel steering angle includes: Get the car's wheelbase, the car's rear wheel track, and the distance from the car's center of mass to the rear axle; The target wheel speeds of the left drive wheel and the right drive wheel of the vehicle are calculated by using the wheelbase, the front wheel turning angle, the rear wheel track, the distance from the center of mass to the rear axle, and the current vehicle speed.

3. The torque control method according to any one of claims 1 to 2, characterized in that: When the vehicle is traveling at high speed, calculating the yaw moment by using the current vehicle speed and the front wheel angle, and performing torque distribution according to the yaw moment, includes: Obtaining the wheelbase, longitudinal acceleration, and lateral acceleration of the vehicle; Obtaining a stability coefficient of the vehicle according to the longitudinal acceleration and the lateral acceleration; Calculating a target yaw rate using the current vehicle speed, the front wheel steering angle, the wheelbase, and the stability coefficient; obtaining an additional yaw moment according to the target yaw angular velocity and the current vehicle speed; The target torque is obtained by using the additional yaw moment to achieve torque distribution for the vehicle.

4. The torque control method according to claim 3, wherein: The obtaining of the additional yaw moment according to the target yaw angular velocity and the current vehicle speed includes: Obtaining an actual yaw rate of the vehicle, a steering state of the vehicle, and a second feedforward control coefficient; calculating a second difference between the target yaw rate and the actual yaw rate; obtaining a second feedback control coefficient by using the second difference and the current vehicle speed; obtaining a second feedforward term by using the current vehicle speed, the target yaw rate, and the steering state; The additional yaw moment is obtained by calculation through the second feedforward control coefficient, the second feedback control coefficient, the second feedforward term, and the second difference.

5. A torque control device, characterized in that: The torque control device comprises: The acquisition module is used to obtain the current speed and front wheel angle of the car while it is driving; an allocation module, configured to obtain target wheel speeds of left and right driving wheels based on the current vehicle speed and the front wheel steering angle when the vehicle is traveling at a low speed; The distribution module is further configured to obtain actual wheel speeds of the left and right drive wheels of the vehicle and a first feedforward control coefficient; calculate a first difference between the target wheel speeds of the left and right drive wheels and the actual wheel speeds of the left and right drive wheels; obtain a first feedback control coefficient based on the current vehicle speed and the first difference; obtain a first feedforward term based on the current vehicle speed and the front wheel steering angle; calculate a compensation torque using the first feedforward control coefficient, the first feedback control coefficient, the first difference, and the first feedforward term; obtain gear lever information and a requested torque of the vehicle; and when the gear lever information of the vehicle is first gear, use the sum of the compensation torque and the requested torque as the target torque; and when the gear lever information of the vehicle is second gear, use the difference between the requested torque and the compensation torque as the target torque. The distribution module is further configured to calculate the yaw moment according to the current vehicle speed and the front wheel angle when the vehicle is traveling at high speed, and perform torque distribution according to the yaw moment.

6. A torque control device, characterized in that: The torque control device includes: a memory, a processor, and a torque control program stored in the memory and executable on the processor, wherein the torque control program is configured to implement the torque control method according to any one of claims 1 to 4.

7. A storage medium, characterized in that: The storage medium stores a torque control program, which implements the torque control method according to any one of claims 1 to 4 when executed by the processor.

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