Front and rear wheel control method, system, electronic device, storage medium and vehicle

Abstract

The present disclosure provides a control method, system, electronic device, storage medium and vehicle for front and rear wheels. The method comprises: obtaining vehicle information; wherein the vehicle information comprises an actual deflection angle of the front wheel; processing the actual deflection angle of the front wheel to obtain an expected deflection angle of the front wheel; judging the deflection direction of the rear wheel of the vehicle according to the vehicle information to obtain the deflection direction of the rear wheel; using the expected deflection angle of the front wheel, determining the deflection angle of the rear wheel based on the yaw rate change rate, the vehicle center of mass side slip angle and the vehicle lateral acceleration; controlling the front wheel of the vehicle according to the expected deflection angle of the front wheel, and controlling the rear wheel of the vehicle according to the rear wheel deflection direction and the rear wheel deflection angle.

Description

Technical Field

[0001] The present disclosure relates to the field of vehicle control technology, and in particular to a control method, system, electronic device, storage medium and vehicle for front and rear wheels. Background Art

[0002] During vehicle driving, especially when driving on curves, factors such as excessive speed or changes in tire adhesion may cause the wheels to slip, making the vehicle prone to understeer or oversteer, causing the vehicle to lose control and lead to a safety accident.

[0003] In view of this, how to avoid vehicle understeer or oversteer problems and improve driving stability and safety has become an important research issue. Summary of the invention

[0004] In view of this, the purpose of the present disclosure is to provide a control method, system, electronic device, storage medium and vehicle for front and rear wheels to solve the problem of understeering or oversteering that occurs when a vehicle is driving in the prior art.

[0005] Based on the above objectives, the first aspect of the present disclosure provides a method for controlling front and rear wheels, comprising:

[0006] Acquiring vehicle information; wherein the vehicle information includes an actual deflection angle of the front wheels;

[0007] Processing the actual deflection angle of the front wheel to obtain a desired deflection angle of the front wheel;

[0008] Determining the rear wheel deflection direction of the vehicle according to the vehicle information to obtain the rear wheel deflection direction;

[0009] Determining the rear wheel yaw angle based on the desired front wheel yaw angle, the vehicle center of mass sideslip angle and the vehicle lateral acceleration;

[0010] The front wheels of the vehicle are controlled according to the desired deflection angle of the front wheels, and the rear wheels of the vehicle are controlled according to the rear wheel deflection direction and the rear wheel deflection angle.

[0011] Based on the same inventive concept, the second aspect of the present disclosure proposes a control system for front and rear wheels, comprising:

[0012] A vehicle information acquisition module is configured to acquire vehicle information; wherein the vehicle information includes an actual deflection angle of the front wheels;

[0013] A front wheel control module is configured to process the actual deflection angle of the front wheel to obtain a desired deflection angle of the front wheel;

[0014] A rear wheel deflection direction acquisition module is configured to determine the rear wheel deflection direction of the vehicle according to the vehicle information to obtain the rear wheel deflection direction;

[0015] a rear wheel deflection angle acquisition module, configured to determine the rear wheel deflection angle based on the desired deflection angle of the front wheel and the yaw rate change rate, the vehicle center of mass sideslip angle and the vehicle lateral acceleration;

[0016] The vehicle control module is configured to control the front wheels of the vehicle according to the desired front wheel turning angle, and to control the rear wheels of the vehicle according to the rear wheel deflection direction and the rear wheel deflection angle.

[0017] Based on the same inventive concept, the third aspect of the present disclosure proposes an electronic device, including a memory, a processor, and a computer program stored in the memory and executable by the processor, wherein the processor implements the method as described above when executing the computer program.

[0018] Based on the same inventive concept, a fourth aspect of the present disclosure proposes a non-transitory computer-readable storage medium, wherein the non-transitory computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a computer to execute the method as described above.

[0019] Based on the same inventive concept, the fifth aspect of the present disclosure proposes a vehicle, which includes the control system of the front and rear wheels described in the second aspect or the electronic device described in the third aspect or the storage medium described in the fourth aspect.

[0020] From the above, it can be seen that the control method, system, electronic device, storage medium and vehicle of the front and rear wheels provided by the present disclosure processes the actual deflection angle of the front wheel to obtain the expected deflection angle of the front wheel, and controls the front wheel of the vehicle according to the expected deflection angle of the front wheel, which is more accurate than directly controlling the front wheel of the vehicle through the steering wheel in the related art. The expected deflection angle of the front wheel is used to determine the deflection angle of the rear wheel based on the yaw rate change rate, the side slip angle of the center of mass of the vehicle and the lateral acceleration of the vehicle. When the yaw rate change rate, the side slip angle of the center of mass and the lateral acceleration of the vehicle all meet the pre-set conditions, the deflection angle of the rear wheel is determined, so that the obtained deflection angle of the rear wheel is more accurate, and the rear wheel can be adjusted and controlled more accurately. In the case of understeering or oversteering of the vehicle, through the above scheme, when the vehicle is turning, the deflection angles of the front and rear wheels are controlled and adjusted together, so that the vehicle is more stable when turning than when only the rear wheels are controlled, thereby improving the safety of driving. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the present disclosure or related technologies, the drawings required for use in the embodiments or related technical descriptions are briefly introduced below. Obviously, the drawings described below are only embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0022] Figure 1 is a flow chart of a method for controlling front and rear wheels according to an embodiment of the present disclosure;

[0023] Figure 2 This is a flowchart of the first part of an embodiment of another application scenario of the present disclosure;

[0024] Figure 3 This is a flowchart of the second part of an embodiment of the present disclosure in another application scenario;

[0025] Figure 4 It is a schematic diagram of the structure of the control system of the front and rear wheels of the embodiment of the present disclosure;

[0026] Figure 5 It is a schematic diagram of the structure of an electronic device according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0027] In order to make the objectives, technical solutions and advantages of the present disclosure more clearly understood, the present disclosure is further described in detail below in combination with specific embodiments and with reference to the accompanying drawings.

[0028] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present disclosure should be understood by people with ordinary skills in the field to which the present disclosure belongs. The "first", "second" and similar words used in the embodiments of the present disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. "Including" or "comprising" and similar words mean that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0029] As mentioned above, during vehicle driving, especially when driving on a curve, there is a problem of wheel slippage, understeering or oversteering of the vehicle due to factors such as excessive vehicle speed or changes in tire adhesion.

[0030] Based on the above description, if Figure 1As shown, the control method of the front and rear wheels proposed in this embodiment includes:

[0031] Step 101, obtaining vehicle information; wherein the vehicle information includes an actual deflection angle of the front wheels.

[0032] In a specific implementation, vehicle information is obtained, and the vehicle information includes basic vehicle information and vehicle operation information, wherein the basic vehicle information includes at least one of the following: vehicle mass or vehicle tire information, and the vehicle operation information includes at least one of the following: vehicle turning angle information, vehicle running speed, or vehicle gear information. There are many ways to obtain vehicle information, for example, corresponding vehicle operation information can be collected through corresponding sensors.

[0033] In the above scheme, the rear wheel deflection direction is judged based on the acquired vehicle information, which improves the accuracy of the judgment. At the same time, the rear wheel deflection angle is obtained based on the rear wheel deflection direction and subsequent calculations, so that the vehicle deflection can be adjusted by adjusting the rear wheels of the vehicle, thereby improving the stability of the vehicle during driving.

[0034] Step 102, processing the actual deflection angle of the front wheel to obtain the expected deflection angle of the front wheel, and controlling the front wheels of the vehicle according to the expected deflection angle of the front wheel.

[0035] In specific implementation, the vehicle information obtained includes the actual deflection angle of the front wheel, and the front wheel angle control coefficient is obtained. The desired deflection angle of the front wheel is obtained by calculating and processing the actual deflection angle of the front wheel and the front wheel angle control coefficient. Among them, the actual deflection angle of the front wheel is the deflection angle of the current front wheel of the vehicle obtained through the steering wheel; the front wheel angle control coefficient is a coefficient reflecting the relationship between the actual deflection angle of the front wheel and the desired deflection angle of the front wheel, which can be obtained by looking up a table and is related to the vehicle speed and the average slip rate of the front wheels of the vehicle or the average slip rate of the front wheels; the desired deflection angle of the front wheel is the deflection angle required by the front wheel when the front wheel is controlled in order to ensure the stability of the vehicle when the vehicle is turning.

[0036] In the above scheme, the desired deflection angle of the front wheel is calculated based on the actual deflection angle of the front wheel and the front wheel steering angle control coefficient. Then, the front wheels of the vehicle are controlled based on the calculated desired deflection angle of the front wheel, which is more accurate than directly controlling the front wheels of the vehicle through the steering wheel in the related art.

[0037] Step 103, judging the deflection direction of the rear wheels of the vehicle according to the vehicle information to obtain the deflection direction of the rear wheels.

[0038] In a specific implementation, the rear wheel deflection direction is determined based on the vehicle information to obtain the rear deflection direction, and the vehicle state is determined based on the vehicle information. In response to the vehicle being in an understeering state, it is determined that the rear wheels and the front wheels of the vehicle are deflected in the opposite direction; in response to the vehicle being in an oversteering state, it is determined that the rear wheels and the front wheels of the vehicle are deflected in the same direction.

[0039] In the above scheme, based on the rear wheel deflection direction and the subsequent calculation of the rear wheel deflection angle, the vehicle deflection is adjusted by adjusting the rear wheels of the vehicle, thereby improving the stability of the vehicle during driving.

[0040] Step 104 : using the desired front wheel steering angle, determining the rear wheel steering angle based on the yaw rate change rate, the vehicle center of mass sideslip angle and the vehicle lateral acceleration.

[0041] In a specific implementation, based on the vehicle front wheel expected deflection angle calculated above, the vehicle center of mass side slip angle function is calculated based on the vehicle two-degree-of-freedom model algorithm. The vehicle rear wheel deflection angle is obtained according to the vehicle front wheel expected deflection angle and the vehicle center of mass side slip angle function. According to the vehicle center of mass side slip angle function obtained above, in response to the parameter information meeting the preset conditions, the rear wheel deflection angle is obtained. Wherein, the preset conditions are that the yaw rate change rate is zero, the vehicle center of mass side slip angle is zero, and the vehicle lateral acceleration is zero.

[0042] In the above scheme, the vehicle center of mass slip angle function is calculated according to the vehicle two-degree-of-freedom model algorithm, and the vehicle rear wheel deflection angle is calculated based on the calculated front wheel expected deflection angle and the calculated vehicle center of mass slip angle function. The calculation result is more accurate, and the vehicle deflection is adjusted together with the rear wheel deflection direction determined in the above steps, thereby improving driving safety. When the yaw rate change rate and the center of mass slip angle both meet the pre-set conditions, the rear wheel deflection angle is obtained, making the calculated rear wheel deflection angle more accurate, thereby achieving precise control of the rear wheel. By adjusting and controlling the rear wheel, the driving smoothness is improved and the safety risk during driving is reduced.

[0043] Step 105: Control the front wheels of the vehicle according to the desired deflection angle of the front wheels, and control the rear wheels of the vehicle according to the rear wheel deflection direction and the rear wheel deflection angle.

[0044] During specific implementation, the desired deflection angle of the front wheel is sent to a controller to control the front wheel, and the rear wheel deflection direction and the rear wheel deflection angle are sent to a controller to control the rear wheel.

[0045] In the above scheme, the front wheels of the vehicle are controlled according to the desired deflection angle of the front wheels, and the rear wheels of the vehicle are controlled according to the deflection direction and the deflection angle of the rear wheels, so as to achieve coordinated control of the front and rear wheels of the vehicle.

[0046] In the above embodiment, the actual deflection angle of the front wheel is processed to obtain the expected deflection angle of the front wheel, and the front wheel of the vehicle is controlled according to the expected deflection angle of the front wheel, which is more accurate than directly controlling the front wheel of the vehicle through the steering wheel in the related art. The expected deflection angle of the front wheel is used to determine the deflection angle of the rear wheel based on the yaw rate change rate, the vehicle center of mass side slip angle and the vehicle lateral acceleration. When the yaw rate change rate, the center of mass side slip angle and the vehicle lateral acceleration all meet the pre-set conditions, the deflection angle of the rear wheel is determined, so that the obtained deflection angle of the rear wheel is more accurate, and the rear wheel can be adjusted and controlled more accurately. In the case of understeering or oversteering of the vehicle, through the above scheme, when the vehicle is turning, the deflection angles of the front and rear wheels are controlled and adjusted together, so that the vehicle is more stable when turning than when only the rear wheels are controlled, thereby improving the safety of driving.

[0047] In some embodiments, the vehicle information includes: vehicle speed, average front wheel slip rate, and average front wheel slip rate;

[0048] Step 102 includes:

[0049] Step 1021, obtain the front wheel angle control coefficient by querying the relationship table of vehicle speed, average front wheel slip rate and front wheel angle control coefficient; or obtain the front wheel angle control coefficient by querying the relationship table of vehicle speed, average front wheel slip rate and front wheel angle control coefficient.

[0050] Step 1022, performing calculation processing based on the front wheel steering angle control coefficient and the actual front wheel deflection angle to obtain the expected front wheel deflection angle:

[0051] δ1=d*δ

[0052] Among them, δ1 is the expected deflection angle of the front wheel, d is the front wheel steering angle control coefficient, and δ is the actual deflection angle of the front wheel.

[0053] In specific implementation, when the vehicle is in a driving state, the vehicle information obtained includes the average slip rate of the front wheels. By querying the relationship table of vehicle speed, average slip rate of the front wheels and front wheel steering angle control coefficient, the front wheel steering angle control coefficient can be determined according to the vehicle speed and the average slip rate of the front wheels. For example, when the vehicle speed is zero and the average slip rate of the front wheels is -0.2%, the front wheel steering angle control coefficient is 0.8.

[0054] When the vehicle is in a braking state, the vehicle information obtained includes the average slip rate of the front wheels. By querying the relationship table of vehicle speed, average slip rate of the front wheels and front wheel steering angle control coefficient, the front wheel steering angle control coefficient can be determined according to the vehicle speed and the average slip rate of the front wheels. For example, when the vehicle speed is zero and the average slip rate of the front wheels is 0.2%, the front wheel steering angle control coefficient is 0.8.

[0055] According to the front wheel steering angle control coefficient and the actual front wheel deflection angle, the expected front wheel deflection angle is obtained:

[0056] δ1=d*δ

[0057] Among them, δ1 is the expected deflection angle of the front wheel, d is the front wheel steering angle control coefficient, and δ is the actual deflection angle of the front wheel.

[0058] The actual front wheel deflection angle is the current front wheel deflection angle of the vehicle obtained through the steering wheel; the front wheel angle control coefficient is a coefficient that reflects the relationship between the actual front wheel deflection angle and the expected front wheel deflection angle, which can be obtained by looking up a table and is related to the vehicle speed and the average slip rate of the vehicle's front wheels or the average slip rate of the front wheels; the expected front wheel deflection angle is the deflection angle required by the front wheel when controlling the front wheel in order to ensure the stability of the vehicle when turning.

[0059] In the above scheme, the desired deflection angle of the front wheel is calculated based on the actual deflection angle of the front wheel and the front wheel steering angle control coefficient. Then, the front wheels of the vehicle are controlled based on the calculated desired deflection angle of the front wheel, which is more accurate than directly controlling the front wheels of the vehicle through the steering wheel in the related art.

[0060] In some embodiments, step 102 includes:

[0061] Step 102A, obtaining the actual deflection angle of the front wheels of the turntable.

[0062] Step 102B, obtaining vehicle status information, and determining a front wheel compensation deflection angle according to the vehicle status information.

[0063] Step 102C, obtaining the desired deflection angle of the front wheel by processing the actual deflection angle of the front wheel and the compensated deflection angle of the front wheel.

[0064] In specific implementation, the actual deflection angle of the front wheel is obtained through the vehicle steering wheel, and the vehicle state information is analyzed and processed to determine the front wheel compensation deflection angle. The desired deflection angle of the front wheel is obtained by calculating and processing the actual deflection angle of the front wheel and the front wheel compensation deflection angle. Among them, the desired deflection angle of the front wheel is the front wheel deflection angle used for controlling and adjusting the vehicle.

[0065] In the above scheme, the expected deflection angle of the vehicle's front wheels is determined based on the actual deflection angle of the front wheels obtained by the steering wheel and the front wheel compensation deflection angle determined according to the vehicle status information, so that accurate control and adjustment of the front wheels can be achieved, which is more accurate than directly controlling the vehicle's front wheels through the steering wheel in related technologies.

[0066] In some embodiments, step 104 includes:

[0067] Step 104A, processing the desired front wheel deflection angle based on the rear wheel turning angle relationship function determined by the yaw rate change rate, the vehicle center of mass sideslip angle and the vehicle lateral acceleration to obtain the rear wheel deflection angle; wherein the rear wheel turning angle relationship function is obtained according to the vehicle two-degree-of-freedom model algorithm.

[0068] In specific implementation, a rear wheel turning angle relationship function is obtained according to a vehicle two-degree-of-freedom model algorithm, and the desired front wheel deflection angle is substituted into the rear wheel turning angle relationship function to obtain a first rear wheel deflection angle.

[0069] In some embodiments, before step 104, the method further includes:

[0070] Step 1041, obtaining a vehicle center of mass sideslip angle function based on a vehicle two-degree-of-freedom model algorithm, wherein the vehicle center of mass sideslip angle function includes a yaw rate change rate, a vehicle center of mass sideslip angle, and a vehicle lateral acceleration.

[0071] Step 1042, determining whether the yaw rate change rate, the vehicle center of mass sideslip angle and the vehicle lateral acceleration meet preset conditions, and obtaining a rear wheel turning angle relationship function according to the vehicle center of mass sideslip angle function and the expected front wheel deflection angle.

[0072] In specific implementation, when the vehicle is turning, due to the influence of the centripetal force, the tire of the vehicle has an additional side force, thereby generating a tire side slip angle, which in turn affects the center of mass side slip angle of the whole vehicle. The smaller the center of mass side slip angle is, the smaller the tendency of the tire to slide is, and the better the handling stability is. The vehicle center of mass side slip angle function is obtained based on the vehicle two-degree-of-freedom model algorithm. According to the vehicle center of mass side slip angle function obtained above, when the yaw rate change rate, the vehicle center of mass side slip angle and the vehicle lateral acceleration meet the preset conditions, the rear wheel turning angle relationship function is obtained. Among them, the preset conditions are that the yaw rate change rate is zero, the vehicle center of mass side slip angle is zero and the vehicle lateral acceleration is zero.

[0073] In the above scheme, the vehicle turning angle relationship function is obtained by calculating the vehicle center of mass sideslip angle function. During the execution of subsequent steps, the rear wheel deflection angle is calculated based on the vehicle turning angle relationship function, and the rear wheel deflection angle is more accurate.

[0074] In some embodiments, step 1041 includes:

[0075] Step 1041A, based on the vehicle two-degree-of-freedom model algorithm, obtain the vehicle center of mass sideslip angle function:

[0076]

[0077] Among them, m is the vehicle mass, a is the distance from the center of mass to the front axle, b is the distance from the center of mass to the rear axle, k1 is the cornering stiffness of the front axle, k2 is the cornering stiffness of the rear axle, u is the longitudinal vehicle speed, is the vehicle acceleration, β is the vehicle center of mass sideslip angle, ω r is the vehicle yaw angular velocity, is the vehicle yaw rate change rate, δ1 is the front wheel deflection angle, δ2 is the rear wheel deflection angle, I z is the rotational inertia of the vehicle.

[0078] During specific implementation, the vehicle center of mass sideslip angle function is obtained based on the vehicle two-degree-of-freedom model algorithm.

[0079] In the above scheme, the vehicle turning angle relationship function is obtained by calculating the vehicle center of mass sideslip angle function. During the execution of subsequent steps, the rear wheel deflection angle is calculated based on the vehicle turning angle relationship function, and the rear wheel deflection angle is more accurate.

[0080] In some embodiments, step 1042 includes:

[0081] Step 1042A, determining that the center of mass sideslip angle is zero, the vehicle lateral acceleration is zero, and the yaw rate change rate is zero, and obtaining the rear wheel deflection angle according to the vehicle center of mass sideslip angle function and the front wheel expected deflection angle:

[0082]

[0083] Where K is the deflection angle coefficient,

[0084] In specific implementation, the center of mass sideslip angle β is zero and the vehicle lateral acceleration is zero, the yaw rate of change Substitute zero into the vehicle's center of mass sideslip angle function to obtain the vehicle's rear wheel deflection angle.

[0085] In the above scheme, when the center of mass slip angle β is zero, the center of mass slip angle can be controlled within a stable working range, so that the rear wheel of the vehicle deflects to ensure the smoothness of the vehicle's driving. On the basis of the center of mass slip angle β being zero, the vehicle's yaw rate change rate It is also zero, which can further improve the stability of the vehicle when turning.

[0086] In some embodiments, step 103 includes:

[0087] Step 1031, judging the vehicle state according to the vehicle information, and determining the vehicle state.

[0088] In a specific implementation, the vehicle information includes vehicle gear information and acceleration information. The vehicle state is judged according to the gear information and the acceleration information to determine whether the vehicle is in a driving state or a braking state.

[0089] The vehicle acceleration information and gear information are obtained through internal vehicle sensors, and the vehicle state is determined based on the vehicle acceleration information and gear information, wherein the vehicle state refers to the state of the vehicle under different accelerations and different gears, including one of the following: forward drive state, forward braking state, reverse braking state or reverse drive state.

[0090] The vehicle acceleration is positive when it points to the front of the vehicle and negative when it points to the rear of the vehicle. In response to the gear information being the forward gear and the acceleration information being positive, the vehicle state is determined to be the forward driving state; in response to the gear information being the forward gear and the acceleration information being negative, the vehicle state is determined to be the forward braking state; in response to the gear information being the reverse gear and the acceleration information being positive, the vehicle state is determined to be the reverse braking state; in response to the gear information being the reverse gear and the acceleration information being negative, the vehicle state is determined to be the reverse driving state.

[0091] Step 1032, in response to determining that the vehicle state is a driving state, calculating the slip rate of the vehicle tire, and determining the rear wheel deflection direction according to the slip rate of the vehicle tire, wherein the slip rate of the vehicle tire includes: front wheel slip rate and rear wheel slip rate.

[0092] In specific implementation, the calculation process of the slip rate of the vehicle tire is as follows: obtaining the wheel speed of the vehicle tire, the rolling radius of the vehicle tire and the longitudinal speed of the vehicle; performing calculations on the wheel speed of the vehicle tire, the rolling radius of the vehicle tire and the longitudinal speed of the vehicle to obtain the slip rate of the vehicle tire, S = (ω·Ru) / (ω·R). Among them, S is the slip rate of the vehicle tire, ω is the wheel speed of the vehicle tire, R is the rolling radius of the vehicle tire, and u is the longitudinal speed of the vehicle.

[0093] Step 1033, in response to determining that the vehicle state is a braking state, calculating the slip rate of the vehicle tire, and determining the rear wheel deflection direction according to the slip rate of the vehicle tire, wherein the slip rate of the vehicle tire includes: a front wheel slip rate and a rear wheel slip rate.

[0094] In specific implementation, the calculation process of the slip rate of the vehicle tire is as follows: obtaining the wheel speed of the vehicle tire, the rolling radius of the vehicle tire and the longitudinal speed of the vehicle; performing calculations on the wheel speed of the vehicle tire, the rolling radius of the vehicle tire and the longitudinal speed of the vehicle to obtain the slip rate of the vehicle tire, K = (u-ω·R) / u. Among them, K is the slip rate of the vehicle tire, ω is the wheel speed of the vehicle tire, R is the rolling radius of the vehicle tire, and u is the longitudinal speed of the vehicle.

[0095] In the above scheme, the slip rate or the slip ratio of the vehicle wheel is calculated for subsequent determination of the deflection direction of the rear wheel, which makes the determination more accurate.

[0096] In some embodiments,

[0097] Step 1032 includes:

[0098] Step 1032A, in response to determining that the vehicle is in a driving state, when at least one front wheel slip rate satisfies a first front wheel slip rate condition, and at least one rear wheel slip rate satisfies a first rear wheel slip rate condition, the vehicle is in an understeering state, and the rear wheel deflection direction of the vehicle is opposite to the front wheel deflection direction.

[0099] Step 1032B, in response to determining that the vehicle is in a driving state, when at least one front wheel slip rate satisfies the front wheel second slip rate condition, and at least one rear wheel slip rate satisfies the rear wheel second slip rate condition, the vehicle is in an oversteering state, and the rear wheel deflection direction of the vehicle is the same as the front wheel deflection direction.

[0100] In specific implementation, the first slip rate condition of the front wheel is to first calculate that at least one front wheel slip rate is less than or equal to -10%, and then calculate at least one rear wheel slip rate is less than or equal to -10%; the second slip rate condition of the front wheel is to first calculate that at least one rear wheel slip rate is less than or equal to -10%, and then calculate at least one front wheel slip rate is less than or equal to -10%. For example, when the vehicle is in a driving state, when at least one front wheel slip rate is first calculated to be less than or equal to -10%, and then at least one rear wheel slip rate is calculated to be less than or equal to -10%, the rear wheel deflection direction of the vehicle is opposite to the front wheel. When at least one rear wheel slip rate is first calculated to be less than or equal to -10%, and then at least one front wheel slip rate is calculated to be less than or equal to -10%, the rear wheel deflection direction of the vehicle is the same direction as the front wheel.

[0101] Step 1033 includes:

[0102] Step 1033A, in response to determining that the vehicle is in a braking state, when at least one front wheel slip rate satisfies a first front wheel slip rate condition, and at least one rear wheel slip rate satisfies a first rear wheel slip rate condition, the vehicle is in an understeering state, and the rear wheel deflection direction of the vehicle is opposite to the front wheel.

[0103] Step 1033B, in response to determining that the vehicle is in a braking state, when at least one front wheel slip rate satisfies the front wheel second slip rate condition, and at least one rear wheel slip rate satisfies the rear wheel second slip rate condition, the vehicle is in an oversteering state, and the rear wheel deflection direction of the vehicle is the same as the front wheel.

[0104] In specific implementation, the first slip rate condition of the rear wheel is that at least one front wheel slip rate is greater than or equal to 10%, and the rear wheel slip rate is equal to 10%; the second slip rate condition of the rear wheel is that at least one rear wheel slip rate is greater than or equal to 10%, and the front wheel slip rate is equal to 10%. For example, when the vehicle is in a braking state, when at least one front wheel slip rate is greater than or equal to 10%, and the rear wheel slip rate is equal to 10%, the rear wheel deflection direction of the vehicle is opposite to the front wheel. When at least one rear wheel slip rate is greater than or equal to 10%, and the front wheel slip rate is equal to 10%, the rear wheel deflection direction of the vehicle is the same as the front wheel.

[0105] In the above scheme, based on the vehicle state, the slip rate or the slip ratio of the vehicle tire is calculated respectively, and the deflection direction of the vehicle rear wheel is determined according to the conditions satisfied by the slip rate or the slip ratio. According to the determined deflection direction of the vehicle rear wheel, the vehicle rear wheel is controlled to achieve the same direction deflection or the opposite direction deflection as the front wheel. When the deflection direction of the vehicle rear wheel is the opposite direction of the front wheel, the front of the vehicle can be prevented from sliding out in the tangent direction of the arc line; when the deflection direction of the vehicle rear wheel is the same direction as the front wheel, the rear of the vehicle can be prevented from sliding out in the tangent direction of the arc line, thereby reducing safety hazards.

[0106] In the above embodiment, the actual deflection angle of the front wheel is processed to obtain the expected deflection angle of the front wheel, and the front wheel of the vehicle is controlled according to the expected deflection angle of the front wheel, which is more accurate than directly controlling the front wheel of the vehicle through the steering wheel in the related art. The expected deflection angle of the front wheel is used to determine the deflection angle of the rear wheel based on the yaw rate change rate, the vehicle center of mass side slip angle and the vehicle lateral acceleration. When the yaw rate change rate, the center of mass side slip angle and the vehicle lateral acceleration all meet the pre-set conditions, the deflection angle of the rear wheel is determined, so that the obtained deflection angle of the rear wheel is more accurate, and the rear wheel can be adjusted and controlled more accurately. In the case of understeering or oversteering of the vehicle, through the above scheme, when the vehicle is turning, the deflection angles of the front and rear wheels are controlled and adjusted together, so that the vehicle is more stable when turning than when only the rear wheels are controlled, thereby improving the safety of driving.

[0107] During vehicle driving, preferably when the vehicle is driving on a curve, the state of the front wheels includes an out-of-control state or a non-out-of-control state.

[0108] In response to the tire force not breaking through the friction circle, it is determined that the front wheels of the vehicle are in a non-out-of-control state, and the steps of the above embodiment are executed to adjust the vehicle deflection by adjusting both the front wheels and the rear wheels of the vehicle.

[0109] The force information of the vehicle tires is obtained, and in response to the tire force breaking through the friction circle, it is determined that the front wheels of the vehicle are in an out-of-control state, and the process of step 103-step 104 described in the above embodiment is executed, and the deflection of the vehicle is adjusted by adjusting the deflection direction and the deflection angle of the rear wheels of the vehicle.

[0110] It should be noted that the embodiments of the present disclosure may be further described in the following manner:

[0111] Based on the same inventive concept, in response to the vehicle being in a driving state, another embodiment of the present disclosure in an application scenario is as follows: Figure 2 As shown, including:

[0112] Step 201, obtaining vehicle information.

[0113] In specific implementation, the vehicle information is monitored and acquired through the ECU (Electronic Control Unit), and the vehicle information includes basic vehicle information, vehicle operation information, vehicle front wheel steering angle information, etc., wherein the basic vehicle information includes vehicle mass, vehicle tire information, etc., and the vehicle operation information includes vehicle steering angle information, vehicle operating speed, vehicle gear information, etc., and the vehicle front wheel steering angle information is acquired through the steering wheel. Through the above scheme, based on the acquired vehicle information, the subsequent steps determine the direction of rear wheel deflection, thereby improving the accuracy of the determination.

[0114] Step 202, determining the vehicle gear information.

[0115] During specific implementation, the vehicle gear information is obtained through internal vehicle sensors, wherein the gear information includes forward gear (D gear) and reverse gear (R gear), which serves as a basis for subsequent determination of the direction of rear wheel deflection of the vehicle.

[0116] Step 203: determine the vehicle running state according to the vehicle longitudinal acceleration information.

[0117] In a specific implementation, the vehicle includes a speed sensor inside, and the longitudinal speed of the vehicle is collected by the vehicle speed sensor. The longitudinal acceleration of the vehicle is calculated according to the acquired longitudinal speed of the vehicle, and the running state of the vehicle is judged according to the longitudinal acceleration information of the vehicle, and the running state of the vehicle includes a driving state and a braking state. Through the above scheme, the running state of the vehicle is judged according to the longitudinal acceleration information of the vehicle. In the subsequent steps, in response to the running state of the vehicle being the driving state, the slip rate of the vehicle wheel is calculated; in response to the running state of the vehicle being the braking state, the slip rate of the vehicle wheel is calculated, so as to judge the deflection direction of the rear wheel of the vehicle in the subsequent steps.

[0118] Step 204, calculating the slip rate of the vehicle wheel.

[0119] In specific implementation, the vehicle information is obtained through sensors, and the vehicle information includes wheel speed, tire rolling radius, longitudinal vehicle speed, gear information, vehicle acceleration information, etc. The vehicle includes a wheel speed sensor and a vehicle speed sensor, the wheel speed is collected by the wheel speed sensor, the longitudinal vehicle speed is collected by the vehicle speed sensor, the tire rolling radius map is obtained according to the drum test, and the tire rolling radius is determined according to the vehicle tire pressure and speed information. The slip rate or slip rate of the vehicle wheel is calculated according to the above vehicle information, and the deflection direction of the rear wheel is determined according to the calculated slip rate. The slip rate of the vehicle wheel is calculated by the following function:

[0120] S=(ω·Ru) / (ω·R)

[0121] Among them, S is the slip rate of the vehicle tire, ω is the wheel speed of the vehicle tire, R is the rolling radius of the vehicle tire, and u is the longitudinal speed of the vehicle.

[0122] Step 205: determining the rear wheel deflection direction according to the slip rate of the vehicle wheel.

[0123] In a specific implementation, the vehicle state is judged according to the calculated slip rate of the vehicle wheel, and the vehicle state refers to the running state of the vehicle in the current state, including understeering state and oversteering state. According to the above scheme, the rear wheel deflection direction is judged by the calculated slip rate, and the rear wheel deflection angle obtained in the following steps is used together to realize the control of the rear wheel of the vehicle, so that the judgment result is more accurate and the driving safety is improved.

[0124] In some embodiments, step 205 specifically includes:

[0125] Step 2051, in response to first calculating that the slip rate of at least one front wheel of the vehicle is less than or equal to -10%, and then calculating that the slip rate of at least one rear wheel of the vehicle is less than or equal to -10%, it is determined that the vehicle is in an understeering state and the rear wheel deflection direction is opposite to the front wheel deflection direction.

[0126] In specific implementation, by judging whether the slip rate of the vehicle wheels is satisfied, firstly calculating that the slip rate of at least one front wheel of the vehicle is less than or equal to -10%, and then calculating that the slip rate of at least one rear wheel of the vehicle is less than or equal to -10%, it is determined that the vehicle is in an understeering state, and the deflection direction of the rear wheels is determined to be opposite to the deflection direction of the front wheels, so as to calculate the rear wheel deflection angle in the subsequent steps, and control the rear wheels to adjust according to the deflection direction opposite to the front wheels and the rear wheel deflection angle, so as to avoid the front of the vehicle from slipping in the tangent direction of the arc line, thereby reducing safety hazards.

[0127] Step 2052, in response to first calculating that the slip rate of at least one rear wheel of the vehicle is less than or equal to -10%, and then calculating that the slip rate of at least one front wheel of the vehicle is less than or equal to -10%, it is determined that the vehicle is in an oversteering state, and the rear wheel deflection direction is the same as the front wheel deflection direction.

[0128] In specific implementation, by judging whether the slip rate of the vehicle wheels is satisfied, firstly calculating that the slip rate of at least one rear wheel of the vehicle is less than or equal to -10%, and then calculating that the slip rate of at least one front wheel of the vehicle is less than or equal to -10%, it is determined that the vehicle is in an oversteering state, and the rear wheel deflection direction is determined to be deflected in the same direction as the front wheel, so as to calculate the rear wheel deflection angle in the subsequent steps, and control the rear wheel to adjust according to the deflection direction deflected in the same direction as the front wheel and the rear wheel deflection angle, so as to avoid the vehicle rear end sliding out in the tangent direction of the arc line, thereby reducing safety hazards.

[0129] Step 2053, determining the rear wheel deflection direction according to the slip rate of the vehicle wheel.

[0130] In a specific implementation, the deflection direction of the rear wheel of the vehicle is determined by the calculated slip rate of the vehicle wheel, wherein the deflection direction includes deflection in the opposite direction to the front wheel and deflection in the same direction as the front wheel. In response to judging that the vehicle is in an understeering state according to the slip rate of the vehicle wheel, the deflection direction of the rear wheel is determined to be deflection in the opposite direction to the front wheel; in response to judging that the vehicle is in an oversteering state according to the slip rate of the vehicle wheel, the deflection direction of the rear wheel is determined to be deflection in the same direction as the front wheel, and the judgment result is more accurate.

[0131] Step 206, obtaining the actual deflection angle of the front wheel.

[0132] During specific implementation, the actual deflection angle of the front wheels of the vehicle is obtained through the vehicle steering wheel.

[0133] Step 207, calculating the expected deflection angle of the front wheels based on the actual deflection angle of the front wheels.

[0134] In specific implementation, the front wheel steering angle control coefficient and the actual front wheel deflection angle are calculated and processed to obtain the expected front wheel deflection angle:

[0135] δ1=d*δ

[0136] Among them, δ1 is the expected deflection angle of the front wheel, d is the front wheel steering angle control coefficient, and δ is the actual deflection angle of the front wheel.

[0137] The front wheel steering angle control coefficient is obtained by querying the relationship table between vehicle speed, front wheel average slip rate and front wheel steering angle control coefficient.

[0138] When the vehicle is in driving state, the vehicle information obtained includes the average slip rate of the front wheels. By querying the relationship table of vehicle speed, average slip rate of the front wheels and front wheel steering angle control coefficient, the front wheel steering angle control coefficient can be determined according to the vehicle speed and the average slip rate of the front wheels. For example, when the vehicle speed is zero and the average slip rate of the front wheels is -0.2%, the front wheel steering angle control coefficient is 0.8.

[0139] When the vehicle is in a braking state, the vehicle information obtained includes the average slip rate of the front wheels. By querying the relationship table of vehicle speed, average slip rate of the front wheels and front wheel steering angle control coefficient, the front wheel steering angle control coefficient can be determined according to the vehicle speed and the average slip rate of the front wheels. For example, when the vehicle speed is zero and the average slip rate of the front wheels is 0.2%, the front wheel steering angle control coefficient is 0.8.

[0140] In some embodiments, step 207 specifically includes:

[0141] Step 2071, calculating the rear wheel deflection angle based on the expected front wheel deflection angle.

[0142] During specific implementation, the vehicle operation information is obtained, and based on the vehicle two-degree-of-freedom model algorithm, the vehicle operation information is processed to obtain the vehicle center of mass sideslip angle function.

[0143] The vehicle operation information includes longitudinal vehicle speed u, vehicle acceleration Vehicle center of mass sideslip angle β, vehicle yaw rate ω r and the vehicle yaw rate of change Substitute the vehicle operation information into the vehicle two-degree-of-freedom model algorithm for calculation and processing to obtain the vehicle center of mass sideslip angle function:

[0144]

[0145] Where m is the vehicle mass, a is the distance from the center of mass to the front axle, b is the distance from the center of mass to the rear axle, k1 is the cornering stiffness of the front axle, k2 is the cornering stiffness of the rear axle, δ1 is the front wheel deflection angle, δ2 is the rear wheel deflection angle, I Z is the rotational inertia of the vehicle.

[0146] Set the sideslip angle β to zero and the lateral acceleration of the vehicle is zero, the yaw rate of change Substitute zero into the vehicle's center of mass sideslip angle function to obtain the vehicle's rear wheel deflection angle:

[0147]

[0148] When the center of mass slip angle β is zero, the center of mass slip angle can be controlled within a stable working range, so that the rear wheel of the vehicle deflects to ensure the smoothness of the vehicle's driving. On the basis of the center of mass slip angle β being zero, the vehicle's yaw rate change rate It is also zero, which can further improve the stability of the vehicle when turning.

[0149] Step 2072: Control the front wheels of the vehicle according to the desired deflection angle of the front wheels.

[0150] During specific implementation, the desired deflection angle of the front wheel is sent to a controller, and the controller controls the front wheels of the vehicle based on the control information, thereby improving driving smoothness and reducing safety risks during driving.

[0151] Step 208: Control the rear wheels of the vehicle according to the rear wheel deflection direction and the rear wheel deflection angle.

[0152] During specific implementation, the rear wheel deflection direction and the rear wheel deflection angle are sent to a controller, and the controller controls the rear wheels of the vehicle based on the control information, wherein the control information includes the rear wheel deflection direction and the rear wheel deflection angle, thereby improving driving smoothness and reducing safety risks during driving.

[0153] Based on the same inventive concept, in response to the vehicle being in a braking state, another embodiment of the present disclosure in an application scenario is as follows: Figure 3 As shown, including:

[0154] Step 301, obtaining vehicle information.

[0155] In specific implementation, the vehicle information is monitored and acquired through the ECU (Electronic Control Unit), and the vehicle information includes basic vehicle information, vehicle operation information, vehicle front wheel steering angle information, etc., wherein the basic vehicle information includes vehicle mass, vehicle tire information, etc., and the vehicle operation information includes vehicle steering angle information, vehicle operating speed, vehicle gear information, etc., and the vehicle front wheel steering angle information is acquired through the steering wheel. Through the above scheme, based on the acquired vehicle information, the subsequent steps determine the direction of rear wheel deflection, thereby improving the accuracy of the determination.

[0156] Step 302, determining the vehicle gear information.

[0157] During specific implementation, the vehicle gear information is obtained through internal vehicle sensors, wherein the gear information includes forward gear (D gear) and reverse gear (R gear), which serves as a basis for subsequent determination of the direction of rear wheel deflection of the vehicle.

[0158] Step 303: determine the vehicle running state according to the vehicle longitudinal acceleration information.

[0159] In a specific implementation, the vehicle includes a speed sensor inside, and the longitudinal speed of the vehicle is collected by the vehicle speed sensor. The longitudinal acceleration of the vehicle is calculated according to the acquired longitudinal speed of the vehicle, and the running state of the vehicle is judged according to the longitudinal acceleration information of the vehicle, and the running state of the vehicle includes a driving state and a braking state. Through the above scheme, the running state of the vehicle is judged according to the longitudinal acceleration information of the vehicle. In the subsequent steps, in response to the running state of the vehicle being the driving state, the slip rate of the vehicle wheel is calculated; in response to the running state of the vehicle being the braking state, the slip rate of the vehicle wheel is calculated, so as to judge the deflection direction of the rear wheel of the vehicle in the subsequent steps.

[0160] Step 304: Calculate the slip rate of the vehicle wheel.

[0161] In specific implementation, the vehicle information is obtained through sensors, and the vehicle information includes wheel speed, tire rolling radius, longitudinal vehicle speed, gear information, vehicle acceleration information, etc. The vehicle includes a wheel speed sensor and a vehicle speed sensor, the wheel speed is collected by the wheel speed sensor, the longitudinal vehicle speed is collected by the vehicle speed sensor, the tire rolling radius map is obtained according to the drum test, and the tire rolling radius is determined according to the vehicle tire pressure and speed information. The slip rate or slip rate of the vehicle wheel is calculated based on the above vehicle information, and the rear wheel deflection direction is determined based on the calculated slip rate. The slip rate of the vehicle wheel is calculated by the following function:

[0162] K=(u-ω·R) / u

[0163] Among them, K is the slip rate of the vehicle tire, ω is the wheel speed of the vehicle tire, R is the rolling radius of the vehicle tire, and u is the longitudinal speed of the vehicle.

[0164] Step 305: determine the rear wheel deflection direction according to the slip rate of the vehicle wheel.

[0165] In a specific implementation, the vehicle state is judged according to the calculated slip rate of the vehicle wheel, and the vehicle state refers to the running state of the vehicle in the current state, including understeering state and oversteering state. According to the above scheme, the rear wheel deflection direction is judged by the calculated slip rate, and the rear wheel deflection angle obtained in the following steps is used together to realize the control of the rear wheel of the vehicle, so that the judgment result is more accurate and the driving safety is improved.

[0166] In some embodiments, step 305 specifically includes:

[0167] Step 3051, in response to calculating that at least one front wheel slip rate of the vehicle is greater than or equal to 10%, and the rear wheel slip rate of the vehicle is equal to 10%, it is determined that the vehicle is in an understeering state, and the rear wheel deflection direction is opposite to the front wheel deflection direction.

[0168] In specific implementation, by judging that the slip rate of the vehicle wheels satisfies that at least one of the front wheel slip rate of the vehicle is greater than or equal to 10%, and the slip rate of the rear wheel of the vehicle is equal to 10%, it is determined that the vehicle is in an understeering state, and the rear wheel deflection direction is determined to be opposite to the front wheel, so that the rear wheel deflection angle can be calculated in the subsequent steps, and the rear wheel is controlled to adjust according to the deflection direction opposite to the front wheel and the rear wheel deflection angle, so as to avoid the front of the vehicle slipping in the tangent direction of the arc line and reduce safety hazards.

[0169] Step 3052, in response to calculating that at least one rear wheel slip rate of the vehicle is greater than or equal to 10%, and the front wheel slip rate of the vehicle is equal to 10%, it is determined that the vehicle is in an oversteering state, and the rear wheel deflection direction is the same as the front wheel deflection direction.

[0170] In specific implementation, by judging that the slip rate of the vehicle wheels satisfies that at least one of the rear wheel slip rate of the vehicle is greater than or equal to 10%, and the slip rate of the front wheel of the vehicle is equal to 10%, it is determined that the vehicle is in an oversteering state, and the rear wheel deflection direction is determined to be the same as the front wheel deflection direction, so that the rear wheel deflection angle can be calculated in the subsequent steps, and the rear wheel is controlled to adjust according to the deflection direction of the same direction as the front wheel and the rear wheel deflection angle, so as to avoid the rear end of the vehicle slipping in the tangent direction of the arc line, thereby reducing safety hazards.

[0171] Step 3053, determining the rear wheel deflection direction according to the slip rate of the vehicle wheel.

[0172] In a specific implementation, the deflection direction of the rear wheel of the vehicle is determined by the calculated slip rate of the vehicle wheel, wherein the deflection direction includes deflection in the opposite direction to the front wheel and deflection in the same direction as the front wheel. In response to judging that the vehicle is in an understeering state according to the slip rate of the vehicle wheel, the deflection direction of the rear wheel is determined to be deflection in the opposite direction to the front wheel; in response to judging that the vehicle is in an oversteering state according to the slip rate of the vehicle wheel, the deflection direction of the rear wheel is determined to be deflection in the same direction as the front wheel, and the judgment result is more accurate.

[0173] Step 306, obtaining the actual deflection angle of the front wheel.

[0174] During specific implementation, the actual deflection angle of the front wheels of the vehicle is obtained through the vehicle steering wheel.

[0175] Step 307, calculating the expected deflection angle of the front wheels based on the actual deflection angle of the front wheels.

[0176] In specific implementation, the front wheel steering angle control coefficient and the actual front wheel deflection angle are calculated and processed to obtain the expected front wheel deflection angle:

[0177] δ1=d*δ

[0178] Among them, δ1 is the expected deflection angle of the front wheel, d is the front wheel steering angle control coefficient, and δ is the actual deflection angle of the front wheel.

[0179] The front wheel steering angle control coefficient is obtained by querying the relationship table between vehicle speed, front wheel average slip rate and front wheel steering angle control coefficient.

[0180] When the vehicle is in driving state, the vehicle information obtained includes the average slip rate of the front wheels. By querying the relationship table of vehicle speed, average slip rate of the front wheels and front wheel steering angle control coefficient, the front wheel steering angle control coefficient can be determined according to the vehicle speed and the average slip rate of the front wheels. For example, when the vehicle speed is zero and the average slip rate of the front wheels is -0.2%, the front wheel steering angle control coefficient is 0.8.

[0181] When the vehicle is in a braking state, the vehicle information obtained includes the average slip rate of the front wheels. By querying the relationship table of vehicle speed, average slip rate of the front wheels and front wheel steering angle control coefficient, the front wheel steering angle control coefficient can be determined according to the vehicle speed and the average slip rate of the front wheels. For example, when the vehicle speed is zero and the average slip rate of the front wheels is 0.2%, the front wheel steering angle control coefficient is 0.8.

[0182] In some embodiments, step 307 specifically includes:

[0183] Step 3071, calculating the rear wheel deflection angle based on the expected front wheel deflection angle.

[0184] During specific implementation, the vehicle operation information is obtained, and based on the vehicle two-degree-of-freedom model algorithm, the vehicle operation information is processed to obtain the vehicle center of mass sideslip angle function.

[0185] The vehicle operation information includes longitudinal vehicle speed u, vehicle acceleration Vehicle center of mass sideslip angle β, vehicle yaw rate ω r and the vehicle yaw rate of change Substitute the vehicle operation information into the vehicle two-degree-of-freedom model algorithm for calculation and processing to obtain the vehicle center of mass sideslip angle function:

[0186]

[0187] Where m is the vehicle mass, a is the distance from the center of mass to the front axle, b is the distance from the center of mass to the rear axle, k1 is the cornering stiffness of the front axle, k2 is the cornering stiffness of the rear axle, δ1 is the front wheel deflection angle, δ2 is the rear wheel deflection angle, I Z is the rotational inertia of the vehicle.

[0188] Set the sideslip angle β to zero and the lateral acceleration of the vehicle is zero, the yaw rate of change Substitute zero into the vehicle's center of mass sideslip angle function to obtain the vehicle's rear wheel deflection angle:

[0189]

[0190] When the center of mass slip angle β is zero, the center of mass slip angle can be controlled within a stable working range, so that the rear wheel of the vehicle deflects to ensure the smoothness of the vehicle's driving. On the basis of the center of mass slip angle β being zero, the vehicle's yaw rate change rate It is also zero, which can further improve the stability of the vehicle when turning.

[0191] Step 3072: Control the front wheels of the vehicle according to the desired deflection angle of the front wheels.

[0192] During specific implementation, the desired deflection angle of the front wheel is sent to a controller, and the controller controls the front wheels of the vehicle based on the control information, thereby improving driving smoothness and reducing safety risks during driving.

[0193] Step 208: Control the rear wheels of the vehicle according to the rear wheel deflection direction and the rear wheel deflection angle.

[0194] During specific implementation, the rear wheel deflection direction and the rear wheel deflection angle are sent to a controller, and the controller controls the rear wheels of the vehicle based on the control information, wherein the control information includes the rear wheel deflection direction and the rear wheel deflection angle, thereby improving driving smoothness and reducing safety risks during driving.

[0195] It should be noted that the method of the embodiment of the present disclosure can be performed by a single device, such as a computer or a server. The method of the present embodiment can also be applied in a distributed scenario and completed by multiple devices cooperating with each other. In the case of such a distributed scenario, one of the multiple devices can only perform one or more steps in the method of the embodiment of the present disclosure, and the multiple devices will interact with each other to complete the described method.

[0196] It should be noted that the above describes some embodiments of the present disclosure. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be performed in an order different from that in the above embodiments and still achieve the desired results. In addition, the processes depicted in the accompanying drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0197] Based on the same inventive concept, corresponding to any of the above-mentioned embodiments and methods, the present disclosure also provides a control system for front and rear wheels.

[0198] refer to Figure 4 , the control system of the front and rear wheels comprises:

[0199] The vehicle information acquisition module 401 is configured to acquire vehicle information; wherein the vehicle information includes an actual deflection angle of the front wheels;

[0200] The front wheel expected deflection angle acquisition module 402 is configured to process the actual front wheel deflection angle to obtain the front wheel expected deflection angle;

[0201] The rear wheel deflection direction acquisition module 403 is configured to determine the rear wheel deflection direction of the vehicle according to the vehicle information to obtain the rear wheel deflection direction;

[0202] The rear wheel deflection angle acquisition module 404 is configured to use the desired deflection angle of the front wheel to determine the rear wheel deflection angle based on the yaw rate change rate, the vehicle center of mass sideslip angle and the vehicle lateral acceleration;

[0203] The vehicle control module 405 is configured to control the front wheels of the vehicle according to the desired deflection angle of the front wheels, and to control the rear wheels of the vehicle according to the rear wheel deflection direction and the rear wheel deflection angle.

[0204] In some embodiments, the vehicle information includes: vehicle speed, average front wheel slip rate, and average front wheel slip rate;

[0205] The front wheel expected deflection angle acquisition module 402 includes:

[0206] The front wheel steering angle control coefficient acquisition unit is configured to obtain the front wheel steering angle control coefficient by querying a table of relationships among vehicle speed, average front wheel slip rate and front wheel steering angle control coefficient; or to obtain the front wheel steering angle control coefficient by querying a table of relationships among vehicle speed, average front wheel slip rate and front wheel steering angle control coefficient;

[0207] The front wheel desired deflection angle acquisition unit is configured to perform calculation processing according to the front wheel steering angle control coefficient and the actual front wheel deflection angle to obtain the front wheel desired deflection angle:

[0208] δ1=d*δ

[0209] Among them, δ1 is the expected deflection angle of the front wheel, d is the front wheel steering angle control coefficient, and δ is the actual deflection angle of the front wheel.

[0210] In some embodiments, the front wheel expected deflection angle acquisition module 402 includes:

[0211] A front wheel actual deflection angle acquisition unit, configured to acquire the front wheel actual deflection angle of the turntable;

[0212] A front wheel compensation deflection angle acquisition unit is configured to acquire vehicle state information and determine a front wheel compensation deflection angle according to the vehicle state information;

[0213] The front wheel expected deflection angle calculation unit is configured to obtain the front wheel expected deflection angle by processing the front wheel actual deflection angle and the front wheel compensation deflection angle.

[0214] In some embodiments, the rear wheel deflection angle acquisition module 404 includes:

[0215] The rear wheel steering angle acquisition unit is configured to process the desired front wheel steering angle based on the rear wheel steering angle relationship function determined by the yaw rate change rate, the vehicle center of mass sideslip angle and the vehicle lateral acceleration to obtain the rear wheel steering angle; wherein the rear wheel steering angle relationship function is obtained according to the vehicle two-degree-of-freedom model algorithm.

[0216] In some embodiments, before the rear wheel deflection angle acquisition module 404, the method further includes:

[0217] A center of mass sideslip angle function acquisition unit is configured to obtain a vehicle center of mass sideslip angle function based on a vehicle two-degree-of-freedom model algorithm, wherein the vehicle center of mass sideslip angle function includes a yaw rate change rate, a vehicle center of mass sideslip angle, and a vehicle lateral acceleration;

[0218] The rear wheel steering angle relationship function acquisition unit is configured to determine whether the yaw rate change rate, the vehicle center of mass sideslip angle and the vehicle lateral acceleration meet preset conditions, and obtain the rear wheel steering angle relationship function according to the vehicle center of mass sideslip angle function and the expected deflection angle of the front wheel.

[0219] In some embodiments, the center of mass sideslip angle function acquisition unit includes:

[0220] The center of mass sideslip angle function acquisition subunit is configured to obtain the vehicle center of mass sideslip angle function based on the vehicle two-degree-of-freedom model algorithm:

[0221]

[0222] Among them, m is the vehicle mass, a is the distance from the center of mass to the front axle, b is the distance from the center of mass to the rear axle, k1 is the cornering stiffness of the front axle, k2 is the cornering stiffness of the rear axle, u is the longitudinal vehicle speed, is the vehicle acceleration, β is the vehicle center of mass sideslip angle, ω r is the vehicle yaw angular velocity, is the vehicle yaw rate change rate, δ1 is the front wheel deflection angle, δ2 is the rear wheel deflection angle, I Z is the rotational inertia of the vehicle.

[0223] In some embodiments, the rear wheel turning angle relationship function acquisition unit includes:

[0224] The rear wheel steering angle relationship function acquisition subunit is configured to determine that the center of mass sideslip angle is zero, the vehicle lateral acceleration is zero, and the yaw rate change rate is zero, and obtain the rear wheel deflection angle according to the vehicle center of mass sideslip angle function and the front wheel expected deflection angle:

[0225]

[0226] In some embodiments, the rear wheel deflection direction acquisition module 303 includes:

[0227] A vehicle state determination unit is configured to determine the vehicle state according to the vehicle information;

[0228] a slip rate calculation unit, configured to calculate the slip rate of the vehicle tire in response to determining that the vehicle state is a driving state, and determine the rear wheel deflection direction according to the slip rate of the vehicle tire, wherein the slip rate of the vehicle tire includes: a front wheel slip rate and a rear wheel slip rate; or

[0229] The slip ratio calculation unit is configured to calculate the slip ratio of the vehicle tire in response to determining that the vehicle state is a braking state, and determine the rear wheel deflection direction according to the slip ratio of the vehicle tire, wherein the slip ratio of the vehicle tire includes: a front wheel slip ratio and a rear wheel slip ratio.

[0230] In some embodiments,

[0231] The slip calculation unit includes:

[0232] a reverse deflection judgment subunit, configured to, in response to determining that the vehicle is in a driving state, when at least one front wheel slip rate satisfies a first front wheel slip rate condition, and at least one rear wheel slip rate satisfies a first rear wheel slip rate condition, determine that the vehicle is in an understeering state, and the rear wheel deflection direction of the vehicle is reverse to the front wheel deflection;

[0233] a same-direction deflection judgment subunit, configured to, in response to determining that the vehicle is in a driving state, when at least one front wheel slip rate satisfies a front wheel second slip rate condition, and at least one rear wheel slip rate satisfies a rear wheel second slip rate condition, determine that the vehicle is in an oversteering state, and the rear wheel deflection direction of the vehicle is the same as that of the front wheel;

[0234] The slip rate calculation unit includes:

[0235] a reverse deflection judgment subunit, configured to, in response to determining that the vehicle is in a braking state, when at least one front wheel slip rate satisfies a first front wheel slip rate condition, and at least one rear wheel slip rate satisfies a first rear wheel slip rate condition, determine that the vehicle is in an understeering state, and the rear wheel deflection direction of the vehicle is reverse to the front wheel;

[0236] The same-direction deflection judgment subunit is configured to respond to determining that the vehicle is in a braking state, at least one front wheel slip rate satisfies the front wheel second slip rate condition, and at least one rear wheel slip rate satisfies the rear wheel second slip rate condition, the vehicle is in an oversteering state, and the rear wheel deflection direction of the vehicle is the same as the front wheel.

[0237] For the convenience of description, the above device is described by dividing it into various modules according to its functions. Of course, when implementing the present disclosure, the functions of each module can be implemented in the same or multiple software and / or hardware.

[0238] The device of the above embodiment is used to implement the corresponding front and rear wheel control method in any of the above embodiments, and has the beneficial effects of the corresponding method embodiment, which will not be repeated here.

[0239] Based on the same inventive concept, corresponding to any of the above-mentioned embodiments and methods, the present disclosure also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the front and rear wheel control method described in any of the above embodiments is implemented.

[0240] Figure 5 A more specific schematic diagram of the hardware structure of an electronic device provided in this embodiment is shown, and the device may include: a processor 1010, a memory 1020, an input / output interface 1030, a communication interface 1040, and a bus 1050. The processor 1010, the memory 1020, the input / output interface 1030, and the communication interface 1040 are connected to each other through the bus 1050 in the device.

[0241] The processor 1010 can be implemented by a general-purpose CPU (Central Processing Unit), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits, and is used to execute relevant programs to implement the technical solutions provided in the embodiments of this specification.

[0242] The memory 1020 may be implemented in the form of ROM (Read Only Memory), RAM (Random Access Memory), static storage device, dynamic storage device, etc. The memory 1020 may store an operating system and other application programs. When the technical solutions provided in the embodiments of this specification are implemented by software or firmware, the relevant program codes are stored in the memory 1020 and are called and executed by the processor 1010.

[0243] The input / output interface 1030 is used to connect the input / output module to realize information input and output. The input / output module can be configured in the device as a component (not shown in the figure), or it can be externally connected to the device to provide corresponding functions. The input device may include a keyboard, a mouse, a touch screen, a microphone, various sensors, etc., and the output device may include a display, a speaker, a vibrator, an indicator light, etc.

[0244] The communication interface 1040 is used to connect a communication module (not shown in the figure) to realize communication interaction between the device and other devices. The communication module can realize communication through a wired mode (such as USB (Universal Serial Bus), network cable, etc.), or through a wireless mode (such as mobile network, WIFI (Wireless Fidelity), Bluetooth, etc.).

[0245] The bus 1050 includes a path that transmits information between the various components of the device (eg, the processor 1010, the memory 1020, the input / output interface 1030, and the communication interface 1040).

[0246] It should be noted that, although the above device only shows the processor 1010, the memory 1020, the input / output interface 1030, the communication interface 1040 and the bus 1050, in the specific implementation process, the device may also include other components necessary for normal operation. In addition, it can be understood by those skilled in the art that the above device may also only include the components necessary for implementing the embodiments of the present specification, and does not necessarily include all the components shown in the figure.

[0247] The electronic device of the above embodiment is used to implement the corresponding front and rear wheel control method in any of the above embodiments, and has the beneficial effects of the corresponding method embodiment, which will not be repeated here.

[0248] Based on the same inventive concept, corresponding to any of the above-mentioned embodiment methods, the present disclosure also provides a non-transitory computer-readable storage medium, wherein the non-transitory computer-readable storage medium stores computer instructions, and the computer instructions are used to enable the computer to execute the front and rear wheel control method as described in any of the above embodiments.

[0249] The computer-readable medium of this embodiment includes permanent and non-permanent, removable and non-removable media, and information storage can be implemented by any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, read-only compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device.

[0250] The computer instructions stored in the storage medium of the above embodiment are used to enable the computer to execute the front and rear wheel control method as described in any of the above embodiments, and have the beneficial effects of the corresponding method embodiments, which will not be repeated here.

[0251] Based on the same inventive concept, corresponding to any of the above-mentioned embodiments and methods, the present application also provides a vehicle, including a control system for the front and rear wheels, or an electronic device, or a storage medium in the above-mentioned embodiments, and the vehicle equipment implements the front and rear wheel control method described in any of the above embodiments.

[0252] The vehicle of the above embodiment is used to implement the front and rear wheel control method described in any of the above embodiments, and has the beneficial effects of the corresponding method embodiments, which will not be repeated here.

[0253] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of the present disclosure (including the claims) is limited to these examples. Based on the concept of the present disclosure, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of the different aspects of the embodiments of the present disclosure as described above, which are not provided in detail for the sake of simplicity.

[0254] In addition, to simplify the description and discussion, and in order not to make the embodiments of the present disclosure difficult to understand, the known power / ground connections to the integrated circuit (IC) chips and other components may or may not be shown in the provided figures. In addition, the device can be shown in the form of a block diagram to avoid making the embodiments of the present disclosure difficult to understand, and this also takes into account the fact that the details of the implementation of these block diagram devices are highly dependent on the platform on which the embodiments of the present disclosure will be implemented (that is, these details should be fully within the scope of understanding of those skilled in the art). Where specific details (e.g., circuits) are set forth to describe exemplary embodiments of the present disclosure, it is apparent to those skilled in the art that the embodiments of the present disclosure can be implemented without these specific details or with changes in these specific details. Therefore, these descriptions should be considered illustrative rather than restrictive.

[0255] Although the present disclosure has been described in conjunction with specific embodiments of the present disclosure, many replacements, modifications and variations of these embodiments will be apparent to those skilled in the art from the foregoing description. For example, other memory architectures (e.g., dynamic RAM (DRAM)) may use the embodiments discussed.

[0256] The embodiments of the present disclosure are intended to cover all such substitutions, modifications and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the embodiments of the present disclosure should be included in the scope of protection of the present disclosure.

Claims

1. A method for controlling front and rear wheels, characterized in that: The method comprises: Acquiring vehicle information; wherein the vehicle information includes an actual deflection angle of the front wheels; Processing the actual deflection angle of the front wheel to obtain a desired deflection angle of the front wheel; Determining the rear wheel deflection direction of the vehicle according to the vehicle information to obtain the rear wheel deflection direction; Determining the rear wheel yaw angle based on the desired front wheel yaw angle, the vehicle center of mass sideslip angle and the vehicle lateral acceleration; The front wheels of the vehicle are controlled according to the desired deflection angle of the front wheels, and the rear wheels of the vehicle are controlled according to the rear wheel deflection direction and the rear wheel deflection angle.

2. The method according to claim 1, characterized in that The vehicle information includes: vehicle speed, average front wheel slip rate and average front wheel slip rate; The processing of the actual deflection angle of the front wheel to obtain the expected deflection angle of the front wheel includes: By querying the relationship table of vehicle speed, average front wheel slip rate and front wheel steering angle control coefficient, the front wheel steering angle control coefficient is obtained; or, by querying the relationship table of vehicle speed, average front wheel slip rate and front wheel steering angle control coefficient, the front wheel steering angle control coefficient is obtained; The desired deflection angle of the front wheel is obtained by processing the front wheel steering angle control coefficient and the actual deflection angle of the front wheel: δ1=d*δ Among them, δ1 is the expected deflection angle of the front wheel, d is the front wheel steering angle control coefficient, and δ is the actual deflection angle of the front wheel.

3. The method according to claim 1, characterized in that The processing of the actual deflection angle of the front wheel to obtain the expected deflection angle of the front wheel includes: Get the actual deflection angle of the front wheel of the turntable; Acquiring vehicle status information, and determining a front wheel compensation deflection angle according to the vehicle status information; The desired deflection angle of the front wheel is obtained by processing the actual deflection angle of the front wheel and the compensated deflection angle of the front wheel.

4. The method according to claim 1, characterized in that: The method of using the expected front wheel deflection angle to determine the rear wheel deflection angle based on the yaw rate change rate, the vehicle center of mass sideslip angle and the vehicle lateral acceleration includes: The desired deflection angle of the front wheel is processed based on the rear wheel turning angle relationship function determined by the yaw rate change rate, the vehicle center of mass sideslip angle and the vehicle lateral acceleration to obtain the rear wheel deflection angle; wherein the rear wheel turning angle relationship function is obtained according to the vehicle two-degree-of-freedom model algorithm.

5. The method according to claim 1, characterized in that Before the rear wheel steering angle relationship function determined based on the yaw rate change rate, the vehicle center of mass sideslip angle and the vehicle lateral acceleration is processed to obtain the rear wheel steering angle, the method further includes: Obtaining a vehicle center of mass sideslip angle function based on a vehicle two-degree-of-freedom model algorithm, wherein the vehicle center of mass sideslip angle function includes a yaw rate change rate, a vehicle center of mass sideslip angle, and a vehicle lateral acceleration; It is determined that the yaw rate change rate, the vehicle center of mass sideslip angle and the vehicle lateral acceleration meet preset conditions, and a rear wheel turning angle relationship function is obtained according to the vehicle center of mass sideslip angle function and the expected front wheel deflection angle.

6. The method according to claim 5, characterized in that The vehicle center of mass sideslip angle function is obtained based on the vehicle two-degree-of-freedom model algorithm, including: Based on the vehicle two-degree-of-freedom model algorithm, the vehicle center of mass sideslip angle function is obtained: Among them, m is the vehicle mass, a is the distance from the center of mass to the front axle, b is the distance from the center of mass to the rear axle, k1 is the cornering stiffness of the front axle, k2 is the cornering stiffness of the rear axle, u is the longitudinal vehicle speed, is the vehicle acceleration, β is the vehicle center of mass sideslip angle, ω r is the vehicle yaw angular velocity, is the vehicle yaw rate change rate, δ1 is the front wheel deflection angle, δ2 is the rear wheel deflection angle, I Z is the rotational inertia of the vehicle.

7. The method according to claim 6, characterized in that The determining that the yaw rate change rate, the vehicle center of mass sideslip angle, and the vehicle lateral acceleration meet a preset condition, and obtaining a rear wheel turning angle relationship function according to the vehicle center of mass sideslip angle function and the front wheel expected deflection angle, includes: Determine that the center of mass sideslip angle is zero, the vehicle lateral acceleration is zero, and the yaw rate change rate is zero, and obtain the rear wheel deflection angle according to the vehicle center of mass sideslip angle function and the expected deflection angle of the front wheel:

8. The method according to claim 1, characterized in that The determining the rear wheel deflection direction of the vehicle according to the vehicle information to obtain the rear wheel deflection direction includes: Judging the vehicle state according to the vehicle information to determine the vehicle state; In response to determining that the vehicle state is a driving state, calculating the slip rate of the vehicle tire, and determining the rear wheel deflection direction according to the slip rate of the vehicle tire, wherein the slip rate of the vehicle tire includes: a front wheel slip rate and a rear wheel slip rate; or, In response to determining that the vehicle state is a braking state, a slip rate of a vehicle tire is calculated, and a rear wheel deflection direction is determined according to the slip rate of the vehicle tire, wherein the slip rate of the vehicle tire includes: a front wheel slip rate and a rear wheel slip rate.

9. The method according to claim 8, characterized in that In response to determining that the vehicle state is a driving state, calculating the slip rate of the vehicle tire, and determining the rear wheel deflection direction according to the slip rate of the vehicle tire, comprising: In response to determining that the vehicle is in a driving state, at least one front wheel slip rate satisfies a first front wheel slip rate condition, When at least one rear wheel slip rate satisfies the rear wheel first slip rate condition, the vehicle is in an understeering state, and the rear wheel deflection direction of the vehicle is opposite to the front wheel deflection direction; In response to determining that the vehicle is in a driving state, when at least one front wheel slip rate satisfies a second front wheel slip rate condition, and at least one rear wheel slip rate satisfies a second rear wheel slip rate condition, the vehicle is in an oversteering state, and the rear wheels of the vehicle deflect in the same direction as the front wheels; In response to determining that the vehicle state is a braking state, calculating the slip rate of the vehicle tire, and determining the rear wheel deflection direction according to the slip rate of the vehicle tire, comprising: In response to determining that the vehicle is in a braking state, when at least one front wheel slip rate satisfies a first front wheel slip rate condition, and at least one rear wheel slip rate satisfies a first rear wheel slip rate condition, the vehicle is in an understeering state, and the rear wheel deflection direction of the vehicle is opposite to that of the front wheel; In response to determining that the vehicle is in a braking state, when at least one front wheel slip rate satisfies a second front wheel slip rate condition, and at least one rear wheel slip rate satisfies a second rear wheel slip rate condition, the vehicle is in an oversteering state, and the rear wheel deflection direction of the vehicle is the same as that of the front wheel.

10. A control system for front and rear wheels, characterized in that: include: A vehicle information acquisition module is configured to acquire vehicle information; wherein the vehicle information includes an actual deflection angle of the front wheels; A front wheel expected deflection angle acquisition module is configured to process the actual front wheel deflection angle to obtain the front wheel expected deflection angle; A rear wheel deflection direction acquisition module is configured to determine the rear wheel deflection direction of the vehicle according to the vehicle information to obtain the rear wheel deflection direction; a rear wheel deflection angle acquisition module, configured to determine the rear wheel deflection angle based on the desired deflection angle of the front wheel and the yaw rate change rate, the vehicle center of mass sideslip angle and the vehicle lateral acceleration; The vehicle control module is configured to control the front wheels of the vehicle according to the desired front wheel turning angle, and to control the rear wheels of the vehicle according to the rear wheel deflection direction and the rear wheel deflection angle.

11. An electronic device, characterized in that: The method comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the method according to any one of claims 1 to 9 is implemented.

12. A non-transitory computer-readable storage medium, characterized in that: The non-transitory computer-readable storage medium stores computer instructions, and the computer instructions are used to cause a computer to execute the method according to any one of claims 1 to 9.

13. A vehicle, characterized in that: The invention comprises the control system for front and rear wheels according to claim 10 or the electronic device according to claim 11 or the storage medium according to claim 12.

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