Vehicle turning radius detection method, vehicle control method, equipment and storage medium

Abstract

The invention discloses a vehicle turning radius detection method, a vehicle control method, equipment and a storage medium. The vehicle turning radius detection method comprises the steps of obtaining a vehicle head steering angle, wheel attitude parameters and factory design parameters of a vehicle; calculating the head steering angle of the vehicle and the factory design parameters to obtain the handlebar steering radius of the vehicle, and calculating the wheel attitude parameters of the vehicle and the factory design parameters to obtain the body roll steering radius of the vehicle, so that the front wheel steering angle and the wheel roll angle of the vehicle during steady-state turning can be considered at the same time; and the handlebar steering radius and the body roll steering radius are subjected to fusion calculation, so that the real-time performance and the accuracy of effective turning radius detection of the motorcycle can be improved.

Description

Technical Field

[0001] The present application relates to the technical field of motorcycle system control, and in particular to a vehicle turning radius detection method, a vehicle control method, a device and a storage medium. Background Art

[0002] Motorcycles are two-wheeled unbalanced vehicles, and their effective turning radius plays an important role in their turning control. Currently, although cars can calculate their effective turning radius through the proportional relationship between the Ackerman angle and the steering wheel angle, the turning principle of motorcycles is different from that of cars. The effective turning radius of motorcycles is not only determined by the steering angle of the front of the vehicle, but also affected by more complex dynamic factors, such as the roll angle of the wheels.

[0003] However, current motorcycle turning skills basically rely on the driver's ability and experience, and there is no unified formula or theory in the industry to accurately calculate the effective turning radius of a motorcycle. Summary of the invention

[0004] The present application provides a vehicle turning radius detection method, a vehicle control method, a device and a storage medium, which can improve the real-time and accuracy of the effective turning radius detection of a motorcycle.

[0005] A technical solution adopted in the present application is to provide a vehicle turning radius detection method, which includes: obtaining the vehicle's front steering angle, wheel posture parameters and factory design parameters. The front steering angle is calculated with the factory design parameters to obtain the vehicle's handlebar steering radius. The wheel posture parameters are calculated with the factory design parameters to obtain the vehicle's body roll steering radius. The handlebar steering radius and the body roll steering radius are integrated and calculated to obtain the vehicle's effective turning radius.

[0006] In some embodiments, the handlebar steering radius and the body roll steering radius are integrated and calculated to obtain the effective turning radius of the vehicle, including: taking the contact point between the rear tire of the vehicle and the ground as the coordinate origin to construct the vehicle kinematic coordinate system. The handlebar steering radius and the body roll steering radius are spatially transformed and projected to obtain the turning parameters in the vehicle kinematic coordinate system; wherein the turning parameters include the center coordinates of the steering radius, the converted handlebar steering radius, the center coordinates of the roll steering radius, and the converted body roll steering radius. According to the turning parameters and the coordinate origin, the turning geometry triangle is determined. The turning geometry triangle and the radius perpendicular to the forward tangent of the tire of the vehicle are solved to obtain the effective turning radius.

[0007] In some embodiments, the handlebar steering radius and the body roll steering radius are spatially transformed and projected to obtain turning parameters in the vehicle kinematic coordinate system, including: performing a rotation coordinate system transformation in three-dimensional space, a three-dimensional transformation matrix operation, and an orthogonal projection to the vehicle kinematic coordinate system on the handlebar steering radius and the body roll steering radius in turn to obtain turning parameters.

[0008] In some embodiments, determining the turning geometry triangle according to the turning parameters and the coordinate origin includes: determining the origin position of the body roll steering radius under the ground plane and the origin position of the handlebar steering radius in the vehicle kinematic coordinate system according to the turning parameters and the position of the coordinate origin. Determine the turning geometry triangle according to the position of the coordinate origin, the origin position of the body roll steering radius under the ground plane, and the origin position of the handlebar steering radius.

[0009] In some embodiments, the factory design parameters include front and rear wheel wheelbases, front steering mechanism parameters, and front wheel tire size parameters; the front steering angle of the vehicle is calculated with the factory design parameters to obtain the handlebar steering radius of the vehicle, including: performing geometric operations on the front steering angle, front and rear wheel wheelbases, front steering mechanism parameters, and front wheel tire size parameters to obtain the handlebar steering radius.

[0010] In some embodiments, the wheel attitude parameters include wheel roll angles, and the factory design parameters include rear tire size parameters; calculating the wheel attitude parameters and the factory design parameters to obtain the vehicle body roll steering radius includes: performing geometric operations on the wheel roll angle and the rear tire size parameters to obtain an actual ground contact rolling radius. Performing geometric operations on the actual ground contact rolling radius and the wheel roll angle to obtain the vehicle body roll steering radius.

[0011] In some embodiments, the handlebar steering radius and the body roll steering radius are integrated and calculated to obtain the effective turning radius of the vehicle, which includes: obtaining the tire slip rate of the vehicle. In response to the wheel posture parameter satisfying the preset stability condition and the tire slip rate satisfying the preset limit condition, the step of integrating the handlebar steering radius and the body roll steering radius to obtain the effective turning radius of the vehicle is performed. In response to the wheel posture parameter not satisfying the stability condition and / or the tire slip rate not satisfying the limit condition, the effective turning radius of the previous cycle is maintained.

[0012] In some embodiments, the wheel attitude parameters include the wheel pitch angle and the wheel yaw angle, and the tire slip rate includes the front wheel slip rate and the rear wheel slip rate; in response to the wheel attitude parameters satisfying the preset stability condition, and the tire slip rate satisfying the preset limit condition, it includes: detecting that the wheel pitch angle is less than the preset vehicle body steady-state pitch angle limit, and determining that the wheel pitch angle satisfies the stability condition. Detecting that the wheel yaw angle is less than the preset vehicle body steady-state yaw angle limit, and determining that the wheel yaw angle satisfies the stability condition. Detecting that the front wheel slip rate is less than the preset first vehicle body steady-state slip rate, and determining that the front wheel slip rate satisfies the limit condition. Detecting that the rear wheel slip rate is less than the preset second vehicle body steady-state slip rate, and determining that the rear wheel slip rate satisfies the limit condition.

[0013] Another technical solution adopted in the present application is: to provide a vehicle control method, the vehicle control method comprising: obtaining an effective turning radius of the vehicle; wherein the effective turning radius is obtained based on any one of the vehicle turning radius detection methods as above; and controlling the vehicle based on the effective turning radius.

[0014] Another technical solution adopted by the present application is to provide an electronic device, the electronic device comprising: a memory for storing executable program codes; a processor for calling and running the executable program codes from the memory, so that the electronic device executes any one of the above vehicle turning radius detection methods or vehicle control methods.

[0015] Another technical solution adopted by the present application is: providing a computer-readable storage medium, the computer-readable storage medium storing a computer program, when the computer program is executed by a processor, implementing any of the above vehicle turning radius detection methods or vehicle control methods.

[0016] The embodiment of the present application provides a vehicle turning radius detection method, which includes: obtaining the front steering angle, wheel attitude parameters and factory design parameters of the vehicle; calculating the front steering angle with the factory design parameters to obtain the handlebar steering radius of the vehicle; calculating the wheel attitude parameters with the factory design parameters to obtain the body roll steering radius of the vehicle; fusing the handlebar steering radius and the body roll steering radius to obtain the effective turning radius of the vehicle. By calculating the front steering angle of the vehicle with the factory design parameters to obtain the handlebar steering radius of the vehicle, and calculating the wheel attitude parameters of the vehicle with the factory design parameters to obtain the body roll steering radius of the vehicle, the front wheel steering angle and wheel roll angle of the vehicle in steady-state turning can be considered at the same time, and the handlebar steering radius and the body roll steering radius are fused and calculated, which can improve the real-time and accuracy of the effective turning radius detection of the motorcycle. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1It is a flow chart of the first embodiment of the vehicle turning radius detection method of the present application; Figure 2 It is a flow chart of the second embodiment of the vehicle turning radius detection method of the present application; Figure 3 It is a logic diagram of an effective turning radius calculation and estimation software unit of a vehicle turning radius detection method in one embodiment of the present application; Figure 4a It is a front view of a motorcycle defined by a whole vehicle coordinate system of a vehicle turning radius detection method of the present application; Figure 4b It is a schematic diagram of the vehicle side defined by the motorcycle vehicle coordinate system of the vehicle turning radius detection method of the present application; Figure 4c It is a schematic diagram of the roof defined by the motorcycle whole vehicle coordinate system of the vehicle turning radius detection method of the present application; Figure 5 It is a schematic diagram of the parameters of the front steering mechanism of a motorcycle in the vehicle turning radius detection method of the present application; Figure 6 It is a schematic diagram of a motorcycle hub tire cross-section of the vehicle turning radius detection method of the present application; Figure 7 This is a schematic diagram of the logic geometry of calculating the steering radius of the handlebar steering wheel of the vehicle turning radius detection method of the present application; Figure 8 This is a schematic diagram of the logic geometry of the vehicle body roll steering radius calculation of the vehicle turning radius detection method of the present application; Fig. 9 This is a schematic diagram of effective turning radius fusion calculation of the vehicle turning radius detection method of the present application; Fig.10 It is a schematic diagram of the vehicle kinematic coordinate system and turning geometry triangle of the vehicle turning radius detection method of the present application; Fig.11 is an exemplary flow chart of a vehicle turning radius detection method in one embodiment of the present application; Fig.12 It is a flow chart of the third embodiment of the vehicle turning radius detection method of the present application; Fig.13 is a logic diagram of an effective turning radius calculation and estimation software unit of a vehicle turning radius detection method in another embodiment of the present application; Fig.14 is an exemplary flow chart of a vehicle turning radius detection method in another embodiment of the present application; Fig.15 is an exemplary structural block diagram of an electronic device of the present application; Fig.16 It is an exemplary structural block diagram of the computer-readable storage medium of the present application. DETAILED DESCRIPTION

[0018] The present application is described in detail below with reference to the accompanying drawings and implementation methods.

[0019] In some embodiments, see Figure 1 , Figure 1 1 is a flow chart of the first embodiment of the vehicle turning radius detection method of the present application. It should be noted that if there are substantially the same results, the method of the present application is not based on Figure 1 The process sequence shown is limited. Figure 1 As shown, the vehicle turning radius detection method includes: Step S101, obtaining the vehicle's front steering angle, wheel posture parameters and factory design parameters.

[0020] The vehicle may be an electric motorcycle.

[0021] The front steering angle refers to the steering angle of the front wheels of the vehicle, that is, the deflection angle of the front of the vehicle relative to the longitudinal axis of the vehicle. The front steering angle can affect the movement path of the front wheels when the vehicle turns.

[0022] The factory design parameters may be fixed parameters set by the manufacturer when designing and producing the vehicle. For example, the factory design parameters may include at least one of the front and rear wheel wheelbases, front steering mechanism parameters, front wheel tire size parameters, and rear wheel tire size parameters of the vehicle.

[0023] The wheel attitude parameter may be an angle parameter describing the wheel attitude in three-dimensional space, and may be used to calculate the wheel attitude change of the vehicle when turning, especially the influence of the body roll on the turning radius.

[0024] For example, the wheel attitude parameter may include at least one of a wheel pitch angle (Pitch), a wheel yaw angle (Yaw), and a wheel roll angle (Roll).

[0025] Step S102, calculating the vehicle head steering angle and the factory design parameters to obtain the vehicle handlebar steering radius.

[0026] The handlebar steering radius may be the shortest distance between the front tire and the steering center during the rotation process when the driver turns the vehicle handlebar. By calculating the vehicle head steering angle and factory design parameters, the handlebar steering radius obtained can be used to estimate the turning situation of the vehicle at any vehicle head steering angle.

[0027] It should be noted that this embodiment takes step S102 being executed before step S103 as an example. In other embodiments, step S102 may also be executed after step S103, or step S102 may be executed simultaneously with step S103.

[0028] Step S103, calculating the wheel attitude parameters and the factory design parameters to obtain the vehicle body roll turning radius.

[0029] The body roll steering radius can be the change in turning radius caused by the tilt of the vehicle body during turning. Since the body roll steering radius will change the actual turning radius, in order to improve the calculation accuracy of the effective turning radius of the vehicle, the body roll steering radius obtained by calculating the wheel attitude parameters and the factory design parameters can be used to estimate the impact of the body roll on the vehicle turning radius.

[0030] Step S104, the handlebar steering radius and the vehicle body roll steering radius are integrated and calculated to obtain the effective turning radius of the vehicle.

[0031] The effective turning radius may be the radius of the circular track when the vehicle is turning in a steady state (stable turning) on ​​the road, that is, the radius of the circular track left by a motorcycle when it makes a complete and stable turn.

[0032] As an illustrative example, when a vehicle turns, not only the steering angle of the front wheel affects the turning radius, but also the roll of the vehicle body affects the actual turning radius. Therefore, by integrating the steering radius of the handlebar and the body roll steering radius, an accurate effective turning radius value can be obtained. The effective turning radius of a motorcycle being ridden can be calculated and estimated in real time, and the effective turning radius is sent to the vehicle's controller area network (Controller Area Network) network and provided to the vehicle instrument, vehicle networking box (T-Box), anti-lock braking system (ABS) and other controllers for use, so that the motorcycle design can be based on the effective turning radius in this embodiment, to achieve higher-level road safety functions, assisted driving, self-balancing algorithms, intelligent driving planning and other functions.

[0033] This embodiment calculates the vehicle's front steering angle with the factory design parameters to obtain the vehicle's handlebar steering radius, and calculates the vehicle's wheel posture parameters with the factory design parameters to obtain the vehicle's body roll steering radius. It can simultaneously take into account the vehicle's front wheel steering angle and wheel roll angle during steady-state turning, and integrate the handlebar steering radius and the body roll steering radius for calculation, which can improve the real-time and accuracy of the motorcycle's effective turning radius detection.

[0034] The inventors considered that there has been no fixed formula or theory in the industry for the scientific explanation of the turning principle of motorcycles. Unlike cars, motorcycles are a two-wheeled unbalanced means of transportation, and their turning skills vary greatly depending on the rider's ability and experience. Although the effective turning radius of a car can be obtained through a certain proportional function through the designed relationship between the front suspension Ackerman angle and the steering wheel angle, the effective turning radius of a motorcycle is determined by factors such as the wheel roll angle in addition to the front wheel steering angle. However, the methods for calculating and monitoring the effective turning radius of motorcycles have always been in an ambiguous state in the industry, and it is difficult to accurately detect the effective turning radius of a motorcycle at the current moment through the various motion state parameters and vehicle design size parameters of the motorcycle at a certain moment.

[0035] Therefore, the present application proposes a method for calculating and monitoring the effective turning radius of a motorcycle, which is applied to the motorcycle Main Vehicle Control Unit (MVCU). The onboard inertial measurement unit (IMU) hardware and software algorithm module in the MVCU is used to achieve real-time calculation and estimation of the effective turning radius of a motorcycle being ridden, and the effective turning radius is sent to the vehicle CAN network for use by other controllers such as vehicle instruments, T-Box, ABS, etc.

[0036] See also Figure 2 , Figure 2 1 is a flow chart of the second embodiment of the vehicle turning radius detection method of the present application. The method comprises the following steps: Step S201, obtaining the vehicle's front steering angle, wheel posture parameters and factory design parameters.

[0037] As an illustrative example, see Figure 3 The vehicle may include a front steering angle sensor hardware, a vehicle controller onboard six-axis IMU hardware, and a vehicle controller hardware. Among them, the vehicle controller hardware is arranged on the motorcycle frame, and the vehicle controller onboard six-axis IMU hardware is arranged on the vehicle controller hardware.

[0038] This embodiment is applied to the vehicle controller hardware of the vehicle, and the vehicle controller hardware may include: Euler angle solution software unit, effective turning radius calculation and estimation software unit. Through the six-axis IMU hardware on the vehicle controller board, the X-axis acceleration, Y-axis acceleration, Z-axis acceleration, X-axis angular velocity, Y-axis angular velocity, and Z-axis angular velocity of the motorcycle are obtained, and these data are input into the Euler angle solution software unit to obtain the wheel posture parameters; when the vehicle is turning, the head steering angle velocity can be obtained through the head steering angle sensor hardware; the factory design parameters of the vehicle can be input through the host computer.

[0039] Among them, the vehicle controller hardware can define the coordinate system of the vehicle. The coordinate system calculations performed by the Euler angle solution software unit and the effective turning radius calculation and estimation software unit in the vehicle controller hardware can follow the following vehicle coordinate system definition.

[0040] The vehicle controller hardware can define the coordinates of the motorcycle and build the vehicle coordinate system. Figure 4a The vehicle front schematic diagram is shown. The coordinate system of the whole vehicle takes the point where the front wheel of the motorcycle touches the ground as the coordinate origin, and the direction of the front of the vehicle when viewed from the side is the X+ direction; please refer to Figure 4b The schematic diagram of the vehicle side is shown, with the origin vertically above the ground as the Z+ direction; please refer to Figure 4c The roof schematic diagram shown is viewed from the head direction with the left handlebar of the vehicle, that is, the right side of the front view, as the Y+ direction. The Euler angle definition conforms to the right-hand screw rule in the flight control. When the vehicle is tilted to the right side from the front direction of the vehicle, the vehicle wheel roll angle is positive. Therefore, the wheel attitude parameters can include the wheel roll angle, wheel pitch angle, and wheel yaw angle of the frame.

[0041] In some embodiments, the factory design parameters may include front and rear wheelbases, front steering mechanism parameters, and front wheel tire size parameters.

[0042] In some embodiments, see Figure 5 The front steering mechanism parameters may include trailing distance, in mm; caster angle, in °; front wheel tire rolling radius, in mm; front fork offset distance, in mm.

[0043] In some embodiments, see Figure 6 The front wheel tire size parameters may include the crown radius when not deflected, in mm; and the maximum dump angle of the tire.

[0044] Step S202, performing geometric calculations on the vehicle head steering angle, the front and rear wheel wheelbases, the front steering mechanism parameters, and the front wheel tire size parameters to obtain the handlebar steering radius.

[0045] As an illustrative example, see Figure 7 , Figure 7 The handlebar steering angle is shown in degrees; and the fork offset distance is shown in mm; the mounting position of the handlebar steering angle sensor hardware can be mounted on the vehicle body. As an exemplary embodiment, the handlebar steering angle sensor hardware can be mounted at the connection point between the front wheel tire and the front frame / battery compartment.

[0046] The following formula (1) can be obtained by geometrically calculating the steering angle of the vehicle head, the parameters of the front steering mechanism (front and rear wheel wheelbase, trailing distance, caster angle, front wheel tire rolling radius, front fork offset distance), and the front wheel tire size parameters (crown radius, maximum tire tilt angle). The steering radius of the handlebar can be calculated using the following formula (1): (1); Among them, A represents the steering radius of the handlebar; B represents the steering angle of the front of the vehicle; C represents the wheelbase of the front and rear wheels; D represents the offset distance of the front fork; and E represents the castor angle.

[0047] Step S203, performing geometric calculation on the wheel roll angle and the rear wheel tire size parameters to obtain an actual ground contact rolling radius.

[0048] See also Figure 8 The rear wheel tire size parameters may include the rear wheel tire rolling radius, in mm; the rear wheel tire crown radius, in mm; and the rear wheel tire contact width, in mm.

[0049] As an illustrative example, since the tire is fixedly mounted on the wheel hub, the wheel hub is connected to the vehicle body through the suspension, and assuming that the suspension is in a compressed state when the vehicle is naturally placed, the turning radius obtained by the driver by rolling the vehicle body is generated by the cross-sectional geometric characteristics of the tire.

[0050] Therefore, please continue to read Figure 8 , the wheel roll angle and rear wheel tire size parameters (rear wheel tire crown radius, rear wheel tire contact width) are geometrically deduced to obtain the following formula (2), and the actual contact rolling radius is calculated by the following formula (2): f= (2); Among them, b represents the tire rolling radius in the vertical state; c represents the rear tire crown radius; d represents the wheel roll angle; e represents the tire ground contact width; and f represents the actual ground contact rolling radius.

[0051] Step S204: geometrically calculate the actual ground contact rolling radius and the wheel roll angle to obtain the vehicle body roll turning radius.

[0052] As an example, the actual ground contact rolling radius and the sine angle of the wheel roll angle are geometrically calculated to obtain the following formula (3), and the body roll steering radius is calculated by the following formula (3): (3); Wherein, a represents the body roll turning radius.

[0053] Step S205, taking the contact point between the rear tire of the vehicle and the ground as the coordinate origin, constructing the vehicle kinematic coordinate system.

[0054] As an illustrative example, see Fig.10 , take the contact point between the rear tire of the motorcycle and the ground as the coordinate origin of the vehicle kinematic coordinate system, and construct the x, y, and z coordinate axes of the vehicle kinematic coordinate system.

[0055] Step S206, performing spatial transformation and projection operation on the handlebar steering radius and the vehicle body roll steering radius to obtain turning parameters in the vehicle kinematic coordinate system.

[0056] Among them, the turning parameters may include the center coordinates of the handlebar steering radius, the converted handlebar steering radius, the center coordinates of the roll steering radius, and the converted body roll steering radius.

[0057] In some embodiments, the turning parameters include the center coordinates of the handlebar steering radius, the converted handlebar steering radius, the center coordinates of the roll steering radius, and the converted vehicle body roll steering radius.

[0058] As an example, when the vehicle actually turns, the steering of the handlebars and the roll of the vehicle body will interact with each other. Therefore, through spatial transformation and projection operations, the steering radius of the handlebars and the roll steering radius of the vehicle body can be converted to the vehicle kinematic coordinate system to improve the analysis and optimization accuracy of the vehicle's turning performance.

[0059] The handlebar steering radius center coordinates may be the handlebar steering radius center coordinates in the vehicle kinematic coordinate system, indicating the steering geometric center controlled by the handlebar. The converted handlebar steering radius may be the value of the handlebar steering radius in the vehicle kinematic coordinate system.

[0060] The center coordinates of the roll steering radius may be the center coordinates of the roll steering radius of the vehicle body in the vehicle kinematic coordinate system, indicating that the steering center of gravity of the vehicle changes as the wheel roll angle of the vehicle body changes. The converted roll steering radius of the vehicle body may be the value of the roll steering radius of the vehicle body in the vehicle kinematic coordinate system.

[0061] In some embodiments, step S206 may include: performing a rotation coordinate system transformation, a three-dimensional transformation matrix operation, and an orthogonal projection on the handlebar steering radius and the vehicle body roll steering radius in three-dimensional space to obtain turning parameters.

[0062] As an illustrative example, see Fig. 9, since most of the steering situations in actual motorcycle riding are completed under the simultaneous action of handlebar steering and roll steering. Therefore, the handlebar steering radius and the body roll steering radius are transformed through the rotation coordinate system in three-dimensional space, three-dimensional transformation matrix operation, and orthogonal projection to the vehicle kinematic coordinate system for operation to obtain the turning parameters, wherein the turning parameters may include the center coordinates of the steering radius, the converted handlebar steering radius, the center coordinates of the roll steering radius, and the converted body roll steering radius.

[0063] For example, the rotation coordinate transformation in the three-dimensional space may be a Rodriguez rotation coordinate transformation.

[0064] Step S207, determining the turning geometric triangle according to the turning parameters and the coordinate origin.

[0065] As an illustrative example, the turning geometry triangle can be used in motorcycle kinematics to analyze the relationship between the handlebar steering and the wheel roll angle, and then determine the geometric relationship of the effective turning radius of the motorcycle when turning. By determining the turning geometry triangle, the effective turning radius of the motorcycle when turning can be estimated more accurately, improving driving stability and safety.

[0066] In some embodiments, please refer to Fig.10 Step S206 may include: determining the origin position of the vehicle body roll steering radius below the ground plane and the origin position of the handlebar steering radius in the vehicle kinematic coordinate system according to the turning parameters and the position of the coordinate origin; determining the turning geometry triangle according to the position of the coordinate origin, the origin position of the vehicle body roll steering radius below the ground plane and the origin position of the handlebar steering radius.

[0067] As an illustrative example, since the vehicle body will roll when turning, the actual effective turning radius is not simply equal to the rear wheel or front wheel trajectory. Therefore, the origin position of the vehicle body roll steering radius below the ground plane can be used to detect the impact of the roll on the overall motion trajectory. At the same time, since the handlebar steering controls the front wheels of the vehicle, the steering radius of the front wheels is different from the trajectory of the rear wheels. Therefore, the origin position of the handlebar steering radius can be used to detect the trajectory of the front wheels of the vehicle. Furthermore, when the vehicle turns, the three origin positions are used to determine the steering geometry triangle, which can be used to analyze the effective turning radius of the vehicle.

[0068] Step S208, solving the perpendicular radius of the turning geometry triangle and the forward tangent line of the tire of the vehicle to obtain an effective turning radius.

[0069] When the motorcycle is moving forward, the contact points between the tire and the ground at each moment will form a trajectory movement consistent with the direction of the motorcycle's travel, and the direction of this trajectory is the forward tangent. The vertical direction of the forward tangent can be a direction perpendicular to the tire forward tangent direction.

[0070] In some embodiments, step S208 may include: solving the perpendicular radius of the turning geometry triangle and the forward tangent line of the tire of the vehicle to obtain the effective turning radius and the center of the effective turning radius.

[0071] As an example, by solving the perpendicular radius of the turning geometry triangle and the vehicle's tire forward tangent line, not only the effective turning radius but also the center of the effective turning radius can be obtained. The center of the effective turning radius is Fig.10 As shown in (X c , Y c , Z c ), which can be used to calculate the linear velocity and angular velocity of the vehicle during a roll turn.

[0072] Please continue reading Fig. 9 and Fig.10 This embodiment takes into account that when the vehicle is turning, the forward direction of the wheels can also affect the turning radius of the vehicle. Therefore, by solving the radius of the turning geometry triangle and the perpendicular direction of the tire forward tangent line, the effective turning radius of the vehicle in steady-state turning can be obtained.

[0073] In an exemplary embodiment, see Fig.11 The effective turning radius calculation and estimation software unit may include a handlebar steering radius calculation logic, a vehicle body roll steering radius calculation logic, and an effective turning radius fusion calculation logic.

[0074] Firstly, the front steering angle, front and rear wheel wheelbase, front steering mechanism parameters, and front wheel tire size parameters are input into the handlebar steering radius calculation logic for geometric calculation to obtain the handlebar steering radius; at the same time, the wheel roll angle and rear wheel tire size parameters are input into the body roll steering radius calculation logic for geometric calculation to obtain the body roll steering radius, which can improve the real-time performance of effective turning radius detection; then, the handlebar steering radius and the body roll steering radius are input into the effective turning radius fusion calculation logic for rotation coordinate system transformation in three-dimensional space, three-dimensional transformation matrix operation, and orthogonal projection to the vehicle kinematic coordinate system to determine the turning geometry triangle, and solve the perpendicular radius of the turning geometry triangle to the forward tangent to obtain the effective turning radius in the motorcycle kinematic coordinate system, which can improve the accuracy of the effective turning radius, realize real-time and efficient dynamic monitoring and calculation of the effective turning radius of the motorcycle, and then be used for path estimation of higher-order motorcycle intelligent driving functions, safe driving and other functions.

[0075] See also Fig.12 , Fig.12 1 is a flow chart of the third embodiment of the vehicle turning radius detection method of the present application. The method comprises the following steps: Step S1201, obtaining the vehicle's front steering angle, wheel posture parameters and factory design parameters.

[0076] Step S1202, calculating the vehicle head steering angle and the factory design parameters to obtain the vehicle handlebar steering radius.

[0077] Step S1203, calculating the wheel attitude parameters and the factory design parameters to obtain the vehicle body roll turning radius.

[0078] The implementation and beneficial effects of step S1201 may be the same as those of step S101 or step S201. The implementation and beneficial effects of step S1202 may be the same as those of step S102 or step S202. The implementation and beneficial effects of step S1203 may be the same as those of step S103 or step S203 and step S204.

[0079] Step S1204, in response to the wheel posture parameters satisfying the preset stability conditions and the tire slip rate satisfying the preset limit conditions, the step of fusing the handlebar steering radius and the body roll steering radius to obtain the effective turning radius of the vehicle is executed.

[0080] As an illustrative example, since the effective turning radius is the turning radius of the vehicle in a stable turning condition, that is, in a non-slip condition, this embodiment uses the wheel posture parameters and the tire slip rate to judge the stability of the vehicle. When the wheel posture parameters meet the stability condition and the tire slip rate meets the limit condition, the vehicle controller confirms that the vehicle is in a stable turning state, and integrates the handlebar steering radius and the body roll steering radius to update the effective turning radius, thereby improving the accuracy of the effective turning radius detection.

[0081] Among them, the stable condition can be used to confirm that the vehicle is in a stable turning state, indicating that the vehicle is not rolling excessively. The restricted condition can be used to confirm that the vehicle is in a stable turning state, indicating that the vehicle is not slipping or losing traction.

[0082] In some embodiments, the wheel attitude parameters include a wheel pitch angle and a wheel yaw angle, and the tire slip rate includes a front wheel slip rate and a rear wheel slip rate.

[0083] In some embodiments, in response to the wheel attitude parameter satisfying a preset stability condition and the tire slip rate satisfying a preset limit condition, the method includes: detecting that the wheel pitch angle is less than a preset vehicle body steady-state pitch angle limit, and determining that the wheel pitch angle satisfies the stability condition. Detecting that the wheel yaw angle is less than a preset vehicle body steady-state yaw angle limit, and determining that the wheel yaw angle satisfies the stability condition. Detecting that the front wheel slip rate is less than a preset first vehicle body steady-state slip rate, and determining that the front wheel slip rate satisfies the limit condition. Detecting that the rear wheel slip rate is less than a preset second vehicle body steady-state slip rate, and determining that the rear wheel slip rate satisfies the limit condition.

[0084] As an illustrative example, the vehicle body steady state pitch angle limit can be set according to the design or safety requirements of the motorcycle, indicating the maximum wheel pitch angle allowed in a stable driving or turning state. If the wheel pitch angle is detected to be greater than or equal to the preset vehicle body steady state pitch angle limit, it means that the front and rear tilt angle of the motorcycle is too large, and the vehicle may have entered an unstable state.

[0085] The body steady state yaw angle limit can be set according to the design or safety requirements of the motorcycle, indicating the maximum wheel yaw angle allowed in a stable driving or turning state. When the wheel yaw angle is detected to be greater than or equal to the preset body steady state yaw angle limit, it means that the motorcycle's wheel yaw angle is too large and the vehicle may be in a slipping or unstable state.

[0086] The first vehicle body steady-state slip rate is used to indicate that the rear wheel slip is kept within a safe range when the vehicle is driving normally and turning. When the front wheel slip rate is detected to be greater than or equal to the preset steady-state limit, it means that the front wheel slip is too large, which may cause the front wheel to lose control or become unstable.

[0087] The second vehicle body steady-state slip rate is used to indicate that the rear wheel slip is kept within a safe range when the vehicle is driving normally and turning. When the rear wheel slip rate is detected to be greater than or equal to the preset steady-state limit, it means that the rear tires may have lost sufficient traction and may slip, drift or lose control. The second vehicle body steady-state slip rate may be equal to or different from the first vehicle body steady-state slip rate.

[0088] Step S1205: In response to the wheel posture parameter not satisfying the stability condition and / or the tire slip rate not satisfying the limit condition, maintaining the effective turning radius of the previous cycle.

[0089] As an illustrative example, when the wheel attitude parameters do not meet the stability condition or the tire slip rate exceeds the limit condition, it means that the vehicle has entered an unstable state, such as vehicle skidding, etc. When the vehicle is not in a stable state, in order to reduce the danger caused by the calculated turning radius being too far away from the actual situation in an unstable state, the vehicle controller can maintain the effective turning radius calculated in the previous cycle.

[0090] In an exemplary embodiment, see Fig.13 The vehicle may include a vehicle head steering angle sensor hardware, a vehicle controller onboard six-axis IMU hardware, and a vehicle controller hardware. The vehicle controller hardware applied to the vehicle in this embodiment may include: an Euler angle solving software unit, an effective turning radius calculation and estimation software unit, and a vehicle slip rate calculation software module.

[0091] When the vehicle turns, the six-axis IMU hardware onboard the vehicle controller can be used to obtain the X-axis acceleration, Y-axis acceleration, Z-axis acceleration, X-axis angular velocity, Y-axis angular velocity, and Z-axis angular velocity, and this data can be input into the Euler angle solution software unit to obtain the wheel posture parameters; the front steering angle velocity can be obtained through the front steering angle sensor hardware; the factory design parameters of the vehicle can be input through the host computer; and the tire slip rate can be obtained through the vehicle slip rate calculation software module.

[0092] Then, the vehicle steering angle, wheel attitude parameters, tire slip rate, and factory design parameters are input into the effective turning radius calculation and estimation software unit for processing, and the effective turning radius is output. Fig.14 The effective turning radius calculation and estimation software unit includes the handlebar steering radius calculation logic and the vehicle body roll steering radius calculation logic.

[0093] The front steering angle, front and rear wheel wheelbase, front steering mechanism parameters, and front wheel tire size parameters are input into the handlebar steering radius calculation logic for geometric calculation to obtain the handlebar steering radius; the wheel roll angle and rear wheel tire size parameters are input into the body roll steering radius calculation logic for geometric calculation to obtain the body roll steering radius, which can improve the real-time performance of effective turning radius detection.

[0094] Then, the handlebar steering radius and the body roll steering radius are input into the effective turning radius fusion calculation logic to perform rotation coordinate system transformation in three-dimensional space, three-dimensional transformation matrix operation, and orthogonal projection to the vehicle kinematic coordinate system to determine the turning geometry triangle. The effective turning radius in the motorcycle kinematic coordinate system is obtained by solving the perpendicular radius of the turning geometry triangle and the forward tangent.

[0095] At this time, it is possible to detect whether the wheel pitch angle is greater than or equal to the vehicle body steady-state pitch angle limit, detect whether the wheel yaw angle is greater than or equal to the vehicle body steady-state yaw angle limit, detect whether the front wheel slip rate is greater than or equal to the first vehicle body steady-state slip rate, and detect whether the rear wheel slip rate is greater than or equal to the second vehicle body steady-state slip rate; if the wheel pitch angle is less than the vehicle body steady-state pitch angle limit, it is determined that the wheel pitch angle is stable; if the wheel yaw angle is less than the vehicle body steady-state yaw angle limit, it is determined that the wheel yaw angle is stable; if the front wheel slip rate is less than the first vehicle body steady-state slip rate, it is determined that the front wheel slip rate is within the limit value; if the rear wheel slip rate is less than the second vehicle body steady-state slip rate, it is determined that the rear wheel slip rate is within the limit; then, it is detected whether the wheel pitch angle is stable, the wheel yaw angle is stable, the front wheel slip rate is within the limit, and the rear wheel slip rate is within the limit; if the wheel pitch angle is stable, the wheel yaw angle is stable, the front wheel slip rate is within the limit, and the rear wheel slip rate is within the limit, the currently calculated effective turning radius is updated and output in real time to other software units of the vehicle controller and the vehicle CAN bus for use by other modules; otherwise, the effective turning radius is maintained at the value of the previous cycle.

[0096] Therefore, this embodiment uses wheel attitude parameters and tire slip rate to judge the stability of the vehicle. When the wheel attitude parameters meet the stability condition and the tire slip rate meets the limit condition, the vehicle controller confirms that the vehicle is in a stable turning state, and integrates the handlebar steering radius and the body roll steering radius to update the effective turning radius, thereby improving the accuracy of the effective turning radius detection. When the wheel attitude parameters do not meet the stability condition, or the tire slip rate does not meet the limit condition, the danger caused by the calculated turning radius being too far away from the actual situation in the unstable state of the vehicle is reduced.

[0097] Another technical solution adopted in the present application is: to provide a vehicle control method, the vehicle control method comprising: obtaining an effective turning radius of the vehicle; wherein the effective turning radius is obtained based on any one of the vehicle turning radius detection methods as above; and controlling the vehicle based on the effective turning radius.

[0098] See also Fig.15 , Fig.15 is an exemplary structural block diagram of the electronic device of the present application. Fig.15 As shown, the electronic device 1500 of the present application may include a processor 1501 and a memory 1502, wherein the processor 1501 and the memory 1502 communicate with each other via a bus. The memory 1502 stores program instructions for vehicle turning radius detection, and when the program instructions are executed by the processor 1501, the processor executes the above-mentioned related method steps to implement a vehicle turning radius detection method or a vehicle control method in the above-mentioned embodiment.

[0099] See also Fig.16 , Fig.16 is an exemplary structural block diagram of the computer-readable storage medium of the present application. Fig.16 As shown, the computer-readable storage medium 1600 stores a computer program 1601. When the computer program 1601 is executed by a processor on a computer, the computer executes the above-mentioned related method steps to implement a vehicle turning radius detection method or a vehicle control method in the above-mentioned embodiment.

[0100] The above scheme obtains the vehicle's front steering angle, wheel attitude parameters and factory design parameters; calculates the front steering angle with the factory design parameters to obtain the vehicle's handlebar steering radius; calculates the wheel attitude parameters with the factory design parameters to obtain the vehicle's body roll steering radius; and fuses the handlebar steering radius and the body roll steering radius to obtain the vehicle's effective turning radius. By calculating the vehicle's front steering angle with the factory design parameters to obtain the vehicle's handlebar steering radius, and calculating the vehicle's wheel attitude parameters with the factory design parameters to obtain the vehicle's body roll steering radius, the front wheel steering angle and wheel roll angle of the vehicle during steady-state turning can be taken into account at the same time, and the handlebar steering radius and the body roll steering radius are fused for calculation, which can improve the real-time and accuracy of the motorcycle's effective turning radius detection.

[0101] In the several embodiments provided in the present application, it should be understood that the disclosed methods, electronic devices and storage media can be implemented in other ways. For example, the device implementation described above is only schematic. For example, the division of modules or units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0102] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0103] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0104] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, server, or network device, etc.) or a processor (processor) to execute all or part of the steps of the vehicle turning radius detection method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program codes.

[0105] The above description is only an implementation method of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly used in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A vehicle turning radius detection method, characterized in that: The vehicle turning radius detection method comprises: Obtain the vehicle's front steering angle, wheel posture parameters and factory design parameters; Calculate the steering angle of the vehicle head and the factory design parameters to obtain the steering radius of the handlebar of the vehicle; Calculating the wheel attitude parameter and the factory design parameter to obtain the body roll turning radius of the vehicle; The handlebar steering radius and the vehicle body roll steering radius are integrated and calculated to obtain the effective turning radius of the vehicle.

2. The vehicle turning radius detection method according to claim 1, characterized in that: The step of fusing the handlebar steering radius and the vehicle body roll steering radius to obtain the effective turning radius of the vehicle includes: Taking the contact point between the rear tire of the vehicle and the ground as the coordinate origin, constructing the vehicle kinematic coordinate system; The handlebar steering radius and the vehicle body roll steering radius are spatially transformed and projected to obtain turning parameters in the vehicle kinematic coordinate system; wherein the turning parameters include the center coordinates of the steering radius, the converted handlebar steering radius, the center coordinates of the roll steering radius, and the converted vehicle body roll steering radius; Determine a turning geometry triangle according to the turning parameters and the coordinate origin; The effective turning radius is obtained by solving the turning geometry triangle and the perpendicular radius of the tire forward tangent of the vehicle.

3. The vehicle turning radius detection method according to claim 2, characterized in that: The spatial transformation and projection operation of the handlebar steering radius and the vehicle body roll steering radius to obtain the turning parameters in the vehicle kinematic coordinate system includes: The handlebar steering radius and the vehicle body roll steering radius are sequentially transformed into a rotating coordinate system in three-dimensional space, subjected to three-dimensional transformation matrix calculation, and orthogonally projected to the vehicle kinematic coordinate system to obtain the turning parameters.

4. The vehicle turning radius detection method according to claim 2, characterized in that: The step of determining a turning geometric triangle according to the turning parameter and the coordinate origin includes: According to the turning parameter and the position of the coordinate origin, in the vehicle kinematic coordinate system, determine the origin position of the vehicle body roll steering radius below the ground plane and the origin position of the handlebar steering radius; The turning geometric triangle is determined according to the position of the coordinate origin, the origin position of the vehicle body roll steering radius below the ground plane, and the origin position of the handlebar steering radius.

5. The vehicle turning radius detection method according to claim 1, characterized in that: The factory design parameters include front and rear wheelbases, front steering mechanism parameters, and front tire size parameters; the calculation of the vehicle head steering angle and the factory design parameters to obtain the handlebar steering radius of the vehicle includes: The steering angle of the vehicle head, the wheelbase of the front and rear wheels, the parameters of the front steering mechanism, and the size parameters of the front wheel tire are subjected to geometric calculation to obtain the steering radius of the handlebar.

6. The vehicle turning radius detection method according to claim 1, characterized in that: The wheel attitude parameter includes a wheel roll angle, and the factory design parameter includes a rear tire size parameter; the wheel attitude parameter and the factory design parameter are calculated to obtain a body roll turning radius of the vehicle, including: Performing geometric calculation on the wheel roll angle and the rear wheel tire size parameter to obtain an actual ground contact rolling radius; The actual ground contact rolling radius and the wheel roll angle are geometrically calculated to obtain the vehicle body roll turning radius.

7. The vehicle turning radius detection method according to any one of claims 1 to 6, characterized in that: The calculation of integrating the handlebar steering radius and the vehicle body roll steering radius to obtain the effective turning radius of the vehicle includes: Obtaining a tire slip rate of the vehicle; In response to the wheel attitude parameter satisfying a preset stability condition and the tire slip rate satisfying a preset limit condition, executing the step of fusing and calculating the handlebar steering radius and the vehicle body roll steering radius to obtain an effective turning radius of the vehicle; In response to the wheel posture parameter not satisfying the stability condition, and / or the tire slip ratio not satisfying the limit condition, maintaining the effective turning radius of the previous cycle.

8. The vehicle turning radius detection method according to claim 7, characterized in that: The wheel attitude parameters include a wheel pitch angle and a wheel yaw angle, and the tire slip rate includes a front wheel slip rate and a rear wheel slip rate; in response to the wheel attitude parameters satisfying a preset stability condition, and the tire slip rate satisfying a preset limit condition, comprising: Detecting that the wheel pitch angle is less than a preset vehicle body steady-state pitch angle limit, and determining that the wheel pitch angle satisfies the stability condition; Detecting that the wheel yaw angle is less than a preset vehicle body steady-state yaw angle limit, and determining that the wheel yaw angle satisfies the stability condition; detecting that the front wheel slip rate is less than a preset first vehicle body steady-state slip rate, and determining that the front wheel slip rate satisfies the limit condition; It is detected that the rear wheel slip rate is less than a preset second vehicle body steady-state slip rate, and it is determined that the rear wheel slip rate meets the limit condition.

9. A vehicle control method, characterized in that: The vehicle control method comprises: Obtaining an effective turning radius of the vehicle; wherein the effective turning radius is obtained based on the vehicle turning radius detection method according to any one of claims 1 to 8; Vehicle control is performed based on the effective turning radius.

10. An electronic device, characterized in that: The electronic device comprises: A memory for storing executable program codes; A processor, configured to call and run the executable program code from the memory, so that the electronic device executes the vehicle turning radius detection method according to any one of claims 1 to 8 or the vehicle control method according to claim 9.

11. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the vehicle turning radius detection method according to any one of claims 1 to 8 or the vehicle control method according to claim 9 is implemented.

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