Automatic parking method and control device for vehicle

Abstract

The invention discloses an automatic parking method of a vehicle and a control device. The method comprises the steps that an automatic parking instruction for the vehicle is acquired; and responding to the automatic parking instruction, and controlling front and rear wheels of the vehicle to rotate at the same time so as to realize automatic parking. When the vehicle is controlled to be automatically parked, the front wheels and the rear wheels of the vehicle are adjusted to steer, so that the parking distance and time required by automatic parking can be reduced, and the automatic parking efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the field of automatic parking, and in particular to an automatic parking method and a control device for a vehicle. Background Art

[0002] Automatic parking means that the car automatically parks itself without manual control. Existing automatic parking systems all achieve automatic parking functions by controlling the front wheel steering. After the vehicle controller uses the on-board sensor to identify the parking space, it sends a parking command through the automatic parking controller and coordinates the steering controller and brake controller to perform automatic parking. However, this will cause the vehicle to need to perform multiple backing and steering operations to adjust the parking path when automatically parking in some narrow parking spaces. The required parking distance and time are relatively long, which affects the efficiency of automatic parking. Summary of the invention

[0003] The embodiment of the present invention provides an automatic parking method and control device for a vehicle, so as to realize steering of the front and rear wheels of the vehicle simultaneously during automatic parking, thereby reducing the parking distance and time required for automatic parking and improving the efficiency of automatic parking.

[0004] In a first aspect, an embodiment of the present invention provides an automatic parking method for a vehicle, comprising:

[0005] Obtain an automatic parking instruction for the vehicle; respond to the automatic parking instruction and control the front and rear wheels of the vehicle to rotate simultaneously to achieve automatic parking.

[0006] It can be seen that by controlling the front and rear wheels of the vehicle to steer at the same time, it is helpful to improve the flexibility of the vehicle during lateral movement, reduce the parking distance and time required for automatic parking, and improve the efficiency of automatic parking.

[0007] In combination with the first aspect, in a possible implementation, the automatic parking method for a vehicle further includes: when controlling the front and rear wheels of the vehicle to rotate simultaneously, the deflection direction of the rear wheels of the vehicle is opposite to the deflection direction of the front wheels of the vehicle.

[0008] When the vehicle is moving, the front and rear wheels deflect in opposite directions, which can reduce the vehicle's equivalent wheelbase, thereby reducing the vehicle's turning diameter when it moves sideways, making the vehicle more flexible when parking automatically.

[0009] In conjunction with the first aspect, in a possible implementation, controlling the front and rear wheels of the vehicle to rotate simultaneously includes:

[0010] Obtaining a front wheel target turning angle value and a rear wheel target turning angle value of the vehicle; determining a target turning angle of a steering wheel of the vehicle according to the front wheel target turning angle value and the rear wheel target turning angle value; and controlling the steering wheel to rotate the target turning angle to control the vehicle to steer.

[0011] By obtaining the target turning angles of the front and rear wheels of the vehicle and determining the target turning angle of the steering wheel of the vehicle, it is possible to simultaneously control the turning of the front and rear wheels of the vehicle by turning the steering wheel, thereby improving the control efficiency of the vehicle over the front and rear wheels and the steering flexibility.

[0012] In combination with the first aspect, in a possible implementation, determining a target steering angle of a steering wheel of a vehicle according to a front wheel target steering angle value and a rear wheel target steering angle value includes:

[0013] Determine a first correspondence between the front wheel angle and the steering wheel angle; determine a second correspondence between the rear wheel angle and the steering wheel angle; and determine a target angle based on the front wheel target angle value, the rear wheel target angle value, the first correspondence, and the second correspondence.

[0014] By determining the correspondence between the vehicle's front wheel angle, rear wheel angle and steering wheel angle, and then obtaining the target steering wheel angle based on the front wheel target angle, rear wheel target angle and the correspondence, it is possible to simultaneously control the vehicle's front and rear wheel rotation target angles through the steering wheel, thereby improving the efficiency of the vehicle's automatic parking.

[0015] In combination with the first aspect, in a possible implementation manner, determining the target turning angle based on the front wheel target turning angle value, the rear wheel target turning angle value, the first corresponding relationship, and the third corresponding relationship includes:

[0016] Performing PID correction on the second corresponding relationship to obtain a third corresponding relationship; and determining the target turning angle based on the front wheel target turning angle value, the rear wheel target turning angle value, the first corresponding relationship, and the third corresponding relationship.

[0017] First, the correspondence between the front and rear wheel angles and the steering wheel angle of the vehicle is determined, and then the obtained correspondence is PID corrected to obtain a new correspondence. Finally, a high-precision target steering wheel angle is determined based on the new correspondence. The vehicle determines the parking path based on the target angle, which is beneficial to improve the accuracy of the vehicle's automatic parking.

[0018] In combination with the first aspect, in a possible implementation manner, performing PID correction on the second corresponding relationship to obtain a third corresponding relationship includes:

[0019] Determine the actual parking position of the vehicle after automatic parking according to the first corresponding relationship and the second corresponding relationship; determine the position deviation between the target parking position and the actual parking position, the target parking position being the expected parking position of the vehicle for automatic parking; use the position deviation as the input of PID to obtain the compensation value of PID output; and determine the third corresponding relationship according to the second corresponding relationship and the compensation value.

[0020] By correcting the correspondence between the rear wheel angle of the vehicle and the steering wheel angle, it is helpful to reduce the parking position error caused by the inaccurate correspondence between the rear wheel angle of the vehicle and the steering wheel angle.

[0021] In conjunction with the first aspect, in a possible implementation manner, determining a first corresponding relationship between a turning angle of a front wheel and a turning angle of a steering wheel includes:

[0022] A front and rear wheel steering angle ratio control equation of the vehicle is established; and a first corresponding relationship is obtained through the front and rear wheel steering angle ratio control equation of the vehicle.

[0023] By establishing a front and rear wheel angle proportional control equation for the vehicle and obtaining a first corresponding relationship between the vehicle's front wheel angle and the steering wheel angle based on the front and rear wheel angle proportional control equation, the accuracy of the obtained first corresponding relationship can be ensured.

[0024] In conjunction with the first aspect, in a possible implementation manner, determining a second correspondence between a rear wheel angle and a steering wheel angle includes:

[0025] The two-degree-of-freedom dynamic equation of the vehicle and the relationship equation between the lateral force of the front and rear wheels and the sideslip angle of the vehicle are established; the rear wheel steering dynamic equation of the vehicle is obtained through the two-degree-of-freedom dynamic equation of the vehicle and the relationship equation between the lateral force of the front and rear wheels and the sideslip angle of the vehicle; the second corresponding relationship is determined through the front and rear wheel steering angle proportional control equation of the vehicle and the rear wheel steering dynamic equation of the vehicle.

[0026] The rear wheel steering dynamics equation is obtained by combining the vehicle's two-degree-of-freedom dynamics equation and the relationship equation between the front and rear wheel lateral forces and the sideslip angle. Then, the correspondence between the rear wheel and steering wheel angle is obtained based on the rear wheel steering dynamics equation and the front and rear wheel proportional relationship. This ensures that the second correspondence obtained has high applicability and accuracy in different parking scenarios.

[0027] In combination with the first aspect, in a possible implementation, the second corresponding relationship is determined by a front and rear wheel steering angle ratio control equation of the vehicle and a rear wheel steering dynamics equation of the vehicle, including:

[0028] The fourth corresponding relationship between the vehicle's center of mass sideslip angle and the steering wheel angle is obtained through the vehicle's front and rear wheel steering angle proportional control equation and the vehicle's rear wheel steering dynamics equation; when the vehicle's center of mass sideslip angle is 0, the fifth corresponding relationship between the vehicle's rear wheel steering angle and the front wheel steering angle is determined through the fourth corresponding relationship and the vehicle's front and rear wheel steering angle proportional control equation; the second corresponding relationship is obtained through the first corresponding relationship and the fifth corresponding relationship.

[0029] When the vehicle is moving sideways, the smaller the sideslip angle is, the better the vehicle stability is. Therefore, determining the second correspondence between the rear wheel angle and the steering wheel angle when the sideslip angle is 0 can ensure the stability of the vehicle when the rear wheels of the subsequent vehicle turn.

[0030] In conjunction with the first aspect, in a possible implementation, obtaining a front wheel target turning angle value and a rear wheel target turning angle value of the vehicle includes:

[0031] A parking path from the current position of the vehicle to a target parking position is obtained, where the target parking position is the parking position of the vehicle in the effective parking space at the current position; a front wheel target turning angle value and a rear wheel target turning angle value of the vehicle are calculated based on the parking path.

[0032] By determining the parking path from the current position of the vehicle to the target parking position, the target turning angle values ​​of the front and rear wheels of the vehicle are calculated. This helps to ensure that the vehicle can reach the target parking position along the planned parking path after being controlled according to the target turning angle value, thereby ensuring the accuracy of automatic parking.

[0033] In combination with the first aspect, in a possible implementation manner, the automatic parking method for a vehicle further includes:

[0034] When an automatic parking instruction is obtained for the vehicle, if at least one of the following conditions is met, the automatic parking instruction will be responded to and the front and rear wheels of the vehicle will be controlled to rotate simultaneously to achieve automatic parking: the vehicle's electric power steering system has no faults, the vehicle's parking indicator light is on, the vehicle's gear is in P gear, the vehicle's speed does not exceed 10KM / h, and the torque of the vehicle's steering wheel force does not exceed 2Nm.

[0035] After receiving the parking instruction, it determines whether the current vehicle status allows automatic parking, and parks the vehicle after all conditions are met. This helps avoid parking failures due to system failures related to automatic parking or human intervention during the automatic parking process, and improves the success rate of automatic parking.

[0036] In a second aspect, an embodiment of the present invention provides a vehicle control device, including:

[0037] The acquisition module is used to acquire the automatic parking instruction for the vehicle; the control module is used to respond to the automatic parking instruction and control the front and rear wheels of the vehicle to rotate simultaneously to achieve automatic parking.

[0038] In a third aspect, an embodiment of the present application provides a vehicle control device, including:

[0039] A memory, a processor, and an automatic parking program for a vehicle stored in the memory and executable on the processor, wherein the automatic parking program for the vehicle is configured to implement part or all of the steps described in any method in the first aspect.

[0040] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, on which an automatic parking program for a vehicle is stored. When the automatic parking program for the vehicle is executed by a processor, some or all of the steps described in any method in the first aspect are implemented.

[0041] In a fifth aspect, an embodiment of the present application provides a computer program product, wherein the computer program product includes a computer program, and the computer program is operable to cause a computer to execute some or all of the steps described in any method of the first aspect of the embodiment of the present application. The computer program product can be a software installation package.

[0042] In a sixth aspect, an embodiment of the present application provides a vehicle, comprising a control device for the vehicle of the second aspect or the third aspect.

[0043] By implementing the embodiment of the present invention, the control device first obtains an automatic parking instruction for the vehicle; then responds to the automatic parking instruction and controls the front and rear wheels of the vehicle to rotate simultaneously to achieve automatic parking. By controlling the vehicle to simultaneously mobilize the front and rear wheels of the vehicle to steer during automatic parking, the parking distance and time required for automatic parking can be reduced, thereby improving the efficiency of automatic parking. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the background technology, the drawings required for use in the embodiments of the present invention or the background technology will be described below.

[0045] Figure 1 is a schematic diagram of the system architecture of an automatic parking method for a vehicle provided in an embodiment of the present application;

[0046] Figure 2 is a flow chart of an automatic parking method for a vehicle provided in an embodiment of the present application;

[0047] Figure 3 is a scene diagram of an automatic parking method for a vehicle provided in an embodiment of the present application;

[0048] Figure 4 is a schematic diagram of a two-degree-of-freedom vehicle dynamics model provided in an embodiment of the present application;

[0049] Figure 5 is an example parameter table of an automatic parking method for a vehicle provided in an embodiment of the present application;

[0050] Figure 6A scene diagram for obtaining a vehicle parking path provided in an embodiment of the present application;

[0051] Figure 7 is a structural schematic diagram of a vehicle control device provided in an embodiment of the present application;

[0052] Figure 8 It is a schematic diagram of the structure of another vehicle control device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0053] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present application.

[0054] The terms "first", "second", "third", etc. in the specification, claims and drawings of this application are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices.

[0055] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0056] Automatic parking means that the car automatically parks itself without manual control. Existing automatic parking systems all achieve automatic parking functions by controlling the front wheel steering. After the vehicle controller uses the on-board sensor to identify the parking space, it sends a parking command through the automatic parking controller and coordinates the steering controller and brake controller to perform automatic parking. However, this will cause the vehicle to need to perform multiple backing and steering operations to adjust the parking path when automatically parking in some narrow parking spaces. The required parking distance and time are relatively long, which affects the efficiency of automatic parking.

[0057] In response to the above-mentioned problems, an embodiment of the present application provides a method and a control device for automatic parking of a vehicle. The control device first obtains an automatic parking instruction for the vehicle; then, in response to the automatic parking instruction, the front and rear wheels of the vehicle are controlled to rotate simultaneously to achieve automatic parking. By controlling the vehicle to turn the front and rear wheels of the vehicle simultaneously during automatic parking, the parking distance and time required for automatic parking can be reduced, thereby improving the efficiency of automatic parking.

[0058] See also Figure 1 , Figure 1 This is a system architecture diagram of an automatic parking method for a vehicle provided in an embodiment of the present application, the system including a vehicle controller (VCU), an automatic parking assist (APA) system, an intelligent power braking system, a shifter (SCU), a four-wheel steering electronic control unit (ECU), a proportional integral derivative (PID) controller, front wheel sensors and rear wheel sensors, and front wheel steering gears and rear wheel steering gears.

[0059] Among them, after receiving the parking instruction, VCU controls APA to determine whether the current vehicle is allowed to perform automatic parking according to the status of VCU and SCU. After determining that automatic parking is possible, APA can identify the effective parking space of the current vehicle position through the radar or camera in the on-board sensor, calculate the parking path and send the vehicle's front and rear wheel angle request values ​​to ECU, and then ECU simulates control of the vehicle's front and rear wheels based on the front and rear wheel angle request values, PID analyzes and corrects the ECU dynamic performance according to the results of the simulation control, and obtains the front and rear wheel angle target values, and finally ECU controls the vehicle's front and rear wheels based on the front and rear wheel angle target values ​​to complete automatic parking.

[0060] Among them, the parking command received by the VCU can be issued by the user through the vehicle's central control platform, mobile phone, vehicle key, electronic watch or other electronic devices; the intelligent power braking system can be an intelligent braking system (IBS) or an intelligent integrated power brake (IPB) system; the front wheel sensor and the rear wheel sensor can be used to obtain information such as the steering angle and speed of the front and rear wheels of the vehicle and transmit the information to the VCU, and the front wheel steering gear and the rear wheel steering gear are used to control the steering of the front and rear wheels under the control of the ECU.

[0061] Based on this, an embodiment of the present application provides an automatic parking method for a vehicle, and the present application is described in detail below with reference to the accompanying drawings.

[0062] See also Figure 2 , Figure 2 is a flow chart of an automatic parking method for a vehicle provided in an embodiment of the present application, such as Figure 2 As shown, the method comprises the following steps:

[0063] S201, the control device obtains an automatic parking instruction for the vehicle.

[0064] The control device is Figure 1 The VCU or a module in the VCU detects in real time an automatic parking instruction for the vehicle, which may be issued by a user through a central control platform of the vehicle, a mobile phone, a vehicle key, an electronic watch or other electronic devices.

[0065] S202, the control device responds to the automatic parking instruction and controls the front and rear wheels of the vehicle to rotate simultaneously to achieve automatic parking.

[0066] When the control device obtains an automatic parking instruction for the vehicle and responds to the automatic parking instruction, the control device controls the rotation of the steering wheel and the front and rear wheels of the vehicle at the same time, thereby performing the steering operation in automatic parking.

[0067] It can be seen that in this example, by simultaneously controlling the front and rear wheels of the vehicle for steering, it is beneficial to improve the flexibility of the vehicle during lateral movement, reduce the parking distance and time required for automatic parking, and improve the efficiency of automatic parking.

[0068] In a possible implementation, when the control device controls the front and rear wheels of the vehicle to rotate simultaneously, the deflection direction of the rear wheels of the vehicle is opposite to the deflection direction of the front wheels of the vehicle.

[0069] In another example, the control device controls the front and rear wheels of the vehicle to deflect in opposite directions when the vehicle speed is low, and controls the front and rear wheels of the vehicle to deflect in the same direction when the vehicle speed is high.

[0070] For example, see Figure 3 , Figure 3 This is a scene diagram of an automatic parking method for a vehicle provided in an embodiment of the present application. The vehicle is at a low speed when performing automatic parking. The dotted arrow in the figure indicates the current driving direction of the vehicle. The vehicle needs to reach parking space P through automatic parking without colliding with vehicles in other parking spaces. Specifically, the arrow indicates the driving direction of the vehicle after the front and rear wheels of the vehicle are turned. It can be seen that when performing automatic parking, the front wheels of the vehicle deflect to the right side of the driving direction of the vehicle, and the rear wheels of the vehicle deflect to the left side of the driving direction of the vehicle, and the rotation direction of the rear wheels is opposite to the deflection direction of the front wheels of the vehicle.

[0071] It can be seen that in this example, the front and rear wheels deflect in opposite directions when the vehicle is moving, which can reduce the vehicle's equivalent wheelbase, thereby reducing the turning diameter of the vehicle when it moves sideways, making the vehicle more flexible during automatic parking.

[0072] In a possible implementation, the control device controls the front and rear wheels of the vehicle to rotate simultaneously, including:

[0073] The control device obtains the front wheel target turning angle value and the rear wheel target turning angle value of the vehicle; the control device determines the target turning angle of the steering wheel of the vehicle according to the front wheel target turning angle value and the rear wheel target turning angle value; the control device controls the steering wheel to rotate the target turning angle to control the vehicle to steer.

[0074] The turning angle values ​​of the two front wheels of the vehicle are the same, the turning angle values ​​of the two rear wheels of the vehicle are the same, the direction of the turning angle value of the front wheels is opposite to the direction of the turning angle value of the rear wheels, and it should be understood that the turning angle value here is a vector. It is stipulated that the direction along the right side of the vehicle's driving direction is the positive direction, when the turning angle value of the front wheel is a positive value, the vehicle turns to the right side of the driving direction, and when the turning angle value of the front wheel is a negative value, the vehicle turns to the left side of the driving direction. For example, the turning angle value of the front wheel can be -5°, 5° or 10°, when the turning angle value of the front wheel is -5°, the turning angle of the rear wheel can be 5°, and when the turning angle value of the front wheel is 5°, the turning angle of the rear wheel can be -5°.

[0075] Among them, the control device controls the front and rear wheels of the vehicle to rotate to the target angle simultaneously by controlling the rotation of the steering wheel of the vehicle. For example, the target steering angle value of the front wheels of the current vehicle for automatic parking is 10°, and the target steering angle value of the rear wheels is -5°. At this time, the vehicle should turn to the right side of the vehicle's driving direction. The control device controls the steering wheel of the vehicle to rotate 5° clockwise to achieve control of the steering angles of the front and rear wheels of the vehicle and complete the steering of automatic parking.

[0076] It can be seen that in this example, by obtaining the target turning angles of the front and rear wheels of the vehicle and determining the target turning angle of the steering wheel of the vehicle, it is possible to simultaneously control the rotation of the front and rear wheels of the vehicle by turning the steering wheel, thereby improving the control efficiency of the vehicle over the front and rear wheels and the steering flexibility.

[0077] In a possible implementation, the control device determines the target steering angle of the vehicle's steering wheel according to the front wheel target steering angle value and the rear wheel target steering angle value, including:

[0078] The control device determines a first correspondence between the front wheel angle and the steering wheel angle; determines a second correspondence between the rear wheel angle and the steering wheel angle; and determines a target angle based on the front wheel target angle value, the rear wheel target angle value, the first correspondence, and the second correspondence.

[0079] The control device determines the angle that the steering wheel should be turned based on the corresponding relationship between the front wheel angle and the steering wheel angle and the corresponding relationship between the rear wheel angle and the steering wheel angle. The corresponding relationship may be a quantitative relationship between two angle values ​​or a function with two angle values ​​as unknowns. Specifically, the function may be a transfer function of the front wheel angle to the steering wheel angle. For example, the corresponding relationship between the front wheel angle and the steering wheel angle may be that the front wheel angle is equal to the product of the steering wheel angle and 2. The corresponding relationship between the front wheel angle and the steering wheel angle may also be the following transfer function G(S):

[0080] S is a complex variable.

[0081] Exemplarily, the first corresponding relationship is determined as the front wheel steering angle value is equal to the clockwise steering wheel steering angle value, and the third corresponding relationship is determined as the rear wheel steering angle value is equal to the counterclockwise steering wheel steering angle value. When the front wheel steering angle value of the vehicle is 5° and the rear wheel steering angle value is -5°, the steering wheel of the vehicle should be turned 5° clockwise; when the front wheel steering angle value of the vehicle is -8° and the rear wheel steering angle value is 8°, the steering wheel of the vehicle should be turned 8° counterclockwise.

[0082] It can be seen that in this example, by determining the correspondence between the front wheel angle, rear wheel angle and steering wheel angle of the vehicle, and then obtaining the target steering wheel angle based on the front wheel target angle, rear wheel target angle and the correspondence, it is possible to simultaneously control the front and rear wheel rotation target angles of the vehicle through the steering wheel, thereby improving the efficiency of automatic parking of the vehicle.

[0083] In a possible implementation, the control device determines the target turning angle based on the front wheel target turning angle value, the rear wheel target turning angle value, the first corresponding relationship, and the third corresponding relationship, including:

[0084] The control device performs PID correction on the second corresponding relationship to obtain a third corresponding relationship; the control device determines the target steering angle based on the front wheel target steering angle value, the rear wheel target steering angle value, the first corresponding relationship and the third corresponding relationship.

[0085] Among them, PID is a common feedback loop component in control applications, which consists of a proportional unit P, an integral unit I and a differential unit D. The use of PID control can eliminate steady-state errors. The relationship between its input e(t) and output u(t) is:

[0086] u(t)=kp[e(t)+1 / TI∫e(t)dt+TD x de(t) / dt],

[0087] In the above formula, the upper and lower limits of the integral are t and 0 respectively, and the functions of the input e(t) and the output u(t) after Laplace transformation are E(s) and U(s) respectively, so the transfer function of PID is:

[0088] G(s)=U(s) / E(s)=kp[1+1 / (TIxS)+TDxS],

[0089] Among them, kp is the proportional coefficient, TI is the integral time constant, TD is the differential time constant, and S is a complex variable.

[0090] It can be seen that in this example, the correspondence between the front and rear wheel angles and the steering wheel angle of the vehicle is first determined, and then the obtained correspondence is PID corrected to obtain a new correspondence. Finally, a high-precision target steering wheel angle is determined based on the new correspondence. The vehicle determines the parking path based on the target angle, which is beneficial to improving the accuracy of the vehicle's automatic parking.

[0091] In one possible implementation, the control device determines the actual parking position of the vehicle after automatic parking according to the first corresponding relationship and the second corresponding relationship; determines the position deviation between the target parking position and the actual parking position, the target parking position being the expected parking position of the vehicle for automatic parking; uses the position deviation as the input of PID to obtain the compensation value of PID output; and determines the third corresponding relationship based on the second corresponding relationship and the compensation value.

[0092] Specifically, the control device performs a simulation request after obtaining the first correspondence and the second correspondence, simulates the actual parking position of the vehicle after controlling the vehicle turning according to the first correspondence and the second correspondence, and uses the position deviation between the actual parking position and the target parking position as the input of PID, and PID then analyzes and corrects the dynamic performance of the system to obtain a compensation value.

[0093] It can be seen that in this example, by correcting the correspondence between the rear wheel angle of the vehicle and the steering wheel angle, it is helpful to reduce the parking position error caused by the inaccurate correspondence between the rear wheel angle of the vehicle and the steering wheel angle.

[0094] In a possible implementation, the control device determines a first corresponding relationship between a turning angle of a front wheel and a turning angle of a steering wheel, including:

[0095] The control device establishes a front and rear wheel steering angle ratio control equation of the vehicle; and obtains a first corresponding relationship through the front and rear wheel steering angle ratio control equation of the vehicle.

[0096] Among them, the front and rear wheel angles are controlled by front and rear wheel angle proportional control, and the front and rear wheel angle functions are δ 1 (S),δ 2 (S), then the front and rear wheel turning angle function refers to the following formula:

[0097]

[0098]

[0099] Among them, δ(S) represents the steering wheel angle signal, n represents the transmission ratio of the front wheel steering system, and G1(S) represents the transfer function of the rear wheel angle relative to the front wheel angle. At this time, δ 1 (S) is the transfer function of the front wheel angle to the steering wheel angle, δ 2 (S) is the transfer function of the rear wheel angle to the steering wheel angle.

[0100] It can be seen that in this example, by establishing the front and rear wheel angle proportional control equation of the vehicle and obtaining the first corresponding relationship between the vehicle's front wheel angle and the steering wheel angle based on the front and rear wheel angle proportional control equation, the accuracy of the obtained first corresponding relationship can be ensured.

[0101] In a possible implementation, determining a second correspondence between a rear wheel angle and a steering wheel angle includes:

[0102] The two-degree-of-freedom dynamic equation of the vehicle and the relationship equation between the lateral force of the front and rear wheels and the sideslip angle of the vehicle are established; the rear wheel steering dynamic equation of the vehicle is obtained through the two-degree-of-freedom dynamic equation of the vehicle and the relationship equation between the lateral force of the front and rear wheels and the sideslip angle of the vehicle; the second corresponding relationship is determined through the front and rear wheel steering angle proportional control equation of the vehicle and the rear wheel steering dynamic equation of the vehicle.

[0103] Among them, the SAE standard coordinate system is used to describe the vehicle movement. During the automatic parking process, the vehicle speed is low and the change range is not large, so the vehicle speed is regarded as a uniform speed state, and the change of vehicle speed is ignored. At the same time, the influence of tire suspension is ignored, that is, the displacement of the car along the Z axis, the pitch angle around the Y axis, and the roll angle around the X axis are all 0. The influence of the ground tangential force on the tire side slip characteristics is not considered, there is no aerodynamic effect, and the changes in tire characteristics caused by the change of load on the left and right tires and the effect of the tire self-aligning torque are ignored. The movement of the car is regarded as a movement parallel to the ground, and only two degrees of freedom are considered: the lateral movement of the car along the Y axis and the yaw movement around the Z axis.

[0104] Based on this, the two-degree-of-freedom dynamic equation of the vehicle can be found in Formula 1 and Formula 2:

[0105] Formula 1:

[0106] Formula 2:

[0107] Among them, see Figure 4 , Figure 4It is a schematic diagram of a two-degree-of-freedom vehicle dynamics model provided in an embodiment of the present application. Fy1 in Formula 1 represents the lateral force of the front wheel, Fy2 represents the lateral force of the rear wheel, ω represents the yaw angular velocity of the vehicle, β represents the sideslip angle of the center of mass, u represents the longitudinal velocity of the center of mass of the vehicle, v represents the lateral velocity of the center of mass of the vehicle, V represents the center of mass velocity of the vehicle, V1 represents the front wheel speed of the vehicle, V2 represents the rear wheel speed of the vehicle, and I in Formula 2 represents the yaw moment of inertia.

[0108] At this time, assuming that the cornering stiffness of the front and rear wheels of the vehicle are K1 and K2 respectively, the relationship between the lateral force of the front and rear wheels and their sideslip angle is:

[0109] Formula 3:

[0110] Formula 4:

[0111] Among them, Formula 3 represents the relationship between the lateral force of the front wheel of the vehicle and its sideslip angle, and Formula 4 represents the relationship between the lateral force of the rear wheel of the vehicle and its sideslip angle. 1 , α 2 They represent the front and rear wheel slip angles, δ1 and δ2 represent the front and rear wheel turning angles, ɑ and b represent the distances from the front and rear axles of the vehicle to the center of mass of the vehicle.

[0112] Specifically, by combining Formula 1, Formula 2, Formula 3 and Formula 4, the vehicle rear wheel steering dynamics equation can be obtained as follows:

[0113] Formula 5:

[0114] Formula 6:

[0115] Wherein, m in Formula 5 represents the mass of the vehicle.

[0116] Among them, the rear wheel angle is controlled by the front and rear wheel angle proportional control, and the front and rear wheel angle functions are δ 1 (S),δ 2 (S), then the front and rear wheel turning angle functions refer to Formula 7 and Formula 8:

[0117] Formula 7:

[0118] Formula 8:

[0119] Among them, δ(S) in Formula 7 and Formula 8 represents the steering wheel angle signal, n represents the transmission ratio of the front wheel steering system, and G1(S) represents the transfer function of the rear wheel angle relative to the front wheel angle. At this time, δ in Formula 7 1 (S) is the transfer function of the front wheel angle to the steering wheel angle, δ 2(S) is the transfer function of the rear wheel angle to the steering wheel angle.

[0120] It can be seen that in this example, the rear wheel steering dynamics equation is obtained by combining the two-degree-of-freedom dynamics equation of the vehicle and the relationship equation between the lateral force of the front and rear wheels and the sideslip angle. Then, the correspondence between the rear wheels and the steering wheel angle is obtained based on the rear wheel steering dynamics equation and the proportional relationship between the front and rear wheels. This ensures that the second correspondence obtained has high applicability and accuracy in different parking scenarios.

[0121] In a possible implementation, the control device determines the second corresponding relationship through the front and rear wheel angle ratio control equation of the vehicle and the rear wheel steering dynamics equation of the vehicle, including:

[0122] The control device obtains the fourth corresponding relationship between the vehicle's center of mass sideslip angle and the steering wheel angle through the vehicle's front and rear wheel angle proportional control equation and the vehicle's rear wheel steering dynamics equation; when the vehicle's center of mass sideslip angle is 0, the control device determines the fifth corresponding relationship between the vehicle's rear wheel angle and the front wheel angle through the fourth corresponding relationship and the vehicle's front and rear wheel angle proportional control equation; the control device obtains the second corresponding relationship through the first corresponding relationship and the fifth corresponding relationship.

[0123] Among them, based on the SAE standard coordinate system, by combining Formula 5, Formula 6, Formula 7 and Formula 8, the transfer function of the vehicle's center of mass sideslip angle relative to the steering wheel angle can be obtained as follows:

[0124]

[0125] Wherein, β(s) in Formula 9 represents the transfer function of the vehicle's center of mass sideslip angle, and S is a complex variable;

[0126] The smaller the side slip angle of the vehicle's center of mass, the better the stability of the vehicle during movement. Substituting the side slip angle of the center of mass equal to zero into Formula 9, the transfer function of the rear wheel angle relative to the front wheel angle is obtained as follows:

[0127] Formula 10:

[0128] Wherein, I in Formula 10 represents the vehicle wheelbase, I = ɑ + b;

[0129] At this time, by combining formula 10, i.e., the transfer function of the rear wheel angle relative to the front wheel angle, and formula 7, i.e., the transfer function of the front wheel angle relative to the steering wheel angle, the transfer function of the rear wheel angle relative to the steering wheel angle can be obtained as follows:

[0130] Formula 11:

[0131] For example, see Figure 5 , Figure 5 is an example parameter table of an automatic parking method for a vehicle provided in an embodiment of the present application. The yaw moment of inertia of the vehicle is equal to 2059 kg·m 2 The mass of the vehicle is 1850kg, the distances from the front and rear axles to the center of mass of the vehicle are 1.30m and 1.40m respectively, and the lateral stiffness of the front and rear wheels of the vehicle are -1.3751x10 5 N.rad -1 , -1.5630x10 5 N.rad -1 , the front-wheel steering system transmission ratio is 16, and the vehicle center of mass speed is 30kph (kph means kilometers per hour).

[0132] At this time, substituting the parameters into the above formula, the transfer function G(S) of the rear wheel angle relative to the steering wheel angle is:

[0133]

[0134] It can be seen that in this example, when the vehicle is moving sideways, the smaller the sideslip angle of the center of mass is, the better the vehicle stability is. Therefore, determining the second correspondence between the rear wheel angle and the steering wheel angle when the sideslip angle of the center of mass of the vehicle is 0 can ensure the stability of the vehicle when the rear wheels of the subsequent vehicle turn.

[0135] In a possible implementation, the control device acquires the front wheel target turning angle value and the rear wheel target turning angle value of the vehicle including:

[0136] The control device obtains a parking path from the current position of the vehicle to a target parking position, where the target parking position is the parking position of the vehicle in an effective parking space at the current position; the control device calculates a front wheel target turning angle value and a rear wheel target turning angle value of the vehicle based on the parking path.

[0137] Among them, the vehicle can identify the effective parking space at the current position through the on-board sensor. The on-board sensor can be a radar or a camera. Specifically, the on-board radar can obtain the distance and angle between the current position of the vehicle and the object by emitting electromagnetic wave signals and receiving echoes reflected by the collision of the object, and then identify the effective parking space where no object exists; the camera can directly obtain the distance and angle between the current position of the vehicle and the object by acquiring the depth information in the collected image, and then identify the effective parking space where no object exists.

[0138] Among them, when determining the parking path from the current position of the vehicle to the target parking position, the Dijkstra algorithm, the Floyd algorithm or the shortest path faster algorithm (SPFA) can be used. These three algorithms all calculate the shortest path from the current position of the vehicle to the target parking position, and use the shortest path as the parking path.

[0139] For example, see Figure 6 , Figure 6 It is a scene diagram for obtaining a vehicle parking path provided in an embodiment of the present application. The vehicle recognizes that the effective parking space at the current position is A through the on-board sensor, and then determines the target parking position C of the vehicle in the effective parking space A. Thereafter, the shortest path B from the current position to the target parking position C is determined according to the algorithm, that is, the trajectory indicated by the dotted arrow in the figure. Finally, the vehicle calculates the front wheel target turning angle value and the rear wheel target turning angle value of the vehicle according to the parking path B.

[0140] It can be seen that in this example, the target turning angle values ​​of the front and rear wheels of the vehicle are calculated by determining the parking path from the current position of the vehicle to the target parking position. This is conducive to ensuring that the vehicle can reach the target parking position along the planned parking path after being controlled according to the target turning angle value, thereby ensuring the accuracy of automatic parking.

[0141] In a possible implementation, the automatic parking method for a vehicle further includes:

[0142] When the control device obtains an automatic parking instruction for the vehicle, it will respond to the automatic parking instruction and control the front and rear wheels of the vehicle to rotate simultaneously to achieve automatic parking if at least one of the following conditions is met: the vehicle's electric power steering system has no faults, the vehicle's parking indicator light is on, the vehicle's gear is in P gear, the vehicle's speed does not exceed the speed threshold, and the torque applied to the vehicle's steering wheel does not exceed the torque threshold.

[0143] In another example, when the control device obtains an automatic parking instruction for the vehicle, all of the following conditions must be met before it can respond to the automatic parking instruction and control the front and rear wheels of the vehicle to rotate simultaneously to achieve automatic parking: the vehicle's electric power steering system has no faults, the vehicle's parking indicator light is on, the vehicle's gear is in P gear, the vehicle's speed does not exceed the speed threshold, and the torque applied to the vehicle's steering wheel does not exceed the torque threshold.

[0144] The vehicle speed threshold may be 10 km / h, and the torque threshold may be 2 Nm. No restrictions are imposed on the vehicle speed threshold and the torque threshold.

[0145] Among them, the vehicle's electric power steering system is responsible for controlling the steering of the front and rear wheels of the vehicle. When obtaining the vehicle speed and making a judgment, the external message information of the intelligent power braking system is obtained at the same time. The external message information of the intelligent power braking system includes the vehicle speed and the vehicle speed status. The control device can judge whether the vehicle speed is overspeeding and whether the vehicle speed status is normal through the external message information of the intelligent power braking system;

[0146] Among them, the torque of the vehicle's steering wheel is directly detected by the EPS steering wheel torque sensor to obtain a numerical value, and the torque of the steering wheel is used to determine whether the driver has intervened in the process of preparing for automatic parking. If the driver has intervened, the automatic parking is stopped.

[0147] It can be seen that in this example, after obtaining the parking instruction, it is determined whether the current vehicle state allows automatic parking, and parking is performed after the vehicle meets all conditions. This is helpful to avoid parking failures caused by system failures related to automatic parking or human intervention during the automatic parking process, and improve the success rate of automatic parking.

[0148] It can be seen that in this embodiment, by controlling the front and rear wheels of the vehicle to steer at the same time, it is beneficial to improve the flexibility of the vehicle when performing lateral movement, reduce the parking distance and time required for automatic parking, and improve the efficiency of automatic parking. When the vehicle moves, the front and rear wheels deflect in opposite directions, which can reduce the equivalent wheelbase of the vehicle, thereby reducing the turning diameter when the vehicle performs lateral movement, making the vehicle more flexible during automatic parking. By obtaining the target turning angles of the front and rear wheels of the vehicle and determining the target turning angle of the steering wheel of the vehicle, it is possible to control the turning of the front and rear wheels of the vehicle by turning the steering wheel at the same time, thereby improving the control efficiency of the front and rear wheels and the steering flexibility of the vehicle. First, the corresponding relationship between the front and rear wheel angles of the vehicle and the steering wheel angle is determined, and then the obtained corresponding relationship is PID corrected to obtain a new corresponding relationship. Finally, the target turning angle of the steering wheel is determined according to the new corresponding relationship. The vehicle determines the parking path based on the target turning angle, which is beneficial to improving the accuracy of the vehicle in automatic parking. When the vehicle is moving sideways, the smaller the sideslip angle of the center of mass, the better the vehicle stability. Therefore, when the sideslip angle of the center of mass of the vehicle is 0, determining the second correspondence between the rear wheel angle and the steering wheel angle can ensure the stability of the vehicle when the rear wheels of the vehicle are subsequently turned. After obtaining the parking instruction, it is determined whether the current vehicle state allows automatic parking, and the vehicle is parked after meeting all conditions, which is conducive to avoiding parking failures caused by system failures related to automatic parking or human intervention during the automatic parking process, and improving the success rate of automatic parking.

[0149] See also Figure 7 , Figure 7 is a schematic diagram of the structure of a vehicle control device provided in an embodiment of the present application, such as Figure 7 As shown, the control device 700 includes:

[0150] An acquisition module 701 is used to acquire an automatic parking instruction for a vehicle;

[0151] The control module 702 is used to respond to the automatic parking instruction and control the front and rear wheels of the vehicle to rotate simultaneously to achieve automatic parking.

[0152] In a possible implementation, the control module 702 is further configured to control the rear wheel deflection direction of the vehicle to be opposite to the front wheel deflection direction of the vehicle when controlling the front and rear wheels of the vehicle to rotate simultaneously.

[0153] In one possible implementation, in terms of controlling the simultaneous rotation of the front and rear wheels of the vehicle, the control module 702 is specifically used to: obtain the front wheel target turning angle value and the rear wheel target turning angle value of the vehicle; determine the target turning angle of the steering wheel of the vehicle based on the front wheel target turning angle value and the rear wheel target turning angle value; control the steering wheel to rotate to the target angle to control the vehicle to turn.

[0154] In a possible implementation, in determining the target steering angle of the steering wheel of the vehicle according to the front wheel target steering angle value and the rear wheel target steering angle value, the control module 702 is specifically configured to:

[0155] Determine a first correspondence between the front wheel angle and the steering wheel angle; determine a second correspondence between the rear wheel angle and the steering wheel angle; and determine a target angle based on the front wheel target angle value, the rear wheel target angle value, the first correspondence, and the second correspondence.

[0156] In a possible implementation, in determining the target turning angle based on the front wheel target turning angle value, the rear wheel target turning angle value, the first corresponding relationship, and the third corresponding relationship, the control module 702 is specifically configured to:

[0157] Performing PID correction on the second corresponding relationship to obtain a third corresponding relationship; and determining the target turning angle based on the front wheel target turning angle value, the rear wheel target turning angle value, the first corresponding relationship, and the third corresponding relationship.

[0158] In a possible implementation, in terms of performing PID correction on the second corresponding relationship to obtain the third corresponding relationship, the control module 702 is specifically configured to:

[0159] Determine the actual parking position of the vehicle after automatic parking according to the first corresponding relationship and the second corresponding relationship; determine the position deviation between the target parking position and the actual parking position, the target parking position being the expected parking position of the vehicle for automatic parking; use the position deviation as the input of PID to obtain the compensation value of PID output; and determine the third corresponding relationship according to the second corresponding relationship and the compensation value.

[0160] In a possible implementation, in determining the first corresponding relationship between the turning angle of the front wheel and the turning angle of the steering wheel, the control module 702 is specifically configured to:

[0161] A front and rear wheel steering angle ratio control equation of the vehicle is established; and a first corresponding relationship is obtained through the front and rear wheel steering angle ratio control equation of the vehicle.

[0162] In a possible implementation, in determining the second corresponding relationship between the steering angle of the rear wheels and the steering wheel angle, the control module 702 is specifically configured to:

[0163] The two-degree-of-freedom dynamic equation of the vehicle and the relationship equation between the lateral force of the front and rear wheels and the sideslip angle of the vehicle are established; the rear wheel steering dynamic equation of the vehicle is obtained through the two-degree-of-freedom dynamic equation of the vehicle and the relationship equation between the lateral force of the front and rear wheels and the sideslip angle of the vehicle; the second corresponding relationship is determined through the front and rear wheel steering angle proportional control equation of the vehicle and the rear wheel steering dynamic equation of the vehicle.

[0164] In a possible implementation, in determining the second corresponding relationship by using the front and rear wheel angle ratio control equation of the vehicle and the rear wheel steering dynamics equation of the vehicle, the control module 702 is specifically configured to:

[0165] The fourth corresponding relationship between the vehicle's center of mass sideslip angle and the steering wheel angle is obtained through the vehicle's front and rear wheel steering angle proportional control equation and the vehicle's rear wheel steering dynamics equation; when the vehicle's center of mass sideslip angle is 0, the fifth corresponding relationship between the vehicle's rear wheel steering angle and the front wheel steering angle is determined through the fourth corresponding relationship and the vehicle's front and rear wheel steering angle proportional control equation; the second corresponding relationship is obtained through the first corresponding relationship and the fifth corresponding relationship.

[0166] In a possible implementation, in terms of obtaining the front wheel target turning angle value and the rear wheel target turning angle value of the vehicle, the control module 702 is specifically configured to:

[0167] A parking path from the current position of the vehicle to a target parking position is obtained, where the target parking position is the parking position of the vehicle in the effective parking space at the current position; a front wheel target turning angle value and a rear wheel target turning angle value of the vehicle are calculated based on the parking path.

[0168] In a possible implementation, the control module 702 is further configured to, upon obtaining an automatic parking instruction for the vehicle, control the front and rear wheels of the vehicle to rotate simultaneously to achieve automatic parking if at least one of the following conditions is met: the electric power steering system of the vehicle has no faults, the parking indicator light of the vehicle is on, the gear position of the vehicle is in the P gear, the speed of the vehicle does not exceed 10 km / h, and the torque of the steering wheel force of the vehicle does not exceed 2 Nm.

[0169] It is worth noting that the specific functional implementation of the vehicle control device 700 is shown in the above Figure 2 The description of the automatic parking method of the vehicle shown in the figure, for example, the acquisition module 701 is used to implement the relevant content of executing S201, and the control module 702 is used to implement the relevant content of executing S202. The various units or modules in the control device 700 of the vehicle can be respectively or completely combined into one or several other units or modules to constitute, or some (some) of the units or modules can be further divided into multiple smaller units or modules in function to constitute, which can achieve the same operation without affecting the realization of the technical effect of the embodiment of the present invention. The above-mentioned units or modules are divided based on logical functions. In actual applications, the function of one unit (or module) is realized by multiple units (or modules), or the function of multiple units (or modules) is realized by one unit (or module).

[0170] Based on the description of the above method embodiments and related device embodiments, please refer to Figure 8 , an embodiment of the present invention also provides a structural schematic diagram of another vehicle control device 800. Figure 8 The control device 800 shown includes a processor 801 , a memory 802 , a communication interface 803 and a bus 804 . The processor 801 , the memory 802 , and the communication interface 803 are connected to each other through the bus 804 .

[0171] Optionally, the memory 802 is a ROM, a static storage device, a dynamic storage device or a RAM.

[0172] The memory 802 can store the automatic parking program of the vehicle. When the automatic parking program stored in the memory 802 is executed by the processor 801, the processor 801 and the communication interface 803 are used to execute Figure 2 The various steps of the automatic parking method for a vehicle of the illustrated embodiment.

[0173] The processor 801 adopts a general-purpose CPU, a microprocessor, an application-specific integrated circuit ASIC, a GPU or one or more integrated circuits to execute relevant programs to perform the image quality processing method of the method embodiment of the present application.

[0174] The processor 801 can also be an integrated circuit chip with signal processing capabilities. In the implementation process, each step of the automatic parking method of the vehicle of the present application can be completed by the hardware integrated logic circuit or software instructions in the processor 801. Optionally, the processor 801 is a general-purpose processor, DSP, ASIC, FPGA or other programmable logic device, discrete gate or transistor logic device, discrete hardware component. The processor can implement or execute the methods, steps and logic block diagrams disclosed in the embodiments of the present application. The general-purpose processor is a microprocessor or the processor is any conventional processor, etc. The steps of the method disclosed in the embodiments of the present application can be directly embodied as a hardware decoding processor to execute, or a combination of hardware and software modules in the decoding processor to execute. The optional software module is located in a random access memory, a flash memory, a read-only memory, a programmable read-only memory or an electrically erasable programmable memory, a register or other mature storage medium in the art. The storage medium is located in the memory 802, and the processor 801 reads the information in the memory 802, and combines its hardware to complete the functions required to be performed by the units included in the control device 800 of a vehicle in an embodiment of the present application, or executes the automatic parking method of the vehicle in the method embodiment of the present application.

[0175] The communication interface 803 uses a transceiver or other related device such as, but not limited to, a transceiver.

[0176] The bus 804 may include a path for transmitting information between various components of the vehicle control device 800 (eg, the memory 802 , the processor 801 , and the communication interface 803 ).

[0177] It should be noted that although Figure 8 The vehicle control device 800 shown in the figure only shows the memory 802, the processor 801, the communication interface 803 and the bus 804, but in the specific implementation process, the technicians in this field should understand that the vehicle control device 800 also includes other devices necessary for normal operation. At the same time, based on specific needs, the technicians in this field should understand that the vehicle control device 800 may also include hardware devices for implementing other additional functions. In addition, the technicians in this field should understand that the vehicle control device 800 may also only include the devices necessary to implement the embodiments of the present application, and does not necessarily include Figure 8 All devices shown in .

[0178] An embodiment of the present application provides a computer-readable storage medium, in which a computer program for electronic data exchange is stored. The computer program includes execution instructions, and the execution instructions are used to execute part or all of the steps of any one of the automatic parking methods for vehicles recorded in the above-mentioned automatic parking method embodiments for vehicles. The above-mentioned computer includes an electronic terminal device.

[0179] An embodiment of the present application provides a computer program product, wherein the computer program product includes a computer program, and the computer program is operable to enable a computer to perform part or all of the steps of any one of the automatic parking methods for a vehicle as recorded in the above method embodiments. The computer program product can be a software installation package.

[0180] An embodiment of the present application provides a vehicle, comprising any one of the vehicle control devices described in the above-mentioned vehicle automatic parking method embodiments.

[0181] It should be noted that, for the sake of simplicity, the embodiments of the automatic parking method for any of the above-mentioned vehicles are all described as a series of action combinations, but those skilled in the art should be aware that the present application is not limited by the described action sequence, because according to the present application, some steps can be performed in other sequences or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in the specification are all preferred embodiments, and the actions involved are not necessarily required by the present application.

[0182] The embodiments of the present application are introduced in detail above. Specific examples are used herein to illustrate the principle and implementation method of an automatic parking method and a control device for a vehicle of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea. At the same time, for a person skilled in the art, according to the idea of ​​an automatic parking method and a control device for a vehicle of the present application, there may be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

[0183] The present application is described with reference to the flowcharts and / or block diagrams of the methods, hardware products, and computer program products of the embodiments of the present application. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of the processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0184] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 The memory may include: a flash disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, etc.

[0185] Although the present application is described herein in conjunction with various embodiments, in the process of implementing the claimed application, those skilled in the art may understand and implement other variations of the disclosed embodiments by viewing the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other components or steps, and "a" or "one" does not exclude multiple situations. Certain measures are recorded in different dependent claims, but this does not mean that these measures cannot be combined to produce good results.

[0186] A person skilled in the art may understand that all or part of the steps in the various methods of the above-mentioned method embodiments of the automatic parking method for any vehicle may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable memory, which may include: a flash drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, etc.

[0187] It can be understood that any product that is controlled or configured to execute the processing method of the flowchart described in an embodiment of an automatic parking method for a vehicle in the present application, such as the device and computer program product in the above flowchart, falls within the scope of the related products described in the present application.

[0188] Obviously, those skilled in the art can make various changes and modifications to the automatic parking method and control device for a vehicle provided by the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A method for automatic parking of a vehicle, characterized in that: The method comprises: Obtaining an automatic parking instruction for the vehicle; In response to the automatic parking instruction, the front and rear wheels of the vehicle are controlled to rotate simultaneously to achieve automatic parking.

2. The method according to claim 1, characterized in that The method further includes: when controlling the front and rear wheels of the vehicle to rotate simultaneously, the deflection direction of the rear wheels of the vehicle is opposite to the deflection direction of the front wheels of the vehicle.

3. The method according to claim 2, characterized in that The controlling the front and rear wheels of the vehicle to rotate simultaneously comprises: Obtaining a front wheel target turning angle value and a rear wheel target turning angle value of the vehicle; Determining a target steering angle of the vehicle's steering wheel according to the front wheel target steering angle value and the rear wheel target steering angle value; The steering wheel is controlled to rotate to the target angle to control the vehicle to turn.

4. The method according to claim 3, characterized in that The step of determining the target steering angle of the steering wheel of the vehicle according to the front wheel target steering angle value and the rear wheel target steering angle value comprises: Determining a first corresponding relationship between the turning angle of the front wheel and the turning angle of the steering wheel; Determining a second corresponding relationship between the turning angle of the rear wheel and the turning angle of the steering wheel; The target turning angle is determined based on the front wheel target turning angle value, the rear wheel target turning angle value, the first corresponding relationship, and the second corresponding relationship.

5. The method according to claim 4, characterized in that The determining the target turning angle based on the front wheel target turning angle value, the rear wheel target turning angle value, the first corresponding relationship, and the second corresponding relationship comprises: Performing PID correction on the second corresponding relationship to obtain a third corresponding relationship; The target turning angle is determined based on the front wheel target turning angle value, the rear wheel target turning angle value, the first corresponding relationship, and the third corresponding relationship.

6. The method according to claim 5, characterized in that The performing PID correction on the second corresponding relationship to obtain a third corresponding relationship includes: determining an actual parking position of the vehicle after automatic parking according to the first corresponding relationship and the second corresponding relationship; determining a position deviation between a target parking position and the actual parking position, the target parking position being a desired parking position for the vehicle to perform automatic parking; Using the position deviation as the input of the PID to obtain a compensation value of the PID output; The third corresponding relationship is determined according to the second corresponding relationship and the compensation value.

7. The method according to claim 4, characterized in that The determining of a first correspondence between the turning angle of the front wheel and the turning angle of the steering wheel comprises: Establishing a front and rear wheel angle proportional control equation of the vehicle; The first corresponding relationship is obtained through a front and rear wheel steering angle ratio control equation of the vehicle.

8. The method according to claim 4 or 7, characterized in that The determining of the second corresponding relationship between the turning angle of the rear wheel and the turning angle of the steering wheel comprises: Establishing a two-degree-of-freedom dynamic equation of the vehicle and a relationship equation between the lateral force of the front and rear wheels and the sideslip angle of the vehicle; Obtaining a rear wheel steering dynamics equation of the vehicle through a two-degree-of-freedom dynamics equation of the vehicle and a relationship equation between the lateral forces of the front and rear wheels of the vehicle and the sideslip angle; The second corresponding relationship is determined by the front and rear wheel steering angle ratio control equation of the vehicle and the rear wheel steering dynamics equation of the vehicle.

9. The method according to claim 8, characterized in that The determining the second corresponding relationship by using the front and rear wheel steering angle ratio control equation of the vehicle and the rear wheel steering dynamics equation of the vehicle includes: A fourth corresponding relationship between the center of mass sideslip angle of the vehicle and the steering wheel angle is obtained through the front and rear wheel steering angle ratio control equation of the vehicle and the rear wheel steering dynamics equation of the vehicle; When the sideslip angle of the center of mass of the vehicle is 0, a fifth corresponding relationship of the rear wheel turning angle of the vehicle relative to the front wheel turning angle is determined by using the fourth corresponding relationship and a control equation of the front and rear wheel turning angle ratio of the vehicle; The second corresponding relationship is obtained through the first corresponding relationship and the fifth corresponding relationship.

10. The method according to any one of claims 3 to 9, characterized in that: The obtaining of the front wheel target turning angle value and the rear wheel target turning angle value of the vehicle comprises: Acquiring a parking path of the vehicle from the current position to a target parking position, wherein the target parking position is a parking position of the vehicle in a valid parking space at the current position; A front wheel target turning angle value and a rear wheel target turning angle value of the vehicle are calculated based on the parking path.

11. The method according to claim 1, characterized in that The method further comprises: When an automatic parking instruction for the vehicle is obtained, if at least one of the following conditions is met, in response to the automatic parking instruction, the front and rear wheels of the vehicle are controlled to rotate simultaneously to achieve automatic parking: The electric power steering system of the vehicle has no faults, the parking indicator light of the vehicle is on, the gear position of the vehicle is in P gear, the speed of the vehicle does not exceed 10KM / h, and the torque of the steering wheel of the vehicle does not exceed 2Nm.

12. A vehicle control device, characterized in that: The device comprises: An acquisition module, used for acquiring an automatic parking instruction for the vehicle; The control module is used to respond to the automatic parking instruction and control the front and rear wheels of the vehicle to rotate simultaneously to achieve automatic parking.

13. A vehicle control device, characterized in that: The device comprises: A memory, a processor, and an automatic parking program for a vehicle stored in the memory and executable on the processor, wherein the processor executes the steps of the automatic parking method for a vehicle as claimed in any one of claims 1 to 11 when executing the automatic parking program for the vehicle.

14. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores an automatic parking program for a vehicle, wherein the automatic parking program for the vehicle includes execution instructions, and the execution instructions are used to execute the steps of the automatic parking method for a vehicle as described in any one of claims 1-11.

15. A vehicle, characterized in that: A control device for a vehicle comprising the control device of claim 12 or 13.

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