Vehicle control method and device and vehicle

Abstract

The invention discloses a vehicle control method and device and a vehicle, and belongs to the technical field of vehicles. Comprising the steps that under the condition that a steering wheel of a target vehicle is kept in the middle and rear wheels of the target vehicle steer abnormally, a target front wheel steering angle is determined on the basis of the difference value between the current rear wheel steering angle of the target vehicle and a target rear wheel steering angle and vehicle parameters, and the target rear wheel steering angle is the angle of the rear wheels of the target vehicle in the middle-back state; the target front wheel rotation angle is the rotation angle of the front wheels of the target vehicle for compensating the abnormal steering of the rear wheels; determining a target compensation torque based on the target front wheel steering angle; and controlling a front wheel motor of the target vehicle to output the target compensation torque so as to keep the target vehicle in a straight driving state by adjusting the front wheel angle of the target vehicle. Thus, the target compensation torque is output through the front wheel motor, track deviation caused by abnormal steering of the rear wheels can be compensated, and therefore the target vehicle can be kept running in a straight line, and the driving safety is improved.

Description

Technical Field

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

[0002] With the development of technology, in order to improve the user's driving experience, most vehicles are currently equipped with rear-wheel steering systems. During the steering process, the front and rear wheels of the vehicle rotate together, which can increase the function of the vehicle's steering system and improve the steering sensitivity. Generally, when the vehicle is driving in a straight line, the steering wheel of the vehicle is in the center state, and the front and rear wheels also remain in the center state, that is, the front wheel angle and the rear wheel angle are both 0.

[0003] However, when the rear-wheel steering system fails, the rear wheels of the vehicle may have unexpected steering problems when the vehicle is traveling in a straight line. That is, when the vehicle is traveling in a straight line, the rear wheels should have been traveling in a centering state, but due to the failure, the rear wheels are traveling at a certain angle. Generally, when the rear wheels turn left or right, the yaw rate of the entire vehicle will increase, which makes the vehicle unstable and increases the danger of driving. Therefore, there is an urgent need for a vehicle control method to solve the problem of rear-wheel steering when the vehicle is traveling in a straight line. Summary of the invention

[0004] The present application provides a vehicle control method, device, vehicle and storage medium, which can control the front wheel motor to output a compensation torque when the rear wheel turns abnormally during the straight-line driving of the vehicle, so that the front wheel can compensate for the trajectory deviation caused by the abnormal steering of the rear wheel, thereby ensuring that the target vehicle can maintain straight-line driving when the rear wheel turns abnormally, thereby improving driving safety. The technical solution includes the following contents.

[0005] In a first aspect, a vehicle control method is provided, the method comprising:

[0006] In the case where the steering wheel of the target vehicle is kept centered and the rear wheels of the target vehicle are abnormally turned, a target front wheel turning angle is determined based on the difference between the current rear wheel turning angle of the target vehicle and the target rear wheel turning angle and vehicle parameters, wherein the target rear wheel turning angle is the angle of the rear wheels of the target vehicle when they are in the centered state, the target front wheel turning angle is the angle that the front wheels of the target vehicle should turn to compensate for the abnormal rear wheel turning, and the vehicle parameters include dynamic vehicle parameters and static vehicle parameters;

[0007] determining a target compensation torque based on the target front wheel steering angle;

[0008] The front wheel motor of the target vehicle is controlled to output the target compensation torque, so as to keep the target vehicle in a straight-line driving state by adjusting the front wheel angle of the target vehicle.

[0009] In the present application, when the steering wheel of the target vehicle is kept back to the center and the rear wheels of the target vehicle are abnormally turned, the target front wheel angle is first determined based on the difference between the current rear wheel angle of the target vehicle and the target rear wheel angle and the vehicle parameters, that is, the angle that the front wheels of the target vehicle should rotate to compensate for the abnormal steering of the rear wheels. Then, based on the target front wheel angle, the target compensation torque is determined, that is, the torque that the front wheels should compensate is determined. Finally, the front wheel motor of the target vehicle is controlled to output the target compensation torque to keep the target vehicle in a straight-line driving state by adjusting the front wheel angle of the target vehicle. In the present application, when the rear wheels of the target vehicle are abnormally turned during the straight-line driving, the front wheel motor outputs the target compensation torque to control the front wheels to rotate a certain angle, so that the trajectory deviation caused by the abnormal steering of the rear wheels can be compensated, so that the target vehicle can be kept in a straight-line driving later, thereby improving the driving safety.

[0010] Optionally, when the steering wheel of the target vehicle is kept centered and the rear wheels of the target vehicle are abnormally turned, before determining the target front wheel turning angle based on the difference between the current rear wheel turning angle of the target vehicle and the target rear wheel turning angle and the vehicle parameters, the method further includes:

[0011] Obtaining a current steering wheel angle, a current rear wheel angle, a target rear wheel angle, and a current yaw rate of the target vehicle;

[0012] Based on the current steering wheel angle, the current rear wheel angle, the target rear wheel angle, and the current yaw rate, it is determined whether the steering wheel of the target vehicle remains centered and whether the rear wheels of the target vehicle are turning abnormally.

[0013] Optionally, the determining whether the steering wheel of the target vehicle remains centered and whether the rear wheels of the target vehicle have abnormal steering based on the current steering wheel angle, the current rear wheel angle, the target rear wheel angle, and the current yaw rate includes:

[0014] Subtracting the target rear wheel turning angle from the current rear wheel turning angle to obtain a rear wheel turning angle difference;

[0015] When the current steering wheel angle is less than or equal to a preset steering wheel angle threshold, the rear wheel angle difference is greater than or equal to a preset difference threshold, and the current yaw angular velocity is greater than or equal to a preset angular velocity threshold, determining that the steering wheel of the target vehicle remains centered and that the rear wheels of the target vehicle are turning abnormally;

[0016] When the current steering wheel angle is less than or equal to the preset steering wheel angle threshold, the rear wheel angle difference is less than the preset difference threshold, and the current yaw angular velocity is less than the preset angular velocity threshold, it is determined that the steering wheel of the target vehicle remains centered and the rear wheels of the target vehicle do not show abnormal steering.

[0017] Optionally, the static vehicle parameters include axle attributes of the target vehicle, the dynamic vehicle parameters include current driving parameters of the target vehicle, and determining the target front wheel turning angle based on the difference between the current rear wheel turning angle of the target vehicle and the target rear wheel turning angle and the vehicle parameters comprises:

[0018] The target front wheel turning angle is determined based on a difference between a current rear wheel turning angle of the target vehicle and a target rear wheel turning angle, the axle attributes, and the current driving parameter.

[0019] Optionally, the axle attributes include front axle cornering stiffness and rear axle cornering stiffness, the current driving parameter includes current vehicle speed, and determining the target front wheel turning angle based on a difference between a current rear wheel turning angle of the target vehicle and a target rear wheel turning angle, the axle attributes, and the current driving parameter comprises:

[0020] Based on the current vehicle speed, determining a first compensation coefficient, the first compensation coefficient being used to represent a ratio between a front wheel angle and a rear wheel angle of the target vehicle at the current vehicle speed;

[0021] Determining a second compensation coefficient based on the front axle cornering stiffness and the rear axle cornering stiffness, the second compensation coefficient being used to represent an inherent angle ratio between a front wheel angle and a rear wheel angle of the target vehicle;

[0022] The target front wheel turning angle is determined based on the first compensation coefficient, the second compensation coefficient, and a rear wheel turning angle difference, where the rear wheel turning angle difference is a difference between a current rear wheel turning angle of the target vehicle and a target rear wheel turning angle.

[0023] Optionally, determining the target front wheel turning angle based on the first compensation coefficient, the second compensation coefficient and the rear wheel turning angle difference includes:

[0024] multiplying the first compensation coefficient by the second compensation coefficient to obtain a target compensation coefficient;

[0025] The rear wheel steering angle difference is multiplied by the target compensation coefficient to obtain the target front wheel steering angle.

[0026] Optionally, before determining the target compensation torque based on the target front wheel steering angle, the method further includes:

[0027] Acquire the current vehicle speed, current steering wheel torque and steering system stiffness of the target vehicle, where the steering system stiffness refers to the ability of the steering system of the target vehicle to resist deformation;

[0028] The determining of the target compensation torque based on the target front wheel steering angle comprises:

[0029] The target compensation torque is determined based on the target front wheel steering angle, the current vehicle speed, the current steering wheel torque, and the steering system stiffness.

[0030] Optionally, determining the target compensation torque based on the target front wheel steering angle, the current vehicle speed, the current steering wheel torque and the steering system stiffness includes:

[0031] Determining a target power-assistance coefficient based on the current vehicle speed, wherein the target power-assistance coefficient refers to a proportional relationship between a torque provided by a steering system and a torque applied by a driver when controlling the steering of the front wheels at the current vehicle speed;

[0032] Multiplying the target power-assist coefficient by the current steering wheel torque to obtain a first power-assist torque;

[0033] Multiplying the target front wheel angle by the steering system stiffness to obtain a second assist torque;

[0034] The sum of the first assist torque and the second assist torque is determined as the target compensation torque.

[0035] Optionally, controlling the front wheel motor of the target vehicle to output the target compensation torque further includes:

[0036] The power assist motor of the target vehicle is controlled to output the target compensation torque based on the current power assist torque.

[0037] Optionally, controlling the power-assisting motor of the target vehicle to output the target compensation torque based on the current power-assisting torque includes:

[0038] Adding the target compensation torque to the current power-assisting torque to obtain a target power-assisting torque;

[0039] The power-assisting motor of the target vehicle is controlled to output the target power-assisting torque to adjust the front wheel angle of the target vehicle.

[0040] Optionally, the target compensation torque is added to the current power-assisting torque to obtain a target power-assisting torque, including:

[0041] Acquiring a first weight corresponding to the target compensation torque and acquiring a second weight corresponding to the current assist torque;

[0042] Based on the first weight and the second weight, the target compensation torque and the current assist torque are weightedly summed to obtain the target assist torque.

[0043] In a second aspect, a vehicle control device is provided, the device comprising:

[0044] A first determination module is used to determine a target front wheel turning angle based on a difference between a current rear wheel turning angle of the target vehicle and a target rear wheel turning angle and vehicle parameters when the steering wheel of the target vehicle is kept centered and the rear wheels of the target vehicle are abnormally turned, wherein the target rear wheel turning angle is an angle of the rear wheels of the target vehicle when the rear wheels are in a centered state, the target front wheel turning angle is an angle that the front wheels of the target vehicle should turn to compensate for the abnormal rear wheel turning, and the vehicle parameters include dynamic vehicle parameters and static vehicle parameters;

[0045] A second determination module, configured to determine a target compensation torque based on the target front wheel steering angle;

[0046] The torque output module is used to control the front wheel motor of the target vehicle to output the target compensation torque, so as to keep the target vehicle in a straight-line driving state by adjusting the front wheel angle of the target vehicle.

[0047] Optionally, the device further comprises:

[0048] A first acquisition module, used to acquire the current steering wheel angle, the current rear wheel angle, the target rear wheel angle and the current yaw angular velocity of the target vehicle;

[0049] The third determination module is used to determine whether the steering wheel of the target vehicle remains centered and whether the rear wheels of the target vehicle have abnormal steering based on the current steering wheel angle, the current rear wheel angle, the target rear wheel angle and the current yaw rate.

[0050] Optionally, the third determining module is used to:

[0051] Subtracting the target rear wheel turning angle from the current rear wheel turning angle to obtain a rear wheel turning angle difference;

[0052] When the current steering wheel angle is less than or equal to a preset steering wheel angle threshold, the rear wheel angle difference is greater than or equal to a preset difference threshold, and the current yaw angular velocity is greater than or equal to a preset angular velocity threshold, determining that the steering wheel of the target vehicle remains centered and that the rear wheels of the target vehicle are turning abnormally;

[0053] When the current steering wheel angle is less than or equal to the preset steering wheel angle threshold, the rear wheel angle difference is less than the preset difference threshold, and the current yaw angular velocity is less than the preset angular velocity threshold, it is determined that the steering wheel of the target vehicle remains centered and the rear wheels of the target vehicle do not show abnormal steering.

[0054] Optionally, the static vehicle parameters include axle attributes of the target vehicle, the dynamic vehicle parameters include current driving parameters of the target vehicle, and the first determination module is used to:

[0055] The target front wheel turning angle is determined based on a difference between a current rear wheel turning angle of the target vehicle and a target rear wheel turning angle, the axle attributes, and the current driving parameter.

[0056] Optionally, the axle attributes include front axle cornering stiffness and rear axle cornering stiffness, the current driving parameter includes current vehicle speed, and the first determination module is used to:

[0057] Based on the current vehicle speed, determining a first compensation coefficient, the first compensation coefficient being used to represent a ratio between a front wheel angle and a rear wheel angle of the target vehicle at the current vehicle speed;

[0058] Determining a second compensation coefficient based on the front axle cornering stiffness and the rear axle cornering stiffness, the second compensation coefficient being used to represent an inherent angle ratio between a front wheel angle and a rear wheel angle of the target vehicle;

[0059] The target front wheel turning angle is determined based on the first compensation coefficient, the second compensation coefficient, and a rear wheel turning angle difference, where the rear wheel turning angle difference is a difference between a current rear wheel turning angle of the target vehicle and a target rear wheel turning angle.

[0060] Optionally, the first determining module is used to:

[0061] multiplying the first compensation coefficient by the second compensation coefficient to obtain a target compensation coefficient;

[0062] The rear wheel steering angle difference is multiplied by the target compensation coefficient to obtain the target front wheel steering angle.

[0063] Optionally, the device further comprises:

[0064] A second acquisition module is used to acquire the current vehicle speed, the current steering wheel torque and the steering system stiffness of the target vehicle, where the steering system stiffness refers to the ability of the steering system of the target vehicle to resist deformation;

[0065] Optionally, the second determining module is used to:

[0066] The target compensation torque is determined based on the target front wheel steering angle, the current vehicle speed, the current steering wheel torque, and the steering system stiffness.

[0067] Optionally, the second determining module is used to:

[0068] Determining a target power-assistance coefficient based on the current vehicle speed, wherein the target power-assistance coefficient refers to a proportional relationship between a torque provided by a steering system and a torque applied by a driver when controlling the steering of the front wheels at the current vehicle speed;

[0069] Multiplying the target power-assist coefficient by the current steering wheel torque to obtain a first power-assist torque;

[0070] Multiplying the target front wheel angle by the steering system stiffness to obtain a second assist torque;

[0071] The sum of the first assist torque and the second assist torque is determined as the target compensation torque.

[0072] Optionally, the torque output module is further used for:

[0073] The power-assisting motor of the target vehicle is controlled to output the target compensation torque based on the current power-assisting torque, where the current power-assisting torque is the power-assisting torque output by the front-wheel motor of the target vehicle when it is determined that the rear wheel has abnormal steering.

[0074] Optionally, the torque output module is further used for:

[0075] Adding the target compensation torque to the current power-assisting torque to obtain a target power-assisting torque;

[0076] The power-assisting motor of the target vehicle is controlled to output the target power-assisting torque to adjust the front wheel angle of the target vehicle.

[0077] Optionally, the torque output module is further used for:

[0078] Acquiring a first weight corresponding to the target compensation torque and acquiring a second weight corresponding to the current assist torque;

[0079] Based on the first weight and the second weight, the target compensation torque and the current assist torque are weightedly summed to obtain the target assist torque.

[0080] In a third aspect, a vehicle is provided, the vehicle comprising:

[0081] A memory for storing executable program codes;

[0082] The processor is used to call and run the executable program code from the memory so that the vehicle executes the above-mentioned vehicle control method.

[0083] In a fourth aspect, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores a computer program, and the computer program implements the above-mentioned vehicle control method when executed by a processor.

[0084] In a fifth aspect, a computer program product comprising instructions is provided, which, when executed on a computer, enables the computer to execute the steps of the above-mentioned vehicle control method.

[0085] It can be understood that the beneficial effects of the second, third, fourth and fifth aspects mentioned above can be found in the relevant description of the first aspect mentioned above, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0086] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0087] Figure 1 It is a schematic diagram of an implementation environment of a vehicle control method provided in an embodiment of the present application;

[0088] Figure 2 is a schematic diagram of a scenario of a vehicle control method provided in an embodiment of the present application;

[0089] Figure 3 is a flow chart of a vehicle control method provided by an embodiment of the present application;

[0090] Figure 4 is a flow chart for determining a target assist torque provided in an embodiment of the present application;

[0091] Figure 5 is a flow chart of another vehicle control method provided by an embodiment of the present application;

[0092] Figure 6 is a structural schematic diagram of a vehicle control device provided in an embodiment of the present application;

[0093] Figure 7 It is a structural schematic diagram of a vehicle provided in an embodiment of the present application. DETAILED DESCRIPTION

[0094] In order to make the objectives, technical solutions and advantages of the present application clearer, the implementation methods of the present application will be further described in detail below with reference to the accompanying drawings.

[0095] It should be understood that the "multiple" mentioned in this application refers to two or more. In the description of this application, unless otherwise specified, " / " means or, for example, A / B can mean A or B; "and / or" in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in order to facilitate the clear description of the technical solution of this application, the words "first" and "second" are used to distinguish between the same items or similar items with basically the same functions and effects. Those skilled in the art can understand that the words "first" and "second" do not limit the quantity and execution order, and the words "first" and "second" do not limit them to be different.

[0096] The application scenario of the embodiment of the present application is first described.

[0097] Figure 1 Schematic diagram of the implementation environment of a vehicle control method provided in an embodiment of the present application. Figure 1 , Figure 1 The vehicle 101 is provided with an electric power steering system 102 (Electric Power Steering, EPS) and a rear wheel steering system 103 .

[0098] Vehicle 101 is a vehicle equipped with the above-mentioned rear-wheel steering system 103. For example, vehicle 101 can be a front-wheel drive vehicle (Front-Wheel Drive, FWD), a rear-wheel drive vehicle (Rear-Wheel Drive, RWD), or a four-wheel drive vehicle (All-Wheel Drive, AWD). The embodiment of the present application does not limit the type of vehicle 101.

[0099] The electric power steering system 102 is a power steering system that directly relies on the motor to provide auxiliary torque, which can provide assistance to the driver to reduce the force used in steering. Generally, the electric power steering system 102 calculates the required power by detecting the steering wheel angle and the speed of the vehicle, and then controls the front wheel motor to rotate to output the corresponding torque to automatically adjust the front wheel angle to provide assistance for steering, thereby saving the driver's force applied to the steering wheel when steering. Generally, when the vehicle is driving at a low speed, especially when the vehicle is turning, the electric power steering system 102 can provide greater assistance, making steering easier.

[0100] The rear-wheel steering system 103 is a technology that can adjust the direction angle of the rear wheels. It improves the handling performance of the vehicle by making the rear wheels of the vehicle rotate in the same direction or in the opposite direction relative to the front wheels under certain conditions. The rear-wheel steering system 103 is composed of a rear-wheel steering controller and a wire-controlled steering gear. It receives the steering wheel angle signal, steering wheel speed signal, etc. sent by the vehicle controller through a wire, and then calculates the required rotation angle based on the received steering wheel angle signal, steering wheel speed signal, etc. In general, when the vehicle is driving normally in a straight line, the rear wheels should always remain straight to avoid causing the vehicle to deviate. When the vehicle turns at a low speed, the rear wheels can cooperate with the front wheels to rotate in the opposite direction to reduce the turning radius; when the vehicle changes lanes at high speed, the rear wheels cooperate with the front wheels to rotate in the same direction to improve vehicle stability.

[0101] In an embodiment of the present application, when the vehicle 101 is traveling in a straight line, if the rear-wheel steering system 103 fails, the rear wheels will steer abnormally. At this time, the electric power steering system 102 can compensate for the trajectory deviation caused by the abnormal steering of the rear wheels, thereby keeping the vehicle 101 traveling in a straight line.

[0102] The application scenarios of the embodiments of the present application are described below.

[0103] For example, Figure 2 is a schematic diagram of a vehicle control method provided in an embodiment of the present application, see Figure 2 , Figure 2 The vehicle 201 is included, and the vehicle 201 keeps traveling in a straight line.

[0104] During the driving process of the vehicle 201, the electric power steering system 102 and the rear wheel steering system 103 respectively obtain the steering wheel angle of the vehicle 201. When the vehicle 201 is driving in a straight line, the steering wheel angle is 0, so the electric power steering system 102 and the rear wheel steering system 103 respectively determine that the front wheel angle and the rear wheel angle are both 0 based on the steering wheel angle. During the driving process of the vehicle 201, the front wheel angle can be controlled to be 0, and the rear wheel angle can be controlled to be 0. Figure 2 As shown, vehicle 201 may travel along trajectory A.

[0105] However, when the rear wheel steering system 103 fails, when the vehicle 201 is traveling in a straight line, the rear wheel angle should be 0, but due to the failure, it may have a certain angle, that is, the rear wheel has an unexpected steering problem, causing the vehicle 201 to deviate from the original driving track. Figure 2 As shown, when the rear wheels unexpectedly turn, the vehicle 201 may travel along track B. In this case, when the rear wheels turn left or right, the yaw rate of the entire vehicle will increase, which makes the vehicle unstable and increases the danger of driving.

[0106] To this end, an embodiment of the present application provides a vehicle control method, which can be applied to a scenario where a vehicle maintains straight driving. For example, the vehicle control method can be applied to a scenario where a vehicle needs to drive straight on a narrow road, or another example, the vehicle control method can be applied to a scenario where a vehicle needs to drive straight on a narrow bridge.

[0107] Specifically, following the above Figure 2 The scene shown illustrates the vehicle control method provided by the embodiment of the present application. During the straight-line driving of vehicle 201, the steering wheel of vehicle 201 remains in the center, but at this time, the rear wheels of vehicle 201 steer abnormally. A front wheel angle is first determined based on the difference between the current rear wheel angle of vehicle 201 and the target rear wheel angle and the vehicle parameters. This front wheel angle is the angle that the front wheels of vehicle 201 should turn to compensate for the abnormal steering of the rear wheels. Then, based on this front wheel angle, a compensation torque is determined, that is, the torque that the front wheels should compensate is determined, and finally the front wheel motor of vehicle 201 is controlled to output this compensation torque.

[0108] In this way, when the rear wheels of the vehicle 201 turn abnormally while the vehicle is traveling in a straight line, a certain compensation torque is output by the front wheel motor to control the front wheels to rotate to a certain angle, so that the trajectory deviation caused by the abnormal steering of the rear wheels can be compensated, thereby maintaining the vehicle 201 in a straight-line driving state even when the rear wheels turn abnormally, thereby improving driving safety.

[0109] The vehicle control method provided in the embodiment of the present application is explained in detail below.

[0110] Figure 3 is a flow chart of a vehicle control method provided in an embodiment of the present application. The method can be applied to a vehicle's VCU (Vehicle Control Unit). Figure 3 , the method comprises the following steps.

[0111] Step 301: When the steering wheel of the target vehicle remains centered and the rear wheels of the target vehicle turn abnormally, the target front wheel angle is determined based on the difference between the current rear wheel angle of the target vehicle and the target rear wheel angle and vehicle parameters, wherein the vehicle parameters include dynamic vehicle parameters and static vehicle parameters.

[0112] The current rear wheel turning angle refers to the angle at which the rear wheels of the target vehicle turn at the current moment.

[0113] The target rear wheel turning angle is the angle of the rear wheels of the target vehicle when they are in the return-to-center state. In the embodiment of the present application, the target rear wheel turning angle can be the rear wheel request turning angle, that is, the angle that the target vehicle requests the rear wheels to turn. Then when the steering wheel of the target vehicle remains in the return-to-center state, the steering wheel turning angle of the target vehicle is also 0. Therefore, in this case, the rear wheel request turning angle should also be 0, that is, the angle of the rear wheels when they are in the return-to-center state.

[0114] It should be understood that the control of the front wheel angle and the rear wheel angle of the target vehicle is performed in cycles. That is, the current steering wheel angle is obtained every preset time, the front wheel angle and the rear wheel angle are calculated, and the front wheel is controlled to respond to the calculated front wheel angle and the rear wheel is controlled to respond to the calculated rear wheel angle. In this case, the target rear wheel angle may also be the rear wheel angle in the previous cycle. In addition, when it is determined that the rear wheel has abnormal steering in the current cycle, the rear wheel angle of the current cycle must be different from the rear wheel angle of the previous cycle. Therefore, when abnormal steering occurs, the target rear wheel angle may also be the rear wheel angle of the previous cycle.

[0115] The target front wheel turning angle is the angle that the front wheels of the target vehicle should turn to compensate for abnormal steering of the rear wheels.

[0116] The vehicle parameters may include dynamic vehicle parameters and static vehicle parameters. Dynamic vehicle parameters refer to vehicle parameters that change with the movement of the target vehicle, such as vehicle speed, engine rotation, output torque, etc. Static vehicle parameters refer to vehicle parameters that do not change with the movement of the target vehicle, that is, the inherent vehicle parameters of the target vehicle, such as the front axle lateral stiffness, wheelbase, weight, etc. of the target vehicle.

[0117] In the embodiment of the present application, the difference between the current rear wheel turning angle of the target vehicle and the target rear wheel turning angle can be used to know how much the rear wheels of the target vehicle have turned, so that the angle that the front wheels should compensate can be determined based on this.

[0118] In this case, the target front wheel angle is determined based on the difference between the current rear wheel angle of the target vehicle and the target rear wheel angle and the vehicle parameters, so that the angle that the front wheel should compensate for when the rear wheel turns abnormally during the driving of the target vehicle can be known. In addition, when the rear wheel turns abnormally, the trajectory deviation caused by the rear wheel turning abnormality can be corrected by compensating a certain angle with the front wheel, so that the target vehicle can continue to drive in a straight line.

[0119] In the embodiment of the present application, the static vehicle parameters may include the axle attributes of the target vehicle, and the dynamic vehicle parameters may include the current driving parameters of the target vehicle. In this case, the operation of step 301 may be: determining the target front wheel angle based on the difference between the current rear wheel angle of the target vehicle and the target rear wheel angle, the axle attributes, and the current driving parameters.

[0120] Axle attributes refer to information related to the axles of the target vehicle, such as axle length, axle weight, wheelbase, front axle lateral stiffness, rear axle lateral stiffness, suspension elasticity, etc.

[0121] Since the steering angle of the front wheel is closely related to the axle and driving parameters when the wheel is turned, the target front wheel steering angle can be determined by referring to the axle attributes and the current driving parameters.

[0122] In this case, based on the difference between the current rear wheel turning angle of the target vehicle and the target rear wheel turning angle, the axle properties and the current driving parameters, it is equivalent to comprehensively combining the inherent vehicle parameters and dynamic driving parameters of the target vehicle to determine the target front wheel angle, thereby improving the accuracy of the target front wheel angle.

[0123] As an embodiment, the axle attributes may include the front axle cornering stiffness and the rear axle cornering stiffness, and the current driving parameter may include the current vehicle speed. In this case, based on the difference between the current rear wheel steering angle of the target vehicle and the target rear wheel steering angle, the axle attributes, and the current driving parameter, the operation of determining the target front wheel steering angle may include the following steps (1) to (3).

[0124] (1) Based on the current vehicle speed, a first compensation coefficient is determined.

[0125] The first compensation coefficient is used to represent the ratio between the front wheel angle and the rear wheel angle of the target vehicle at the current vehicle speed.

[0126] When the wheels are turning, their rotation angle will be affected by the vehicle speed. For example, when the vehicle is turning, the greater the speed, the greater the rotation angle is to achieve a quick turn. Therefore, a first compensation coefficient can be determined based on the current vehicle speed. In this way, a ratio between the front wheel angle and the rear wheel angle is determined considering a certain vehicle speed during the driving process.

[0127] Optionally, the operation of step (1) may be: based on the current vehicle speed, obtaining a corresponding compensation coefficient from the first corresponding relationship and determining it as the first compensation coefficient.

[0128] The first corresponding relationship is the corresponding relationship between the vehicle speed and the compensation coefficient. The first corresponding relationship includes multiple vehicle speeds and multiple compensation coefficients, wherein the multiple vehicle speeds correspond one-to-one to the multiple compensation coefficients, that is, any one of the multiple vehicle speeds has a corresponding compensation coefficient.

[0129] For example, the following Table 1 is an example of the first corresponding relationship. Referring to Table 1, Table 1 includes multiple vehicle speeds and multiple compensation coefficients, and the multiple vehicle speeds and the multiple compensation coefficients correspond one to one. For example, if the current vehicle speed is 40, then it can be determined from the following Table 1 that the first compensation coefficient is 0.3.

[0130] Table 1

[0131] Speed Compensation coefficient 20 0.2 40 0.3 60 0.4 …… ……

[0132] The embodiment of the present application only uses Table 1 as an example to illustrate the first corresponding relationship, and does not constitute a limitation to the embodiment of the present application.

[0133] (2) Determine a second compensation coefficient based on the front axle cornering stiffness and the rear axle cornering stiffness.

[0134] The second compensation coefficient is used to represent an inherent angle ratio between the front wheel angle and the rear wheel angle of the target vehicle.

[0135] Since the first compensation coefficient is the ratio between the front wheel angle and the rear wheel angle taking into account the current vehicle speed, but the target vehicle is also related to fixed parameters such as the front axle and the rear axle when turning, and the most relevant ones are usually the front axle lateral stiffness and the rear axle lateral stiffness, the second compensation coefficient can also be determined based on the front axle lateral stiffness and the rear axle lateral stiffness.

[0136] Optionally, the operation of step (2) may be: dividing the front axle cornering stiffness by the rear axle cornering stiffness to obtain a second compensation coefficient.

[0137] In this case, the second compensation coefficient is positively correlated with the front axle cornering stiffness and negatively correlated with the rear axle cornering stiffness.

[0138] In the embodiment of the present application, the axle attribute may also include suspension elasticity. That is, the target vehicle is also related to the front axle suspension elasticity and the rear axle suspension elasticity when turning. In this case, the step of determining the second compensation coefficient may also include: dividing the rear axle suspension elasticity by the front axle suspension elasticity to obtain the second compensation coefficient.

[0139] In this case, the second compensation coefficient is positively correlated with the elasticity of the rear axle suspension and negatively correlated with the elasticity of the front axle suspension.

[0140] Optionally, the second compensation coefficient may be determined comprehensively based on the front axle lateral stiffness, the rear axle lateral stiffness, the front axle suspension elasticity, and the rear axle suspension elasticity, so that a more accurate second compensation coefficient may be determined.

[0141] Specifically, based on the front axle cornering stiffness, the rear axle cornering stiffness, the front axle suspension elasticity, and the rear axle suspension elasticity, the second compensation coefficient is determined by the following formula (1).

[0142]

[0143] It should be noted that data such as the front axle lateral stiffness, rear axle lateral stiffness, front axle suspension elasticity, and rear axle suspension elasticity may be related to the vehicle model, that is, the front axle lateral stiffness, rear axle lateral stiffness, and front axle suspension elasticity, and rear axle suspension elasticity corresponding to different vehicle models may be different, and the embodiments of the present application do not limit this.

[0144] (3) Determine a target front wheel turning angle based on the first compensation coefficient, the second compensation coefficient, and the rear wheel turning angle difference.

[0145] The rear wheel turning angle difference is the difference between the current rear wheel turning angle of the target vehicle and the target rear wheel turning angle.

[0146] In this case, based on the first compensation coefficient, the second compensation coefficient and the rear wheel angle difference, it is equivalent to determining the target front wheel angle by comprehensively considering the ratio between the front wheel angle and the rear wheel angle of the target vehicle at the current vehicle speed and the inherent ratio between the front wheel angle and the rear wheel angle, which is equivalent to determining the compensation coefficient by comprehensively considering various angle ratios, thereby determining a more accurate target front wheel angle.

[0147] Specifically, the operation of step (3) may be: multiplying the first compensation coefficient by the second compensation coefficient to obtain a target compensation coefficient; and multiplying the rear wheel steering angle difference by the target compensation coefficient to obtain a target front wheel steering angle.

[0148] For example, the first compensation coefficient is 1.1, the second compensation coefficient is 1.3, and the rear wheel turning angle difference is 20°. Then the target front wheel turning angle is 1.1×1.3×20=1.43×20=28.6°. That is, in order to compensate for the 20° abnormal turning of the rear wheel, the front wheel of the target vehicle needs to turn 28.6° to correct the abnormal turning caused by the abnormal rear wheel to ensure that the target vehicle drives straight.

[0149] It is worth noting that in the embodiment of the present application, before step 301, it can also be determined whether the target vehicle is traveling in a straight line.

[0150] Specifically, the steering wheel angle of the target vehicle is obtained in multiple cycles; when the steering wheel angles in multiple cycles are all less than a preset steering wheel angle threshold, it is determined that the target vehicle is traveling in a straight line, otherwise, it is determined that the target vehicle is not traveling in a straight line.

[0151] The preset steering wheel angle threshold can be set in advance, and the preset steering wheel angle threshold can be set according to the steering wheel angle when the front wheel appears an angle. In an embodiment of the present application, the preset steering wheel angle threshold can be set smaller, for example, the preset steering wheel angle threshold can be set to 3°.

[0152] When the steering wheel angles of multiple cycles are all less than the preset steering wheel angle threshold, it means that the steering wheel angles of multiple cycles are all small and less than the steering wheel angle when the front wheel has an angle. Therefore, it can be determined that the steering wheel of the target vehicle remains centered and the front wheel has no angle, which means that the target vehicle is driving in a straight line.

[0153] When there is a steering wheel angle greater than a preset steering wheel angle threshold in multiple cycles, it means that the steering wheel angle of this cycle is large and the front wheel has an angle, then it can be determined that the target vehicle is not driving in a straight line.

[0154] Furthermore, after determining that the target vehicle is traveling in a straight line, it is also possible to continuously detect whether the steering wheel of the target vehicle is returned to the center and whether the rear wheels of the target vehicle are turning abnormally.

[0155] Specifically, first obtain the current steering wheel angle, current rear wheel angle, target rear wheel angle and current yaw rate of the target vehicle; then, based on the current steering wheel angle, current rear wheel angle, target rear wheel angle and current yaw rate of the target vehicle, determine whether the steering wheel of the target vehicle remains centered and whether the rear wheels of the target vehicle have abnormal steering.

[0156] The current yaw rate refers to the angular velocity of the target vehicle rotating around the vertical axis at the current moment, and is usually used to describe the steering behavior of the vehicle. Since the yaw rate of the vehicle changes when the rear wheels of the vehicle have an angle, the current yaw rate can be obtained.

[0157] In this case, by combining the current steering wheel angle, the current rear wheel angle, the target rear wheel angle and the current yaw rate, it is possible to accurately determine whether the steering wheel of the target vehicle is centered and whether the rear wheels are turning abnormally.

[0158] Among them, based on the current steering wheel angle, current rear wheel angle, target rear wheel angle and current yaw angular velocity of the target vehicle, the operation of determining whether the steering wheel of the target vehicle remains centered and whether the rear wheels of the target vehicle have abnormal steering may be: subtracting the target rear wheel angle from the current rear wheel angle to obtain a rear wheel angle difference; when the current steering wheel angle is less than or equal to a preset steering wheel angle threshold and the rear wheel angle difference is greater than or equal to a preset difference threshold and the current yaw angular velocity is greater than or equal to a preset angular velocity threshold, determining that the steering wheel of the target vehicle remains centered and the rear wheels of the target vehicle have abnormal steering; when the current steering wheel angle is less than or equal to the preset steering wheel angle threshold and the rear wheel angle difference is less than the preset difference threshold and the current yaw angular velocity is less than the preset angular velocity threshold, determining that the steering wheel of the target vehicle remains centered and the rear wheels of the target vehicle have not abnormally steered.

[0159] The preset difference threshold can be set in advance, and the preset difference threshold can be set relatively large. For example, the preset difference threshold can be set to 1°.

[0160] The preset angular velocity threshold can be set in advance, and the preset angular velocity threshold can be set relatively large. For example, the preset angular velocity threshold can be set to 1° / s (degrees per second).

[0161] In this case, when the current steering wheel angle is less than or equal to the preset steering wheel angle threshold, it means that the steering wheel remains centered at the current moment, and then it can be further determined whether the rear wheels of the target vehicle have abnormal steering. When the rear wheel angle difference is greater than or equal to the preset difference threshold, it means that the rear wheel angle difference is large, that is, the difference between the current rear wheel angle and the target rear wheel angle is large, which means that the current rear wheel angle is large. In addition, when the current yaw angular velocity is greater than or equal to the preset angular velocity threshold, it means that the current yaw angular velocity is large, which means that the whole vehicle has a tendency to turn. Then, when the current rear road angle is large and the whole vehicle has a tendency to turn, it can be said that the rear wheels have abnormal steering.

[0162] When the rear wheel angle difference is less than the preset difference threshold, it means that the rear wheel angle difference is normal, that is, the difference between the current rear wheel angle and the target rear wheel angle is relatively normal, which means that the current rear wheel angle is normal. In addition, when the current yaw angular velocity is less than the preset angular velocity threshold, it means that the current yaw angular velocity is small, which means that the yaw angular velocity of the whole vehicle is normal, and there is no turning trend. In this case, it can be determined that the rear wheel has no abnormal turning.

[0163] It is worth noting that, in the case of abnormal steering of the rear wheels of the target vehicle, the angle to be compensated by the front wheels of the target vehicle can be determined through the above step 301, so that the driving track of the target vehicle can be corrected by compensating a certain angle later. That is, steps 302 and 303 can be continued to be executed later.

[0164] Step 302: Determine a target compensation torque based on the target front wheel steering angle.

[0165] In the embodiment of the present application, the target vehicle has an electric power steering system. When controlling the front wheel steering, the electric power steering system can be used to control the front wheels to rotate a certain angle. However, the electric power steering system causes the front wheels of the target vehicle to rotate a certain angle by outputting a certain torque. Therefore, in the embodiment of the present application, the target compensation torque can also be determined based on the target front wheel turning angle.

[0166] In this case, the target compensation torque is the torque to be compensated by the electric power steering system, and is the torque to be output on the basis of the current output torque. That is, the front wheels of the target vehicle can be rotated by the target front wheel turning angle by outputting the target compensation torque. In the embodiment of the present application, the direction of the target compensation torque can be the same as the direction of the current yaw angular velocity.

[0167] Optionally, before determining the target compensation torque, the current vehicle speed, the current steering wheel torque, and the steering system stiffness of the target vehicle may be acquired first.

[0168] The steering system stiffness of the target vehicle refers to the ability of the steering system of the target vehicle to resist deformation. The steering system stiffness can be calibrated when the target vehicle is produced and stored in the memory of the target vehicle.

[0169] In this case, the operation of step 302 may be: determining the target compensation torque based on the target front wheel angle, the current vehicle speed, the current steering wheel torque and the stiffness of the steering system.

[0170] Since the front wheel rotation angle is affected by many factors, such as the current speed of the target vehicle, the torque applied by the user to the steering wheel, the stiffness of the steering system, etc., the target compensation torque can also be calculated based on these parameters.

[0171] Specifically, based on the target front wheel angle, the current vehicle speed, the current steering wheel torque and the steering system stiffness, the operation of determining the target compensation torque can be: based on the current vehicle speed, determine the target assist coefficient; multiply the target assist coefficient by the current steering wheel torque to obtain a first assist torque; multiply the target front wheel angle by the steering system stiffness to obtain a second assist torque; and determine the sum of the first assist torque and the second assist torque as the target compensation torque.

[0172] The target power assist coefficient refers to the proportional relationship between the torque provided by the electric power steering system and the torque applied by the driver when controlling the front wheel steering at the current vehicle speed.

[0173] The first assist torque is the torque required by the electric power steering system to overcome the force applied by the user on the steering wheel, and the second assist torque is the torque required by the electric power steering system to overcome the system stiffness during steering.

[0174] Since the electric power steering system not only has to overcome the force applied by the user on the steering wheel (providing power assistance to the user) when steering, but also has to overcome the reverse force caused by the system stiffness of the steering system, the first power assist torque and the second power assist torque can be calculated to determine the target compensation torque based on the first power assist torque and the second power assist torque.

[0175] In this case, the sum of the first assist torque and the second assist torque is determined as the target compensation torque, so that the target compensation torque can offset the force applied by the user on the steering wheel and the reverse force caused by the stiffness of the steering system, thereby obtaining a more accurate target compensation torque, so that the front wheel angle can be adjusted more accurately later.

[0176] Among them, based on the current vehicle speed, the operation of determining the target power assist coefficient can be: when the current vehicle speed is less than or equal to the target vehicle speed threshold, the target power assist coefficient is determined to be the first coefficient; when the current vehicle speed is greater than the target vehicle speed threshold, the target power assist coefficient is determined to be the second coefficient.

[0177] The first coefficient and the second coefficient may be pre-set, and the first coefficient is a target power assist coefficient when the target vehicle is at a low speed, and the second coefficient is a target power assist coefficient when the target vehicle is at a high speed.

[0178] As an implementation method, the target power assist coefficient may also be determined according to the following formula (2).

[0179]

[0180] Among them, k is the target assistance coefficient, k l is the first coefficient, k h is the second coefficient, v is the current vehicle speed, v th is the target vehicle speed threshold. α is a parameter for smooth transition, which can be set in advance.

[0181] For example, the first coefficient is 0.5, the second coefficient is 0.2, the smooth transition parameter is 1, the current vehicle speed is 30, and the target vehicle speed threshold is 50. The target power assist coefficient is determined by the above formula (2) as shown below.

[0182]

[0183] Step 303: Control the front wheel motor of the target vehicle to output the target compensation torque, so as to keep the target vehicle in a straight-line driving state by adjusting the front wheel angle of the target vehicle.

[0184] In this case, the target vehicle's front wheel motor is controlled to output a target compensation torque to control the front wheels to rotate to a certain angle, so that the front wheels can compensate for the trajectory deviation caused by abnormal steering of the rear wheels, thereby subsequently keeping the target vehicle in a straight-line driving state, thereby improving driving safety.

[0185] In the embodiment of the present application, the target vehicle's electric power steering system can also be used to control the power-assisted motor to output the target compensation torque. In this case, the electric power steering system sends a signal to the power-assisted motor to output the target compensation torque, so that the power-assisted motor of the target vehicle can be controlled to output the target compensation torque.

[0186] Optionally, the power assist motor of the target vehicle may be controlled to output a target compensation torque based on the current power assist torque.

[0187] Specifically, the target compensation torque is added to the current power-assist torque to obtain the target power-assist torque; the power-assist motor of the target vehicle is controlled to output the target power-assist torque to adjust the front wheel angle of the target vehicle.

[0188] The current power-assist torque is the power-assist torque output by the power-assist motor of the target vehicle when it is determined that the rear wheel has abnormal steering. It should be understood that in the embodiment of the present application, when the current steering wheel angle is 0, the current front wheel angle should be 0, and then the current power-assist torque can be 0.

[0189] When the current assist torque is 0, the target assist torque is also the target compensation torque.

[0190] Among them, the operation of adding the target compensation torque to the current assist torque to obtain the target assist torque can be: obtaining the first weight corresponding to the target compensation torque and obtaining the second weight corresponding to the current assist torque; based on the first weight and the second weight, weightedly summing the target compensation torque and the current assist torque to obtain the target assist torque.

[0191] The first weight and the second weight may be set in advance by a technician.

[0192] In this case, by weighted summing the target compensation torque and the current assist torque, the front wheels can be slowly rotated to gradually make the front wheel angle reach the target front wheel angle, so that the rotation of the front wheels of the target vehicle can be smoother and smoother, rather than directly outputting the target compensation torque to make the front wheels suddenly rotate to the target front wheel angle. In this way, the user experience can be improved.

[0193] It is worth noting that in the embodiment of the present application, the target compensation torque can be determined in multiple rounds of iterations, and during the multiple rounds of iterations, the target compensation torque determined in each round is added to the current power-assisting torque to obtain the target power-assisting torque.

[0194] The above-mentioned multiple-round iteration process is explained by taking a three-round iteration process.

[0195] In the first round of iteration, the target front wheel angle is determined based on the current rear wheel angle, the target rear wheel angle (the positive angle of the rear wheel in the previous cycle) and vehicle parameters, and the target compensation torque is determined based on the target front wheel angle. The target compensation torque and the current power-assisting torque are weighted and summed to obtain the target power-assisting torque for the first round of iteration, and the power-assisting motor is controlled to output the target power-assisting torque for the first round of iteration.

[0196] During the second round of iteration, the target power-assist torque is the current power-assist torque of the second round of iteration. The target front wheel angle is subtracted from the current front wheel angle to obtain the front wheel turning angle of the second round of iteration, and the target compensation torque is determined based on the front wheel turning angle of the second round of iteration. Then, the target compensation torque determined in the second round of iteration is weightedly summed with the current power-assist torque to obtain the target power-assist torque determined in the second round of iteration, and the power-assist motor is subsequently controlled to output the target power-assist torque of the second round of iteration.

[0197] During the third round of iteration, the target power-assist torque is the current power-assist torque of the third round of iteration. The front wheel turning angle of the second round of iteration is subtracted from the current front wheel turning angle to obtain the front wheel turning angle of the third round of iteration, and the target compensation torque is determined based on the front wheel turning angle of the third round of iteration. Then, the target compensation torque determined in the third round of iteration is weightedly summed with the current power-assist torque to obtain the target power-assist torque determined in the third round of iteration, and the power-assist motor is subsequently controlled to output the target power-assist torque of the third round of iteration.

[0198] In this case, the first weight and the second weight can be adaptively changed during multiple iterations, and the change trend can be that the first weight becomes larger and larger during multiple iterations, and the second weight becomes smaller and smaller during multiple iterations. In this way, more target compensation torque is output during multiple iterations, so that the front wheel angle gradually increases to achieve the purpose of correcting the trajectory deviation.

[0199] In addition, during the multiple rounds of iterative updating process, the current rear wheel steering angle can be detected in real time. In this case, the compensation torque can be iteratively updated based on the current rear wheel steering angle detected in real time.

[0200] Specifically, during multiple rounds of iterative updating, the current rear wheel steering angle detected in real time is obtained, the rear wheel steering angle difference is updated based on the current rear wheel steering angle detected in real time and the target rear wheel steering angle, and the target front wheel steering angle is determined based on the updated rear wheel steering angle difference and the vehicle parameters of the target vehicle. Thereafter, the target compensation torque is determined based on the determined target front wheel steering angle, thereby achieving continuous updating of the target compensation torque based on the rear wheel steering angle detected in real time during multiple rounds of iterative updating, and further continuously adjusting the target compensation torque output by the front wheel motor during multiple rounds of iterative updating.

[0201] For ease of understanding, now combined Figure 4The process of determining the target assist torque in the embodiment of the present application is described. For example, Figure 4 A flow chart for determining target assist torque provided in an embodiment of the present application.

[0202] like Figure 4 As shown, the difference (rear wheel angle difference) between the current rear wheel angle of the target vehicle and the rear wheel angle of the previous cycle (target rear wheel angle) is first calculated, and then the rear wheel angle difference is multiplied by the target compensation coefficient to obtain the target front wheel angle. The target front wheel angle is then subjected to torque calculation to calculate the target compensation torque required for the front wheel to rotate the target front wheel angle. The target compensation torque is then weighted and summed with the current power-assisted torque to obtain the compensated power-assisted torque, which is the target power-assisted torque.

[0203] It is worth noting that in the embodiment of the present application, after the target vehicle is powered on, the vehicle controller continuously detects the steering wheel angle, rear wheel angle, and yaw angular velocity. When it is detected that the current steering wheel angle is less than or equal to the preset steering wheel angle threshold, and the rear wheel angle difference is greater than or equal to the preset difference threshold, and the current yaw angular velocity is greater than or equal to the preset angular velocity threshold, it is determined that the target vehicle has abnormal rear wheel steering while maintaining straight driving. At this time, the vehicle controller can send an unexpected steering compensation function activation signal to the EPS system. After the EPS system receives the signal, the unexpected steering compensation function is activated, and a signal that the function has been activated is fed back to the vehicle controller. Thereafter, the EPS system can execute the above steps 301-303 to calculate a target compensation torque, so that the power-assisted motor can output the target compensation torque based on the current output torque, thereby realizing the correction of the trajectory deviation caused by abnormal steering of the rear wheels by rotating the front wheels by a certain angle.

[0204] In addition, in the above-mentioned process of compensating torque through the front wheels, the vehicle controller also keeps detecting the steering wheel angle and the rear wheel angle. When the current steering wheel angle is less than or equal to the preset steering wheel angle threshold, the rear wheel angle difference is less than the preset difference threshold, and the current yaw angular velocity is less than the preset angular velocity threshold, it is determined that the rear wheels are working normally. Then, an unexpected steering compensation function exit command signal can be sent to the EPS system. After receiving the command signal, the EPS system turns off the unexpected steering compensation function and controls the motor output according to the normal power assist torque.

[0205] For ease of understanding, now combined Figure 5 The vehicle control method provided in the embodiment of the present application is exemplarily described. For example, Figure 5 is a flow chart of another vehicle control method provided in an embodiment of the present application, see Figure 5 , assuming that the preset steering wheel angle threshold is 3°, the preset angular velocity threshold is 1° / s, and the preset difference threshold is 1°. Figure 5The process includes steps 501 to 507.

[0206] Step 501: Obtain the current steering wheel angle, the current rear wheel angle, and the current yaw rate, and calculate the rear wheel angle difference.

[0207] Step 502: Determine whether the current steering wheel angle is less than 3°. If the current steering wheel angle is less than 3°, execute the following step 503.

[0208] Step 503: Determine whether the rear wheel steering angle difference is greater than or equal to 1°, and whether the current yaw rate is greater than or equal to 1° / s. If the rear wheel steering angle difference is greater than or equal to 1° and the current yaw rate is greater than or equal to 1° / s, execute the following step 504; otherwise, execute step 507.

[0209] Step 504: Determine a target front wheel steering angle based on the rear wheel steering angle difference and the vehicle parameters of the target vehicle.

[0210] Step 505: Determine the target compensation torque based on the target front wheel steering angle.

[0211] Step 506: Control the front wheel motor to output the target compensation torque, and execute the above step 503.

[0212] Step 507: Determine that there is no abnormality in the rear wheel, and do not enable the unexpected steering compensation function.

[0213] In an embodiment of the present application, when the steering wheel of the target vehicle is kept back to the center and the rear wheels of the target vehicle are turning abnormally, the vehicle controller first determines the target front wheel angle based on the difference between the current rear wheel angle of the target vehicle and the target rear wheel angle and the vehicle parameters, that is, determines the angle that the front wheels of the target vehicle should rotate to compensate for the abnormal steering of the rear wheels. Then, based on the target front wheel angle, the target compensation torque is determined, that is, the torque that the front wheels should compensate is determined. Finally, the front wheel motor of the target vehicle is controlled to output the target compensation torque to keep the target vehicle in a straight-line driving state by adjusting the front wheel angle of the target vehicle. In the present application, when the rear wheels of the target vehicle are turning abnormally during the straight-line driving process, the front wheel motor outputs the target compensation torque to control the front wheels to rotate a certain angle, so that the trajectory deviation caused by the abnormal steering of the rear wheels can be compensated, so that the target vehicle can be kept in a straight-line driving later, thereby improving the driving safety.

[0214] Figure 6 is a schematic diagram of the structure of a vehicle control device provided in an embodiment of the present application. The vehicle control device can be implemented by software, hardware or a combination of both to form part or all of a vehicle, and the vehicle can be as follows Figure 7 Vehicle shown. See Figure 6The device includes: a first determination module 601, a second determination module 602 and a torque output module 603.

[0215] The first determination module 601 is used to determine the target front wheel turning angle based on the difference between the current rear wheel turning angle of the target vehicle and the target rear wheel turning angle and vehicle parameters when the steering wheel of the target vehicle remains centered and the rear wheels of the target vehicle have abnormal steering. The target rear wheel turning angle is the angle of the rear wheels of the target vehicle when they are in the centered state. The target front wheel turning angle is the angle that the front wheels of the target vehicle should turn to compensate for the abnormal steering of the rear wheels. The vehicle parameters include dynamic vehicle parameters and static vehicle parameters.

[0216] A second determination module 602 is used to determine a target compensation torque based on a target front wheel steering angle;

[0217] The torque output module 603 is used to control the front wheel motor of the target vehicle to output the target compensation torque, so as to keep the target vehicle in a straight-line driving state by adjusting the front wheel angle of the target vehicle.

[0218] Optionally, the device further comprises:

[0219] A first acquisition module is used to acquire a current steering wheel angle, a current rear wheel angle, a target rear wheel angle and a current yaw angular velocity of the target vehicle;

[0220] The third determination module is used to determine whether the steering wheel of the target vehicle remains centered and whether the rear wheels of the target vehicle have abnormal steering based on the current steering wheel angle, the current rear wheel angle, the target rear wheel angle and the current yaw rate.

[0221] Optionally, the third determining module is used to:

[0222] Subtract the target rear wheel angle from the current rear wheel angle to obtain the rear wheel angle difference;

[0223] When the current steering wheel angle is less than or equal to a preset steering wheel angle threshold, the rear wheel angle difference is greater than or equal to a preset difference threshold, and the current yaw angular velocity is greater than or equal to a preset angular velocity threshold, determining that the steering wheel of the target vehicle remains centered and that the rear wheels of the target vehicle are turning abnormally;

[0224] When the current steering wheel angle is less than or equal to a preset steering wheel angle threshold, the rear wheel angle difference is less than a preset difference threshold, and the current yaw angular velocity is less than a preset angular velocity threshold, it is determined that the steering wheel of the target vehicle remains centered and the rear wheels of the target vehicle do not show abnormal steering.

[0225] Optionally, the static vehicle parameters include axle attributes of the target vehicle, and the dynamic vehicle parameters include current driving parameters of the target vehicle. The first determination module 601 is used to:

[0226] The target front wheel steering angle is determined based on the difference between the current rear wheel steering angle of the target vehicle and the target rear wheel steering angle, axle properties, and current driving parameters.

[0227] Optionally, the axle attributes include front axle cornering stiffness and rear axle cornering stiffness, the current driving parameter includes current vehicle speed, and the first determining module 601 is used to:

[0228] Based on the current vehicle speed, determining a first compensation coefficient, the first compensation coefficient being used to represent a ratio between a front wheel angle and a rear wheel angle of the target vehicle at the current vehicle speed;

[0229] Determining a second compensation coefficient based on the front axle cornering stiffness and the rear axle cornering stiffness, the second compensation coefficient being used to represent an inherent angle ratio between a front wheel angle and a rear wheel angle of the target vehicle;

[0230] A target front wheel turning angle is determined based on the first compensation coefficient, the second compensation coefficient, and the rear wheel turning angle difference, where the rear wheel turning angle difference is the difference between the current rear wheel turning angle of the target vehicle and the target rear wheel turning angle.

[0231] Optionally, the first determining module 601 is used to:

[0232] Multiplying the first compensation coefficient by the second compensation coefficient to obtain a target compensation coefficient;

[0233] Multiply the rear wheel steering angle difference by the target compensation coefficient to obtain the target front wheel steering angle.

[0234] Optionally, the device further comprises:

[0235] The second acquisition module is used to acquire the current speed of the target vehicle, the current steering wheel torque and the stiffness of the steering system of the target vehicle, where the stiffness of the steering system refers to the ability of the steering system of the target vehicle to resist deformation;

[0236] Optionally, the second determining module 602 is used to:

[0237] The target compensation torque is determined based on the target front wheel angle, the current vehicle speed, the current steering wheel torque and the steering system stiffness.

[0238] Optionally, the second determining module 602 is used to:

[0239] Based on the current vehicle speed, a target power assist coefficient is determined, which refers to the proportional relationship between the torque provided by the steering system and the torque applied by the driver when controlling the front wheel steering at the current vehicle speed;

[0240] Multiply the target power-assist coefficient by the current steering wheel torque to obtain a first power-assist torque;

[0241] The target front wheel angle is multiplied by the stiffness of the steering system to obtain the second assist torque;

[0242] The sum of the first assist torque and the second assist torque is determined as the target compensation torque.

[0243] Optionally, the torque output module 603 is further used for:

[0244] The power-assisting motor of the target vehicle is controlled to output a target compensation torque based on a current power-assisting torque, where the current power-assisting torque is the power-assisting torque output by the power-assisting motor of the target vehicle when an abnormal steering occurs in the rear wheels.

[0245] Optionally, the torque output module 603 is further used for:

[0246] The target compensation torque is added to the current power-assisting torque to obtain the target power-assisting torque;

[0247] The power-assisting motor of the target vehicle is controlled to output the target power-assisting torque to adjust the front wheel angle of the target vehicle.

[0248] Optionally, the torque output module 603 is further used for:

[0249] Obtaining a first weight corresponding to the target compensation torque and obtaining a second weight corresponding to the current assist torque;

[0250] Based on the first weight and the second weight, the target compensation torque and the current assist torque are weightedly summed to obtain the target assist torque.

[0251] In an embodiment of the present application, when the steering wheel of the target vehicle is kept back to the center and the rear wheels of the target vehicle are abnormally turned, the target front wheel angle is first determined based on the difference between the current rear wheel angle of the target vehicle and the target rear wheel angle and the vehicle parameters, that is, the angle that the front wheels of the target vehicle should rotate to compensate for the abnormal steering of the rear wheels. Then, based on the target front wheel angle, the target compensation torque is determined, that is, the torque that the front wheels should compensate is determined. Finally, the front wheel motor of the target vehicle is controlled to output the target compensation torque to keep the target vehicle in a straight-line driving state by adjusting the front wheel angle of the target vehicle. In the present application, when the rear wheels of the target vehicle are abnormally turned during the straight-line driving, the front wheel motor outputs the target compensation torque to control the front wheels to rotate a certain angle, so that the trajectory deviation caused by the abnormal steering of the rear wheels can be compensated, so that the target vehicle can be kept in a straight-line driving later, thereby improving the driving safety.

[0252] It should be noted that: the vehicle control device provided in the above embodiment only uses the division of the above-mentioned functional modules as an example to illustrate when the rear wheels of the vehicle turn abnormally to control the vehicle accordingly. In actual applications, the above-mentioned functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0253] The functional units and modules in the above embodiments may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit, and the above integrated units may be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the protection scope of the embodiments of the present application.

[0254] The vehicle control device and vehicle control method embodiments provided in the above embodiments belong to the same concept. The specific working process of the units and modules in the above embodiments and the technical effects brought about can be found in the method embodiment part and will not be repeated here.

[0255] Figure 7 It is a structural schematic diagram of a vehicle provided in an embodiment of the present application.

[0256] For example, Figure 7 As shown, the vehicle 700 includes: a memory 71 and a processor 70, wherein the memory 71 stores an executable program code 72, and the processor 70 is used to call and execute the executable program code 72 to perform the above-mentioned vehicle control method.

[0257] In this embodiment, the functional modules of the vehicle can be divided according to the above method example. For example, each functional module can be corresponded, or two or more functions can be integrated into one processing module. The above integrated module can be implemented in the form of hardware. It should be noted that the division of modules in this embodiment is schematic and is only a logical function division. There may be other division methods in actual implementation.

[0258] In the case of dividing each functional module according to each function, the vehicle may include: a first determination module, a second determination module and a torque output module. It should be noted that all relevant contents of each step involved in the above method embodiment can be referred to the functional description of the corresponding functional module, which will not be repeated here.

[0259] The vehicle provided in this embodiment is used to execute the above-mentioned vehicle control method, and thus can achieve the same effect as the above-mentioned implementation method.

[0260] In the case of an integrated unit, the vehicle may include a processing module and a storage module. The processing module may be used to control and manage the actions of the vehicle. The storage module may be used to support the vehicle in executing corresponding program codes and data.

[0261] The processing module may be a processor or a controller, which may implement or execute various exemplary logic blocks, modules and circuits shown in conjunction with the disclosure of the present application. The processor may also be a combination that implements computing functions, such as a combination of one or more microprocessors, a combination of digital signal processing (DSP) and a microprocessor, etc. The storage module may be a memory.

[0262] This embodiment also provides a computer-readable storage medium, in which a computer program code is stored. When the computer program code is run on a computer, the computer executes the above-mentioned related method steps to implement the above-mentioned vehicle control method in the above-mentioned embodiment.

[0263] This embodiment also provides a computer program product. When the computer program product is run on a computer, the computer is enabled to execute the above-mentioned related steps to implement the above-mentioned vehicle control method in the above-mentioned embodiment.

[0264] Among them, the vehicle, computer-readable storage medium, computer program product or chip provided in this embodiment are all used to execute the method provided above. Therefore, the beneficial effects that can be achieved can refer to the beneficial effects in the method provided above and will not be repeated here.

[0265] Through the description of the above implementation methods, technical personnel in the relevant field can understand that for the convenience and brevity of description, only the division of the above-mentioned functional modules is used as an example. In actual applications, the above-mentioned functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0266] In the embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are schematic, for example, the division of modules or units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0267] The above contents are only specific implementation methods of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A vehicle control method, characterized in that: The method comprises: In the case where the steering wheel of the target vehicle is kept centered and the rear wheels of the target vehicle are abnormally turned, a target front wheel turning angle is determined based on the difference between the current rear wheel turning angle of the target vehicle and the target rear wheel turning angle and vehicle parameters, wherein the target rear wheel turning angle is the angle of the rear wheels of the target vehicle when they are in the centered state, the target front wheel turning angle is the angle that the front wheels of the target vehicle should turn to compensate for the abnormal rear wheel turning, and the vehicle parameters include dynamic vehicle parameters and static vehicle parameters; determining a target compensation torque based on the target front wheel steering angle; The front wheel motor of the target vehicle is controlled to output the target compensation torque, so as to keep the target vehicle in a straight-line driving state by adjusting the front wheel angle of the target vehicle.

2. The method according to claim 1, characterized in that Before determining the target front wheel turning angle based on the difference between the current rear wheel turning angle of the target vehicle and the target rear wheel turning angle and the vehicle parameters when the steering wheel of the target vehicle remains centered and the rear wheels of the target vehicle are turning abnormally, the method further includes: Obtaining a current steering wheel angle, a current rear wheel angle, a target rear wheel angle, and a current yaw rate of the target vehicle; Based on the current steering wheel angle, the current rear wheel angle, the target rear wheel angle, and the current yaw rate, it is determined whether the steering wheel of the target vehicle remains centered and whether the rear wheels of the target vehicle are turning abnormally.

3. The method according to claim 2, characterized in that The determining, based on the current steering wheel angle, the current rear wheel angle, the target rear wheel angle, and the current yaw rate, whether the steering wheel of the target vehicle remains centered and whether the rear wheels of the target vehicle have abnormal steering, comprises: Subtracting the target rear wheel turning angle from the current rear wheel turning angle to obtain a rear wheel turning angle difference; When the current steering wheel angle is less than or equal to a preset steering wheel angle threshold, the rear wheel angle difference is greater than or equal to a preset difference threshold, and the current yaw angular velocity is greater than or equal to a preset angular velocity threshold, determining that the steering wheel of the target vehicle remains centered and that the rear wheels of the target vehicle are turning abnormally; When the current steering wheel angle is less than or equal to the preset steering wheel angle threshold, the rear wheel angle difference is less than the preset difference threshold, and the current yaw angular velocity is less than the preset angular velocity threshold, it is determined that the steering wheel of the target vehicle remains centered and the rear wheels of the target vehicle do not show abnormal steering.

4. The method according to claim 1, characterized in that The static vehicle parameters include axle attributes of the target vehicle, the dynamic vehicle parameters include current driving parameters of the target vehicle, and the target front wheel steering angle is determined based on the difference between the current rear wheel steering angle of the target vehicle and the target rear wheel steering angle and the vehicle parameters, including: The target front wheel turning angle is determined based on a difference between a current rear wheel turning angle of the target vehicle and a target rear wheel turning angle, the axle attributes, and the current driving parameter.

5. The method according to claim 4, characterized in that The axle attributes include front axle cornering stiffness and rear axle cornering stiffness, the current driving parameters include current vehicle speed, and determining the target front wheel turning angle based on the difference between the current rear wheel turning angle of the target vehicle and the target rear wheel turning angle, the axle attributes, and the current driving parameters, includes: Based on the current vehicle speed, determining a first compensation coefficient, the first compensation coefficient being used to represent a ratio between a front wheel angle and a rear wheel angle of the target vehicle at the current vehicle speed; Determining a second compensation coefficient based on the front axle cornering stiffness and the rear axle cornering stiffness, the second compensation coefficient being used to represent an inherent angle ratio between a front wheel angle and a rear wheel angle of the target vehicle; The target front wheel turning angle is determined based on the first compensation coefficient, the second compensation coefficient, and a rear wheel turning angle difference, where the rear wheel turning angle difference is a difference between a current rear wheel turning angle of the target vehicle and a target rear wheel turning angle.

6. The method according to claim 5, characterized in that The determining the target front wheel turning angle based on the first compensation coefficient, the second compensation coefficient and the rear wheel turning angle difference comprises: multiplying the first compensation coefficient by the second compensation coefficient to obtain a target compensation coefficient; The rear wheel steering angle difference is multiplied by the target compensation coefficient to obtain the target front wheel steering angle.

7. The method according to claim 1, characterized in that Before determining the target compensation torque based on the target front wheel steering angle, the method further includes: Acquire the current vehicle speed, current steering wheel torque and steering system stiffness of the target vehicle, where the steering system stiffness refers to the ability of the steering system of the target vehicle to resist deformation; The determining of the target compensation torque based on the target front wheel steering angle comprises: The target compensation torque is determined based on the target front wheel steering angle, the current vehicle speed, the current steering wheel torque, and the steering system stiffness.

8. The method according to claim 7, characterized in that The determining the target compensation torque based on the target front wheel steering angle, the current vehicle speed, the current steering wheel torque and the steering system stiffness comprises: Determining a target power-assistance coefficient based on the current vehicle speed, wherein the target power-assistance coefficient refers to a proportional relationship between a torque provided by a steering system and a torque applied by a driver when controlling the steering of the front wheels at the current vehicle speed; Multiplying the target power-assist coefficient by the current steering wheel torque to obtain a first power-assist torque; Multiplying the target front wheel angle by the steering system stiffness to obtain a second assist torque; The sum of the first assist torque and the second assist torque is determined as the target compensation torque.

9. A vehicle control device, characterized in that: The device comprises: A first determination module is used to determine a target front wheel turning angle based on a difference between a current rear wheel turning angle of the target vehicle and a target rear wheel turning angle and vehicle parameters when the steering wheel of the target vehicle is kept centered and the rear wheels of the target vehicle are abnormally turned, wherein the target rear wheel turning angle is an angle of the rear wheels of the target vehicle when the rear wheels are in a centered state, the target front wheel turning angle is an angle that the front wheels of the target vehicle should turn to compensate for the abnormal rear wheel turning, and the vehicle parameters include dynamic vehicle parameters and static vehicle parameters; A second determination module, configured to determine a target compensation torque based on the target front wheel steering angle; The torque output module is used to control the front wheel motor of the target vehicle to output the target compensation torque so as to keep the target vehicle in a straight-line driving state by adjusting the front wheel angle of the target vehicle.

10. A vehicle, characterized in that: The vehicle comprises: A memory for storing executable program codes; A processor, configured to call and run the executable program code from the memory so that the vehicle executes the method according to any one of claims 1 to 8.

Images