Three-wheeled vehicle speed control methods, devices, vehicle equipment, and computer program products

Abstract

This application provides a method, device, vehicle equipment, and computer program product for speed control of a three-wheeled vehicle. The method includes: for each target wheel of the three-wheeled vehicle, first determining the slip ratio and driving force coefficient of the target wheel when the vehicle is turning; the target wheel includes an inner wheel and an outer wheel; determining the driving force coefficient deviation and driving force coefficient torque correction amount of the target wheel based on the driving force coefficient; when the slip ratio of each target wheel is outside the target range and the driving force coefficient deviation of the target wheel is greater than a target threshold, determining the slip ratio weight value and slip ratio torque correction amount of the target wheel based on the slip ratio of the target wheel; then determining the driving torque of the target wheel based on the slip ratio weight value, slip ratio torque correction amount, and driving force coefficient torque correction amount, and controlling the speed of the target wheel according to the driving torque of the target wheel to achieve differential control. The technical solution provided by this application can improve the driving stability of three-wheeled vehicles.

Description

Technical Field

[0001] This application relates to the field of vehicle control technology, and in particular to a method, device, vehicle equipment, and computer program product for controlling the rotational speed of a three-wheeled vehicle. Background Technology

[0002] With the advancement of technology, three-wheeled electric vehicles have been widely used in logistics distribution, agricultural production, and short-distance travel due to their advantages such as simple structure, low cost, and strong load-bearing capacity.

[0003] In related technologies, three-wheeled electric vehicles typically adopt a centralized drive scheme, which rigidly connects the left and right drive wheels to transmit power. This drive scheme has the risk of tipping over during turning and has low driving reliability. Summary of the Invention

[0004] In view of this, embodiments of this application provide a method, device, vehicle equipment, and computer program product for controlling the rotational speed of a three-wheeled vehicle, which can improve the driving reliability of a three-wheeled vehicle when turning.

[0005] To achieve the above objectives, in a first aspect, embodiments of this application provide a method for controlling the rotational speed of a three-wheeled vehicle, the method comprising: For each target wheel of the three-wheeled vehicle, determine the slip ratio and driving force coefficient of the target wheel when the three-wheeled vehicle turns; the target wheel includes the inner wheel and the outer wheel; The driving force coefficient deviation and driving force coefficient torque correction of the target wheel are determined based on the driving force coefficient of the target wheel. When the slip ratio of each target wheel is outside the target range and the deviation of the driving force coefficient of the target wheel is greater than the target threshold, the slip ratio weight value and slip ratio torque correction amount of the target wheel are determined based on the slip ratio of the target wheel. The driving torque of the target wheel is determined based on the slip ratio weight value, slip ratio torque correction amount, and driving force coefficient torque correction amount of the target wheel. The rotational speed of the target wheel is controlled based on the driving torque of the target wheel.

[0006] In one possible implementation of the first aspect, determining the driving force coefficient of the target wheel includes: Determine the vertical load on the target wheel; The driving force coefficient of the target wheel is determined based on the driving force and vertical load of the target wheel; Furthermore, the torque correction amount of the target wheel's driving force coefficient is determined based on the target wheel's driving force coefficient and the fuzzy PID control algorithm.

[0007] In one possible implementation of the first aspect, determining the driving torque of the target wheel based on the slip ratio weight value, the slip ratio torque correction, and the driving force coefficient torque correction includes: The driving torque of the target wheel is determined by weighting the slip ratio weight value, slip ratio torque correction value, driving force coefficient weight value, and driving force coefficient torque correction value; the sum of the slip ratio weight value and the driving force coefficient weight value is 1.

[0008] In one possible implementation of the first aspect, determining the slip ratio weight value and slip ratio torque correction amount of the target wheel based on the slip ratio of the target wheel includes: The angular velocity deviation of the target wheels is determined when the slip ratio of at least one target wheel is greater than or equal to a first threshold, and the slip ratio of each target wheel is less than or equal to a second threshold. Determine the slip ratio deviation of the target wheel relative to the target slip ratio; The slip ratio weight value of the target wheel is determined based on the angular velocity deviation and slip ratio deviation of the target wheel; Based on the slip ratio deviation of the target wheel, the slip ratio torque correction amount of the target wheel is determined by a proportional-integral algorithm.

[0009] In one possible implementation of the first aspect, determining the slip ratio weight value of the target wheel based on the slip ratio of the target wheel includes: If the slip ratio of each target wheel is less than the first threshold, the weight value of the driving force coefficient of the target wheel is adjusted to 1. If the slip ratio of at least one target wheel is greater than the second threshold, the slip ratio weight of the target wheel is adjusted to 1; the second threshold is greater than the first threshold.

[0010] In one possible implementation of the first aspect, if the slip ratio of each target wheel is greater than or equal to a third threshold and less than or equal to a fourth threshold, the driving force coefficient weight value of the target wheel is adjusted, and the adjusted driving force coefficient weight value is greater than the target value; the third threshold is greater than the first threshold, the fourth threshold is less than the second threshold, and the target value is greater than 0.5; If the slip ratio of at least one target wheel is greater than the first threshold and less than the second threshold, the slip ratio weight value of the target wheel is adjusted, and the adjusted slip ratio weight value is greater than the target value.

[0011] In one possible implementation of the first aspect, the method further includes, prior to determining the slip ratio deviation: The magic formula is used to determine the correspondence between the slip ratio and the driving force coefficient under the current road conditions; The slip ratio corresponding to the maximum driving force coefficient is determined as the target slip ratio.

[0012] Secondly, embodiments of this application provide a speed control device for a three-wheeled vehicle, the device comprising: The determination module is used to determine the slip ratio and driving force coefficient of each target wheel of a three-wheeled vehicle when the vehicle is turning; the target wheels include inner wheels and outer wheels; the module determines the driving force coefficient deviation and driving force coefficient torque correction of the target wheels based on the driving force coefficient; when the slip ratio of each target wheel is outside the target range and the driving force coefficient deviation of the target wheel is greater than the target threshold, the module determines the slip ratio weight value and slip ratio torque correction of the target wheels based on the slip ratio; and the module determines the driving torque of the target wheels based on the slip ratio weight value, slip ratio torque correction, and driving force coefficient torque correction. The control module is used to control the rotational speed of the target wheel based on the drive torque of the target wheel.

[0013] In one possible implementation of the second aspect, the determining module is specifically used for: Determine the vertical load on the target wheel; The driving force coefficient of the target wheel is determined based on the driving force and vertical load of the target wheel; The torque correction amount for the target wheel's driving force coefficient is determined based on the target wheel's driving force coefficient, including: The torque correction amount of the target wheel's driving force coefficient is determined based on the target wheel's driving force coefficient and the fuzzy PID control algorithm.

[0014] In one possible implementation of the second aspect, the determining module is specifically used for: The driving torque of the target wheel is determined by weighting the slip ratio weight value, slip ratio torque correction value, driving force coefficient weight value, and driving force coefficient torque correction value; the sum of the slip ratio weight value and the driving force coefficient weight value is 1.

[0015] In one possible implementation of the second aspect, the determining module is specifically used for: The angular velocity deviation of the target wheels is determined when the slip ratio of at least one target wheel is greater than or equal to a first threshold, and the slip ratio of each target wheel is less than or equal to a second threshold. Determine the slip ratio deviation of the target wheel relative to the target slip ratio; The slip ratio weight value of the target wheel is determined based on the angular velocity deviation and slip ratio deviation of the target wheel; Based on the slip ratio deviation of the target wheel, the slip ratio torque correction amount of the target wheel is determined by a proportional-integral algorithm.

[0016] In one possible implementation of the second aspect, the determining module is specifically used for: If the slip ratio of each target wheel is less than the first threshold, the weight value of the driving force coefficient of the target wheel is adjusted to 1. If the slip ratio of at least one target wheel is greater than the second threshold, the slip ratio weight of the target wheel is adjusted to 1; the second threshold is greater than the first threshold.

[0017] In one possible implementation of the second aspect, the determining module is specifically used to: adjust the driving force coefficient weight value of the target wheel when the slip ratio of each target wheel is greater than or equal to the third threshold and less than or equal to the fourth threshold, wherein the adjusted driving force coefficient weight value is greater than the target value; the third threshold is greater than the first threshold, the fourth threshold is less than the second threshold, and the target value is greater than 0.5; If the slip ratio of at least one target wheel is greater than the first threshold and less than the second threshold, the slip ratio weight value of the target wheel is adjusted, and the adjusted slip ratio weight value is greater than the target value.

[0018] In one possible implementation of the second aspect, the determining module is further configured to: determine the correspondence between the slip ratio and the driving force coefficient under the current road conditions using the magic formula before determining the slip ratio deviation; The slip ratio corresponding to the maximum driving force coefficient is determined as the target slip ratio.

[0019] Thirdly, embodiments of this application provide a vehicle device, including: a memory and a processor, wherein the memory is used to store a computer program; and the processor is used to execute the method described in the first aspect or any embodiment of the first aspect when the computer program is invoked.

[0020] Fourthly, embodiments of this application provide a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the method described in the first aspect or any embodiment of the first aspect.

[0021] Fifthly, embodiments of this application provide a computer program product that, when run on a vehicle device, causes the vehicle device to execute the speed control method for a three-wheeled vehicle as described in any of the first aspects.

[0022] The technical solution provided in this application includes: for each target wheel of a three-wheeled vehicle, determining the slip ratio and driving force coefficient of the target wheel when the three-wheeled vehicle is turning; the target wheel includes an inner wheel and an outer wheel; then, determining the driving force coefficient deviation and driving force coefficient torque correction amount of the target wheel based on the driving force coefficient of the target wheel; when the slip ratio of each target wheel is outside the target range and the driving force coefficient deviation of the target wheel is greater than the target threshold, determining the slip ratio weight value and slip ratio torque correction amount of the target wheel based on the slip ratio of the target wheel, and determining the driving torque of the target wheel based on the slip ratio weight value, slip ratio torque correction amount, and driving force coefficient torque correction amount of the target wheel; controlling the rotational speed of the target wheel based on the driving torque of the target wheel, thereby realizing electronic differential control of the three-wheeled vehicle under turning conditions, reducing the risk of vehicle rollover, and improving the driving safety and reliability of the vehicle. Attached Figure Description

[0023] Figure 1 A flowchart illustrating the speed control method for a three-wheeled vehicle provided in an embodiment of this application; Figure 2 This is a schematic diagram of a three-wheeled vehicle turning as provided in an embodiment of this application; Figure 3 A schematic diagram illustrating the relationship between the slip ratio and driving force coefficient of a dry asphalt pavement provided in an embodiment of this application; Figure 4 This is a schematic diagram of the speed control device provided in the embodiments of this application; Figure 5 This is a schematic diagram of the structure of the vehicle equipment provided in the embodiments of this application. Detailed Implementation

[0024] To facilitate understanding of the technical solutions in the embodiments of this application, some terms involved in the embodiments of this application will be explained below: 1. Electronic Differential Control (EDC): A purely electronically controlled differential that independently adjusts the speed of each drive wheel motor to achieve the required speed of the drive wheels, thereby enabling various motion controls such as vehicle steering and stability.

[0025] 2. Pulse Width Modulation (PWM): A common method for controlling the motor terminal voltage by adjusting the pulse duty cycle.

[0026] 3. Ackermann Steering Model: A classic kinematic model that describes the geometric relationship between the inner and outer wheel speeds when a vehicle is steering.

[0027] 4. PID: A classic feedback control algorithm consisting of three components: proportional, integral, and derivative.

[0028] 5. Fuzzy PID: An improved controller that introduces fuzzy inference rules and membership functions on the basis of classic PID to adaptively adjust PID parameters.

[0029] 6. Brushless DC Motor (BLDC): A permanent magnet brushless DC motor suitable for hub drives.

[0030] 7. Vehicle Control Unit (VCU): The core controller that coordinates and controls all systems of the vehicle.

[0031] 8.Q12: A fixed-point number representation that retains 12 integer digits before the decimal point, often used for efficient numerical operations in embedded systems.

[0032] 9. Slip ratio: The percentage of the difference between the actual linear velocity of the wheel and the theoretical pure rolling linear velocity to the theoretical pure rolling linear velocity, used to characterize the slip state between the tire and the ground.

[0033] 10. Driving force coefficient: The ratio of driving force to vertical load, reflecting the adhesion state between the driving wheel and the ground.

[0034] The terminology used in the implementation section of this application is only for explaining specific embodiments of this application and is not intended to limit this application. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments.

[0035] When a three-wheeled vehicle turns, the linear speed required for the inner wheel is lower than that for the outer wheel. Although traditional mechanical differentials can achieve differential function, they use planetary gear mechanical transmission, which is complex in structure, bulky, and expensive to manufacture. At the same time, the internal friction loss of the differential is large, resulting in low energy utilization and a shortened driving range. In addition, it requires a through shaft to connect the two drive wheels, which raises the chassis and shifts the vehicle's center of gravity, further reducing turning stability and increasing the risk of rollover.

[0036] When a three-wheeled vehicle without a differential gear makes a fast turn, the two drive wheels rotate at the same speed, causing the inner wheel to slip and the outer wheel to spin. This causes the vehicle's center of gravity to shift outward, posing a risk of rollover and resulting in low driving reliability.

[0037] The embodiments of this application are described below with reference to the accompanying drawings.

[0038] Figure 1 This is a flowchart illustrating the speed control method for a three-wheeled vehicle provided in an embodiment of this application, as shown below. Figure 1 As shown, the method may include the following steps: Step S110: For each target wheel of the three-wheeled vehicle, determine the slip ratio and driving force coefficient of the target wheel when the three-wheeled vehicle turns.

[0039] Taking a three-wheeled vehicle turning left as an example, the left wheel (or left rear wheel) can be the inner wheel, and the right wheel is the outer wheel. Conversely, when turning right, the left wheel can be the outer wheel, and the right wheel is the inner wheel. For ease of explanation, the following text will use the left wheel as the inner wheel and the right wheel as the outer wheel as an example.

[0040] The target wheel may include an inner wheel and an outer wheel. The slip ratio of the target wheel may include the slip ratio of the inner wheel and the slip ratio of the outer wheel. The driving force coefficient of the target wheel may include the driving force coefficient of the inner wheel and the driving force coefficient of the outer wheel.

[0041] For example, the inner wheel slip ratio can be determined by using the formula λ=(ω·RV) / max(V,V_min), where λ is the slip ratio, ω is the wheel angular velocity, R is the wheel radius of the target wheel, V is the vehicle center of gravity velocity, and V_min is a preset minimum speed threshold to prevent the denominator from being zero. The minimum speed threshold can be set according to actual needs, and this application embodiment does not impose any special limitations on it.

[0042] Similarly, the above formula can also be used to calculate the slip ratio of the outer wheels of three-wheeled vehicles.

[0043] In some embodiments, wheel angular velocity can be directly measured by a wheel speed sensor, which can be a Hall sensor or encoder built into the motor, wherein the sampling frequency of the Hall sensor can be set to ≥1kHz. The controller can calculate and determine the slip ratio based on the wheel angular velocity data collected by the wheel speed sensor. For example, the controller can be equipped with a processor with a 120MHz processing speed, a built-in digital signal processor, support for Q-format fixed-point arithmetic, a 12-bit analog-to-digital converter, a sampling rate ≥500kbps, 6-channel pulse-width modulation (PWM) output, adjustable dead time, 2-channel asynchronous communication and 2-channel synchronous communication interfaces, and sufficient random access memory or flash memory. The controller's communication interface can support master-slave communication, using full-duplex serial communication with a baud rate of 115200bps; and can exchange data such as tilt angle, speed, differential ratio, steering state, and steering depth. The controller can also have a microsecond-level timer interrupt synchronization mechanism to ensure the real-time performance of data exchange, thereby improving the reliability of the vehicle control system. In other embodiments, a distributed architecture using a Controller Area Network (CAN) bus can be selected to improve system scalability and reliability; Ethernet communication can be used to support higher data rates and complex protocols; and wireless communication (such as Bluetooth) can be used to reduce wiring complexity.

[0044] The driving force coefficient can be the ratio of driving force to vertical load. The driving force can be determined by the formula F_i=T_i / R_eff, where T_i is the output torque of the motor of the i-th driving wheel (unit: N·m). For a permanent magnet synchronous motor, its torque can be calculated by T=(3 / 2)IqPnψf, where Pn is the number of pole pairs of the motor, ψf is the flux linkage of the permanent magnet, Iq is the quadrature axis current, and R_eff is the effective rolling radius of the tire (unit: m).

[0045] When turning a three-wheeled vehicle, refer to Figure 2 The calculation of vertical load needs to consider the influence of centrifugal force. Centrifugal force can be determined by vehicle mass, vehicle speed, and the turning radius of the center of gravity. The corresponding formula can be expressed as: F=m*v*v / R0 tanθ=L / Rr tanβ=lr / Rr R0 = sqrt(Rr*Rr + lr*lr) Torque balance equation about the x-axis: Fnrl*C / 2 + F*H*cos*cosFnrr*C / 2 Equation for torque balance about the y-axis: m*g*lf=F*H*sinos*lFnrr*L+Fnrl*L Fnrl=m*g*lf / (2*L)-F*H*(sinβ / (2*L)+cosβ / C) Fnrr=m*g*lf / (2*L)-F*H*(sinβ / (2*L)-cosβ / C) Where F is the centrifugal force, θ is the front wheel steering angle, β is the sideslip angle, C is the wheelbase between the inner and outer wheels of the three-wheeled vehicle (i.e., the rear wheel spacing), L is the wheelbase (distance from the center of the front wheel to the center of the rear wheel), lf and lr are the distances from the center of gravity to the front and rear axles, respectively, H is the height of the center of gravity above the ground, Rr is the turning radius of the rear axle center, R0 is the turning radius of the center of gravity, Fnrl is the vertical load on the left rear wheel, and Fnrr is the vertical load on the right rear wheel. The inner wheel driving force coefficient and outer wheel driving force coefficient of the three-wheeled vehicle during turning can be determined using the above formulas.

[0046] Step S120: Determine the driving force coefficient deviation and driving force coefficient torque correction amount of the target wheel based on the driving force coefficient of the target wheel.

[0047] After determining the inner wheel driving force coefficient and the outer wheel driving force coefficient, the difference between them can be calculated and defined as the driving force coefficient deviation. The driving force coefficient deviation and its corresponding rate of change are used as inputs to a fuzzy PID control algorithm (or fuzzy controller). The fuzzy PID control algorithm then determines the torque correction amount for the target wheel's driving force coefficient. The rate of change is the derivative of the target wheel's driving force coefficient deviation with respect to time.

[0048] For example, before using the fuzzy PID control algorithm, a fuzzy rule base or knowledge base can be constructed. Taking the fuzzy rule base as an example, for each input variable, it can be divided into multiple fuzzy levels (or fuzzy subsets). For instance, the universe of discourse of the input variable e can be {-3, -2, -1, 0, 1, 2, 3}, and the corresponding linguistic values ​​are {NB, NM, NS, ZO, PS, PM, PB}, uniformly distributed from negative to positive. Similarly, the universe of discourse and corresponding linguistic values ​​of the input variable ec can also be obtained. The meaning of the linguistic values ​​can be found in Table 1.

[0049] Table 1

[0050] A fuzzy subset is defined, and the membership function characterizes the degree to which an input belongs to a certain fuzzy subset. This is represented on the function graph by the shape of each membership function. The shape of the membership function curve directly determines the dynamic characteristics of the control system: generally, membership functions with a larger slope and faster change have higher resolution and faster control response; while membership functions with a gentler slope have a relatively slower control response but better stability. In fuzzy systems, the curve shapes of membership functions include triangles, Gaussians, trapezoids, and bell shapes, etc. The appropriate function form can be selected according to the actual working conditions; this application does not impose any special restrictions on this. The membership degree takes values ​​of [0,1], where 0 represents no membership at all, 1 represents full membership, and values ​​between these values ​​represent partial membership.

[0051] In this embodiment, both the rotational speed deviation and the rate of change of deviation include seven types, resulting in 49 possible combinations. Each combination can correspond to a control rule, and the fuzzy rule base can contain 49 control rules. For example, the form can be: if e is NB and ec is NB, then Kp increases significantly, Ki decreases significantly, and Kd increases moderately. Here, e is the rotational speed deviation, and ec is the rate of change of deviation.

[0052] It is understandable that the above example uses 49 control rules. In actual operation, the number of control rules can be adjusted according to the actual situation, such as 36. This application does not impose any special restrictions on the specific number of control rules.

[0053] In some embodiments, fuzzy rules can be constructed for the proportional coefficient Kp, integral coefficient Ki, and derivative coefficient Kd. In the fuzzy PID control algorithm, the value of the proportional coefficient Kp directly determines the dynamic response characteristics of the vehicle control system. Increasing Kp can effectively improve the system response speed and reduce steady-state deviation, but an excessively large Kp will lead to a significant increase in overshoot, and may even cause system oscillation and instability; conversely, a smaller Kp, while beneficial for suppressing overshoot and enhancing system stability, will reduce the response speed and prolong the settling time.

[0054] In some embodiments, a phased adaptive adjustment strategy can be adopted. Specifically, in the initial adjustment phase, a larger Kp value is used to accelerate the system response and rapidly approach the target value; in the middle adjustment phase, the Kp value is appropriately reduced to suppress overshoot and improve system stability while ensuring a certain response speed; and in the later adjustment phase, the Kp value is increased again to eliminate steady-state error and improve control accuracy. Based on the above analysis, the fuzzy rule definition of Kp is shown in Table 2.

[0055] Table 2

[0056] The integral coefficient Ki can eliminate steady-state deviation. However, due to factors such as saturation nonlinearity, the integral element is prone to integral saturation in the initial stage of regulation, resulting in a large overshoot.

[0057] Therefore, in the embodiments of this application, the integral action can be adjusted in stages. In the initial stage of adjustment, in order to suppress integral saturation, the integral action should be appropriately weakened or even reduced to zero; in the middle stage of adjustment, in order to avoid adverse effects on system stability, the integral action should be kept moderate; in the later stage of adjustment, the integral action is enhanced to effectively reduce steady-state error and improve control accuracy.

[0058] Based on the above analysis, the Ki fuzzy rules are shown in Table 3.

[0059] Table 3

[0060] The differential coefficient Kd can be adjusted for large inertia processes to improve the dynamic characteristics of vehicle control systems.

[0061] Kd can characterize the changing trend of the deviation signal and introduce an effective early correction signal into the system before the deviation signal changes significantly, thereby accelerating the system response speed, shortening the settling time, suppressing oscillations, and ultimately optimizing the dynamic performance of the system. Therefore, the value of Kd has a significant impact on the dynamic characteristics of the system: too large a Kd will cause the braking action to be ahead of the adjustment process, resulting in a longer settling time; too small a Kd will cause the braking action to be lagging, resulting in an increased overshoot.

[0062] Based on the above analysis, a phased adaptive adjustment strategy can be adopted for Kd. In the initial stage of adjustment, the derivative action should be increased to obtain a smaller overshoot or even avoid overshoot altogether. In the middle stage of adjustment, since the dynamic characteristics of the system are more sensitive to changes in Kd, Kd should be appropriately reduced and kept stable to maintain the adjustment quality of the system. In the later stage of adjustment, the value of Kd needs to be further reduced to weaken the influence of braking on the controlled process and compensate for the extended adjustment time caused by the larger Kd value in the early stage.

[0063] The Kd fuzzy rules are shown in Table 4.

[0064] Table 4

[0065] Based on the aforementioned fuzzy rule base, the dynamic adjustment of the proportional, integral, and derivative coefficients can achieve precise control of the torque correction of the driving force coefficient. This ensures that the road surface provides maximum adhesion and sufficient lateral adhesion, meeting the stability and maneuverability requirements of the vehicle when driving in a straight line, thus achieving optimal control performance.

[0066] The above explanation uses fuzzy PID control algorithm as an example. In other embodiments, other implementation methods can also be used: for example, neural network PID control, which utilizes the strong nonlinear fitting capability of deep neural networks to further improve the system's modeling accuracy for complex dynamic characteristics; adaptive sliding mode control, which adjusts the sliding surface parameters in real time through adaptive laws to effectively suppress parameter perturbations and external disturbances, thereby enhancing system robustness; and model predictive control, which performs multi-step prediction and rolling optimization based on the vehicle dynamics model, and can simultaneously achieve multi-objective coordinated control such as speed tracking, energy consumption reduction, and rollover risk suppression.

[0067] Step S130: When the slip ratio of each target wheel is outside the target range and the deviation of the driving force coefficient of the target wheel is greater than the target threshold, determine the slip ratio weight value and slip ratio torque correction amount of the target wheel based on the slip ratio of the target wheel.

[0068] Optionally, before determining the slip ratio weight value and the slip ratio torque correction amount, the angular velocity deviation of the target wheel can be determined first. Then, the slip ratio deviation of the target wheel relative to the target slip ratio can be determined. The slip ratio weight value of the target wheel can be determined based on the angular velocity deviation and slip ratio deviation of the target wheel. Based on the slip ratio deviation of the target wheel, the slip ratio torque correction amount of the target wheel can be determined using a proportional-integral algorithm.

[0069] For example, we can first determine the actual rotational speed and the theoretical rotational speed of the target wheel. The theoretical rotational speed can be obtained using the Ackermann formula. Taking the left wheel (or left rear wheel) as the inner wheel as an example, refer to... Figure 2 The Ackermann formula can be expressed as: Vi = V × (1 - (C × tanθ) / (2L)), where Vi is the theoretical speed, V is the actual speed (which can be determined by wheel speed sensors), C is the wheelbase between the inner and outer wheels of the three-wheeled vehicle (i.e., the rear wheel spacing), L is the wheelbase (distance between the center of the front wheel and the center of the rear wheel), and θ is the front wheel steering angle, which can be detected by a front wheel camber sensor. The theoretical speed Vo of the outer wheel can also be determined using the above formula. When performing the calculation, a lookup table method or the CORDIC algorithm can be used to reduce the computational load.

[0070] To improve steering angle detection accuracy and anti-interference capability, the front wheel camber sensor can adopt a dual Hall sensor configuration: sensors are installed at the left and right steering limit positions respectively, and steering angle data is acquired through differential measurement, effectively suppressing environmental interference and ensuring the accuracy of the detection results. In some embodiments, alternative or supplementary sensor solutions can be selected according to accuracy requirements and functional needs: rotary encoders achieve high-precision measurement of wheel speed / steering angle (resolution up to 0.01° level) through high-resolution pulse output, meeting the needs of fine motion detection under extreme conditions; a combination of microelectromechanical system (MEMS) gyroscope and accelerometer, through sensor fusion algorithms, achieves inertial navigation-level vehicle attitude (such as yaw angle and roll angle) measurement, unaffected by positioning signal obstruction, and suitable for complex environments such as tunnels and urban canyons; machine vision systems capture visual information such as road markings and vehicle trajectories through cameras, and combine them with image processing algorithms (such as edge detection and feature matching) to identify the current steering state and road environment, supplementing the blind spot monitoring capability of traditional sensors. The above solution complements the existing Hall sensor solution, and can be flexibly adapted to scenarios such as high-precision testing, navigation in complex environments, and vision-assisted steering, significantly improving the system's adaptability and robustness.

[0071] After determining the theoretical speed of the target wheel, the deviation of the actual speed from the theoretical speed can be determined. For example, the difference between the theoretical and actual speeds can be calculated and defined as the speed deviation, thus yielding the inner wheel speed deviation and the outer wheel speed deviation. Then, the theoretical speed deviation can be calculated using the formula e_ω=ω. ω actually yields the angular velocity deviation of the outer wheel and the angular velocity deviation of the inner wheel.

[0072] Optionally, when determining the slip ratio deviation of the target wheel relative to the target slip ratio, the inner wheel slip ratio deviation can be determined based on the difference between the inner wheel slip ratio and the target slip ratio, and the outer wheel slip ratio deviation can be determined based on the difference between the outer wheel slip ratio and the target slip ratio.

[0073] The target slip ratio can be a calculated value. For example, when calculating the target slip ratio, the magic formula can be used: μ(λ) = D·sin(C·arctan(B·λ-E·(B·λ-arctan(B·λ)))) to determine the correspondence between the slip ratio and the driving force coefficient under the current road conditions. Here, D is the peak factor (determining μ_peak, which is related to road conditions), C is the shape factor (usually taken as 1.3~1.6), B is the stiffness factor (determining the initial slope of the curve), and E is the curvature factor (determining the attenuation characteristics after the peak). B, C, D, and E are fitting parameters that accurately reflect the attenuation characteristics of lateral force in the peak adhesion zone and the complete slip zone.

[0074] Figure 3A schematic diagram illustrating the relationship between the slip ratio and driving force coefficient of a dry asphalt pavement provided in an embodiment of this application. (See also...) Figure 3 Taking dry asphalt pavement as an example, the adhesion characteristics between the tire and the road surface are described by a μ-λ curve, exhibiting a pattern of initial increase followed by decrease. This can be exemplarily categorized into an elastic deformation zone, a peak adhesion zone, and a complete slip zone. Specifically, the slip ratio in the elastic deformation zone can range from 0% to 5%, with the driving force coefficient increasing approximately linearly. Within this range, the tire tread blocks undergo elastic deformation, ensuring full contact between the tire tread and the road surface, and friction increases linearly with the slip ratio. The slip ratio in the peak adhesion zone can range from 15% to 20%, where the driving force coefficient reaches its maximum value μ_peak. Within this range, the tire's elastic deformation and sliding friction are dynamically balanced, resulting in the highest adhesion utilization and maximum friction. The slip ratio in the complete slip zone can range from greater than 30%, with the driving force coefficient decreasing from its peak value to the pure sliding friction coefficient μ_s. Within this range, the tire tread slides relative to the road surface over a large area, and kinetic energy is converted into heat energy and dissipated. In some embodiments, the slip ratio corresponding to the maximum driving force coefficient can be determined as the target slip ratio.

[0075] In some embodiments, the target slip ratio may also be an empirical value set by those skilled in the art based on engineering experience, such as 0.175. For ease of description, the following illustrative example uses a target slip ratio of 0.175.

[0076] Optionally, the slip ratio weight value can be determined according to the formula w_λ=clamp((|e_λ| / 0.1+|e_ω| / 20) / 2, 0,1). Where w_λ is the slip ratio weight value; e_λ is the slip ratio of the target wheel; e_ω is the angular velocity deviation of the target wheel; 0.1 is the first normalization factor, representing the maximum allowable absolute deviation; when |e_λ|=0.1 (i.e., λ=0.075 or 0.275), this term is 1. If the deviation is larger, |e_λ| / 0.1>1, and normalization and truncation (clamp(value,0,1)) can ensure that the final output value will not be less than the lower limit of 0, nor greater than the upper limit of 1. 20 is the second normalization factor, which is the angular velocity deviation threshold; when |e_ω|=20, w_λ is 0.

[0077] By taking the absolute values ​​of e_λ and e_ω, we can focus only on the magnitude of the values ​​without being affected by directional factors, thereby improving the reliability of the system.

[0078] Based on the slip ratio deviation of the target wheel, a proportional-integral (PI) algorithm can be used to determine the slip ratio torque correction of the target wheel, thereby obtaining the slip ratio torque corrections for the inner wheel and the outer wheel. The sign of the slip ratio torque correction value of the target wheel indicates whether slippage has occurred. For example, a negative value for the inner wheel slip ratio torque correction indicates that slippage has occurred on the inner wheel.

[0079] Step S140: Determine the driving torque of the target wheel based on the slip ratio weight value, slip ratio torque correction amount, and driving force coefficient torque correction amount of the target wheel.

[0080] Based on the slip ratio weight value, the driving force coefficient weight value can be determined according to the formula w_μ=1-w_λ, where w_μ is the driving force coefficient weight value, that is, the sum of the slip ratio weight value and the driving force coefficient weight value is 1.

[0081] In one alternative implementation, the driving torque of the target wheel can be determined by weighting the target wheel's slip ratio weight value, slip ratio torque correction amount, driving force coefficient weight value, and driving force coefficient torque correction amount. The weighting formula can be: ΔT_left=w_λ·ΔT_λ_left+w_μ·ΔT_μ_left ΔT_right=w_λ·ΔT_λ_right+w_μ·ΔT_μ_right Where ΔT_left is the driving torque of the inner wheel, ΔT_right is the driving torque of the outer wheel, ΔT_λ_left is the inner wheel slip ratio torque correction, ΔT_right is the outer wheel driving torque, ΔT_λ_right is the outer wheel slip ratio torque correction, w_λ is the slip ratio weight value, and w_μ is the driving force coefficient weight value. ΔT_μ_left = -ΔT_μ_right, which keeps the total driving force of the vehicle constant.

[0082] The driving torque of the inner wheel and the driving torque of the outer wheel can be determined using the above formula, so as to facilitate subsequent adjustment of the rotational speed of the inner and outer wheels.

[0083] In an optional implementation, when determining the slip ratio weight value and slip ratio torque correction amount of the target wheel, if there is a slip ratio of at least one target wheel that is greater than or equal to a first threshold, and the slip ratio of each target wheel is less than or equal to a second threshold, taking a first threshold of 0.10 and a second threshold of 0.25 as an example, the slip ratio weight value and slip ratio torque correction amount can be determined in the manner described in step S130.

[0084] Optionally, if the slip ratio of each target wheel is less than the first threshold, the weight value of the driving force coefficient of the target wheel can be adjusted to 1. For example, considering the slip ratio weight value formula: w_λ=clamp((|e_λ| / 0.1+|e_ω| / 20) / 2, 0,1), if the slip ratio of the target wheels is less than 0.10, the slip ratio is at a low level, and the driving force coefficient increases approximately linearly. Optionally, the weight value of the driving force coefficient of the target wheel can be adjusted to 1 to increase the driving torque, so that the driving force coefficient torque correction can be applied independently to the drive of the target wheel motor to correct the torque.

[0085] If the slip ratio of at least one target wheel is greater than a second threshold, the slip ratio weight value of the target wheel is adjusted to 1. For example, if the slip ratio of at least one target wheel is greater than 0.25, then as the slip ratio increases, the driving force coefficient gradually decreases from its peak value. Optionally, the slip ratio weight value of the target wheel can be adjusted to 1, that is, the driving torque is independently corrected by the slip ratio torque correction amount to reduce the torque.

[0086] In an optional implementation, if the slip ratio of each target wheel is determined to be greater than or equal to a third threshold and less than or equal to a fourth threshold, the driving force coefficient weight value of the target wheel can be adjusted. The adjusted driving force coefficient weight value is greater than the target value, wherein the third threshold is greater than the first threshold, the fourth threshold is less than the second threshold, and the target value is greater than 0.5. Taking a third threshold of 0.15, a fourth threshold of 0.20, and a target value of 0.8 as an example, if the slip ratios of both the inner and outer wheels are within the range of [0.15, 0.20], then the driving force coefficient weight value can be greater than 0.8, and the slip ratio weight value can be less than 0.2, so that the driving force coefficient balance is the primary factor when the vehicle is driving.

[0087] Optionally, if the slip ratio of at least one target wheel is greater than a first threshold and less than a second threshold, the slip ratio weight value of the target wheel can be adjusted so that the adjusted slip ratio weight value is greater than the target value. For example, if the slip ratio of at least one target wheel is within the range of [0.20, 0.25], the slip ratio weight value can be increased so that the slip ratio weight value is greater than 0.8 and the driving force coefficient weight value is less than 0.2, so that the vehicle is mainly controlled by slip ratio when driving.

[0088] The target value can be set according to actual needs, and this application embodiment does not impose any special restrictions on it.

[0089] In one alternative implementation, if the slip ratios of the target wheels are all within the target range (e.g., [0.15, 0.20]), it can be determined that the current tire elastic deformation and sliding friction have achieved dynamic equilibrium, the tire adhesion utilization rate has reached its maximum, and the vehicle is in a stable steering state. At this time, the controller can output the current driving torque at a constant rate to maintain stable vehicle driving.

[0090] In another alternative implementation, when the difference between the inner wheel drive force coefficient and the outer wheel drive force coefficient is less than a target threshold, it can be determined that the current distribution of driving force between the left and right wheels is relatively reasonable, the road surface adhesion is fully utilized, and the vehicle is in a stable driving state. At this time, the controller can also output the current driving torque at a constant rate to maintain the vehicle's stability. This target threshold can be flexibly set according to actual working conditions. Ideally, the difference between the inner and outer wheel drive force coefficients approaches zero. At this time, the distribution of driving force between the left and right wheels reaches the optimal level, and both wheels approach their respective adhesion limits simultaneously, allowing the vehicle to maximize the use of road surface adhesion.

[0091] Step S150: Control the rotational speed of the target wheel according to the driving torque of the target wheel.

[0092] In this embodiment, the inner and outer wheels can be driven independently by hub motors. After determining the driving torque of the target wheel, the torque command is converted into a target quadrature-axis current command via a current loop, controlling the motor phase current to match the target torque. The current loop adjusts the PWM duty cycle in real time at a sampling frequency of 10–20 kHz, changing the effective voltage and current applied to the motor windings, so that the electromagnetic torque accurately tracks the target torque, thereby achieving independent adjustment of the left and right motor speeds and precise torque distribution.

[0093] Alternatively, in addition to independent drive by the hub motor, a combination of wheel-side motor and reduction gear structure can be selected to achieve speed control, or a hydraulic motor can be used for drive, thus adapting to heavy-duty working conditions.

[0094] In some embodiments, sensors can be periodically checked for malfunctions. For example, this can be done by checking whether the output value of analog signals from Hall sensors, after conversion by an analog-to-digital converter, is limited to the effective range (0-4095) of a 12-bit ADC, checking the logical consistency of readings from the left and right Hall sensors, and detecting abnormal trends in the rate of angle change. If any sensor malfunction is detected, the vehicle's maximum speed can be limited, for example, to no more than 15 km / h, and a fixed differential ratio (0.5:0.5) can be used to alert the driver via a buzzer or indicator light, thereby improving driving safety. Optionally, fault codes can also be recorded for subsequent diagnostics.

[0095] In this embodiment, the controller may include at least two, so that in the event of a failure of the main controller, the slave controller can take over to maintain basic driving functions and improve driving safety. When supplying power to the vehicle, various options can be flexibly selected, such as lithium iron phosphate batteries, lithium titanate batteries, supercapacitor-battery hybrid systems, or fuel cell-battery hybrid systems. This embodiment does not impose any particular limitation on the power supply method.

[0096] Optionally, to meet the real-time and reliability requirements of the three-wheeled vehicle speed control system, an interrupt-driven hierarchical real-time scheduling mechanism is adopted. This mechanism uses interrupt priority to achieve time-series coordination of different tasks. The specific scheduling strategy is as follows: a 62.5μs high-frequency interrupt is used for PWM generation and current sampling to ensure the real-time performance of motor control; a 1ms interrupt performs speed calculation and filtering, processing kinematic data; a 10ms interrupt runs the differential control algorithm to achieve precise torque distribution; and a 100ms interrupt handles communication and status monitoring to ensure overall system monitoring. This mechanism, through time-slice division, balances high-frequency control and low-frequency monitoring, ensuring both real-time performance and stability.

[0097] The speed control method for a three-wheeled vehicle provided in this application includes: for each target wheel of the three-wheeled vehicle, determining the slip ratio and driving force coefficient of the target wheel when the three-wheeled vehicle is turning; the target wheel includes an inner wheel and an outer wheel; determining the driving force coefficient deviation and driving force coefficient torque correction amount of the target wheel based on the driving force coefficient of the target wheel; when the slip ratio of each target wheel is outside the target range and the driving force coefficient deviation of the target wheel is greater than the target threshold, determining the slip ratio weight value and slip ratio torque correction amount of the target wheel based on the slip ratio weight value, slip ratio torque correction amount and driving force coefficient torque correction amount of the target wheel; determining the driving torque of the target wheel based on the slip ratio weight value, slip ratio torque correction amount and driving force coefficient torque correction amount of the target wheel; and controlling the speed of the target wheel based on the driving torque of the target wheel. This application provides a technical solution that finds the optimal balance between longitudinal driving force and lateral stability, supporting rapid adaptation to different hardware platforms and vehicle configurations. This solution combines the classic Ackermann steering model with fuzzy PID adaptive control, optimizing PID parameters in real time through fuzzy inference. This allows the controller to dynamically adjust based on real-time errors, adapting to different vehicle speeds, steering angles, and load conditions, keeping the speed tracking error within 2% and the response time less than 50ms. Furthermore, this solution is a purely electronic differential control scheme, eliminating mechanical transmission components, achieving a transmission efficiency exceeding 95%, and reducing overall energy consumption by 15%–20%, resulting in a cost reduction of over 40% compared to mechanical differential solutions. Through slip ratio closed-loop control, the tire slip ratio is maintained within the optimal adhesion range of 0.15–0.2, combined with a left and right wheel drive force coefficient balancing strategy to prevent unilateral slippage, ensuring optimal tire adhesion during cornering and reducing rollover risk by over 60%. In addition, this solution does not require complex machining. It only requires configuring software parameters to adapt to three-wheeled models with different wheelbases, track widths and motor characteristics. It has the advantages of high precision, fast response and low cost, which significantly improves the reliability and safety of vehicle driving.

[0098] Those skilled in the art will understand that the above embodiments are exemplary and not intended to limit this application. Where possible, the execution order of one or more of the above steps can be adjusted, or they can be selectively combined to obtain one or more other embodiments. Those skilled in the art can arbitrarily select and combine the above steps as needed, and all those that do not depart from the essence of this application fall within the protection scope of this application.

[0099] Based on the same inventive concept, as an implementation of the above method, this application provides a speed control device for a three-wheeled vehicle. This device embodiment corresponds to the aforementioned method embodiment. For ease of reading, this device embodiment will not repeat the details of the aforementioned method embodiment one by one, but it should be clear that the device in this embodiment can correspondingly implement all the contents of the aforementioned method embodiment.

[0100] Figure 4 This is a schematic diagram of the speed control device provided in the embodiments of this application, as shown below. Figure 4 As shown, the apparatus provided in this embodiment includes: The determination module 100 is used to determine the slip ratio and driving force coefficient of each target wheel of the three-wheeled vehicle when the vehicle is turning; the target wheel includes the inner wheel and the outer wheel; the driving force coefficient deviation and driving force coefficient torque correction of the target wheel are determined based on the driving force coefficient of the target wheel; when the slip ratio of each target wheel is outside the target range and the driving force coefficient deviation of the target wheel is greater than the target threshold, the slip ratio weight value and slip ratio torque correction of the target wheel are determined based on the slip ratio of the target wheel; and the driving torque of the target wheel is determined based on the slip ratio weight value, slip ratio torque correction and driving force coefficient torque correction of the target wheel. The control module 200 is used to control the rotational speed of the target wheel according to the driving torque of the target wheel.

[0101] In one possible implementation, the determining module 100 is specifically used for: Determine the vertical load on the target wheel; The driving force coefficient of the target wheel is determined based on the driving force and vertical load of the target wheel; Furthermore, the torque correction amount of the target wheel's driving force coefficient is determined based on the target wheel's driving force coefficient and the fuzzy PID control algorithm.

[0102] In one possible implementation, the determining module 100 is specifically used for: The driving torque of the target wheel is determined by weighting the slip ratio weight value, slip ratio torque correction value, driving force coefficient weight value, and driving force coefficient torque correction value; the sum of the slip ratio weight value and the driving force coefficient weight value is 1.

[0103] In one possible implementation, the determining module 100 is specifically used for: The angular velocity deviation of the target wheels is determined when the slip ratio of at least one target wheel is greater than or equal to a first threshold, and the slip ratio of each target wheel is less than or equal to a second threshold. Determine the slip ratio deviation of the target wheel relative to the target slip ratio; The slip ratio weight value of the target wheel is determined based on the angular velocity deviation and slip ratio deviation of the target wheel; Based on the slip ratio deviation of the target wheel, the slip ratio torque correction amount of the target wheel is determined by a proportional-integral algorithm.

[0104] In one possible implementation, the determining module 100 is specifically used for: If the slip ratio of each target wheel is less than the first threshold, the weight value of the driving force coefficient of the target wheel is adjusted to 1. If the slip ratio of at least one target wheel is greater than the second threshold, the slip ratio weight of the target wheel is adjusted to 1; the second threshold is greater than the first threshold.

[0105] In one possible implementation, the determining module 100 is specifically used to: adjust the driving force coefficient weight value of the target wheel when the slip ratio of each target wheel is greater than or equal to a third threshold and less than or equal to a fourth threshold, wherein the adjusted driving force coefficient weight value is greater than the target value; the third threshold is greater than the first threshold, the fourth threshold is less than the second threshold, and the target value is greater than 0.5; If the slip ratio of at least one target wheel is greater than the first threshold and less than the second threshold, the slip ratio weight value of the target wheel is adjusted, and the adjusted slip ratio weight value is greater than the target value.

[0106] In one possible implementation, the determining module 100 is further configured to: determine the correspondence between the slip ratio and the driving force coefficient under the current road conditions using a magic formula before determining the slip ratio deviation; The slip ratio corresponding to the maximum driving force coefficient is determined as the target slip ratio.

[0107] The speed control device for the three-wheeled vehicle provided in this embodiment can execute the above-described method embodiment. Its implementation principle and technical effect are similar, and will not be repeated here.

[0108] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is merely an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit. Furthermore, the specific names of the functional units and modules are only for easy differentiation and are not intended to limit the scope of protection of this application. The specific working process of the units and modules in the above system can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0109] Based on the same inventive concept, this application also provides a vehicle device. Figure 5 This is a schematic diagram of the structure of the vehicle equipment provided in the embodiments of this application, such as... Figure 5As shown, the vehicle equipment provided in this embodiment includes a memory 210 and a processor 220. The memory 210 is used to store computer programs; the processor 220 is used to execute the method described in the above method embodiment when the computer program is invoked.

[0110] The vehicle equipment provided in this embodiment can execute the above method embodiment, and its implementation principle and technical effect are similar, so it will not be described again here.

[0111] This application also provides a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the methods described in the above-described method embodiments.

[0112] This application also provides a computer program product that, when run on a vehicle device, enables the vehicle device to implement the method described in the above-described method embodiments.

[0113] In the above embodiments, implementation can be achieved entirely or partially through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented entirely or partially as a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted through the computer-readable storage medium. The computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, or magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., a solid-state drive (SSD)).

[0114] Those skilled in the art will understand that implementing all or part of the processes in the above embodiments can be accomplished by a computer program instructing related hardware. This program can be stored in a computer-readable storage medium, and when executed, it can include the processes described in the above method embodiments. The aforementioned storage medium can include various media capable of storing program code, such as ROM or random access memory (RAM), magnetic disks, or optical disks.

[0115] The naming or numbering of steps in this application does not mean that the steps in the method flow must be executed in the time / logical order indicated by the naming or numbering. The execution order of the named or numbered process steps can be changed according to the technical purpose to be achieved, as long as the same or similar technical effect can be achieved.

[0116] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0117] In the embodiments provided in this application, it should be understood that the disclosed apparatus / devices and methods can be implemented in other ways. For example, the apparatus / device embodiments described above are merely illustrative. For instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0118] It should be understood that, when used in this application specification and the appended claims, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or a collection thereof.

[0119] In the description of this application, unless otherwise stated, " / " indicates that the objects before and after are in an "or" relationship. For example, A / B can mean A or B. "And / or" in this application is merely a description of the relationship between the related objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, and B exists alone. A and B can be singular or plural.

[0120] Furthermore, in the description of this application, unless otherwise stated, "multiple" means two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c can mean: a, b, c, ab, ac, bc, or abc, where a, b, and c can be single or multiple.

[0121] As used in this application specification and the appended claims, the term "if" may be interpreted, depending on the context, as "when," "once," "in response to determination," or "in response to detection." Similarly, the phrase "if determined" or "if detected [the described condition or event]" may be interpreted, depending on the context, as meaning "once determined," "in response to determination," "once detected [the described condition or event]," or "in response to detection [the described condition or event]."

[0122] Furthermore, in the description of this application and the appended claims, the terms "first," "second," "third," etc., are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments described herein can be implemented in a sequence other than that illustrated or described herein.

[0123] References to "one embodiment" or "some embodiments" in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized.

[0124] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A method for controlling the rotational speed of a three-wheeled vehicle, characterized in that, The method includes: For each target wheel of the three-wheeled vehicle, determine the slip ratio and driving force coefficient of the target wheel when the three-wheeled vehicle turns; the target wheel includes the inner wheel and the outer wheel; The driving force coefficient deviation and driving force coefficient torque correction of the target wheel are determined based on the driving force coefficient of the target wheel. When the slip ratio of each target wheel is outside the target range and the deviation of the driving force coefficient of the target wheel is greater than the target threshold, the slip ratio weight value and slip ratio torque correction amount of the target wheel are determined according to the slip ratio of the target wheel. The driving torque of the target wheel is determined based on the slip ratio weight value of the target wheel, the slip ratio torque correction amount, and the driving force coefficient torque correction amount. The rotational speed of the target wheel is controlled based on the driving torque of the target wheel.

2. The method according to claim 1, characterized in that, Determining the driving force coefficient of the target wheel includes: Determine the vertical load on the target wheel; The driving force coefficient of the target wheel is determined based on the driving force of the target wheel and the vertical load. Determining the torque correction amount of the driving force coefficient of the target wheel based on the driving force coefficient of the target wheel includes: The torque correction amount of the target wheel's driving force coefficient is determined based on the target wheel's driving force coefficient and the fuzzy PID control algorithm.

3. The method according to claim 1 or 2, characterized in that, Determining the drive torque of the target wheel based on the slip ratio weight value, the slip ratio torque correction, and the drive force coefficient torque correction includes: The driving torque of the target wheel is determined by weighting the slip ratio weight value, the slip ratio torque correction amount, the driving force coefficient weight value, and the driving force coefficient torque correction amount; the sum of the slip ratio weight value and the driving force coefficient weight value is 1.

4. The method according to claim 3, characterized in that, The slip ratio weight value and slip ratio torque correction amount of the target wheel are determined based on the slip ratio of the target wheel, including: The angular velocity deviation of the target wheels is determined when the slip ratio of at least one target wheel is greater than or equal to a first threshold, and the slip ratio of each target wheel is less than or equal to a second threshold. Determine the slip ratio deviation of the target wheel relative to the target slip ratio; The slip ratio weight value of the target wheel is determined based on the angular velocity deviation and slip ratio deviation of the target wheel; Based on the slip ratio deviation of the target wheel, the slip ratio torque correction amount of the target wheel is determined using a proportional-integral algorithm.

5. The method according to claim 3, characterized in that, The slip ratio weight value of the target wheel is determined based on the slip ratio of the target wheel, including: If the slip ratio of each target wheel is less than the first threshold, the weight value of the driving force coefficient of the target wheel is adjusted to 1. If the slip ratio of at least one target wheel is greater than a second threshold, the slip ratio weight value of the target wheel is adjusted to 1; the second threshold is greater than the first threshold.

6. The method according to claim 5, characterized in that, If the slip ratio of each target wheel is greater than or equal to the third threshold and less than or equal to the fourth threshold, the driving force coefficient weight value of the target wheel is adjusted, and the adjusted driving force coefficient weight value is greater than the target value; the third threshold is greater than the first threshold, the fourth threshold is less than the second threshold, and the target value is greater than 0.5; If the slip ratio of at least one target wheel is greater than a first threshold and less than a second threshold, the slip ratio weight value of the target wheel is adjusted, and the adjusted slip ratio weight value is greater than the target value.

7. The method according to claim 4, characterized in that, Before determining the slip ratio deviation, the method further includes: The magic formula is used to determine the correspondence between the slip ratio and the driving force coefficient under the current road conditions; The slip ratio corresponding to the maximum value of the driving force coefficient is determined as the target slip ratio.

8. A speed control device for a three-wheeled vehicle, characterized in that, include: A determination module is used to determine the slip ratio and driving force coefficient of each target wheel of the three-wheeled vehicle when the three-wheeled vehicle is turning; The target wheel includes an inner wheel and an outer wheel; the driving force coefficient deviation and driving force coefficient torque correction of the target wheel are determined based on the driving force coefficient of the target wheel; When the slip ratio of each target wheel is outside the target range and the deviation of the driving force coefficient of the target wheel is greater than the target threshold, the slip ratio weight value and slip ratio torque correction amount of the target wheel are determined according to the slip ratio of the target wheel; and the driving torque of the target wheel is determined according to the slip ratio weight value, the slip ratio torque correction amount and the driving force coefficient torque correction amount of the target wheel. The control module is used to control the rotational speed of the target wheel based on the driving torque of the target wheel.

9. A vehicle device, characterized in that, include: A memory and a processor, the memory being used to store a computer program; the processor being used to execute the method as described in any one of claims 1-7 when the computer program is invoked.

10. A computer program product, characterized in that, When the computer program product is run on a vehicle device, it causes the vehicle device to perform the method as described in any one of claims 1-7.

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