A method and device for lateral control of a vehicle

Abstract

This application discloses a method and apparatus for lateral control of a vehicle. In this method, target steering characteristic parameters, the current longitudinal speed of the target vehicle, and the actual characteristic speed of the target vehicle are acquired; based on the ratio of the current longitudinal speed to the target characteristic speed, the target yaw rate of the target vehicle is determined; and based on the target yaw rate, the wheels of the target vehicle are controlled to steer. It is evident that the target steering characteristic parameters, which vary with the driving characteristics of different drivers, can be used to calculate a target yaw rate that adapts to the driving habits of different drivers, thereby improving the driver's control over the vehicle.

Description

Technical Field

[0001] This application relates to the field of vehicle control technology, and in particular to a method and apparatus for lateral control of a vehicle. Background Technology

[0002] Vehicle handling refers to the difference between the desired outcome and the driver's anticipated objective when maneuvering the vehicle, including steering, braking, accelerator, and other technical and conditional configurations, is achieved due to inherent vehicle problems or external factors. Therefore, vehicle handling is of paramount importance to the driver.

[0003] Among these factors, the accuracy of lateral control is a crucial indicator of vehicle handling. Currently, vehicles typically incorporate active safety control systems. For example, Active Front Steering (AFS) assists drivers in lateral control, improving driving safety. However, some drivers may struggle to adapt to AFS, thus affecting their ability to control the vehicle.

[0004] Therefore, improving vehicle handling has become an urgent problem to be solved. Summary of the Invention

[0005] In view of this, embodiments of this application provide a lateral control method and apparatus for a vehicle, which aims to improve vehicle handling.

[0006] In a first aspect, embodiments of this application provide a method for lateral control of a vehicle, the method comprising:

[0007] The target steering characteristic parameters, the current longitudinal speed of the target vehicle, and the actual characteristic speed of the target vehicle are obtained; the target steering characteristic parameters are used to characterize the driving characteristics of the target driver driving the target vehicle; the target steering characteristic parameters are positively correlated with the steering sensitivity of the target vehicle;

[0008] The target yaw rate of the target vehicle is determined based on the ratio of the current longitudinal speed of the target vehicle to the target characteristic speed of the target vehicle; the target characteristic speed of the target vehicle is determined based on the product of the target steering characteristic parameter and the actual characteristic speed of the target vehicle.

[0009] Based on the target yaw rate, the wheels of the target vehicle are controlled to steer.

[0010] Optionally, obtaining the target steering characteristic parameters, the current longitudinal speed of the target vehicle, and the actual characteristic speed of the target vehicle specifically includes:

[0011] The target vehicle's steering characteristic parameters, current longitudinal speed, actual characteristic speed, current steering wheel angle, and vehicle characteristic parameters are obtained; the vehicle characteristic parameters are used to characterize the hardware features of the target vehicle.

[0012] Determining the target yaw rate of the target vehicle based on the ratio of its current longitudinal speed to its target characteristic speed specifically includes:

[0013] A first ratio is obtained based on the ratio of the current longitudinal speed of the target vehicle to the target characteristic speed of the target vehicle;

[0014] Multiply the first ratio by the vehicle characteristic parameters of the target vehicle to obtain the first product;

[0015] Multiply the current longitudinal speed of the target vehicle and the current steering wheel angle of the target vehicle to obtain a second product;

[0016] The target yaw rate of the target vehicle is determined based on the ratio of the second product to the first product.

[0017] Optionally, the target characteristic speed of the target vehicle is obtained in the following manner:

[0018] The target characteristic speed of the target vehicle is determined by multiplying the target steering characteristic parameter, the characteristic speed coefficient of the target vehicle, and the actual characteristic speed of the target vehicle.

[0019] Optionally, the target vehicle includes a steering characteristic parameter editing control, and the acquisition of the target steering characteristic parameters specifically includes:

[0020] In response to the target driver's editing operation on the steering characteristic parameter editing control, the target steering characteristic parameter is obtained.

[0021] Optionally, the lateral control method for the vehicle further includes:

[0022] Obtain the lateral slope of the road where the target vehicle is located and the mass of the target vehicle;

[0023] Multiply the lateral slope and the mass of the target vehicle to determine the target yaw rate compensation speed of the target vehicle;

[0024] Determining the target yaw rate of the target vehicle based on the ratio of its current longitudinal speed to its target characteristic speed specifically includes:

[0025] The desired yaw rate of the target vehicle is determined based on the ratio of the current longitudinal speed of the target vehicle to the target characteristic speed of the target vehicle.

[0026] The target yaw rate of the target vehicle is determined by adding the desired yaw rate of the target vehicle to the target yaw rate compensation rate.

[0027] Optionally, obtaining the lateral slope of the road where the target vehicle is located specifically includes:

[0028] The predicted lateral acceleration of the center of gravity of the target vehicle, the actual lateral acceleration of the center of gravity of the target vehicle, and the roll angle of the target vehicle are obtained.

[0029] The acceleration difference is obtained by subtracting the predicted lateral acceleration of the target vehicle's center of gravity from the actual lateral acceleration of the target vehicle's center of gravity.

[0030] The lateral slope is obtained by subtracting the arcsine of the acceleration difference from the tilt angle of the target vehicle.

[0031] Optionally, obtaining the lateral slope of the road where the target vehicle is located and the mass of the target vehicle specifically includes:

[0032] The lateral slope of the road where the target vehicle is located, the mass of the target vehicle, the current steering wheel angle of the target vehicle, the steering characteristic parameters of the target vehicle, and the vehicle characteristic parameters of the target vehicle are obtained.

[0033] The step of multiplying the lateral slope and the mass of the target vehicle to determine the target yaw angle compensation speed of the target vehicle specifically includes:

[0034] Multiply the lateral slope by the mass of the target vehicle to determine the lateral slope component of the target vehicle's center of gravity;

[0035] A second ratio is obtained based on the ratio of the steering characteristic parameters of the target vehicle to the current steering wheel angle of the target vehicle;

[0036] The target vehicle's yaw rate gain is determined by multiplying its desired yaw rate by the second ratio; the target vehicle's desired yaw rate is determined based on the ratio of the target vehicle's current longitudinal speed to its target characteristic speed.

[0037] The target yaw rate compensation speed of the target vehicle is determined by multiplying the lateral slope component of the target vehicle's center of gravity, the vehicle characteristic parameters of the target vehicle, and the yaw rate gain of the target vehicle.

[0038] Optionally, the lateral control method for the vehicle further includes:

[0039] The wheel speed difference between the left wheel speed and the right wheel speed of the target vehicle is obtained, as well as the current brake pedal depth of the target vehicle.

[0040] Determining the target yaw rate of the target vehicle based on the ratio of its current longitudinal speed to its target characteristic speed specifically includes:

[0041] If the wheel speed difference is less than or equal to the wheel speed difference threshold, or the current brake pedal depth is less than or equal to the depth threshold, then the target yaw rate of the target vehicle is determined based on the ratio of the current longitudinal speed of the target vehicle to the target characteristic speed of the target vehicle.

[0042] If the wheel speed difference is greater than the wheel speed difference threshold, and the current brake pedal pressure depth is greater than the pressure depth threshold, then the preset yaw rate is determined as the target yaw rate of the target vehicle.

[0043] Optionally, controlling the wheels of the target vehicle to steer based on the target yaw rate specifically includes:

[0044] Feedforward control is performed on the wheel steering of the target vehicle based on the target yaw rate, and feedback control is performed on the wheel steering of the target vehicle based on the target yaw rate, the current yaw rate of the target vehicle, and the yaw rate of the target vehicle at the kth sampling time, and the target wheel steering angle value of the target vehicle is output; where k is an integer greater than 0.

[0045] The target wheel angle value is input to the wheel steering actuator of the target vehicle to control the wheels of the target vehicle to steer.

[0046] Secondly, embodiments of this application provide a lateral control device for a vehicle, the device comprising:

[0047] The acquisition module is used to acquire target steering characteristic parameters, the current longitudinal speed of the target vehicle, and the actual characteristic speed of the target vehicle; the target steering characteristic parameters are used to characterize the driving characteristics of the target driver driving the target vehicle; the target steering characteristic parameters are positively correlated with the steering sensitivity of the target vehicle;

[0048] The determination module is used to determine the target yaw rate of the target vehicle based on the ratio of the current longitudinal speed of the target vehicle to the target characteristic speed of the target vehicle; the target characteristic speed of the target vehicle is determined based on the product of the target steering characteristic parameter and the actual characteristic speed of the target vehicle.

[0049] The control module is used to control the wheels of the target vehicle to steer based on the target yaw rate.

[0050] Thirdly, embodiments of this application provide a lateral control device for a vehicle, the device including a memory and a processor:

[0051] The memory is used to store computer programs and transmit the computer programs to the processor;

[0052] The processor is configured to execute the computer program to cause the device to perform the lateral control method for the vehicle described in the first aspect above.

[0053] Fourthly, embodiments of this application provide a computer-readable storage medium storing a computer program, wherein when the computer program is run, a device running the computer program implements the lateral control method for a vehicle described in the first aspect above.

[0054] Compared with the prior art, the embodiments of this application have the following beneficial effects:

[0055] This application provides a method and apparatus for lateral control of a vehicle. In this method, target steering characteristic parameters, the current longitudinal speed of the target vehicle, and the actual characteristic speed of the target vehicle are acquired. The target steering characteristic parameters characterize the driving characteristics of the target driver. The target steering characteristic parameters are positively correlated with the steering sensitivity of the target vehicle. The target yaw rate of the target vehicle is determined based on the ratio of the current longitudinal speed to the target characteristic speed. The target characteristic speed is determined by multiplying the target steering characteristic parameters by the actual characteristic speed. Based on the target yaw rate, the wheels of the target vehicle are controlled to steer. Therefore, this method acquires target steering characteristic parameters characterizing the driving characteristics of the target driver, calculates the target characteristic speed based on these parameters, and then determines the target yaw rate based on the ratio of the current longitudinal speed to the target characteristic speed. The target steering characteristic parameters, which vary with the driving characteristics of different drivers, can calculate a target yaw rate that adapts to the driving habits of different drivers, improving the driver's experience with active safety control systems such as AFS (Adaptive Front-lighting) and thus enhancing the driver's control over the vehicle. Attached Figure Description

[0056] To more clearly illustrate the technical solutions in this embodiment or the prior art, the drawings used in the description of the embodiment or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0057] Figure 1 A flowchart illustrating a lateral control method for a vehicle provided in an embodiment of this application;

[0058] Figure 2 A schematic diagram illustrating the definition of an ISO coordinate system direction, provided in an embodiment of this application;

[0059] Figure 3 A flowchart illustrating a specific lateral control method for a vehicle provided in this application embodiment;

[0060] Figure 4 This is a schematic diagram illustrating the comparison of lateral drift of a target vehicle under adverse operating conditions with and without AFS control, provided as an embodiment of this application.

[0061] Figure 5 A schematic diagram showing the comparison of target yaw rate obtained with different values ​​of target steering characteristic parameters, as provided in an embodiment of this application;

[0062] Figure 6 This is a schematic diagram comparing the steering wheel angles obtained with different values ​​of the target steering characteristic parameter, as provided in an embodiment of this application.

[0063] Figure 7 This is a schematic diagram illustrating the control effect of AFS control on a target vehicle under normal operating conditions, provided in an embodiment of this application.

[0064] Figure 8 This is a schematic diagram of the structure of a vehicle lateral control device provided in an embodiment of this application. Detailed Implementation

[0065] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0066] Currently, existing vehicle lateral control methods typically utilize active safety control systems such as AFS (Adaptive Front-lighting) to assist drivers in lateral control of the vehicle. However, there may be situations where drivers cannot adapt to the vehicle's AFS, resulting in yaw rates obtained based on AFS exceeding the driver's expectations and thus affecting the driver's control over the vehicle.

[0067] To address the aforementioned problems, this application provides a method and apparatus for lateral control of a vehicle. In this method, target steering characteristic parameters, the current longitudinal speed of the target vehicle, and the actual characteristic speed of the target vehicle are acquired. The target steering characteristic parameters characterize the driving characteristics of the target driver. The target steering characteristic parameters are positively correlated with the steering sensitivity of the target vehicle. A target yaw rate is determined based on the ratio of the current longitudinal speed to the target characteristic speed of the target vehicle. The target characteristic speed is determined by multiplying the target steering characteristic parameters by the actual characteristic speed of the target vehicle. Based on the target yaw rate, the wheels of the target vehicle are steered. Therefore, the target steering characteristic parameters, which vary with the driving characteristics of different drivers, can be used to calculate a target yaw rate that adapts to the driving habits of different drivers, improving the driver's experience with active safety control systems such as AFS, and thus enhancing the driver's control over the vehicle.

[0068] The following description, in conjunction with the accompanying drawings, details the specific implementation of the vehicle lateral control method and device in the embodiments of this application.

[0069] See Figure 1 The figure is a flowchart of a vehicle lateral control method provided in an embodiment of this application, combined with... Figure 1 As shown, it can specifically include:

[0070] S101: Obtain the target steering characteristic parameters, the current longitudinal speed of the target vehicle, and the actual characteristic speed of the target vehicle.

[0071] For ease of understanding, the following embodiments all use the example of a target vehicle triggering the AFS function to describe in detail the lateral control method for a vehicle provided in this application. It should be noted that this application does not limit the type of active safety control system installed on the target vehicle.

[0072] As an example, when the yaw rate error ω of the target vehicle Err Greater than the AFS activation yaw rate threshold ω inThr Furthermore, the target vehicle's sideslip angle β is greater than the AFS activation yaw rate threshold β. inThr Then the AFS function of the target vehicle will be activated.

[0073] In related technologies, when a vehicle's AFS (Adaptive Front-lighting) function is activated, it assists the driver in lateral control. However, this AFS is an auxiliary control system designed with fixed parameters, ignoring the different driving habits of different drivers. For example, for the same vehicle, driver A might habitually lightly press the accelerator when turning, while driver B might habitually press the accelerator slightly harder. In other words, it ignores the differences in vehicle handling between different drivers, resulting in the same assistance effect from AFS for the same vehicle on different drivers. This leads to some drivers having lower acceptance of AFS and being unable to better adapt to the vehicle's lateral assist system.

[0074] This application introduces a target steering characteristic parameter, which characterizes the driving characteristics of a target driver operating the target vehicle; the target steering characteristic parameter is positively correlated with the steering sensitivity of the target vehicle. The target steering characteristic parameter can vary according to different drivers' driving habits.

[0075] In one possible implementation of this application, the target vehicle may include a steering characteristic parameter editing control. Therefore, obtaining the target steering characteristic parameters may specifically include: obtaining the target steering characteristic parameters in response to the target driver's editing operation on the steering characteristic parameter editing control. Before driving the target vehicle, the target user can edit the steering characteristic parameter editing control and input the target steering characteristic parameters.

[0076] It should be noted that the target steering characteristic parameter can also be adaptively set by the target vehicle according to the driver's habits, and this application does not limit this.

[0077] As can be seen, the target driver can independently edit the target steering characteristic parameters through the target vehicle's human-machine interface, which is the steering characteristic parameter editing control, so that the performance of the target vehicle is more in line with their own driving habits when driving the target vehicle.

[0078] As an example, the steering characteristic parameter editing control may include six steering characteristic parameter options, namely 0, 1, 2, 3, 4 and 5. As the steering characteristic parameter gradually increases, the steering sensitivity of the vehicle gradually increases. That is, for the same steering angle of the target vehicle, the pressure of the target driver on the brake pedal can gradually decrease, that is, the braking pedal pressure depth gradually decreases.

[0079] For ease of understanding, the target vehicle is defined using the ISO coordinate system in this application. See details for further information. Figure 2 The diagram shows the orientation definition of the ISO coordinate system for the target vehicle. +x represents the positive direction of the x-axis, +y represents the positive direction of the y-axis, +ω represents the yaw angle with counterclockwise as the positive direction, and the lateral acceleration of the center of mass with the leftward direction as the positive direction.

[0080] S102: Determine the target yaw rate of the target vehicle based on the ratio of the current longitudinal speed of the target vehicle to the target characteristic speed of the target vehicle.

[0081] The target characteristic speed of the target vehicle is determined based on the product of the target steering characteristic parameter and the actual characteristic speed of the target vehicle.

[0082] The actual characteristic speed of the target vehicle refers to the maximum speed that the target vehicle can reach under ideal conditions. Control systems such as AFS on the target vehicle usually calculate the target yaw rate based on the actual characteristic speed of the target vehicle. However, in this application, the target steering characteristic parameters are introduced based on the actual characteristic speed to determine the target characteristic speed of the target vehicle, thereby making the calculated target yaw rate more in line with the driving habits of the target driver and improving the vehicle's handling.

[0083] In one possible implementation of this application, S101 may specifically include: acquiring the target steering characteristic parameters, the current longitudinal speed of the target vehicle, the actual characteristic speed of the target vehicle, the current steering wheel angle of the target vehicle, and the vehicle characteristic parameters of the target vehicle; the vehicle characteristic parameters of the target vehicle are used to characterize the hardware features of the target vehicle. The vehicle characteristic parameters of the target vehicle may include, but are not limited to, the wheelbase of the target vehicle and the vehicle steering ratio of the target vehicle.

[0084] Accordingly, S102 may specifically include: obtaining a first ratio based on the ratio of the current longitudinal speed of the target vehicle to the target characteristic speed of the target vehicle; multiplying the first ratio by the vehicle characteristic parameters of the target vehicle to obtain a first product; multiplying the current longitudinal speed of the target vehicle by the current steering wheel angle of the target vehicle to obtain a second product; and determining the target yaw rate of the target vehicle based on the ratio of the second product to the first product.

[0085] It is evident that considering the vehicle characteristic parameters of the target vehicle and the current driving data (i.e., the current longitudinal speed and the current steering wheel angle) when calculating the target yaw angle helps to calculate a more accurate target yaw rate.

[0086] In one possible implementation of this application, the target characteristic speed of the target vehicle can be obtained by multiplying the target steering characteristic parameter, the characteristic speed coefficient of the target vehicle, and the actual characteristic speed of the target vehicle to determine the target characteristic speed of the target vehicle.

[0087] Therefore, a characteristic speed coefficient of the target vehicle is introduced to control the calculated target characteristic speed within a certain range, so as to avoid it differing too much from the actual characteristic speed and deviating from the true performance of the target vehicle.

[0088] As an example, the target characteristic speed of a target vehicle can be represented by the following formula:

[0089]

[0090] Among them, u ch u represents the actual characteristic speed of the target vehicle. chΔ S represents the target characteristic speed of the target vehicle, P represents the target steering characteristic parameter, and the range of P is [0, M]. max S represents the coefficient of the maximum characteristic speed of the target vehicle. min S represents the minimum characteristic speed coefficient of the target vehicle. max and S min The settings can be based on the characteristics of the target vehicle, and this application does not limit this. Based on the above example, if the range of P is [0, 5], then M in the above formula is 5.

[0091] As an example, the target yaw rate of the target vehicle can be expressed by the following formula:

[0092]

[0093] Where, ω Est U represents the target yaw rate of the target vehicle. chΔ Let δ represent the target characteristic speed of the target vehicle, u represent the current longitudinal speed of the target vehicle, and δ represent the target characteristic speed of the target vehicle. SW This indicates the current steering wheel angle of the target vehicle, L represents the wheelbase of the target vehicle, and Ratio represents the steering ratio of the target vehicle.

[0094] Furthermore, considering that the road conditions where the target vehicle is located may have a lateral slope, and that the lateral slope may affect the target driver's handling stability of the target vehicle, in order to improve the handling stability of the vehicle, in one possible embodiment of this application, the lateral control method of the vehicle may further include: obtaining the lateral slope of the road conditions where the target vehicle is located and the mass of the target vehicle; multiplying the lateral slope and the mass of the target vehicle to determine the target yaw rate compensation speed of the target vehicle; correspondingly, S102 may specifically include: determining the desired yaw rate of the target vehicle based on the ratio of the current longitudinal speed of the target vehicle to the target characteristic speed of the target vehicle; adding the desired yaw rate of the target vehicle to the target yaw rate compensation speed to determine the target yaw rate of the target vehicle.

[0095] Therefore, by taking into account the impact of the lateral slope of the road conditions where the target vehicle is located when the target driver is manipulating the target vehicle, the vehicle's handling stability is improved.

[0096] As an example, the target yaw rate of the target vehicle can also be expressed by the following formula:

[0097] ω Est =ω Est1 +ω Est2

[0098] Where, ω Est ω represents the target yaw rate of the target vehicle. Est1 Let ω represent the desired yaw rate of the target vehicle. Est2 This indicates the target yaw rate compensation speed of the target vehicle.

[0099] Based on the above example, ω Est1 This can be expressed by the following formula:

[0100]

[0101] The meanings of the formula parameters mentioned above are the same as those in the previous text, and will not be repeated here.

[0102] Therefore, based on the driving habits of the target driver, the influence of the lateral slope of the road conditions on the lateral control is further considered, resulting in a more accurate target yaw rate. This improves the handling stability of the target vehicle while enhancing maneuverability.

[0103] In one possible implementation of this application, obtaining the lateral slope of the road conditions where the target vehicle is located may specifically include: obtaining the predicted lateral acceleration of the target vehicle's center of gravity, the actual lateral acceleration of the target vehicle's center of gravity, and the tilt angle of the target vehicle; subtracting the predicted lateral acceleration of the target vehicle's center of gravity from the actual lateral acceleration of the target vehicle to obtain an acceleration difference; and subtracting the arcsine of the acceleration difference from the tilt angle of the target vehicle to obtain the lateral slope.

[0104] As an example, the predicted lateral acceleration of the center of mass can be obtained from a two-degree-of-freedom vehicle dynamics model of the target vehicle, specifically expressed by the following formula:

[0105] a y =v′+u×ω=u×ω

[0106] Among them, a yLet v represent the predicted lateral acceleration of the target vehicle's center of mass, v' represent the target vehicle's current speed, v′ represent the derivative of the target vehicle's current speed, u represent the target vehicle's current longitudinal speed, and ω represent the target vehicle's current yaw rate.

[0107] The actual lateral acceleration of the center of mass can be measured by sensors on the target vehicle. For example, the sensors can be inertial measuring units (IMUs), but this application does not limit this to them.

[0108] The predicted lateral acceleration of the center of mass calculated from the two-degree-of-freedom vehicle dynamics model can be used to correct the actual lateral acceleration of the center of mass measured by the inertial sensor, resulting in a new predicted lateral acceleration of the center of mass. The predicted lateral acceleration of the center of mass can also be expressed by the following formula:

[0109]

[0110] Among them, a y a represents the predicted lateral acceleration of the target vehicle's center of mass. yIMU This represents the actual lateral acceleration of the center of mass as measured by the IMU sensor, where g represents the acceleration due to gravity. θ represents the roll angle of the target vehicle. bank This indicates the lateral slope of the road conditions described by the target vehicle.

[0111] The aforementioned roll angle is the maximum angle between the vehicle's body plane and the ground that the vehicle can withstand when it makes a sharp turn to one side at a certain speed (a rollover occurs if this angle is greater). The roll angle of the target vehicle can be expressed by the following formula:

[0112]

[0113] in, Let RG represent the roll angle of the target vehicle, and let a represent the roll gradient of the target vehicle's center of gravity. y This represents the predicted lateral acceleration of the target vehicle's center of mass.

[0114] Based on the above three formulas combined, the lateral slope of the road condition described by the target vehicle can be expressed as follows:

[0115]

[0116] Therefore, when calculating the lateral slope of the road conditions where the target vehicle is located based on the above formula, there is no need to add an additional sensor to measure the lateral slope, thus saving vehicle manufacturing costs.

[0117] In one possible implementation of this application, the acquisition of the lateral slope of the road conditions where the target vehicle is located and the mass of the target vehicle may specifically include: acquiring the lateral slope of the road conditions where the target vehicle is located, the mass of the target vehicle, the current steering wheel angle of the target vehicle, the steering characteristic parameters of the target vehicle, and the vehicle characteristic parameters of the target vehicle; correspondingly, the multiplication of the lateral slope and the mass of the target vehicle to determine the target yaw rate compensation speed of the target vehicle may be further subdivided into the following steps: multiplying the lateral slope and the mass of the target vehicle to determine the target vehicle's yaw rate compensation speed. The lateral slope component of the center of gravity of the target vehicle; a second ratio is obtained based on the ratio of the steering characteristic parameters of the target vehicle to the current steering wheel angle of the target vehicle; the desired yaw rate of the target vehicle is multiplied by the second ratio to determine the yaw rate gain of the target vehicle; the desired yaw rate of the target vehicle is determined based on the ratio of the current longitudinal speed of the target vehicle to the target characteristic speed of the target vehicle; the lateral slope component of the center of gravity of the target vehicle, the vehicle characteristic parameters of the target vehicle, and the yaw rate gain of the target vehicle are multiplied to determine the target yaw rate compensation speed of the target vehicle.

[0118] The lateral slope component of the center of gravity of the aforementioned target vehicle is typically expressed as mgsinθ. bank However, considering that in practical applications, the lateral slope is usually a small value, therefore mgsinθ bank It can be approximated by human mgθ bank .

[0119] As an example, the target yaw rate compensation speed of the aforementioned target vehicle can be expressed by the following formula:

[0120]

[0121] Where, ω Est2 Let represent the target yaw rate compensation velocity, 'a' represent the horizontal distance between the front axle and the center of gravity of the target vehicle, 'b' represent the horizontal distance between the rear axle and the center of gravity of the target vehicle, 'k1' represent the front wheel lateral stiffness of the target vehicle, 'k2' represent the rear wheel lateral stiffness of the target vehicle, and 'mgθ' represent the target yaw rate compensation velocity. bank ω represents the lateral slope component of the target vehicle's center of gravity. Gain This is expressed as the yaw rate gain of the target vehicle. Here, a, b, k1, and k2 are all vehicle characteristic parameters of the target vehicle mentioned above.

[0122] The yaw rate gain of the target vehicle can be expressed by the following formula:

[0123]

[0124] Where, ωGain Let ω be the yaw rate gain of the target vehicle. Est1 This represents the desired yaw rate of the target vehicle, as detailed in the formula mentioned above. Ratio represents the vehicle steering ratio of the target vehicle (i.e., the steering characteristic parameter of the target vehicle mentioned above). δ SW This represents the current steering wheel angle of the target vehicle.

[0125] The target yaw rate of the target vehicle can be expressed by the following formula:

[0126]

[0127] The meanings of the parameters can be found in the examples above, and will not be repeated here.

[0128] S103: Based on the target yaw rate, control the wheels of the target vehicle to steer.

[0129] In one possible implementation of this application, S103 may specifically include: performing feedforward control on the wheel steering of the target vehicle based on the target yaw rate, and performing feedback control on the wheel steering of the target vehicle based on the target yaw rate, the current yaw rate of the target vehicle, and the yaw rate of the target vehicle at the kth sampling time, and outputting the target wheel angle value of the target vehicle; where k is an integer greater than 0; inputting the target wheel angle value to the wheel steering actuator of the target vehicle to control the wheels of the target vehicle to steer.

[0130] As an example, the wheel steering of a target vehicle can be controlled by feedback using a PID controller. The target wheel steering angle can then be expressed by the following formula:

[0131]

[0132] Where, δ F Represented as the target wheel steering angle value, ω Err,k ω represents the yaw rate error at time k. Err,k-1 ω represents the yaw rate error at time k-1. Err,k-2 K represents the yaw rate error at time k-2. p K i and K d These are the coefficients of the PID controller.

[0133] It is evident that by employing feedforward control and incremental PID feedback control on the target yaw rate of the target vehicle, the algorithm complexity is simplified, the real-time performance and reliability of the algorithm are improved, and the driver's control over the vehicle is further guaranteed.

[0134] Furthermore, to improve the driving safety of the target driver when the target vehicle is in adverse conditions such as vehicle skidding, the lateral control method of the vehicle may further include: obtaining the wheel speed difference between the left wheel speed and the right wheel speed of the target vehicle, and the current brake pedal depressing depth of the target vehicle; correspondingly, S102 may specifically include: if the wheel speed difference is less than or equal to a wheel speed difference threshold, or the current brake pedal depressing depth is less than or equal to a depressing depth threshold, then determining the target yaw rate of the target vehicle based on the ratio of the current longitudinal speed of the target vehicle to the target characteristic speed of the target vehicle; if the wheel speed difference is greater than the wheel speed difference threshold, and the current brake pedal depressing depth is greater than the depressing depth threshold, then determining a preset yaw rate as the target yaw rate of the target vehicle. The preset yaw rate can be 0, and this application does not limit it to this.

[0135] Based on the difference in wheel speeds and the current brake pedal depth of the target vehicle, it is determined whether the vehicle is in adverse or normal operating conditions. Under adverse operating conditions, the preset yaw rate of 0 can be directly determined as the target yaw rate of the target vehicle. Under normal operating conditions, the target yaw rate of the target vehicle can be determined based on the ratio of the current longitudinal speed of the target vehicle to the target characteristic speed of the target vehicle.

[0136] A wheel speed difference greater than the wheel speed difference threshold indicates that the target vehicle may be in a state of severe slippage. A current brake pedal depth greater than the aforementioned depth threshold indicates that the driver has pressed the brake pedal to a certain depth, which may be a strong defensive behavior after the driver perceives the instability of the target vehicle. That is, the driver is likely to turn the steering wheel quickly and significantly in order to maintain the stability of the target vehicle. In this case, which is a severe condition where the driver has high requirements for the real-time control and effectiveness of the target vehicle, AFS can directly take over to further improve the handling stability of the target vehicle and enhance the driver's driving safety.

[0137] In related technologies, most research on vehicle handling stability control focuses on complex algorithms such as MPC and LQR. While these algorithms can achieve good control results in theory, they place high demands on the controller and observations, making them difficult to apply quickly in engineering practice. In contrast, the consideration of lateral slope and adverse operating conditions in this application requires only simple calculations, eliminating the need for complex algorithms. This reduces the requirements on the target vehicle's controller and observations, enabling rapid application in engineering practice.

[0138] As an example, see Figure 3 The flowchart illustrates a specific method for lateral control of a vehicle. (Combined with...) Figure 3As shown, the specific lateral control method for this vehicle may include the following steps:

[0139] S301: Determine the yaw rate error ω Err Is it greater than the yaw rate threshold ω? inThr And whether the centroid sideslip angle β is greater than the centroid sideslip angle threshold β inThr .

[0140] S302: If so, activate the AFS function.

[0141] S303: If not, then AFS function will not be activated.

[0142] S304: Determine the speed u of the left wheel of the target vehicle. whl The speed u of the right wheel of the target vehicle whr Is the difference in wheel speeds greater than the wheel speed difference threshold u? whThr And determine the current brake pedal depth D brk Is it greater than the pressure depth threshold D? brkThr .

[0143] S305: If so, activate the adverse operating mode of the target vehicle, so that AFS takes over the target vehicle and sets the target yaw rate of the target vehicle to 0.

[0144] S306: If not, activate the normal operating mode of the target vehicle so that AFS can assist the target vehicle.

[0145] S307: Calculate the desired yaw rate of the target vehicle based on the target steering characteristic parameters.

[0146] S308: Calculate the target yaw rate compensation speed based on the lateral slope of the target vehicle's current condition.

[0147] S309: Add the desired yaw rate of the target vehicle to the target yaw rate compensation speed, where the target yaw rate of the target vehicle is the target yaw rate.

[0148] S310: Based on the target yaw rate of the target vehicle, output the target wheel steering angle value of the target vehicle to control the wheels of the target vehicle to steer.

[0149] The specific implementation methods of S301-S310 can be found in the specific implementation methods of S201-S203, and will not be repeated here.

[0150] To demonstrate the beneficial effects of the vehicle lateral control method provided in this application, comparative verification was conducted.

[0151] As an example, see Figure 4This figure is a schematic diagram comparing the lateral drift of a target vehicle under adverse operating conditions with and without AFS control, according to an embodiment of this application. Combined with... Figure 4 As shown, under adverse operating conditions, without the AFS function, the lateral offset value of the target vehicle gradually increases, indicating that the target vehicle may skid, posing a danger. However, under adverse operating conditions, using the lateral control method provided in this application embodiment keeps the lateral offset value near 0, which can prevent vehicle skidding and improve driving safety.

[0152] As an example, see Figure 5 This figure is a schematic diagram comparing the target yaw rate obtained with different values ​​of target steering characteristic parameters according to an embodiment of this application. Combined with... Figure 5 As shown, the target yaw rate calculated from different target steering characteristic parameters is different, which can be adapted to the driving habits of different drivers and improve the driver's control of the vehicle.

[0153] As an example, see Figure 6 This figure is a schematic diagram comparing the steering wheel angles obtained with different values ​​of the target steering characteristic parameter according to an embodiment of this application. Combined with... Figure 6 As shown, different target steering characteristic parameters result in different steering wheel angles, that is, different steering responsiveness, which can be adapted to the driving habits of different drivers and improve the driver's control over the vehicle.

[0154] As an example, see Figure 7 This figure is a schematic diagram illustrating the control effect of AFS control on a target vehicle under normal operating conditions, according to an embodiment of this application. Combined with... Figure 7 As shown, by using feedforward and incremental PID feedback control, the difference between the actual yaw rate of the target vehicle and the calculated target yaw rate is minimized, thereby improving the real-time performance and reliability of the algorithm and ensuring the vehicle's maneuverability.

[0155] The above are some specific implementations of the lateral control method for a vehicle provided in the embodiments of this application. Based on this, this application also provides a corresponding lateral control device for a vehicle. The lateral control device for a vehicle provided in the embodiments of this application will be described below from the perspective of functional modularity.

[0156] See Figure 8 The figure is a schematic diagram of the structure of a vehicle lateral control device according to an embodiment of this application. The vehicle lateral control device 800 may include:

[0157] The acquisition module 810 is used to acquire target steering characteristic parameters, the current longitudinal speed of the target vehicle, and the actual characteristic speed of the target vehicle; the target steering characteristic parameters are used to characterize the driving characteristics of the target driver driving the target vehicle; the target steering characteristic parameters are positively correlated with the steering sensitivity of the target vehicle;

[0158] The determining module 820 is used to determine the target yaw rate of the target vehicle based on the ratio of the current longitudinal speed of the target vehicle to the target characteristic speed of the target vehicle; the target characteristic speed of the target vehicle is determined based on the product of the target steering characteristic parameter and the actual characteristic speed of the target vehicle.

[0159] The control module 830 is used to control the wheels of the target vehicle to steer based on the target yaw rate.

[0160] As one implementation method, the acquisition module 810 is specifically used for:

[0161] The target vehicle's steering characteristic parameters, current longitudinal speed, actual characteristic speed, current steering wheel angle, and vehicle characteristic parameters are obtained; the vehicle characteristic parameters are used to characterize the hardware features of the target vehicle.

[0162] Accordingly, module 820 is defined as being used specifically for:

[0163] A first ratio is obtained based on the ratio of the current longitudinal speed of the target vehicle to the target characteristic speed of the target vehicle;

[0164] Multiply the first ratio by the vehicle characteristic parameters of the target vehicle to obtain the first product;

[0165] Multiply the current longitudinal speed of the target vehicle and the current steering wheel angle of the target vehicle to obtain a second product;

[0166] The target yaw rate of the target vehicle is determined based on the ratio of the second product to the first product.

[0167] As one implementation method, the target characteristic speed of the target vehicle is obtained through the following unit:

[0168] The determining unit is used to multiply the target steering characteristic parameter, the characteristic speed coefficient of the target vehicle, and the actual characteristic speed of the target vehicle to determine the target characteristic speed of the target vehicle.

[0169] In one implementation, the target vehicle includes a steering characteristic parameter editing control and an acquisition module, specifically used for:

[0170] In response to the target driver's editing operation on the steering characteristic parameter editing control, the target steering characteristic parameter is obtained.

[0171] In one embodiment, the lateral control device 800 of the vehicle may further include:

[0172] The road condition and vehicle quality acquisition module is used to obtain the lateral slope of the road where the target vehicle is located and the mass of the target vehicle.

[0173] The speed determination module is used to multiply the lateral slope and the mass of the target vehicle to determine the target yaw angle compensation speed of the target vehicle;

[0174] Accordingly, module 820 is defined as being used specifically for:

[0175] The desired yaw rate of the target vehicle is determined based on the ratio of the current longitudinal speed of the target vehicle to the target characteristic speed of the target vehicle.

[0176] The target yaw rate of the target vehicle is determined by adding the desired yaw rate of the target vehicle to the target yaw rate compensation rate.

[0177] As one implementation method, the road condition and vehicle quality acquisition module is specifically used for:

[0178] The predicted lateral acceleration of the center of gravity of the target vehicle, the actual lateral acceleration of the center of gravity of the target vehicle, and the roll angle of the target vehicle are obtained.

[0179] The acceleration difference is obtained by subtracting the predicted lateral acceleration of the target vehicle's center of gravity from the actual lateral acceleration of the target vehicle's center of gravity.

[0180] The lateral slope is obtained by subtracting the arcsine of the acceleration difference from the tilt angle of the target vehicle.

[0181] As one implementation method, the road condition and vehicle quality acquisition module is specifically used for:

[0182] The lateral slope of the road where the target vehicle is located, the mass of the target vehicle, the current steering wheel angle of the target vehicle, the steering characteristic parameters of the target vehicle, and the vehicle characteristic parameters of the target vehicle are obtained.

[0183] Accordingly, the speed determination module is specifically used for:

[0184] Multiply the lateral slope by the mass of the target vehicle to determine the lateral slope component of the target vehicle's center of gravity;

[0185] A second ratio is obtained based on the ratio of the steering characteristic parameters of the target vehicle to the current steering wheel angle of the target vehicle;

[0186] The target vehicle's yaw rate gain is determined by multiplying its desired yaw rate by the second ratio; the target vehicle's desired yaw rate is determined based on the ratio of the target vehicle's current longitudinal speed to its target characteristic speed.

[0187] The target yaw rate compensation speed of the target vehicle is determined by multiplying the lateral slope component of the target vehicle's center of gravity, the vehicle characteristic parameters of the target vehicle, and the yaw rate gain of the target vehicle.

[0188] In one embodiment, the lateral control device 800 of the vehicle may further include:

[0189] The wheel speed difference and pedal pressure depth acquisition module is used to acquire the wheel speed difference between the left wheel speed and the right wheel speed of the target vehicle, as well as the current brake pedal pressure depth of the target vehicle.

[0190] Accordingly, a module is defined, specifically for:

[0191] If the wheel speed difference is less than or equal to the wheel speed difference threshold, or the current brake pedal depth is less than or equal to the depth threshold, then the target yaw rate of the target vehicle is determined based on the ratio of the current longitudinal speed of the target vehicle to the target characteristic speed of the target vehicle.

[0192] If the wheel speed difference is greater than the wheel speed difference threshold, and the current brake pedal pressure depth is greater than the pressure depth threshold, then the preset yaw rate is determined as the target yaw rate of the target vehicle.

[0193] Accordingly, as one implementation method, it is specifically used for:

[0194] Feedforward control is performed on the wheel steering of the target vehicle based on the target yaw rate, and feedback control is performed on the wheel steering of the target vehicle based on the target yaw rate, the current yaw rate of the target vehicle, and the yaw rate of the target vehicle at the kth sampling time, and the target wheel steering angle value of the target vehicle is output; where k is an integer greater than 0.

[0195] The target wheel angle value is input to the wheel steering actuator of the target vehicle to control the wheels of the target vehicle to steer.

[0196] This application also provides a corresponding vehicle lateral control device and a computer-readable storage medium for implementing the solution provided in this application.

[0197] The lateral control device of the vehicle includes a memory and a processor. The memory is used to store a computer program, and the processor is used to execute the computer program so that the device performs the lateral control method of the vehicle according to any embodiment of this application.

[0198] The computer-readable storage medium stores a computer program, and when the computer program is run, the device running the computer program implements the lateral control method for a vehicle according to any embodiment of this application.

[0199] In the embodiments of this application, the terms "first" and "second" (if they exist) are used only as name identifiers and do not represent the order of first and second.

[0200] As can be seen from the above description of the embodiments, those skilled in the art can clearly understand that all or part of the steps in the methods of the above embodiments can be implemented by means of software plus a general-purpose hardware platform. Based on this understanding, the technical solution of this application can be embodied in the form of a software product. This computer software product can be stored in a readable storage medium, such as a read-only memory (ROM) / RAM, magnetic disk, optical disk, etc., including several instructions to cause a computer device (which may be a personal computer, a server, or a network communication device such as a router) to execute the methods described in various embodiments or some parts of the embodiments of this application.

[0201] It should be noted that the various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, for the device embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and the relevant parts can be referred to the description of the method embodiments. The device embodiments described above are merely illustrative, and the units described as separate components may or may not be physically separate. The components indicated as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of the solution in this embodiment according to actual needs.

[0202] The above description is merely one specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for lateral control of a vehicle, characterized in that, The method includes: The target steering characteristic parameters, the current longitudinal speed of the target vehicle, and the actual characteristic speed of the target vehicle are obtained; the target steering characteristic parameters are used to characterize the driving characteristics of the target driver driving the target vehicle; the target steering characteristic parameters are positively correlated with the steering sensitivity of the target vehicle; The target yaw rate of the target vehicle is determined based on the ratio of the current longitudinal speed of the target vehicle to the target characteristic speed of the target vehicle; the target characteristic speed of the target vehicle is determined based on the product of the target steering characteristic parameter and the actual characteristic speed of the target vehicle. Based on the target yaw rate, the wheels of the target vehicle are controlled to steer.

2. The method according to claim 1, characterized in that, The acquisition of the target steering characteristic parameters, the current longitudinal speed of the target vehicle, and the actual characteristic speed of the target vehicle specifically includes: The target vehicle's steering characteristic parameters, current longitudinal speed, actual characteristic speed, current steering wheel angle, and vehicle characteristic parameters are obtained; the vehicle characteristic parameters are used to characterize the target vehicle's hardware features. Determining the target yaw rate of the target vehicle based on the ratio of its current longitudinal speed to its target characteristic speed specifically includes: A first ratio is obtained based on the ratio of the current longitudinal speed of the target vehicle to the target characteristic speed of the target vehicle; Multiply the first ratio by the vehicle characteristic parameters of the target vehicle to obtain the first product; Multiply the current longitudinal speed of the target vehicle and the current steering wheel angle of the target vehicle to obtain a second product; The target yaw rate of the target vehicle is determined based on the ratio of the second product to the first product.

3. The method according to claim 2, characterized in that, The target characteristic speed of the target vehicle is obtained in the following way: The target characteristic speed of the target vehicle is determined by multiplying the target steering characteristic parameter, the characteristic speed coefficient of the target vehicle, and the actual characteristic speed of the target vehicle.

4. The method according to any one of claims 1-3, characterized in that, The target vehicle includes a steering characteristic parameter editing control, and the acquisition of the target steering characteristic parameters specifically includes: In response to the target driver's editing operation on the steering characteristic parameter editing control, the target steering characteristic parameter is obtained.

5. The method according to claim 1, characterized in that, The method further includes: Obtain the lateral slope of the road where the target vehicle is located and the mass of the target vehicle; Multiply the lateral slope and the mass of the target vehicle to determine the target yaw rate compensation speed of the target vehicle; Determining the target yaw rate of the target vehicle based on the ratio of its current longitudinal speed to its target characteristic speed specifically includes: The desired yaw rate of the target vehicle is determined based on the ratio of the current longitudinal speed of the target vehicle to the target characteristic speed of the target vehicle. The target yaw rate of the target vehicle is determined by adding the desired yaw rate of the target vehicle to the target yaw rate compensation rate.

6. The method according to claim 5, characterized in that, The acquisition of the lateral slope of the road where the target vehicle is located specifically includes: The predicted lateral acceleration of the center of gravity of the target vehicle, the actual lateral acceleration of the center of gravity of the target vehicle, and the roll angle of the target vehicle are obtained. The acceleration difference is obtained by subtracting the predicted lateral acceleration of the target vehicle's center of gravity from the actual lateral acceleration of the target vehicle's center of gravity. The lateral slope is obtained by subtracting the arcsine of the acceleration difference from the tilt angle of the target vehicle.

7. The method according to claim 5, characterized in that, The acquisition of the lateral slope of the road where the target vehicle is located and the mass of the target vehicle specifically includes: The lateral slope of the road where the target vehicle is located, the mass of the target vehicle, the current steering wheel angle of the target vehicle, the steering characteristic parameters of the target vehicle, and the vehicle characteristic parameters of the target vehicle are obtained. The step of multiplying the lateral slope and the mass of the target vehicle to determine the target yaw angle compensation speed of the target vehicle specifically includes: Multiply the lateral slope by the mass of the target vehicle to determine the lateral slope component of the target vehicle's center of gravity; A second ratio is obtained based on the ratio of the steering characteristic parameters of the target vehicle to the current steering wheel angle of the target vehicle; The target vehicle's yaw rate gain is determined by multiplying its desired yaw rate by the second ratio; the target vehicle's desired yaw rate is determined based on the ratio of the target vehicle's current longitudinal speed to its target characteristic speed. The target yaw rate compensation speed of the target vehicle is determined by multiplying the lateral slope component of the target vehicle's center of gravity, the vehicle characteristic parameters of the target vehicle, and the yaw rate gain of the target vehicle.

8. The method according to claim 1, characterized in that, The method further includes: The wheel speed difference between the left wheel speed and the right wheel speed of the target vehicle is obtained, as well as the current brake pedal depth of the target vehicle. Determining the target yaw rate of the target vehicle based on the ratio of its current longitudinal speed to its target characteristic speed specifically includes: If the wheel speed difference is less than or equal to the wheel speed difference threshold, or the current brake pedal depth is less than or equal to the depth threshold, then the target yaw rate of the target vehicle is determined based on the ratio of the current longitudinal speed of the target vehicle to the target characteristic speed of the target vehicle. If the wheel speed difference is greater than the wheel speed difference threshold, and the current brake pedal pressure depth is greater than the pressure depth threshold, then the preset yaw rate is determined as the target yaw rate of the target vehicle.

9. The method according to claim 1, characterized in that, The step of controlling the wheels of the target vehicle to steer based on the target yaw rate specifically includes: Feedforward control is performed on the wheel steering of the target vehicle based on the target yaw rate, and feedback control is performed on the wheel steering of the target vehicle based on the target yaw rate, the current yaw rate of the target vehicle, and the yaw rate of the target vehicle at the kth sampling time, and the target wheel steering angle value of the target vehicle is output; where k is an integer greater than 0. The target wheel angle value is input to the wheel steering actuator of the target vehicle to control the wheels of the target vehicle to steer.

10. A lateral control device for a vehicle, characterized in that, The device includes: The acquisition module is used to acquire target steering characteristic parameters, the current longitudinal speed of the target vehicle, and the actual characteristic speed of the target vehicle; the target steering characteristic parameters are used to characterize the driving characteristics of the target driver driving the target vehicle; the target steering characteristic parameters are positively correlated with the steering sensitivity of the target vehicle; The determination module is used to determine the target yaw rate of the target vehicle based on the ratio of the current longitudinal speed of the target vehicle to the target characteristic speed of the target vehicle; the target characteristic speed of the target vehicle is determined based on the product of the target steering characteristic parameter and the actual characteristic speed of the target vehicle. The control module is used to control the wheels of the target vehicle to steer based on the target yaw rate.

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