Torque control method, device and equipment and computer readable storage medium

Abstract

The invention provides a torque control method, device and equipment and a computer readable storage medium. The method comprises the steps that the current slip angle and the current yaw velocity of a target vehicle are obtained; according to the current slip angle, a preset expected slip angle, the current yaw velocity and a preset expected yaw velocity, a target sliding mode control function is solved, a target control quantity is obtained, and the target control quantity comprises a torque difference value of the left side and the right side of the target vehicle; the target sliding mode control function is obtained according to a target sliding mode surface function and a target reaching law function; and controlling the target vehicle according to the torque difference value. Compared with traditional PID control, the physical state and the physical characteristics of the vehicle meet the sliding mode control function, and the stability and the accuracy of torque control can be improved in the face of external interference or parameter change.

Description

Technical Field

[0001] Embodiments of the present invention relate to the field of torque control, and in particular, to a torque control method, device, equipment, and computer-readable storage medium. Background Art

[0002] With the popularity of electric vehicles, people have higher and higher requirements for driving controllability. During vehicle driving, in order to achieve precise steering of the vehicle, torque vector control is the key link to achieve stable driving control. At present, the products on the market mainly use proportional integral differential (PID) and other methods to determine the torque control during vehicle driving. However, this method has a high dependence on accurate system parameter settings, and the torque control is easily affected by parameter changes or external factors, and has the problem of poor stability. Summary of the invention

[0003] Embodiments of the present invention provide a torque control method, device, equipment and computer-readable storage medium, which improve the stability of torque control during vehicle driving.

[0004] In order to solve the above technical problems, the first aspect of the present invention provides a torque control method, comprising:

[0005] Obtaining a current sideslip angle of a target vehicle and a current yaw rate of the target vehicle;

[0006] Solving a target sliding mode control function according to the current slip angle, the preset desired slip angle, the current yaw rate and the preset desired yaw rate to obtain a target control amount, wherein the target control amount includes a torque difference between the left and right sides of the target vehicle, and the target sliding mode control function is obtained according to a target sliding mode surface function and a target reaching law function;

[0007] The target vehicle is controlled according to the torque difference.

[0008] The present invention solves the target sliding mode control function by using the current slip angle, the preset desired slip angle, the current yaw rate and the preset desired yaw rate to obtain the target control quantity, which includes the torque difference between the left and right sides of the target vehicle, thereby realizing torque control of the target vehicle. Compared with the traditional PID control, the physical state and physical characteristics of the vehicle satisfy the sliding mode control function. When facing external interference or parameter changes, the slip angle and yaw rate of the vehicle are maintained within the range of stable operation according to the vehicle state (such as the current slip angle and the current yaw rate) and the preset parameters (such as the desired slip angle, the desired yaw rate, the relevant parameters of the target sliding mode surface function and the relevant parameters of the target approaching law function), thereby ensuring the stability of the torque control. At the same time, this method does not need to rely on accurate system parameter settings, can effectively reduce the influence of external interference or parameter changes on the torque control, and improve the robustness of the torque control. In addition, compared with the technical solutions of neural network or fuzzy control, the target sliding mode control function is solved to realize torque control, which has the characteristics of fast response, can shorten the response time and improve the hardware processing speed.

[0009] In some implementations of the first aspect, obtaining a current sideslip angle of the target vehicle includes:

[0010] Obtaining current lateral data, longitudinal data and front wheel turning angle of the target vehicle;

[0011] The preset dynamic equation of the target vehicle is solved according to the lateral data, the longitudinal data and the front wheel turning angle to obtain the current sideslip angle of the target vehicle.

[0012] This implementation solves the preset dynamic equation through the current lateral data, longitudinal data and front wheel turning angle of the target vehicle to obtain the current sideslip angle of the target vehicle, which can be more consistent with the physical state and physical characteristics of the target vehicle and has higher accuracy than the current sideslip angle directly collected by the sensor.

[0013] In some implementations of the first aspect, solving the target sliding mode control function to obtain the target control amount includes:

[0014] Obtaining the target sliding surface function and the target reaching law function;

[0015] Discretizing the target reaching law function and the target sliding surface function to obtain a discretized reaching law function and a discretized sliding surface function;

[0016] Substitute the discretized reaching law function and the discretized sliding surface function into a preset discrete system and solve them to obtain the target control quantity.

[0017] In some implementations of the first aspect, obtaining the target sliding surface function includes:

[0018] Solving an initial sliding mode surface function according to the current slip angle, the preset desired slip angle, the current yaw rate, the preset desired yaw rate, and the initial sliding mode control parameter to determine a position of a system state point corresponding to the target vehicle on the sliding mode surface;

[0019] According to the position of the system state point on the sliding surface and in accordance with a first preset rule, a target sliding mode control parameter of the sliding surface function is determined to obtain a target sliding surface function.

[0020] In some implementations of the first aspect, the target sliding surface function includes:

[0021]

[0022] Wherein, S is the target sliding surface, C1 is the first sliding mode control parameter, C2 is the second sliding mode control parameter, Δβ is the difference between the current sideslip angle and the preset desired sideslip angle, Δω is the difference between the current yaw angular velocity and the preset desired yaw angular velocity, and t is time.

[0023] In some implementations of the first aspect, obtaining the target reaching law function specifically includes:

[0024] Solving an initial sliding mode surface function according to the current slip angle, the preset desired slip angle, the current yaw rate, the preset desired yaw rate, and the initial sliding mode control parameter to determine a position of a system state point corresponding to the target vehicle on the sliding mode surface;

[0025] According to the position of the system state point on the sliding surface and in accordance with a second preset rule, a target reaching law parameter of the target reaching law function is determined to obtain the target reaching law function.

[0026] In some implementations of the first aspect, the target reaching law function includes:

[0027]

[0028] in, is the target reaching law function, S is the target sliding surface, ε is the first reaching law parameter, μ is the second reaching law parameter, and arctan is the inverse tangent function.

[0029] In some implementations of the first aspect, the target vehicle includes a left drive motor and a right drive motor; and controlling the target vehicle according to the torque difference includes:

[0030] Half of the torque difference is distributed to the left drive motor or the right drive motor to achieve control of the target vehicle.

[0031] This implementation distributes half of the solved torque difference to the left drive motor or the right drive motor, thereby meeting the actual torque difference requirement of the target vehicle and achieving effective torque distribution and control.

[0032] In some implementations of the first aspect, the target vehicle includes a left drive motor and a right drive motor; and controlling the target vehicle according to the torque difference includes:

[0033] Acquiring a torque limit value of the left drive motor and a torque limit value of the right drive motor;

[0034] According to the torque limit of the left drive motor and the torque limit of the right drive motor, the torque difference is distributed to the left drive motor and the right drive motor to achieve control of the target vehicle.

[0035] The second aspect of the present invention provides a torque control device, including an acquisition module, a solution module and a torque control module; wherein:

[0036] The acquisition module is used to acquire the current sideslip angle of the target vehicle and the current yaw rate of the target vehicle;

[0037] The solving module is used to solve the target sliding mode control function according to the current sideslip angle, the preset desired sideslip angle, the current yaw rate and the preset desired yaw rate to obtain a target control amount, wherein the target control amount includes a torque difference between the left and right sides of the target vehicle, and the target sliding mode control function is obtained according to a target sliding mode surface function and a target reaching law function;

[0038] The torque control module is used to control the target vehicle according to the torque difference.

[0039] In some implementations of the second aspect, the acquisition module includes a first acquisition unit, where the first acquisition unit is configured to:

[0040] Obtaining current lateral data, longitudinal data and front wheel turning angle of the target vehicle;

[0041] The preset dynamic equation of the target vehicle is solved according to the lateral data, the longitudinal data and the front wheel turning angle to obtain the current sideslip angle of the target vehicle.

[0042] In some implementations of the second aspect, the solution module includes a solution unit, and the solution unit is used to:

[0043] Obtaining the target sliding surface function and the target reaching law function;

[0044] Discretizing the target reaching law function and the target sliding surface function to obtain a discretized reaching law function and a discretized sliding surface function;

[0045] Substitute the discretized reaching law function and the discretized sliding surface function into a preset discrete system and solve them to obtain the target control quantity.

[0046] In some implementations of the second aspect, the solving unit includes a first obtaining subunit, and the first obtaining subunit is used to:

[0047] Solving an initial sliding mode surface function according to the current slip angle, the preset desired slip angle, the current yaw rate, the preset desired yaw rate, and the initial sliding mode control parameter to determine a position of a system state point corresponding to the target vehicle on the sliding mode surface;

[0048] According to the position of the system state point on the sliding surface and in accordance with a first preset rule, a target sliding mode control parameter of the sliding surface function is determined to obtain a target sliding surface function.

[0049] In some implementations of the second aspect, the target sliding surface function includes:

[0050]

[0051] Wherein, S is the target sliding surface, C1 is the first sliding mode control parameter, C2 is the second sliding mode control parameter, Δβ is the difference between the current sideslip angle and the preset desired sideslip angle, Δω is the difference between the current yaw angular velocity and the preset desired yaw angular velocity, and t is time.

[0052] In some implementations of the second aspect, the solving unit includes a second obtaining subunit, and the second obtaining subunit is used to:

[0053] Solving an initial sliding mode surface function according to the current slip angle, the preset desired slip angle, the current yaw rate, the preset desired yaw rate, and the initial sliding mode control parameter to determine a position of a system state point corresponding to the target vehicle on the sliding mode surface;

[0054] According to the position of the system state point on the sliding surface and in accordance with a second preset rule, a target reaching law parameter of the target reaching law function is determined to obtain the target reaching law function.

[0055] In some implementations of the second aspect, the target reaching law function includes:

[0056]

[0057] in, is the target reaching law function, S is the target sliding surface, ε is the first reaching law parameter, μ is the second reaching law parameter, and arctan is the inverse tangent function.

[0058] In some implementations of the second aspect, the target vehicle includes a left drive motor and a right drive motor; the torque control module includes a first control unit, and the first control unit is used to: distribute half of the torque difference to the left drive motor or the right drive motor to achieve control of the target vehicle.

[0059] In some implementations of the second aspect, the target vehicle includes a left drive motor and a right drive motor; the torque control module includes a second control unit, and the second control unit is used to: obtain the torque limit of the left drive motor and the torque limit of the right drive motor; according to the torque limit of the left drive motor and the torque limit of the right drive motor, distribute the torque difference to the left drive motor and the right drive motor to achieve control of the target vehicle.

[0060] The third aspect of the present application provides a torque control device, including a processor, a memory, a communication interface and a communication bus, wherein the processor, the memory and the communication interface communicate with each other through the communication bus; the memory is used to store at least one executable instruction, and the executable instruction enables the processor to perform the operation of the torque control method.

[0061] The fourth aspect of the present application provides a computer-readable storage medium, in which at least one executable instruction is stored. When the executable instruction is executed on a torque control device / apparatus, the torque control device / apparatus performs the operation of the torque control method. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 : A flow chart of the first embodiment of the torque control method provided in the present application.

[0063] Figure 2 : A flow chart of a second embodiment of the torque control method provided in the present application.

[0064] Figure 3 : A flow chart of the third embodiment of the torque control method provided in the present application.

[0065] Figure 4 : A schematic diagram of the principle of an embodiment of the sliding surface design provided in the present application.

[0066] Figure 5 : A flow chart of a preferred implementation of the third embodiment of the torque control method provided in the present application.

[0067] Figure 6 : A flow chart of the fourth embodiment of the torque control method provided in the present application.

[0068] Figure 7 : A flow chart of the fifth embodiment of the torque control method provided in the present application.

[0069] Figure 8 : A flow chart of the sixth embodiment of the torque control method provided in the present application.

[0070] Fig. 9 : A schematic structural diagram of an embodiment of a torque control device provided in the present application.

[0071] Fig.10 : A schematic structural diagram of an embodiment of a torque control device provided in the present application. DETAILED DESCRIPTION

[0072] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0073] Embodiment 1

[0074] According to relevant technical records, the products currently on the market mainly use a control method based on proportional integral derivative (PID). However, this method has a high dependence on accurate system parameter settings, and torque control is easily affected by parameter changes or external factors, and has problems such as poor stability and robustness.

[0075] In addition, the industry also uses control methods such as fuzzy control or neural network prediction, but these methods require a lot of calculations, have high requirements for hardware, and the advantage of response speed is not obvious.

[0076] To this end, in response to one or more of the above technical problems, an embodiment of the present application provides a torque control method, which solves a target sliding mode control function by using a current sideslip angle, a preset desired sideslip angle, a current yaw rate, and a preset desired yaw rate to obtain a target control quantity, wherein the target control quantity includes a torque difference between the left and right sides of the target vehicle, thereby achieving torque control of the target vehicle. Compared with traditional PID control, the physical state and physical characteristics of the vehicle satisfy the sliding mode control function. When facing external interference or parameter changes, the sliding mode control function is used according to the vehicle state (such as the current sideslip angle and the current yaw rate) and pre-set parameters (such as The method can maintain the vehicle's sideslip angle and yaw rate within the range of stable operation by using the desired sideslip angle, desired yaw rate, relevant parameters of the target sliding mode function and relevant parameters of the target reaching law function, thereby ensuring the stability of the torque control. At the same time, this method does not need to rely on precise system parameter settings, and can effectively reduce the impact of external interference or parameter changes on the torque control, thereby improving the robustness of the torque control. In addition, compared with the technical solutions of neural networks or fuzzy control, the target sliding mode control function is solved to achieve torque control, which has the characteristics of fast response, can shorten the response time and improve the hardware processing speed.

[0077] Figure 1 A flowchart of an embodiment of the torque control method provided by the present invention. The torque control method described in the embodiment of the present invention can be applied to a vehicle terminal, which can be a domain controller for controlling torque, and the domain controller is used to perform the operation of the torque control method described in the present invention.

[0078] like Figure 1 As shown, the method includes steps S101 to S103; each step is specifically as follows:

[0079] Step S101, obtaining a current sideslip angle of a target vehicle and obtaining a current yaw angular velocity of the target vehicle.

[0080] In this step, the target vehicle is provided with an inertial navigation system. When the target vehicle has a steering requirement, the current yaw angular velocity of the target vehicle can be acquired through the inertial navigation system.

[0081] Optionally, the target vehicle may also be provided with a preset type of sensor, and when the target vehicle has a steering demand, the current yaw angular velocity of the target vehicle may be acquired through the sensor.

[0082] It can be understood that the above-mentioned inertial navigation system can also be used to obtain lateral data of the vehicle, such as lateral acceleration; the inertial navigation system can also be used to obtain longitudinal data, such as longitudinal speed.

[0083] In some embodiments, the target vehicle may also be provided with a gyroscope, which may be used to collect vehicle status information including but not limited to the lateral velocity, longitudinal velocity, lateral acceleration, longitudinal acceleration and / or yaw rate of the target vehicle. The current yaw rate of this step may also be obtained in real time by the gyroscope.

[0084] Step S102, solving a target sliding mode control function according to the current sideslip angle, the preset desired sideslip angle, the current yaw rate and the preset desired yaw rate to obtain a target control variable.

[0085] In this step, the target control amount includes the torque difference between the left and right sides of the target vehicle, and the target sliding mode control function is obtained according to the target sliding mode surface function and the target reaching law function.

[0086] The expected sideslip angle and expected yaw rate described in this step are both preset values.

[0087] For the convenience of further description below, in this embodiment, the current slip angle is represented by β, the current yaw rate is represented by ω, and the desired slip angle is represented by β d , the desired yaw rate is expressed as ω d The difference between the current slip angle and the preset desired slip angle is expressed as Δβ=β-β d , the difference between the current yaw rate and the preset desired yaw rate is expressed as Δω=ω-ω d .

[0088] In order to achieve precise torque control during the driving of the target vehicle, the current slip angle β and the preset desired slip angle β are ideally d The difference Δβ between them is zero, and the preset desired sideslip angle β d is also zero, and the difference Δω between the current yaw rate and the preset desired yaw rate is zero.

[0089] By using the above-mentioned current slip angle, the preset desired slip angle, the current yaw rate and the preset desired yaw rate, the sliding mode control function is solved. Compared with the traditional PID control, the physical state and physical characteristics of the vehicle satisfy the sliding mode control function. When facing external interference or parameter changes, the vehicle's slip angle and yaw rate are maintained within the range of stable operation according to the vehicle state and pre-set parameters, which can effectively improve the robustness of the torque difference solution result.

[0090] Step S103: controlling the target vehicle according to the torque difference.

[0091] In this step, the torque difference is the torque difference between the left and right sides of the target vehicle, and the torque difference is obtained by the above target control amount. The target vehicle is controlled based on the torque difference to ensure that the sideslip angle and yaw rate of the vehicle are within the range of stable operation.

[0092] It should be noted that traditional technical solutions such as the above-mentioned PID control often rely on precise and large-scale system parameter settings, while this step can reduce the impact of external interference or parameter changes on the target vehicle through sliding mode control and limited parameter settings, thereby improving the robustness of torque control; on the other hand, traditional torque control solutions based on neural networks often rely on a large number of training data sets, and neural networks occupy a large amount of computing resources. It has been verified that the torque control method based on sliding mode control in this embodiment has the characteristics of rapid response compared to the technical solution of neural networks, which can reduce the occupation of computing resources and effectively shorten the response time, thereby improving the hardware processing speed.

[0093] exist Figure 1 Based on the embodiment shown, Figure 2 FIG. 1 shows a flow chart of step S101 provided in another embodiment of the present application. It should be noted that Figure 1 The same steps are not repeated here. Figure 2 As shown, step S101 includes step S201 and step S202, which are described in detail as follows:

[0094] Step S201, obtaining the current lateral data, longitudinal data and front wheel turning angle of the target vehicle.

[0095] Step S202: solving a preset dynamic equation of the target vehicle according to the lateral data, the longitudinal data and the front wheel turning angle to obtain a current sideslip angle of the target vehicle.

[0096] In this embodiment, the lateral data may include lateral velocity, lateral acceleration and / or lateral force, etc., and the longitudinal data may include longitudinal velocity, longitudinal acceleration and / or longitudinal force, etc.

[0097] Exemplarily, the lateral force and the longitudinal force may be obtained according to the magic formula of the tire model: F(x)=D·sin(C·arctan(B·xE(B·x-arctan(B·x))))+Sv.

[0098] Wherein, x is the independent variable, which can represent the tire's sideslip angle or longitudinal slip rate in different situations, B, D and E are coefficients, C is the curve shape factor and C determines whether the curve F(x) is a lateral force, longitudinal force or a restoring moment, and Sv is the horizontal offset value of the origin of the coordinate axis established considering the pseudo-side slip effect and pseudo-roll effect.

[0099] Furthermore, the kinetic equation also satisfies:

[0100] ma y =(F flX +F frX )*sinδ+(F flY +F frY )*cosδ+F rlX +F rrX .

[0101] Among them, F flX , F frX , F flY , F frY , F rlX and F rrX is the tire force. F flX Indicates the left positive longitudinal tire force, F frX Indicates the right positive longitudinal tire force, F flY Indicates the positive lateral tire force on the left side, F frY Indicates the right positive lateral tire force, F rlX represents the left reverse longitudinal tire force, F rrX represents the right reverse longitudinal tire force, a y is the lateral acceleration, δ is the front wheel turning angle, and m is the mass of the target vehicle. y The formula is part of the kinetic equation for the F obtained from the sensor or the magic formula above. flX , F frX , F flY , F frY , F rlX and F rrX The tire forces are combined with the lateral acceleration obtained by the inertial navigation to solve the front wheel turning angle of the target vehicle. In this step, the lateral data may also include the left positive lateral tire force and the right positive lateral tire force; the longitudinal data may include the left positive longitudinal tire force, the right positive longitudinal tire force, the left reverse longitudinal tire force and the right reverse longitudinal tire force.

[0102] Optionally, the above-mentioned dynamic equation, i.e., a seven-degree-of-freedom dynamic model, is established based on the yaw angular velocity, lateral acceleration, longitudinal velocity provided by the inertial navigation, the lateral force and longitudinal force calculated by the magic formula, and the current front wheel turning angle of the target vehicle. The dynamic model is pre-constructed before step S101, and the above-mentioned current sideslip angle can be obtained by solving the dynamic model.

[0103] It has been verified that although the current sideslip angle of the target vehicle can also be directly obtained through the sensor, there is a great deviation between the current sideslip angle directly obtained by the sensor and the actual sideslip angle. Therefore, this embodiment solves the preset dynamic equation of the target vehicle through the above-mentioned lateral data, longitudinal data and front wheel rotation angle, and the obtained current sideslip angle can be more consistent with the physical state and physical characteristics of the target vehicle than the prior art, and the obtained current sideslip angle also has higher accuracy.

[0104] exist Figure 1 Based on the embodiment shown, Figure 3 FIG. 2 shows a flow chart of step S102 provided in another embodiment of the present application. Figure 1 The same steps are not repeated here. Figure 3 As shown, step S102 includes steps S301 to S303, which are described in detail as follows:

[0105] Step S301, obtaining the target sliding surface function, obtaining the target reaching law function.

[0106] Step S302: discretize the target reaching law function and the target sliding surface function to obtain a discretized reaching law function and a discretized sliding surface function.

[0107] Step S303: Substitute the discretized reaching law function and the discretized sliding surface function into a preset discrete system, and solve them to obtain the target control variable.

[0108] In some optional embodiments, the controller of the target vehicle adopts a microcontroller unit (MCU). Therefore, before solving the sliding mode control function, this embodiment discretizes the target approach law function and the target sliding surface function, and substitutes the discretized approach law function and sliding surface function into a preset discrete system and solves them, so that the target control quantity can meet the characteristics of the microcontroller unit, thereby obtaining a more accurate target control quantity.

[0109] In some preferred embodiments, during the sliding mode control process, it is possible to consider adjusting the sliding mode control parameters and the reaching law parameters in real time according to the state of the target vehicle to obtain the target sliding mode control parameters and the target reaching law parameters, so as to further improve the accuracy and stability of the torque control of the target vehicle.

[0110] For example, Figure 4As shown, the system control point can be designed as (0,0), and the parameter adjustment can consider the area the current system is in. When the system is in the fast approach area, the overshoot area (which can also be understood as exceeding the sliding surface), the danger area or the rollback area, the vehicle may face understeering, oversteering and / or vehicle instability, so the parameters need to be designed accordingly in different areas.

[0111] Figure 4 The straight line corresponding to the linear function shown (for example ) is the objective function. The ideal control state of the vehicle is to control the system state point corresponding to the target vehicle on the objective function (the horizontal axis is The vertical axis x is only used as an example to facilitate the explanation of the technical solution).

[0112] When the vehicle starts torque control, the sliding mode control parameters and the reaching law parameters use initial values. In the subsequent torque control process, the initial sliding mode control parameters and the initial reaching law parameters can be updated according to the first preset rule and / or the second preset rule to obtain the target sliding mode control parameters and the target reaching law parameters, thereby obtaining the target sliding mode surface function and the target reaching law function.

[0113] In some embodiments, Figure 5 As shown, the step S301 of obtaining the target sliding surface function specifically includes steps S501 and S502, which are described in detail as follows:

[0114] Step S501, solving the initial sliding mode surface function according to the current sideslip angle, the preset desired sideslip angle, the current yaw rate, the preset desired yaw rate and the initial sliding mode control parameters, and determining the position of the system state point corresponding to the target vehicle on the sliding mode surface.

[0115] Step S502: According to the position of the system state point on the sliding surface and in accordance with a first preset rule, a target sliding mode control parameter of the sliding surface function is determined to obtain a target sliding surface function.

[0116] Exemplarily, the target sliding surface function can be designed as follows:

[0117]

[0118] Wherein, S is the target sliding surface, C1 is the first sliding mode control parameter, C2 is the second sliding mode control parameter, and t is time.

[0119] Based on the first preset rule, according to the current sideslip angle, the preset desired sideslip angle, the current yaw rate, the preset desired yaw rate and the initial sliding mode control parameters (initial values ​​of C1 and C2), the initial sliding mode surface function is solved to obtain S. At this time, according to the current sideslip angle β, the preset desired sideslip angle β d , the current yaw rate ω and the preset desired yaw rate ω d , we can get the two-dimensional independent variable [Δβ, Δω], and by combining it with the dependent variable S, we can determine the position of the system state point on the sliding surface ([Δβ, Δω], S).

[0120] When finding the position of the system state point on the sliding surface, for example, Figure 4 When the system needs to quickly approach the target yaw rate, it is possible to consider reducing the sliding mode control parameters (such as C1 and / or C2) to get closer to the target function. Figure 4 When the target vehicle is in the overshoot area shown, it may face the problem of oversteering. The yaw angle and / or sideslip angle have deviated. The system needs to fall back to the sliding surface. At this time, the parameter adjustment target does not need to be too aggressive to prevent large vibration on the sliding surface. At this time, try to control the parameters C1 and / or C2 within a smaller range. Figure 4 When the system enters the out-of-control area as shown, it is possible to consider increasing the sliding mode control parameters C1 and / or C2 in order to adjust the system state point back to the objective function.

[0121] exist Figure 3 Based on the embodiment shown, Figure 6 FIG. 2 shows a flow chart of step S102 provided in another embodiment of the present application. Figure 3 The same steps are not repeated here. Figure 6 As shown, step S301 includes steps S601 to S602, which are described in detail as follows:

[0122] Step S601, solving the initial sliding mode surface function according to the current sideslip angle, the preset desired sideslip angle, the current yaw rate, the preset desired yaw rate and the initial sliding mode control parameters, and determining the position of the system state point corresponding to the target vehicle on the sliding mode surface.

[0123] Step S602: According to the position of the system state point on the sliding surface and in accordance with a second preset rule, a target reaching law parameter of the target reaching law function is determined to obtain the target reaching law function.

[0124] Optionally, the target reaching law function may adopt an exponential reaching law For example Among them, ε is the first reaching law parameter, μ is the second reaching law parameter, sgn is the sign function. C1, C2, ε and μ are all adjustable parameters.

[0125] In addition, according to the control requirements of different application scenarios or different system characteristics, further expansion can be considered in the selection of sliding surface and reaching law. For example, in the selection of sliding surface, sliding surface based on adaptive, neural network, fuzzy sliding or integral sliding can be selected, and in the selection of reaching law, reaching law based on constant speed reaching law, exponential power reaching law or adaptive reaching law can be considered.

[0126] Considering that in some application scenarios, the vehicle physical system based on the above exponential approach law has a chattering problem on the sliding surface, in some preferred implementations, the sign function can be replaced with the inverse tangent function arctan(S), that is, The reaching law design based on the inverse tangent function can effectively reduce the above-mentioned jitter problem. In addition, the reaching law design can satisfy the Lyapunov function or Lyapunov function, thereby ensuring the convergence of the system in some scenarios.

[0127] For example, in Figure 4 In the fast approaching area shown in the figure, according to the second preset rule, you can consider increasing the approaching law parameters (such as ε and μ). In the overshoot area shown in the figure, control the approaching law parameters ε and μ to be adjusted in a small range as much as possible to prevent large vibration on the sliding surface; Figure 4 When the system is in the dangerous area shown in the figure, it is on the edge of "out of control" and the reaching law parameters should be adjusted quickly to pull the system state point back to the vicinity of the objective function. Figure 4 When the out-of-control area is shown, it means that the system of the target vehicle may be in an "out-of-control" state, and it is necessary to adjust the reaching law parameters (ε and / or μ) and / or the sliding mode control parameters (C1 and / or C2) in order to quickly pull the system back to the objective function.

[0128] It can be understood that in some embodiments, the above-mentioned reaching law parameters and sliding mode control parameters can be adjusted separately or simultaneously according to the target vehicle system state, that is, the first preset rule or the second preset rule is adopted alone, or the first preset rule and the second preset rule are adopted simultaneously to realize torque control, and the adjustment of the above-mentioned reaching law parameters and sliding mode control parameters is intelligently controlled by the vehicle controller.

[0129] In addition, in order to eliminate the parameter jump caused by the change of regions due to external influences at the intersection of various regions, this example designs a fusion region to fuse the reaching law parameters and sliding surface parameters of each region, avoid the occurrence of the above phenomenon, and achieve a smooth transition of the reaching law parameters and sliding surface parameters of different regions.

[0130] The target sliding mode control function designed based on the above-mentioned implementation methods needs to be input into the controller in step S103 to perform torque control on the target vehicle. Considering that the current controller adopts MCU (microcontroller unit), the continuous system needs to be discretized so as to complete the torque control of the target vehicle based on the controller.

[0131] Exemplarily, the target reaching law function can be discretized as: At the same time, the discretized sliding surface function S(k+1)=CX(k+1) is substituted into the discrete system X(k+1)=AX(k)+BU(k). Among them, ΔT is the time variation, A is the state matrix, B is the input matrix, k is the time, and X is the state variable. By solving the above discrete system, the target control quantity U(k) can be obtained.

[0132] In this process, the reaching law function is the derivative of the sliding surface function, which can reflect the rate of change of k at a certain moment on the sliding surface function with respect to the time change ΔT, that is, Substitute the sliding surface function with independent variables k and k-1 into the discrete system, for example, S(k+1)=CX(k+1)=C[AX(k)+BU(k)]. Similarly, for S(k), it is: S(k)=CX(k)=C[AX(k-1)+BU(k-1)].

[0133] At this time, substitute S(k+1) and S(k) into the discrete system into the reaching law function and εsgn(S(k))+μS(k). The result is an equation about X(k), U(k), C, A, and B. When X(k), C, A, and B are all known, the unknown quantity U(k) can be obtained, which is the target control quantity.

[0134] like Figure 7 As shown, in some preferred embodiments, the target vehicle includes a left drive motor and a right drive motor; step S103 specifically includes step S701, specifically:

[0135] Step S701: Distribute half of the torque difference to the left drive motor or the right drive motor to control the target vehicle.

[0136] For example, when the torque difference U(k) is obtained, it can be distributed to the left and right motors according to the following formula: left =Tq rig h t ±0.5U(k). Where, Tqleft is the left motor torque, Tq right is the right motor torque.

[0137] Thus, the torque control of the target vehicle meets the adjustment requirements of the vehicle state, so that the current sideslip angle and the current yaw rate of the target vehicle tend to the ideal state.

[0138] like Figure 8 As shown, considering that the capacity of one side of the motor is limited, in some preferred embodiments, it can be further considered to add torque transfer in the torque control process. For example, step S103 also includes steps S801 to S802, each of which specifically includes:

[0139] Step S801, obtaining the torque limit value Tq of the left drive motor letotal and the torque limit Tq of the right drive motor ritotal .

[0140] Step S802: according to the torque limit value Tq of the left drive motor letotal and the torque limit Tq of the right drive motor ritotal , distribute the torque difference to the left drive motor and the right drive motor to achieve control of the target vehicle.

[0141] For example, when the target control amount, i.e., the torque difference, is 100, the torques to be allocated to the left drive motor and the right drive motor are +50 and -50 respectively. letotal When the torque limit is +30, the left drive motor can be controlled to work at the above torque limit of +30, while the right drive motor works at a torque of -70. At this time, it can be ensured that the torque difference between the two motors (i.e., the target control amount) is 100 unchanged.

[0142] For example, Tq left =Tq right ±(Tq letotal -Tq left ).

[0143] Or: Tq right =Tq left ±(Tq ritotal -Tq right ).

[0144] Among them, Tq letotal Refers to the left motor torque limit, Tq ritotal Refers to the right motor torque limit.

[0145] In addition to the above-mentioned torque distribution to the left and right motors, the torque distribution of the motors corresponding to the four wheels can also be considered based on factors such as economic cost.

[0146] For example, according to the vertical load of the four wheels, the torque distribution of the front and rear wheels is realized, and then according to the torque control method of the embodiment of the present application, the torque distribution of the left and right motors is realized.

[0147] In addition, please refer to Fig. 9 An embodiment of the present invention also provides a torque control device 900, including an acquisition module 901, a solution module 902 and a torque control module 903; wherein,

[0148] The acquisition module 901 is used to acquire the current sideslip angle of the target vehicle and the current yaw angular velocity of the target vehicle.

[0149] The solving module 902 is used to solve the target sliding mode control function according to the current sideslip angle, the preset desired sideslip angle, the current yaw angular velocity and the preset desired yaw angular velocity to obtain a target control quantity, wherein the target control quantity includes the torque difference between the left and right sides of the target vehicle, and the target sliding mode control function is obtained according to a target sliding mode surface function and a target reaching law function.

[0150] The torque control module 903 is used to control the target vehicle according to the torque difference.

[0151] In some preferred embodiments, the acquisition module 901 includes a first acquisition unit, and the first acquisition unit is used to:

[0152] Obtaining current lateral data, longitudinal data and front wheel turning angle of the target vehicle;

[0153] The preset dynamic equation of the target vehicle is solved according to the lateral data, the longitudinal data and the front wheel turning angle to obtain the current sideslip angle of the target vehicle.

[0154] In some preferred embodiments, the solution module 902 includes a solution unit, and the solution unit is used to:

[0155] Obtaining the target sliding surface function and the target reaching law function;

[0156] Discretizing the target reaching law function and the target sliding surface function to obtain a discretized reaching law function and a discretized sliding surface function;

[0157] Substitute the discretized reaching law function and the discretized sliding surface function into a preset discrete system and solve them to obtain the target control quantity.

[0158] In some preferred embodiments, the solving unit comprises a first obtaining subunit, and the first obtaining subunit is used to:

[0159] Solving an initial sliding mode surface function according to the current slip angle, the preset desired slip angle, the current yaw rate, the preset desired yaw rate, and the initial sliding mode control parameter to determine a position of a system state point corresponding to the target vehicle on the sliding mode surface;

[0160] According to the position of the system state point on the sliding surface and in accordance with a first preset rule, a target sliding mode control parameter of the sliding surface function is determined to obtain a target sliding surface function.

[0161] In some preferred embodiments, the target sliding surface function includes:

[0162]

[0163] Wherein, S is the target sliding surface, C1 is the first sliding mode control parameter, C2 is the second sliding mode control parameter, Δβ is the difference between the current sideslip angle and the preset desired sideslip angle, Δω is the difference between the current yaw angular velocity and the preset desired yaw angular velocity, and t is time.

[0164] In some preferred embodiments, the solving unit comprises a second obtaining subunit, and the second obtaining subunit is used to:

[0165] Solving an initial sliding mode surface function according to the current slip angle, the preset desired slip angle, the current yaw rate, the preset desired yaw rate, and the initial sliding mode control parameter to determine a position of a system state point corresponding to the target vehicle on the sliding mode surface;

[0166] According to the position of the system state point on the sliding surface and in accordance with a second preset rule, a target reaching law parameter of the target reaching law function is determined to obtain the target reaching law function.

[0167] In some preferred embodiments, the target reaching law function comprises:

[0168]

[0169] in, is the target reaching law function, S is the target sliding surface, ε is the first reaching law parameter, μ is the second reaching law parameter, and arctan is the inverse tangent function.

[0170] In some preferred embodiments, the target vehicle includes a left drive motor and a right drive motor; the torque control module 903 includes a first control unit, and the first control unit is used to: distribute half of the torque difference to the left drive motor or the right drive motor to achieve control of the target vehicle.

[0171] In some preferred embodiments, the target vehicle includes a left drive motor and a right drive motor; the torque control module 903 includes a second control unit, and the second control unit is used to: obtain the torque limit of the left drive motor and the torque limit of the right drive motor; according to the torque limit of the left drive motor and the torque limit of the right drive motor, distribute the torque difference to the left drive motor and the right drive motor to achieve control of the target vehicle.

[0172] For the device embodiment, since it is basically similar to the method embodiment, the relevant description can refer to the partial description of the method embodiment.

[0173] Fig.10 A schematic structural diagram of an embodiment of a torque control device of the present invention is shown, comprising: a processor, a memory, a communication interface and a communication bus, wherein the processor, the memory and the communication interface communicate with each other via the communication bus.

[0174] The memory is used to store at least one executable instruction, and the executable instruction enables the processor to execute the operation of the above-mentioned torque control method.

[0175] like Fig.10 As shown, the torque control device may include: a processor 1002 , a communications interface 1004 , a memory 1006 , and a communication bus 1008 .

[0176] The processor 1002, the communication interface 1004, and the memory 1006 communicate with each other via a communication bus 1008. The communication interface 1004 is used to communicate with other devices such as a client or other server network elements. The processor 1002 is used to execute a program 1010, which can specifically execute the relevant steps in the above-mentioned torque control method embodiment.

[0177] Specifically, the program 1010 may include program code, which includes computer-executable instructions.

[0178] The processor 1002 may be a central processing unit (CPU), or an application-specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiment of the present invention. The one or more processors included in the torque control device may be processors of the same type, such as one or more CPUs; or may be processors of different types, such as one or more CPUs and one or more ASICs.

[0179] The memory 1006 is used to store the program 1010. The memory 1006 may include a high-speed RAM memory, and may also include a non-volatile memory (non-volatile memory), such as at least one disk memory.

[0180] In addition, the present invention application also provides an embodiment of a computer-readable storage medium, in which at least one executable instruction is stored. When the executable instruction is executed on the torque control device / apparatus, the torque control device / apparatus performs the operation of the torque control method.

[0181] The algorithms or displays provided herein are not inherently related to any particular computer, virtual system or other device. In addition, the embodiments of the present invention are not directed to any particular programming language.

[0182] In the description provided herein, a large number of specific details are described. However, it is understood that embodiments of the present invention can be practiced without these specific details. Similarly, in order to simplify the present invention and help understand one or more of the various inventive aspects, in the above description of exemplary embodiments of the present invention, the various features of the embodiments of the present invention are sometimes grouped together into a single embodiment, figure, or description thereof. Wherein, the claims that follow the specific embodiment are hereby expressly incorporated into the specific embodiment, wherein each claim itself is a separate embodiment of the present invention.

[0183] Those skilled in the art will appreciate that the modules in the devices in the embodiments may be adaptively changed and arranged in one or more devices different from the embodiments. The modules or units or components in the embodiments may be combined into one module or unit or component, and further may be divided into a plurality of submodules or subunits or subcomponents. Except that at least some of such features and / or processes or units are mutually exclusive.

[0184] It should be noted that the above embodiments illustrate the present invention rather than limit it, and that those skilled in the art may devise alternative embodiments without departing from the scope of the appended claims. In the claims, any reference symbol between brackets shall not be construed as a limitation on the claims. The word "comprising" does not exclude the presence of elements or steps not listed in the claims. The word "one" or "an" preceding an element does not exclude the presence of a plurality of such elements. The present invention may be implemented by means of hardware comprising a number of different elements and by means of a suitably programmed computer. In a unit claim enumerating a number of devices, several of these devices may be embodied by the same hardware item. The use of the words first, second, and third, etc. does not indicate any order. These words may be interpreted as names. The steps in the above embodiments, unless otherwise specified, should not be understood as limitations on the order of execution.

[0185] The specific embodiments described above further describe the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. It is particularly pointed out that for those skilled in the art, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the scope of protection of the present invention.

Claims

1. A torque control method, characterized in that: include: Obtaining a current sideslip angle of a target vehicle and a current yaw rate of the target vehicle; Solving a target sliding mode control function according to the current slip angle, the preset desired slip angle, the current yaw rate and the preset desired yaw rate to obtain a target control amount, wherein the target control amount includes a torque difference between the left and right sides of the target vehicle, and the target sliding mode control function is obtained according to a target sliding mode surface function and a target reaching law function; The target vehicle is controlled according to the torque difference.

2. A torque control method according to claim 1, characterized in that: The obtaining of the current sideslip angle of the target vehicle comprises: Obtaining current lateral data, longitudinal data and front wheel turning angle of the target vehicle; The preset dynamic equation of the target vehicle is solved according to the lateral data, the longitudinal data and the front wheel turning angle to obtain the current sideslip angle of the target vehicle.

3. A torque control method according to claim 1, characterized in that: The target sliding mode control function is solved to obtain the target control quantity, including: Obtaining the target sliding surface function and the target reaching law function; Discretizing the target reaching law function and the target sliding surface function to obtain a discretized reaching law function and a discretized sliding surface function; Substitute the discretized reaching law function and the discretized sliding surface function into a preset discrete system and solve them to obtain the target control quantity.

4. A torque control method as claimed in claim 3, characterized in that: The obtaining of the target sliding surface function comprises: Solving the initial sliding mode surface function according to the current sideslip angle, the preset desired sideslip angle, the current yaw rate, the preset desired yaw rate and the initial sliding mode control parameters to determine the position of the system state point corresponding to the target vehicle on the sliding mode surface; According to the position of the system state point on the sliding surface and in accordance with a first preset rule, a target sliding mode control parameter of the sliding surface function is determined to obtain a target sliding surface function.

5. A torque control method as claimed in claim 4, characterized in that: The target sliding surface function includes: Wherein, S is the target sliding surface, C1 is the first sliding mode control parameter, C2 is the second sliding mode control parameter, Δβ is the difference between the current sideslip angle and the preset desired sideslip angle, Δω is the difference between the current yaw angular velocity and the preset desired yaw angular velocity, and t is time.

6. A torque control method as claimed in claim 3, characterized in that: The obtaining of the target reaching law function specifically includes: Solving the initial sliding mode surface function according to the current sideslip angle, the preset desired sideslip angle, the current yaw rate, the preset desired yaw rate and the initial sliding mode control parameters to determine the position of the system state point corresponding to the target vehicle on the sliding mode surface; According to the position of the system state point on the sliding surface and in accordance with a second preset rule, a target reaching law parameter of the target reaching law function is determined to obtain the target reaching law function.

7. A torque control method according to claim 6, characterized in that: The target reaching law function includes: in, is the target reaching law function, S is the target sliding surface, ε is the first reaching law parameter, μ is the second reaching law parameter, and arctan is the inverse tangent function.

8. A torque control method as claimed in claim 1, characterized in that: The target vehicle includes a left drive motor and a right drive motor; and controlling the target vehicle according to the torque difference includes: Half of the torque difference is distributed to the left drive motor or the right drive motor to achieve control of the target vehicle.

9. A torque control method as claimed in claim 1, characterized in that: The target vehicle includes a left drive motor and a right drive motor; and controlling the target vehicle according to the torque difference includes: Acquiring a torque limit value of the left drive motor and a torque limit value of the right drive motor; According to the torque limit of the left drive motor and the torque limit of the right drive motor, the torque difference is distributed to the left drive motor and the right drive motor to achieve control of the target vehicle.

10. A torque control device, characterized in that: It includes an acquisition module, a solution module and a torque control module; wherein, The acquisition module is used to acquire the current sideslip angle of the target vehicle and the current yaw rate of the target vehicle; The solving module is used to solve the target sliding mode control function according to the current sideslip angle, the preset desired sideslip angle, the current yaw rate and the preset desired yaw rate to obtain a target control amount, wherein the target control amount includes a torque difference between the left and right sides of the target vehicle, and the target sliding mode control function is obtained according to a target sliding mode surface function and a target reaching law function; The torque control module is used to control the target vehicle according to the torque difference.

11. A torque control device, characterized in that: It includes a processor, a memory, a communication interface and a communication bus, wherein the processor, the memory and the communication interface communicate with each other through the communication bus; The memory is used to store at least one executable instruction, and the executable instruction enables the processor to perform the operation of the torque control method as described in any one of claims 1 to 9.

12. A computer-readable storage medium, characterized in that: The storage medium stores at least one executable instruction, and when the executable instruction is executed on the torque control device / apparatus, the torque control device / apparatus performs the operation of the torque control method as described in any one of claims 1 to 9.

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