Vehicle control method, device and equipment and storage medium

Abstract

The invention discloses a vehicle control method, device and equipment and a storage medium, and relates to the technical field of steering control, and the vehicle control method comprises the steps that the initial position, the running angle and the target position of a vehicle are obtained, and the vehicle is controlled to run according to the initial position and the running angle; when the vehicle runs to the target position, the wheel speed pulse variable quantity of the vehicle is obtained; and Ackerman offset is calculated according to the wheel speed pulse variable quantity, and the vehicle is controlled according to the Ackerman offset. The Ackerman offset can be determined by calculating the wheel speed pulse variable quantity through the initial position, the driving angle and the target position of the vehicle, so that the vehicle is accurately controlled to drive to the target position.

Description

Technical Field

[0001] The present application relates to the field of steering control technology, and in particular to vehicle control methods, devices, equipment and storage media. Background Art

[0002] In current vehicle dynamics control and automated driving assistance systems, precise steering control is a key requirement for achieving smooth and safe driving of the vehicle. To achieve precise steering control, the vehicle needs to accurately calculate the steering angle of each wheel during the steering process to avoid understeering or oversteering, while reducing tire side slip and wear, and ensuring that the vehicle can travel along the predetermined trajectory in low-speed automated driving and parking scenarios. The Ackerman offset is the offset between the ideal geometric center and the actual center of motion when the vehicle is turning. The need to achieve precise steering control places high demands on the accuracy of the calibration of the Ackerman offset.

[0003] However, the existing Ackerman offset calibration method has certain limitations. The traditional calibration method is cumbersome and difficult to guarantee accuracy. In addition, in sharp turns or complex road conditions, the vehicle's dynamic characteristics, such as roll, tire lateral force, and center of gravity offset, will affect the vehicle's actual driving path, resulting in a deviation between the ideal path and the actual path. This results in insufficient steering control accuracy under complex working conditions, making it difficult to meet the high-precision, automated steering control requirements of autonomous driving and advanced driver assistance systems.

[0004] The above contents are only used to assist in understanding the technical solution of the present application and do not constitute an admission that the above contents are prior art. Summary of the invention

[0005] The main purpose of the present application is to provide a vehicle control method, device, equipment and storage medium, aiming to solve the technical problems that the traditional Ackerman offset calibration process is cumbersome and the calibration accuracy is low.

[0006] To achieve the above objectives, the present application proposes a vehicle control method, the method comprising:

[0007] Acquiring an initial position, a driving angle, and a target position of a vehicle, and controlling the vehicle to travel according to the initial position and the driving angle;

[0008] When the vehicle travels to the target position, obtaining a wheel speed pulse change of the vehicle;

[0009] An Ackerman offset is calculated according to the wheel speed pulse variation, and the vehicle is controlled according to the Ackerman offset.

[0010] In one embodiment, the step of calculating the Ackerman offset according to the wheel speed pulse variation comprises:

[0011] Get the vehicle wheelbase;

[0012] Calculating the front wheel turning radius and the rear wheel turning radius according to the wheel speed pulse variation;

[0013] An Ackerman shift is calculated according to the front wheel turning radius, the rear wheel turning radius, and the vehicle wheelbase.

[0014] In one embodiment, the step of calculating the front wheel turning radius and the rear wheel turning radius according to the wheel speed pulse variation comprises:

[0015] According to the wheel speed pulse variation, the front wheel speed pulse variation, the rear wheel speed pulse variation and the wheel travel distance are obtained;

[0016] Calculating the front wheel turning radius according to the front wheel speed pulse change and the wheel travel distance;

[0017] The rear wheel turning radius is calculated according to the rear wheel speed pulse change and the wheel travel distance.

[0018] In one embodiment, the step of obtaining an initial position, a driving angle, and a target position of a vehicle, and controlling the vehicle to travel according to the initial position and the driving angle includes:

[0019] Get the initial position of the vehicle;

[0020] Connecting the vehicle to a controller area network and sending a driving instruction to the controller area network so that the controller area network calibrates a driving angle of the vehicle based on the driving instruction;

[0021] The vehicle is controlled to travel according to the initial position and the travel angle.

[0022] In one embodiment, after the step of calculating the Ackerman offset according to the wheel speed pulse variation, the method further includes:

[0023] Obtaining the vehicle's driving speed, steering wheel angle, vehicle mass, center of gravity height, and suspension stiffness;

[0024] Calculating a center of gravity offset according to the driving speed, the steering wheel angle, the vehicle mass, the center of gravity height, and the suspension stiffness;

[0025] The Ackerman shift is corrected according to the center of gravity shift.

[0026] In one embodiment, the step of calculating the center of gravity offset according to the driving speed, the steering wheel angle, the vehicle mass, the center of gravity height and the suspension stiffness comprises:

[0027] Obtaining the tire cornering stiffness of the vehicle, and obtaining the tire slip angle according to the driving speed and the steering wheel angle;

[0028] Calculating a roll angle according to the tire cornering stiffness and the slip angle;

[0029] The center of gravity offset is calculated according to the roll angle.

[0030] In one embodiment, the step of calculating the roll angle according to the tire cornering stiffness and the slip angle comprises:

[0031] Calculating tire lateral force according to the sideslip angle and the tire cornering stiffness;

[0032] The roll angle is calculated according to the vehicle mass, the center of gravity height, the suspension stiffness, and the tire lateral force.

[0033] In addition, to achieve the above-mentioned purpose, the present application also proposes a vehicle control device, the vehicle control device comprising: a driving module, used to obtain an initial position, a driving angle and a target position of a vehicle, and control the vehicle to travel according to the initial position and the driving angle;

[0034] An obtaining module, when the vehicle travels to the target position, obtains the wheel speed pulse variation of the vehicle;

[0035] A calculation module calculates an Ackerman offset according to the wheel speed pulse change.

[0036] In addition, to achieve the above-mentioned purpose, the present application also proposes a vehicle control device, which includes: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the computer program is configured to implement the steps of the vehicle control method as described above.

[0037] In addition, to achieve the above-mentioned purpose, the present application also proposes a storage medium, which is a computer-readable storage medium, and a computer program is stored on the storage medium. When the computer program is executed by a processor, the steps of the vehicle control method described above are implemented.

[0038] In addition, to achieve the above-mentioned purpose, the present application also provides a computer program product, which includes a computer program, and when the computer program is executed by a processor, the steps of the vehicle control method described above are implemented.

[0039] One or more technical solutions proposed in this application have at least the following technical effects:

[0040] The invention adopts the technical effects of obtaining the initial position, driving angle and target position of the vehicle, controlling the vehicle to travel according to the initial position and the driving angle; obtaining the wheel speed pulse variation of the vehicle when the vehicle travels to the target position; calculating the Ackerman offset according to the wheel speed pulse variation, and controlling the vehicle according to the Ackerman offset, which solves the problems of complex operation, difficult alignment and low measurement accuracy in the traditional Ackerman offset calibration process. Compared with the existing vertical line measurement method, it greatly reduces the manual operation steps, improves the accuracy and efficiency of calibration, and realizes high automation and precision guarantee of the calibration process. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0042] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0043] Figure 1 A schematic diagram of a flow chart provided for the first embodiment of the vehicle control method of the present application;

[0044] Figure 2 A flow chart of the second embodiment of the vehicle control method of the present application;

[0045] Figure 3 A geometric diagram of a vehicle turning path of a vehicle control method provided in Embodiment 2 of the present application;

[0046] Figure 4 A flow chart of the third embodiment of the vehicle control method of the present application;

[0047] Figure 5 This is a schematic diagram of the module structure of the vehicle control device according to an embodiment of the present application;

[0048] Figure 6 Schematic diagram of the device structure of the hardware operating environment involved in the vehicle control method in the embodiment of the present application.

[0049] The purpose, features and advantages of this application will be further described in conjunction with the embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0050] It should be understood that the specific embodiments described herein are only used to explain the technical solutions of the present application and are not used to limit the present application.

[0051] In order to better understand the technical solution of the present application, a detailed description will be given below in conjunction with the accompanying drawings and specific implementation methods.

[0052] The main solution of the embodiment of the present application is: obtaining the initial position, driving angle and target position of the vehicle, and controlling the vehicle to travel according to the initial position and the driving angle;

[0053] When the vehicle travels to the target position, obtaining a wheel speed pulse change of the vehicle;

[0054] An Ackerman offset is calculated according to the wheel speed pulse variation, and the vehicle is controlled according to the Ackerman offset.

[0055] In this embodiment, for the convenience of description, the following description is made by taking identification of the vehicle control device as the execution subject.

[0056] Since the traditional Ackerman offset calibration process in the prior art is cumbersome and the calibration accuracy is not high, the present application provides a solution, which adopts the method of obtaining the initial position, driving angle and target position of the vehicle, and controlling the vehicle to travel according to the initial position and the driving angle; when the vehicle travels to the target position, the wheel speed pulse change of the vehicle is obtained; the Ackerman offset is calculated according to the wheel speed pulse change, and the technical effect of controlling the vehicle according to the Ackerman offset solves the problems of complex operation, difficult alignment and low measurement accuracy in the traditional Ackerman offset calibration process. Compared with the existing vertical line measurement method, it greatly reduces the manual operation steps, improves the accuracy and efficiency of calibration, and realizes high automation and precision guarantee of the calibration process.

[0057] It should be noted that the execution subject of this embodiment may be a computing service device with data processing, network communication and program running functions, such as a tablet computer, a personal computer, a mobile phone, etc., or an electronic device capable of realizing the above functions, a vehicle control device, etc. The following takes a vehicle control device as an example to illustrate this embodiment and the following embodiments.

[0058] Based on this, the embodiment of the present application provides a vehicle control method, referring to Figure 1 , Figure 1 This is a flow chart of the first embodiment of the vehicle control method of the present application.

[0059] In this embodiment, the vehicle control device method includes steps S10 to S30:

[0060] Step S10, obtaining the initial position, driving angle and target position of the vehicle, and controlling the vehicle to travel according to the initial position and driving angle.

[0061] It should be noted that the above-mentioned initial position may be the specific position of the vehicle at the beginning of the calibration process, and this position will serve as the starting point for the subsequent driving of the vehicle. The initial position may be determined by a positioning system, such as GPS or a positioning device installed on the vehicle, or by using an artificial marking method to determine the position of the vehicle by physical marks. The purpose of positioning is to record where the vehicle starts to travel for subsequent calibration and offset calculation, and the specific acquisition method is not limited in this embodiment. The above-mentioned driving angle may refer to the driving direction of the vehicle relative to the initial position. The driving angle can reflect the steering state and driving trajectory of the vehicle. The above-mentioned target position may be a predetermined position that the vehicle plans to reach, usually a target point pre-set to complete the calibration process.

[0062] It is understandable that to control the vehicle from the initial position to the target position, it is necessary to keep the steering wheel angle unchanged while driving at a low and constant speed to ensure that the vehicle does not slip or is affected by other uncontrollable factors.

[0063] Exemplarily, the Ackerman offset calibration is performed in an open test site, and the initial position of the vehicle is a specific landmark in the site, which is determined manually or by GPS. The steering wheel angle is fixed at a specific value through the CAN bus device, such as a 30-degree left turn. The target position is when the vehicle returns to the initial position or the specified end position after circling an arc. During the entire driving process, the steering angle of the steering wheel is kept unchanged through the CAN bus, and the vehicle travels at a constant speed from the initial position to circumvent a circle with a known radius. When the vehicle reaches the target position, it stops and marks the position for the next offset calculation. Through this process, the precise control of each parameter of the vehicle during the detour is ensured, thereby ensuring the reliability and accuracy of the calibration results.

[0064] Step S20, when the vehicle reaches the target position, obtaining the wheel speed pulse change of the vehicle.

[0065] It should be noted that the above wheel speed pulse variation refers to the total number of changes in pulse signals collected by the vehicle's wheel speed sensor, which is usually located on the wheel, during the vehicle's driving process. These pulse signals can reflect the number of rotations of the wheel and the distance traveled. The wheel speed sensor determines the vehicle's driving distance by recording the pulse signal emitted every time the wheel rotates a certain angle. Each pulse represents a specific distance that the wheel has rotated, so the cumulative number of pulses can be used to calculate the total distance traveled by the vehicle. The wheel speed pulse variation is obtained at the end position of the Ackerman offset calibration process in order to subsequently calculate the actual driving distance of the vehicle and further calibrate the Ackerman offset.

[0066] It is understandable that the wheel speed pulse signal acquisition method can be that the CAN bus device is connected to the vehicle's control system to collect the pulse signal emitted by the vehicle's wheel speed sensor. When the vehicle is driving, the wheel speed sensor sends the pulse signal to the CAN bus, and the CAN bus device transmits these signals to the host computer software to record the pulse changes during the entire driving process. When the vehicle reaches the target position, the host computer software will record the total number of pulse signals at this time and compare it with the number of pulses at the initial position, so as to obtain the change in the wheel speed pulse during the entire driving process.

[0067] Exemplarily, the initial position is marked as point A, and the target position is when the vehicle returns to point A after traveling around a circular trajectory with a fixed radius. During the driving process of the vehicle, the wheel speed sensor on the wheel continuously generates pulse signals, which are transmitted to the host computer through the CAN bus. Assume that each pulse represents a certain angle of rotation of the wheel, such as 5 degrees. When the vehicle reaches the target position, that is, completes a full circle of driving movement, the wheel speed pulse change recorded by the host computer software is 500 pulses, which means that the vehicle's wheels have rotated 500 times by an angle of 5 degrees, which can be used to calculate the total distance traveled by the vehicle.

[0068] Step S30, calculating the Ackerman offset according to the wheel speed pulse variation, and controlling the vehicle according to the Ackerman offset.

[0069] It should be noted that the above Ackerman offset reflects the steering characteristics of the vehicle when turning. The smaller the offset, the more the vehicle can run along the ideal Ackerman geometry path, thereby reducing tire slip and understeer. After obtaining the Ackerman offset, it can be used as an input parameter to adjust the vehicle's steering control strategy. For example, if the Ackerman offset is large, it means that the steering angle of the vehicle has not reached the ideal state, which may cause understeer or oversteer. At this time, it is necessary to adjust the steering wheel angle or vehicle speed to ensure that the vehicle can run along the ideal path.

[0070] It will be appreciated that the offset may be calculated by combining the distance travelled by the front and rear wheels with the geometric characteristics of the vehicle, such as the wheelbase, the position of the front and rear wheels, etc.

[0071] In a feasible implementation, step S10 may include steps S11 to S13:

[0072] Step S11, obtaining the initial position of the vehicle.

[0073] Step S12, connecting the vehicle to a controller area network, and sending a driving instruction to the controller area network, so that the controller area network calibrates the driving angle of the vehicle based on the driving instruction.

[0074] Step S13, controlling the vehicle to travel according to the initial position and the travel angle.

[0075] It can be understood that the above steps S11 to S13 represent that the vehicle is connected to the CAN bus device from the initial position, and the CAN signal is used to control the steering wheel to be fixed at a certain angle. For example, starting from point A, the vehicle is controlled to travel according to the calibrated driving angle, such as turning left 30 degrees. The CAN bus connection enables the host computer to continuously receive data such as wheel speed pulse signals and steering wheel angles, and control the vehicle's throttle and steering wheel angle to ensure that the vehicle travels smoothly to the target position in the predetermined direction. Through low-speed and uniform speed control, the vehicle can accurately complete detours or turns to ensure the accuracy of data collection.

[0076] It should be noted that the above-mentioned controller area network (CAN) is a network system for vehicle-mounted communications, which can connect multiple control units inside the vehicle to achieve real-time data transmission and control signal transmission. In this step, the vehicle is physically connected to the controller area network in order to allow the controller to communicate and transmit commands with the various control units of the vehicle. After connecting to the controller area network, various sensor data of the vehicle, such as steering wheel angle, vehicle speed, wheel speed pulse, etc., can be collected and transmitted to the central control system in real time for subsequent calculation and control.

[0077] This embodiment provides a vehicle control method, which solves the technical problems of the traditional Ackerman offset calibration method, such as cumbersome operation, high difficulty, and difficulty in ensuring calibration accuracy, by using the vehicle positioning system to obtain the initial position and the CAN bus device to control the steering wheel angle and throttle to keep the vehicle running at a low and uniform speed, and achieves the beneficial effects of simplifying the operation steps, improving the calibration accuracy, and achieving a higher degree of automation. By accurately controlling the vehicle to travel from the initial position to the target position, and collecting the wheel speed pulse change during the driving process, the Ackerman offset is calculated in combination with the geometric characteristics of the vehicle, and then the steering control strategy of the vehicle is optimized to ensure that the vehicle can travel along the ideal path, reduce tire slip and understeering, and improve the maneuverability and safety of the vehicle. At the same time, the two steps of ensuring that the vehicle is perpendicular to the baseline in the original process are completely cancelled. The calibration personnel only need to mark the starting position of the vehicle and then lightly step on the accelerator, and control the vehicle to go around once and stop at the starting position. This will reduce the operation steps and time in the calibration process and simplify the difficulty of operation.

[0078] Based on the first embodiment of the present application, in the second embodiment of the present application, the same or similar contents as those in the above-mentioned embodiment 1 can be referred to the above introduction, and will not be repeated in the following. Figure 2 , step S30 of the vehicle control method includes steps S31 to S33:

[0079] Step S31, obtaining the vehicle wheelbase.

[0080] It should be noted that the above-mentioned vehicle wheelbase refers to the horizontal distance between the front and rear axles of the vehicle, usually in meters or millimeters. It is one of the important parameters describing the geometric characteristics of the vehicle and has a direct impact on the vehicle's handling, stability and steering performance.

[0081] Step S32, calculating the front wheel turning radius and the rear wheel turning radius according to the wheel speed pulse change.

[0082] It should be noted that the above-mentioned front wheel turning radius and rear wheel turning radius represent the turning radii of the front wheels and rear wheels respectively. These two values ​​are used to describe the actual driving trajectory of the front and rear wheels of the vehicle during the detour. Usually, the turning radius of the front wheels is larger than that of the rear wheels, because the front wheels guide the steering of the vehicle, while the rear wheels follow along the path of the front wheels.

[0083] Please refer to Figure 3 , Figure 3 A geometric diagram of a vehicle turning path according to the first embodiment of the vehicle control method of the present application.

[0084] like Figure 3 As shown, R is the turning radius of the front wheel, r is the turning radius of the rear wheel, L is the vehicle wheelbase, that is, the distance between the front and rear wheels, a is the Ackerman offset, O represents the turning center of the vehicle, θ is the turning radius of the front wheel and is the angle between the vehicle wheelbase.

[0085] It is understandable that Figure 3 The geometric relationship between the angle θ and the angle θ can be obtained as follows:

[0086]

[0087] Where L is the vehicle wheelbase, a is the Ackerman offset, and R is the turning radius of the front wheel.

[0088] From the geometric relationship and the cosine theorem, we can get the following equation 2:

[0089]

[0090] Where L is the vehicle wheelbase, a is the Ackerman offset, R is the turning radius of the front wheel, and r is the turning radius of the rear wheel.

[0091] In a feasible implementation, step S32 may include steps S321 to S323:

[0092] From the above formula 1 and formula 2, we can get the following formula 3:

[0093]

[0094] Where L is the vehicle wheelbase, a is the Ackerman offset, R is the turning radius of the front wheel, and r is the turning radius of the rear wheel.

[0095] Step S321, obtaining the front wheel speed pulse change, the rear wheel speed pulse change and the wheel travel distance according to the wheel speed pulse change.

[0096] It should be noted that during the calibration process, the wheel speed pulse changes of the front and rear wheels are obtained independently because their driving trajectories and distances during vehicle turning are usually different. Through the independent recording of the wheel speed sensor, the front wheel speed pulse change and the rear wheel speed pulse change can be obtained. The front wheel speed pulse change and the rear wheel speed pulse change respectively represent the number of times the front and rear wheels rotate during the entire driving process, that is, the driving distance of the front and rear wheels.

[0097] In addition, it should be noted that the wheel travel distance refers to the actual path length that the wheels travel during the vehicle's driving process. Since the front and rear wheels of the vehicle travel along the same predetermined trajectory during the calibration process, the travel distances of the front and rear wheels are the same. This distance is determined based on the wheel speed pulse change recorded by the wheel speed sensor and is used for the subsequent Ackerman offset calculation.

[0098] Step S322, calculating the front wheel turning radius according to the front wheel speed pulse change and the wheel travel distance.

[0099] It can be understood that by using the front wheel speed pulse change and the known wheel travel distance, the turning radius of the front wheel, that is, the radius of the arc trajectory of the front wheel during the vehicle turning process, can be derived. The calculation of the front wheel turning radius is as follows:

[0100]

[0101] Where n f is the front wheel speed pulse change, k is the wheel travel distance, and R is the turning radius of the front wheel.

[0102] Step S323, calculating the rear wheel turning radius according to the rear wheel speed pulse change and the wheel travel distance.

[0103] It is understandable that the rear wheel turning radius can be calculated using the rear wheel speed pulse change and the wheel travel distance, which represents the radius of the arc path taken by the rear wheel of the vehicle when turning. The rear wheel turning radius is calculated as follows:

[0104]

[0105] Where n r is the change in the rear wheel speed pulse, k is the wheel travel distance, and r is the turning radius of the rear wheel.

[0106] Step S33, calculating the Ackerman shift according to the front wheel turning radius, the rear wheel turning radius and the vehicle wheelbase.

[0107] It can be understood that the Ackerman offset is obtained by combining the calculated front wheel turning radius, rear wheel turning radius and vehicle wheelbase. Combining the above equations 3, 4 and 5, it can be known that the calculation of the Ackerman offset is as follows:

[0108]

[0109] Where L is the vehicle wheelbase, a is the Ackerman offset, R is the turning radius of the front wheel, r is the turning radius of the rear wheel, k is the wheel travel distance, and n is f is the front wheel speed pulse change, n r is the rear wheel speed pulse change.

[0110] This embodiment provides a vehicle control method, which solves the technical problem of the difficulty in accurately measuring and calculating the Ackerman offset of the vehicle in the traditional method by obtaining the vehicle wheelbase and using the wheel speed pulse change to calculate the turning radius of the front and rear wheels respectively, and achieves the beneficial effects of improving the calibration accuracy of the Ackerman offset, simplifying the measurement process, and reducing human errors, thereby optimizing the steering control performance of the vehicle and improving the vehicle's handling and driving safety. The calibration personnel do not need to perform any measurements throughout the process. The data sent by the sensor is collected by the CAN bus and sent to the upper computer software. The calibration result can be directly calculated to achieve a higher degree of automation. Through accurate geometric relationships and mathematical model calculations, this embodiment can more accurately reflect the steering characteristics of the vehicle in actual driving, and provide important parameter support for the adjustment and optimization of the vehicle steering system.

[0111] Based on the first embodiment of the present application, in the third embodiment of the present application, the same or similar contents as those in the above-mentioned embodiment 1 can be referred to the above introduction, and will not be repeated in the following. Figure 4 After step S30, the vehicle control method further includes steps S40 to S60:

[0112] Step S40, obtaining the vehicle's driving speed, steering wheel angle, vehicle mass, center of gravity height, and suspension stiffness.

[0113] It should be noted that the above-mentioned driving speed may be the real-time driving speed of the vehicle during the calibration process, and the speed is an important parameter that affects the turning radius and steering characteristics of the vehicle. The above-mentioned steering wheel angle may be the rotation angle of the steering wheel set by the driver input or the automatic control system command, which directly affects the front wheel steering angle of the vehicle, thereby affecting the turning path of the vehicle. The above-mentioned vehicle mass may be the overall mass of the vehicle, including the unloaded mass and the load. The vehicle mass will have a significant impact on the steering characteristics, roll characteristics, etc. of the vehicle. The above-mentioned center of gravity height may refer to the vertical height of the center of mass of the vehicle relative to the ground. The center of gravity height affects the roll characteristics of the vehicle, that is, the stability and degree of roll of the vehicle when turning. Last season, the suspension stiffness described the elastic characteristics of the vehicle suspension system, that is, the ability of the suspension system to resist compression. The suspension stiffness has a direct impact on the roll angle of the vehicle when turning and the stability of the vehicle.

[0114] Step S50, calculating the center of gravity offset according to the driving speed, steering wheel angle, vehicle mass, center of gravity height and suspension stiffness.

[0115] It should be noted that the above-mentioned center of gravity offset can be the lateral displacement of the vehicle's center of mass relative to the static position caused by factors such as lateral force and roll when the vehicle is turning. This offset is an important parameter for analyzing the vehicle's steering stability and handling characteristics, and affects the vehicle's dynamic performance when turning.

[0116] It is understandable that the higher the driving speed, the greater the lateral acceleration of the vehicle, which will directly increase the lateral force, thereby affecting the degree of center of gravity shift. The steering wheel angle determines the curvature and turning radius of the vehicle's turn, and therefore affects the size of the lateral force of the vehicle during the turn. The greater the mass of the vehicle, the greater the inertial force generated during the turn, which increases the center of gravity shift. The higher the center of gravity height, the more significant the vehicle's roll effect when turning, which intensifies the center of gravity shift. A high center of gravity makes the vehicle more likely to roll under the action of lateral forces. Suspension stiffness describes the suspension system's ability to resist compression. The stiffer the suspension, the less the vehicle's roll and center of gravity shift when turning; the softer the suspension, the more likely the vehicle will have a larger degree of center of gravity shift.

[0117] In a feasible implementation, step S50 may include steps S51 to S53:

[0118] Step S51, obtaining the tire cornering stiffness of the vehicle, and obtaining the tire slip angle according to the driving speed and the steering wheel angle.

[0119] It should be noted that the above tire cornering stiffness can be the magnitude of the lateral force generated by a unit slip angle when the tire is subjected to lateral force. It describes the tire's ability to respond to lateral deformation and is an important parameter for evaluating the lateral force generated by the tire during steering.

[0120] It is understood that the slip angle refers to the angle between the actual driving direction of the tire and its driving direction relative to the vehicle body. During the vehicle steering process, the deformation of the tire causes the wheel to not move completely in the direction of steering, but there is a certain degree of "slippage", resulting in a slip angle. The tire's slip angle can be deduced based on the vehicle's driving speed and steering wheel angle. The faster the driving speed and the larger the steering wheel angle, the larger the slip angle.

[0121] Step S52, calculating the roll angle according to the tire cornering stiffness and the slip angle.

[0122] It should be noted that the above roll angle refers to the inclination angle of the vehicle body relative to the horizontal plane due to the lateral acceleration and tire lateral force during the vehicle turning process. The roll angle reflects the lateral dynamic performance of the vehicle when turning and affects the stability of the vehicle.

[0123] In a feasible implementation, step S52 may include steps S521 to S522:

[0124] Step S521, calculating the tire lateral force according to the sideslip angle and the tire cornering stiffness.

[0125] It should be noted that the above tire lateral force can be the force generated by the tire due to the side slip angle, which is used to overcome the lateral slip generated during the turning process so that the vehicle can travel along the predetermined turning trajectory. The greater the tire lateral force, the more stable the vehicle is during the turning process. The calculation of the tire lateral force is as follows:

[0126] F y =C α ×α(Formula 7)

[0127] In the formula, C α is the cornering stiffness of the tire, α is the slip angle of the tire, and the slip angle of the tire can be derived from the vehicle speed and the steering wheel angle.

[0128] Step S522, calculating the roll angle according to the vehicle mass, center of gravity height, suspension stiffness and tire lateral force.

[0129] It can be understood that the roll angle of the vehicle during cornering can be calculated by combining the vehicle mass, center of gravity height and suspension stiffness. The roll angle is calculated as follows:

[0130]

[0131] In the formula, K roll is the roll stiffness of the vehicle suspension, F y is the lateral force of the tire, m and h are the mass and center of gravity height of the vehicle respectively.

[0132] Step S53, calculating the center of gravity offset according to the roll angle.

[0133] It should be noted that the above-mentioned center of gravity offset may refer to the amount of movement of the center of gravity in the lateral direction when the vehicle rolls. The center of gravity offset is derived from the roll angle, indicating the lateral displacement of the center of gravity caused by the roll of the vehicle during the turning process. The calculation of the center of gravity offset is as follows:

[0134]

[0135] In the formula, h is the height of the center of gravity, angle is the roll angle.

[0136] Step S60, correcting the Ackerman shift according to the center of gravity shift.

[0137] It can be understood that the Ackerman offset describes the degree of deviation between the ideal geometric trajectory and the actual trajectory when the vehicle is turning. Under the influence of the center of gravity offset, the steering trajectory of the vehicle will change, so the original Ackerman offset needs to be corrected to reflect the changes caused by the center of gravity offset. The correction of the Ackerman offset is as follows:

[0138] a′=a+k×Δy (Formula 10)

[0139] Where a′ is the corrected Ackerman shift, a is the original Ackerman shift, Δy is the center of gravity shift caused by roll, and k is the adjustment coefficient, which is used to adapt to the characteristics of different vehicles.

[0140] This embodiment provides a vehicle control method, which obtains the vehicle's driving speed, steering wheel angle, vehicle mass, center of gravity height and suspension stiffness in real time, and calculates the center of gravity offset by combining these parameters, thereby solving the problem of inaccurate calculation of Ackerman offset due to factors such as roll during vehicle steering, which in turn affects the vehicle's steering stability and maneuverability. By introducing the correction of the center of gravity offset, this embodiment can more accurately reflect the steering characteristics of the vehicle in actual driving, achieving the beneficial effects of improving the accuracy of Ackerman offset calibration, optimizing the vehicle steering control strategy, and enhancing the vehicle's driving safety and stability. In addition, the tire cornering stiffness and the characteristics of the suspension system are also considered, and the vehicle dynamics model is further refined, providing more comprehensive data support for the analysis and improvement of vehicle dynamic performance.

[0141] It should be noted that the above examples are only used to understand the present application and do not constitute a limitation on the vehicle control method of the present application. More simple transformations based on this technical concept are all within the scope of protection of the present application.

[0142] This application also provides a vehicle control device, please refer to Figure 5, the vehicle control device comprises:

[0143] The driving module 10 is used to obtain the initial position, driving angle and target position of the vehicle, and control the vehicle to travel according to the initial position and the driving angle;

[0144] An obtaining module 20 obtains a wheel speed pulse variation of the vehicle when the vehicle travels to the target position;

[0145] The calculation module 30 calculates the Ackerman offset according to the wheel speed pulse change.

[0146] The vehicle control device provided by the present application adopts the vehicle control method in the above embodiment, which can solve the technical problems that the traditional Ackerman offset calibration process is cumbersome and the calibration accuracy is not high. Compared with the prior art, the beneficial effects of the vehicle control device provided by the present application are the same as the beneficial effects of the vehicle control method provided by the above embodiment, and other technical features in the vehicle control device are the same as the features disclosed in the above embodiment method, which will not be repeated here.

[0147] In one embodiment, the calculation module 30 is further used to obtain the vehicle wheelbase; calculate the front wheel turning radius and the rear wheel turning radius according to the wheel speed pulse change; calculate the Ackerman offset according to the front wheel turning radius, the rear wheel turning radius and the vehicle wheelbase.

[0148] In one embodiment, the calculation module 30 is also used to obtain the front wheel speed pulse change, the rear wheel speed pulse change and the wheel travel distance according to the wheel speed pulse change; calculate the front wheel turning radius according to the front wheel speed pulse change and the wheel travel distance; calculate the rear wheel turning radius according to the rear wheel speed pulse change and the wheel travel distance.

[0149] In one embodiment, the driving module 10 is also used to obtain the initial position of the vehicle; connect the vehicle to a controller area network, and send a driving instruction to the controller area network so that the controller area network calibrates the driving angle of the vehicle based on the driving instruction; and control the driving of the vehicle according to the initial position and the driving angle.

[0150] In one embodiment, the calculation module 30 is further used to obtain the vehicle's driving speed, steering wheel angle, vehicle mass, center of gravity height and suspension stiffness; calculate the center of gravity offset according to the driving speed, the steering wheel angle, the vehicle mass, the center of gravity height and the suspension stiffness; and correct the Ackerman offset according to the center of gravity offset.

[0151] In one embodiment, the calculation module 30 is further used to obtain the tire cornering stiffness of the vehicle, obtain the tire slip angle according to the driving speed and the steering wheel angle; calculate the roll angle according to the tire cornering stiffness and the slip angle; and calculate the center of gravity offset according to the roll angle.

[0152] In one embodiment, the calculation module 30 is further used to calculate the tire lateral force according to the sideslip angle and the tire cornering stiffness; and calculate the roll angle according to the vehicle mass, the center of gravity height, the suspension stiffness and the tire lateral force.

[0153] The present application provides a vehicle control device, which includes: at least one processor; and a memory that is communicatively connected to the at least one processor; wherein the memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the vehicle control method in the above-mentioned embodiment one.

[0154] Reference below Figure 6 , which shows a schematic diagram of the structure of a vehicle control device suitable for implementing an embodiment of the present application. The vehicle control device in the embodiment of the present application may include, but is not limited to, mobile terminals such as mobile phones, laptop computers, digital broadcast receivers, PDAs (Personal Digital Assistants), PADs (Portable Application Descriptions), PMPs (Portable Media Players), vehicle-mounted terminals (such as vehicle-mounted navigation terminals), etc., and fixed terminals such as digital TVs, desktop computers, etc. Figure 6 The vehicle control device shown is merely an example and should not bring any limitation to the functions and scope of use of the embodiments of the present application.

[0155] like Figure 6As shown, the vehicle control device may include a processing device 1001 (e.g., a central processing unit, a graphics processor, etc.), which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM: Read Only Memory) 1002 or a program loaded from a storage device 1003 to a random access memory (RAM: Random Access Memory) 1004. In RAM1004, various programs and data required for the operation of the vehicle control device are also stored. The processing device 1001, ROM1002, and RAM1004 are connected to each other through a bus 1005. An input / output (I / O) interface 1006 is also connected to the bus. Generally, the following systems can be connected to the I / O interface 1006: an input device 1007 including, for example, a touch screen, a touch pad, a keyboard, a mouse, an image sensor, a microphone, an accelerometer, a gyroscope, etc.; an output device 1008 including, for example, a liquid crystal display (LCD: Liquid Crystal Display), a speaker, a vibrator, etc.; a storage device 1003 including, for example, a magnetic tape, a hard disk, etc.; and a communication device 1009. The communication device 1009 can allow the vehicle control device to communicate with other devices wirelessly or by wire to exchange data. Although the figure shows a vehicle control device with various systems, it should be understood that it is not required to implement or have all the systems shown. More or fewer systems can be implemented or have alternatively.

[0156] In particular, according to the embodiments disclosed in the present application, the process described above with reference to the flowchart can be implemented as a computer software program. For example, the embodiments disclosed in the present application include a computer program product, which includes a computer program carried on a computer-readable medium, and the computer program includes a program code for executing the method shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed from a network through a communication device, or installed from a storage device 1003, or installed from a ROM 1002. When the computer program is executed by the processing device 1001, the above-mentioned functions defined in the method of the embodiment disclosed in the present application are executed.

[0157] The vehicle control device provided by the present application adopts the vehicle control method in the above embodiment, which can solve the technical problems that the traditional Ackerman offset calibration process is cumbersome and the calibration accuracy is not high. Compared with the prior art, the beneficial effects of the vehicle control device provided by the present application are the same as the beneficial effects of the vehicle control method provided by the above embodiment, and the other technical features in the vehicle control device are the same as the features disclosed in the method of the previous embodiment, which will not be repeated here.

[0158] It should be understood that the various parts disclosed in this application can be implemented by hardware, software, firmware or a combination thereof. In the description of the above embodiments, specific features, structures, materials or characteristics can be combined in any one or more embodiments or examples in a suitable manner.

[0159] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

[0160] The present application provides a computer-readable storage medium having computer-readable program instructions (ie, computer programs) stored thereon, and the computer-readable program instructions are used to execute the vehicle control method in the above-mentioned embodiment.

[0161] The computer-readable storage medium provided in the present application may be, for example, a USB flash drive, but is not limited to electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, systems or devices, or any combination of the above. More specific examples of computer-readable storage media may include, but are not limited to: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In this embodiment, the computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in combination with an instruction execution system, system or device. The program code contained on the computer-readable storage medium may be transmitted using any appropriate medium, including but not limited to: wires, optical cables, RF (Radio Frequency), etc., or any suitable combination of the above.

[0162] The computer-readable storage medium may be included in the vehicle control device; or may exist independently without being assembled into the vehicle control device.

[0163] The computer-readable storage medium carries one or more programs, and when the one or more programs are executed by the vehicle control device, the vehicle control device: vehicle control.

[0164] Computer program code for performing the operations of the present application may be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, C++, and conventional procedural programming languages ​​such as "C" or similar programming languages. The program code may be executed entirely on the user's computer, partially on the user's computer, as a separate software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0165] The flow chart and block diagram in the accompanying drawings illustrate the possible architecture, function and operation of the system, method and computer program product according to various embodiments of the present application. In this regard, each square box in the flow chart or block diagram can represent a module, a program segment or a part of a code, and the module, the program segment or a part of the code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the square box can also occur in a sequence different from that marked in the accompanying drawings. For example, two square boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each square box in the block diagram and / or flow chart, and the combination of the square boxes in the block diagram and / or flow chart can be implemented with a dedicated hardware-based system that performs a specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0166] The modules involved in the embodiments described in this application may be implemented by software or hardware, wherein the name of the module does not constitute a limitation on the unit itself in some cases.

[0167] The readable storage medium provided by the present application is a computer-readable storage medium, which stores computer-readable program instructions (i.e., computer programs) for executing the above-mentioned vehicle control method, and can solve the technical problems that the traditional Ackerman offset calibration process is cumbersome and the calibration accuracy is not high. Compared with the prior art, the beneficial effects of the computer-readable storage medium provided by the present application are the same as the beneficial effects of the vehicle control method provided by the above-mentioned embodiment, and will not be repeated here.

[0168] The present application also provides a computer program product, comprising a computer program, wherein when the computer program is executed by a processor, the steps of the vehicle control method as described above are implemented.

[0169] The computer program product provided by the present application can solve the technical problems that the traditional Ackerman offset calibration process is cumbersome and the calibration accuracy is low. Compared with the prior art, the beneficial effects of the computer program product provided by the present application are the same as the beneficial effects of the vehicle control method provided by the above embodiment, which will not be repeated here.

[0170] The above descriptions are only some embodiments of the present application, and are not intended to limit the patent scope of the present application. All equivalent structural changes made using the contents of the present application specification and drawings under the technical concept of the present application, or direct / indirect applications in other related technical fields are included in the patent protection scope of the present application.

Claims

1. A vehicle control method, characterized in that: The method comprises: Acquiring an initial position, a driving angle, and a target position of a vehicle, and controlling the vehicle to travel according to the initial position and the driving angle; When the vehicle travels to the target position, obtaining a wheel speed pulse change of the vehicle; An Ackerman offset is calculated according to the wheel speed pulse variation, and the vehicle is controlled according to the Ackerman offset.

2. The method according to claim 1, characterized in that The step of calculating the Ackerman offset according to the wheel speed pulse variation comprises: Get the vehicle wheelbase; Calculating the front wheel turning radius and the rear wheel turning radius according to the wheel speed pulse variation; An Ackerman shift is calculated according to the front wheel turning radius, the rear wheel turning radius, and the vehicle wheelbase.

3. The method according to claim 2, characterized in that The step of calculating the front wheel turning radius and the rear wheel turning radius according to the wheel speed pulse variation comprises: According to the wheel speed pulse variation, the front wheel speed pulse variation, the rear wheel speed pulse variation and the wheel travel distance are obtained; Calculating the front wheel turning radius according to the front wheel speed pulse change and the wheel travel distance; The rear wheel turning radius is calculated according to the rear wheel speed pulse change and the wheel travel distance.

4. The method according to claim 1, characterized in that The steps of obtaining the initial position, driving angle and target position of the vehicle and controlling the driving of the vehicle according to the initial position and the driving angle include: Get the initial position of the vehicle; Connecting the vehicle to a controller area network and sending a driving instruction to the controller area network so that the controller area network calibrates a driving angle of the vehicle based on the driving instruction; The vehicle is controlled to travel according to the initial position and the travel angle.

5. The method according to claim 1, characterized in that After the step of calculating the Ackerman offset according to the wheel speed pulse variation, the method further includes: Obtaining the vehicle's driving speed, steering wheel angle, vehicle mass, center of gravity height, and suspension stiffness; Calculating a center of gravity offset according to the driving speed, the steering wheel angle, the vehicle mass, the center of gravity height, and the suspension stiffness; The Ackerman shift is corrected according to the center of gravity shift.

6. The method according to claim 5, characterized in that The step of calculating the center of gravity offset according to the driving speed, the steering wheel angle, the vehicle mass, the center of gravity height and the suspension stiffness comprises: Obtaining the tire cornering stiffness of the vehicle, and obtaining the tire slip angle according to the driving speed and the steering wheel angle; Calculating a roll angle according to the tire cornering stiffness and the slip angle; The center of gravity offset is calculated according to the roll angle.

7. The method according to claim 6, characterized in that The step of calculating the roll angle according to the tire cornering stiffness and the slip angle comprises: Calculating tire lateral force according to the sideslip angle and the tire cornering stiffness; The roll angle is calculated according to the vehicle mass, the center of gravity height, the suspension stiffness, and the tire lateral force.

8. A vehicle control device, characterized in that: The device comprises: A driving module, used to obtain an initial position, a driving angle, and a target position of a vehicle, and control the vehicle to travel according to the initial position and the driving angle; An obtaining module, when the vehicle travels to the target position, obtains the wheel speed pulse variation of the vehicle; A calculation module calculates an Ackerman offset according to the wheel speed pulse change.

9. A vehicle control device, characterized in that: The device comprises: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the computer program is configured to implement the steps of the vehicle control method according to any one of claims 1 to 7.

10. A storage medium, characterized in that: The storage medium is a computer-readable storage medium, and a computer program is stored on the storage medium. When the computer program is executed by a processor, the steps of the vehicle control method according to any one of claims 1 to 7 are implemented.

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