Vehicle control method and device, storage medium and electronic device

Abstract

The invention discloses a vehicle control method and device, a storage medium and an electronic device.The method comprises the steps that the current demand torque of a target vehicle in the driving process is determined, and the current demand torque is used for determining the current slip rate of the target vehicle; the expected slip rate of the target vehicle is determined based on the road state of the road where the target vehicle is located and the reference vehicle speed of the target vehicle, and the closed-loop demand torque of the target vehicle under the expected slip rate is obtained; and updating the current demand torque by using a closed-loop control instruction generated based on the closed-loop demand torque to obtain a target demand torque, and controlling the target vehicle to run according to the target demand torque. By the adoption of the technical scheme, the technical problem that the vehicle control stability is poor is solved.

Description

Technical Field

[0001] This application relates to the field of vehicle control, and more specifically, to a vehicle control method and apparatus, a storage medium and an electronic device. Background Technology

[0002] When accelerating on low-friction surfaces, torque reduction is generally needed to suppress wheel slippage. The core of torque reduction control is controlling the engine's output torque. Torque represents the engine's ability to generate rotational force, directly affecting vehicle acceleration and speed. However, different speed ranges have different characteristics, and the challenges of torque reduction control vary. For example, at lower speeds during start-up, wheel slippage can easily occur, meaning the wheel speed drops too low to the reference speed, resulting in weak starting power. At medium speeds, dynamic and static friction cycles frequently occur, leading to uneven acceleration and a poor driving experience. At high speeds, excessive longitudinal driving force often causes lateral instability. To better control the vehicle, related technologies generally use traction control systems to detect wheel slippage and automatically adjust torque output to prevent excessive wheel slippage. However, this method's torque reduction effect is unstable, easily resulting in excessive torque reduction or insufficient torque, leading to poor vehicle control stability.

[0003] There is currently no effective solution to the technical problem of poor vehicle control stability in related technologies.

[0004] Therefore, it is necessary to improve the relevant technology to overcome the aforementioned defects. Summary of the Invention

[0005] This application provides a vehicle control method and apparatus, a storage medium and an electronic device to at least solve the technical problem of poor vehicle control stability.

[0006] According to one aspect of the embodiments of this application, a vehicle control method is provided, comprising: determining the current required torque of a target vehicle during driving; determining the desired slip ratio of the target vehicle based on the road conditions of the road where the target vehicle is located and the reference speed of the target vehicle, and obtaining the closed-loop required torque of the target vehicle under the desired slip ratio; updating the current required torque using a closed-loop control command generated based on the closed-loop required torque to obtain a target required torque, and controlling the target vehicle to drive according to the target required torque.

[0007] In an exemplary embodiment, determining the desired slip ratio of the target vehicle based on the road condition of the road where the target vehicle is located and the reference speed of the target vehicle includes: obtaining the current road surface adhesion coefficient corresponding to the road condition; determining a first preset slip ratio corresponding to the current road surface adhesion coefficient, wherein multiple first preset slip ratios correspond to different vehicle speeds; determining the first preset slip ratio with the target speed among the multiple first preset slip ratios as a second preset slip ratio, and determining the second preset slip ratio as the desired slip ratio, wherein the target speed represents the reference speed of the target vehicle.

[0008] In an exemplary embodiment, obtaining the closed-loop required torque of the target vehicle under the desired slip ratio includes: determining the desired wheel speed of the target vehicle based on the reference vehicle speed of the target vehicle and the desired slip ratio; if the difference between the current wheel speed of the target vehicle and the desired wheel speed is less than a preset value, using the desired wheel speed as the closed-loop control target, performing closed-loop control on the current wheel speed of the target vehicle, and generating a first closed-loop required torque.

[0009] In an exemplary embodiment, obtaining the closed-loop required torque of the target vehicle under the desired slip ratio includes: determining the desired wheel speed of the target vehicle based on the reference vehicle speed of the target vehicle and the desired slip ratio; if the difference between the current wheel speed of the target vehicle and the desired wheel speed is greater than a preset value, using the dynamic wheel speed of the target vehicle as the closed-loop control target, performing closed-loop control on the current wheel speed of the target vehicle, and generating a second closed-loop required torque.

[0010] In an exemplary embodiment, determining the desired wheel speed of the target vehicle based on the reference vehicle speed and the desired slip ratio includes: calculating the desired wheel speed using a piecewise function corresponding to the reference vehicle speed and the desired slip ratio, wherein the piecewise function is expressed as follows: desired wheel speed = 1 / (1-desired slip ratio) × 5kph, where the reference vehicle speed < 5kph; desired wheel speed = 1 / (1-desired slip ratio) × the reference vehicle speed, where the reference vehicle speed < 30kph; desired wheel speed = [1 / (1-desired slip ratio)-1] × 30kph + the reference vehicle speed, where the reference vehicle speed > 5kph.

[0011] In an exemplary embodiment, before performing closed-loop control on the current wheel speed of the target vehicle with the dynamic wheel speed of the target vehicle as the closed-loop control target, the method further includes: determining the dynamic wheel speed of the target vehicle, including: generating a wheel speed smoothing curve describing the change of the target vehicle from the current wheel speed to the desired wheel speed according to a smoothing control strategy, wherein the curve parameters on the wheel speed smoothing curve represent the dynamic wheel speed, and different dynamic wheel speeds correspond to dynamic wheel speed change rates.

[0012] In an exemplary embodiment, before updating the current required torque using the closed-loop control command generated based on the closed-loop required torque to obtain the target required torque, the method further includes: generating the closed-loop control command based on the closed-loop required torque, including: calculating the feedforward torque required for the closed-loop control and calculating the wheel adhesion of the target vehicle during the closed-loop control process using the generated wheel speed smoothing curve; generating the closed-loop control command based on the sum of the closed-loop required torque, the feedforward torque, and the wheel adhesion.

[0013] In one exemplary embodiment, calculating the feedforward torque required for the closed-loop control includes: obtaining the average actual motor torque and average wheel adhesion of the target vehicle when performing closed-loop control using a generated wheel speed smoothing curve; and determining the feedforward torque based on the difference between the average actual motor torque and the average wheel adhesion.

[0014] In an exemplary embodiment, the wheel adhesion is calculated as follows: when performing closed-loop control using a generated wheel speed smoothing curve, if it is determined that the difference between the current wheel speed of the target vehicle and the desired wheel speed is less than a preset value, the actual motor torque and wheel inertial torque of the target vehicle are obtained; the wheel adhesion is determined based on the difference between the actual motor torque and the wheel inertial torque; wherein the wheel inertial torque is obtained based on the wheel rotational inertia, wheel speed change rate, and tire radius of the target vehicle.

[0015] In an exemplary embodiment, after updating the current demand torque using a closed-loop control command generated based on the closed-loop demand torque to obtain a target demand torque, and controlling the target vehicle to travel according to the target demand torque, the method further includes: obtaining the actual speed of the target vehicle after traveling according to the target demand; determining the actual slip ratio of the target vehicle based on the road conditions of the road where the target vehicle is located and the actual speed of the target vehicle; if it is determined that the difference between the actual slip ratio and the expected slip ratio is less than a preset difference, sending the actual slip ratio and the actual speed to a target object, and determining whether to update the expected slip ratio based on the response information of the target object.

[0016] According to another aspect of the embodiments of this application, a vehicle control device is also provided, comprising: a determining module, configured to determine the current required torque of a target vehicle during driving; an acquiring module, configured to determine the desired slip ratio of the target vehicle based on the road conditions of the road where the target vehicle is located and the reference speed of the target vehicle, and acquire the closed-loop required torque of the target vehicle under the desired slip ratio; and a controlling module, configured to update the current required torque using a closed-loop control command generated based on the closed-loop required torque to obtain a target required torque, and control the target vehicle to drive according to the target required torque.

[0017] According to another aspect of the embodiments of this application, a computer-readable storage medium is also provided, wherein a computer program is stored in the computer program, and the computer program is configured to execute the above-described vehicle control method when it is run.

[0018] According to another aspect of the embodiments of this application, an electronic device is also provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the vehicle control method described above through the computer program.

[0019] According to another aspect of this application, a computer program product is also provided, including a computer program that, when executed by a processor, implements the steps in any of the above method embodiments.

[0020] This application determines the current torque demand of a target vehicle during its operation; determines the desired slip ratio of the target vehicle based on the road conditions and the reference speed of the target vehicle; obtains the closed-loop torque demand of the target vehicle under the desired slip ratio; updates the current torque demand using a closed-loop control command generated based on the closed-loop torque demand, obtains the target torque demand, and controls the target vehicle to drive according to the target torque demand. In other words, this application obtains the corresponding closed-loop torque demand based on the reference speed and desired slip ratio, with the desired slip ratio as the target; then generates a torque reduction command (i.e., a closed-loop control command) based on the closed-loop torque demand; and replaces the current torque demand with the torque reduction command to obtain the latest torque demand (i.e., the target torque demand). The vehicle's acceleration and speed can be controlled according to this latest torque demand, achieving precise control of the wheel slip ratio, improving the stability of vehicle acceleration on low-friction surfaces, enhancing the dynamic performance of electric four-wheel drive vehicles on low-friction surfaces, solving the technical problem of poor vehicle control stability, and improving vehicle control stability. Attached Figure Description

[0021] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0022] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a hardware structure block diagram of a vehicle terminal for a vehicle control method according to an embodiment of this application;

[0024] Figure 2 This is a flowchart of a vehicle control method according to an embodiment of this application;

[0025] Figure 3 This is a schematic diagram of the calculation window for dynamic wheel speed and feedforward average value during smooth control according to an embodiment of this application;

[0026] Figure 4 This is a structural block diagram of a vehicle control device according to an embodiment of this application. Detailed Implementation

[0027] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0028] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application 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 of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0029] The methods and embodiments provided in this application can be executed in a vehicle terminal, a cloud server, or a similar computing device. Taking running on a vehicle terminal as an example, Figure 1 This is a hardware structure block diagram of a vehicle terminal according to an embodiment of the vehicle control method of this application. For example... Figure 1 As shown, the vehicle terminal may include one or more ( Figure 1 Only one is shown in the diagram. A processor 102 (which may include, but is not limited to, a microprocessor (MCU) or a field-programmable gate array (FPGA)) and a memory 104 for storing data are also shown. The vehicle terminal may further include a transmission device 106 for communication functions and an input / output device 108. Those skilled in the art will understand that... Figure 1 The structure shown is for illustrative purposes only and does not limit the structure of the vehicle terminal described above. For example, the vehicle terminal may also include components that are more... Figure 1 The more or fewer components shown, or having the same Figure 1 The different configurations shown.

[0030] The memory 104 can be used to store computer programs, such as application software programs and modules, like the computer program corresponding to the vehicle control method in this embodiment. The processor 102 executes various functional applications and data processing by running the computer program stored in the memory 104, thus implementing the aforementioned method. The memory 104 may include high-speed random access memory and non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory 104 may further include memory remotely located relative to the processor 102, and these remote memories can be connected to the vehicle terminal via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0031] The transmission device 106 is used to receive or send data via a network. Specific examples of the network described above may include a wireless network provided by the vehicle terminal's communication provider. In one example, the transmission device 106 includes a Network Interface Controller (NIC), which can connect to other network devices via a base station to communicate with the Internet. In another example, the transmission device 106 may be a Radio Frequency (RF) module used to communicate wirelessly with a cloud server.

[0032] This embodiment provides a vehicle control method. Figure 2 This is a flowchart of a vehicle control method according to an embodiment of this application, such as... Figure 2 As shown, the process includes the following steps:

[0033] Step S202: Determine the current torque demand of the target vehicle during driving;

[0034] It's important to note that the required torque for a vehicle refers to the engine output torque needed under specific driving conditions, such as acceleration, hill climbing, or traction. This torque is a key indicator of a vehicle's power performance, affecting its acceleration from a standstill, hill-climbing ability, and traction. In terms of vehicle control, adjusting the required torque can reduce wheel slippage and maintain vehicle stability and traction.

[0035] Step S204: Determine the desired slip ratio of the target vehicle based on the road conditions of the road where the target vehicle is located and the reference speed of the target vehicle, and obtain the closed-loop required torque of the target vehicle under the desired slip ratio;

[0036] Step S206: Update the current demand torque using the closed-loop control command generated based on the closed-loop demand torque to obtain the target demand torque, and control the target vehicle to drive according to the target demand torque.

[0037] Optionally, in the process of updating the current demand torque using the closed-loop control command generated based on the closed-loop demand torque to obtain the target demand torque, the feedforward torque in the process of smoothing the slip ratio according to the closed-loop demand torque in the closed-loop control command, and the corresponding attached feedforward, the sum of these three values ​​is used to replace the current demand torque to obtain the target demand torque.

[0038] Optionally, after the target vehicle has traveled according to the target required torque, the actual slip ratio can be determined based on the actual speed of the target vehicle, and the control effect on the slip ratio can be determined based on the comparison between the actual slip ratio and the expected slip ratio.

[0039] Through the above steps, this application determines the current required torque of the target vehicle during its driving process; determines the desired slip ratio of the target vehicle based on the road conditions of the road where the target vehicle is located and the reference speed of the target vehicle, and obtains the closed-loop required torque of the target vehicle under the desired slip ratio; updates the current required torque using a closed-loop control command generated based on the closed-loop required torque to obtain the target required torque, and controls the target vehicle to drive according to the target required torque. In other words, this application obtains the corresponding closed-loop required torque based on the reference speed and desired slip ratio, with the desired slip ratio as the target, then generates a torque reduction command (i.e., a closed-loop control command) based on the closed-loop required torque, and uses the torque reduction command to replace the current required torque to obtain the latest required torque (i.e., the target required torque). The acceleration and speed of the vehicle can be controlled according to this latest required torque, achieving precise control of the wheel slip ratio, improving the stability of the vehicle's acceleration on low-friction surfaces, enhancing the dynamic performance of electric four-wheel drive vehicles on low-friction surfaces, solving the technical problem of poor vehicle control stability, and improving vehicle control stability.

[0040] In an exemplary embodiment, the step of determining the desired slip ratio of the target vehicle based on the road condition of the road where the target vehicle is located and the reference speed of the target vehicle specifically includes: obtaining the current road surface adhesion coefficient corresponding to the road condition; determining a first preset slip ratio corresponding to the current road surface adhesion coefficient, wherein multiple first preset slip ratios correspond to different vehicle speeds; determining the first preset slip ratio with the target vehicle speed among the multiple first preset slip ratios as a second preset slip ratio, and determining the second preset slip ratio as the desired slip ratio, wherein the target vehicle speed represents the reference speed of the target vehicle.

[0041] Optionally, this embodiment can adjust the target slip ratio (i.e., the desired slip ratio) in real time based on lateral stability and dynamic requirements, combined with vehicle speed. For example, the slip ratio set at low vehicle speeds can be higher than the slip ratio set at medium and high vehicle speeds, which improves the starting dynamics at low vehicle speeds and also improves the lateral stability at medium and high vehicle speeds.

[0042] For example, the process of setting a target slip ratio is illustrated below. For ice surfaces, if the vehicle speed is 0-10 kph, a relatively high target slip ratio can be set, such as 8%. If the vehicle speed is 10-20 kph, a target slip ratio of 4% can be set. If the vehicle speed is above 20 kph, a target slip ratio of 2% can be set. The target slip ratio is in the range [0, 1].

[0043] For snow surfaces with a higher coefficient of friction than ice, higher speed ranges can be set. For example, at speeds of 0-20 kph, a target slip ratio of 8% can be set; at speeds of 20-50 kph, a target slip ratio of 4% can be set; and at speeds above 50 kph, a target slip ratio of 2% can be set. The slip ratios set above can be confirmed through subsequent real-vehicle calibration.

[0044] In an exemplary embodiment, the technical solution for obtaining the closed-loop required torque of the target vehicle under the desired slip ratio is described by the following process: determining the desired wheel speed of the target vehicle based on the reference vehicle speed and the desired slip ratio; if the difference between the current wheel speed of the target vehicle and the desired wheel speed is less than a preset value, using the desired wheel speed as the closed-loop control target, performing closed-loop control on the current wheel speed of the target vehicle, and generating the first closed-loop required torque.

[0045] In this application, the difference between the current wheel speed and the desired wheel speed can generally be understood as the difference between the current wheel speed and the desired wheel speed.

[0046] It is understood that the desired wheel speed is the static wheel speed of the vehicle when stationary. Optionally, if the difference between the current wheel speed of the target vehicle and the desired wheel speed is less than a preset value, it can be determined that when the actual wheel speed of the vehicle exceeds a certain threshold of the desired wheel speed, smooth wheel speed control can be performed, i.e., the Profile flag is set. It should be noted that in automation or control systems, when the term "Profile" is mentioned, it refers to a control strategy used to smoothly transition from one state to another. In this application, the "Profile" flag being set means that the wheel speed needs to be smoothly adjusted according to specified rules. Through this embodiment, when the Profile is not activated (not set), in the PID closed-loop control of wheel speed, the desired wheel speed is used as the control target to perform PID control on the actual wheel speed, outputting the closed-loop required torque.

[0047] In one exemplary embodiment, another technical solution for obtaining the closed-loop demand torque of the target vehicle under the desired slip ratio is further proposed. The specific steps include: determining the desired wheel speed of the target vehicle based on the reference vehicle speed of the target vehicle and the desired slip ratio; if the difference between the current wheel speed of the target vehicle and the desired wheel speed is determined to be greater than a preset value, using the dynamic wheel speed of the target vehicle as the closed-loop control target, performing closed-loop control on the current wheel speed of the target vehicle, and generating a second closed-loop demand torque.

[0048] Similarly, in this embodiment, when the "Profile" flag is active (activated), the actual wheel speed can be controlled using PID control with the dynamic wheel speed as the control target during the PID closed-loop control of wheel speed, outputting the required closed-loop torque. In this embodiment, when the Profile is active, the initial value of the integral term corresponding to the wheel speed accumulates from the proportional term of the previous moment to avoid torque step jumps.

[0049] In an exemplary embodiment, determining the desired wheel speed of the target vehicle based on the reference vehicle speed and the desired slip ratio specifically includes: calculating the desired wheel speed using a piecewise function corresponding to the reference vehicle speed and the desired slip ratio, wherein the piecewise function is expressed as follows: desired wheel speed = 1 / (1-desired slip ratio) × 5kph, where the reference vehicle speed < 5kph; desired wheel speed = 1 / (1-desired slip ratio) × the reference vehicle speed, where the reference vehicle speed < 30kph; desired wheel speed = [1 / (1-desired slip ratio)-1] × 30kph + the reference vehicle speed, where the reference vehicle speed > 5kph.

[0050] The aforementioned expected wheel speed can be understood as the static wheel speed of a vehicle when it is stationary. The calculation principle of static wheel speed can be referred to as follows:

[0051] "If (reference vehicle speed < 5 kph), static wheel speed = 1 / (1 - target slip ratio) * 5 kph;

[0052] elseif(reference speed < 30 kph), static wheel speed = 1 / (1 - target slip ratio) * reference speed;

[0053] else, static wheel speed = [1 / (1-target slip ratio)-1]*30kph+reference vehicle speed, end.

[0054] In an exemplary embodiment, before performing closed-loop control on the current wheel speed of the target vehicle with the dynamic wheel speed of the target vehicle as the closed-loop control target, the dynamic wheel speed of the target vehicle can be further determined. Specifically, this includes generating a wheel speed smoothing curve to describe the change of the target vehicle from the current wheel speed to the desired wheel speed according to a smoothing control strategy. The curve parameters on the wheel speed smoothing curve represent the dynamic wheel speed, and different dynamic wheel speeds correspond to dynamic wheel speed change rates.

[0055] The smooth control strategy refers to starting from the current wheel speed and focusing on the desired wheel speed, using a smooth control algorithm to achieve a smooth transition between the two. Optionally, the smooth control algorithm may include, but is not limited to, PID (Proportional-Integral-Derivative) control algorithm, Model Predictive Control Algorithm (MPCA), Dynamic Matrix Control Algorithm (DMCA), polynomial or spline curve fitting genetic algorithm, or other global optimization algorithms, Iterative Learning Control Algorithm (ILCA), Sliding Mode Control Algorithm (SMCA), and fuzzy logic control algorithm.

[0056] In this embodiment, the dynamic wheel speed of the target vehicle can be understood as the dynamic wheel speed of the vehicle while it is in motion. When the actual wheel speed exceeds a certain threshold of the static wheel speed, the Profile flag is activated. Then, taking the current actual wheel speed as the starting point and the static wheel speed as the ending point, a smooth Profile line (i.e., a smooth wheel speed change curve) is drawn, forming a shape like... Figure 3 The dynamic wheel speed shown here, specifically, involves identifying the current wheel speed (i.e., the starting wheel speed) and then setting a target wheel speed—the ultimate goal of wheel speed adjustment. Then, specific algorithms, such as trapezoidal or S-curve curves, are used to generate a smooth curve that describes the transition path from the current wheel speed to the target wheel speed. This process typically involves calculating the wheel speed values ​​that should be achieved at different points in time. By continuously and dynamically adjusting the wheel speed according to this smooth curve over time, the changes in wheel speed can be made as gradual as possible, avoiding the shock or discomfort caused by sudden acceleration or deceleration. After a period of adjustment, the wheel speed will smoothly reach the set target wheel speed.

[0057] The smooth control concept presented in this application can be applied to motion control in industrial automation, speed control in elevators, and acceleration control in automobiles. By using profile control, the system can be ensured to change states quickly and smoothly, improving efficiency and user experience. In practical applications, factors such as the system's dynamic characteristics, load variations, and safety constraints can be further considered to ensure the system's stability and safety throughout the transition process.

[0058] Optionally, the theoretical torque required for the Profile is calculated based on the wheel's moment of inertia and the dynamic wheel speed change rate, and can be used as feedforward for subsequent control using the dynamic target wheel speed. Specifically, the theoretical torque required for the Profile = wheel moment of inertia * dynamic target wheel speed change rate / tire radius.

[0059] In an exemplary embodiment, before updating the current required torque using the closed-loop control command generated based on the closed-loop required torque to obtain the target required torque, the process of generating the closed-loop control command based on the closed-loop required torque further includes: calculating the feedforward torque required for the closed-loop control and calculating the wheel adhesion of the target vehicle during the closed-loop control process using the generated wheel speed smoothing curve; and generating the closed-loop control command based on the sum of the closed-loop required torque, the feedforward torque, and the wheel adhesion.

[0060] Optionally, for electric four-wheel drive vehicles, this application can obtain a smooth control strategy for wheel speed based on the Profile control strategy, calculate the corresponding desired wheel speed with the desired slip rate as the target, use the smooth control strategy to calculate the corresponding dynamic wheel speed in reverse, and then use the closed-loop demand torque generated by the dynamic wheel speed change rate to obtain a new demand torque by smoothing the feedforward torque and wheel adhesion during the control process. The new demand torque is then used to control the vehicle, thereby improving the vehicle's acceleration performance and stability on low-friction surfaces.

[0061] This embodiment sets the dynamic wheel speed through Profile and then uses an adhesion feedforward + closed-loop feedback control method to smoothly transition the actual wheel speed to the dynamic wheel speed, thereby achieving precise control of the wheel slip ratio and improving the dynamic performance of electric four-wheel drive vehicles on low-friction surfaces. This embodiment can replace the current required torque with a closed-loop control command obtained by adding the feedforward torque, adhesion feedforward (i.e., wheel adhesion as mentioned above), and closed-loop required torque, and then calculate the actual slip ratio based on the new vehicle speed. If there is an error between the actual slip ratio and the desired slip ratio, but the effect is better, the desired slip ratio can be updated to the actual slip ratio.

[0062] In an exemplary embodiment, the process of calculating the feedforward torque required for the closed-loop control may include: obtaining the average actual motor torque and average wheel adhesion of the target vehicle when performing closed-loop control using the generated wheel speed smoothing curve; and determining the feedforward torque based on the difference between the average actual motor torque and the average wheel adhesion.

[0063] It's important to note that in vehicle dynamics, wheel adhesion refers to the frictional force at the contact point between the wheel and the road surface. This force is crucial for the vehicle's dynamic performance, including acceleration, deceleration, and steering. Wheel adhesion is generally considered in terms of both the actual torque of the motor and the wheel's inertial torque. The actual torque of the motor refers to the actual torque output by the motor, which directly affects the wheel's rotational speed and acceleration. The wheel's inertial torque refers to the inertial torque generated by the wheel's mass distribution and shape, which affects the wheel's dynamic response during acceleration and deceleration. Wheel adhesion is the frictional force between the wheel and the road surface, and it is influenced by factors such as the road surface material, tire type, and the contact area between the tire and the road surface.

[0064] In an exemplary embodiment, the wheel adhesion is calculated as follows: when performing closed-loop control using a generated wheel speed smoothing curve, if it is determined that the difference between the current wheel speed of the target vehicle and the desired wheel speed is less than a preset value, the actual motor torque and wheel inertial torque of the target vehicle are obtained; the wheel adhesion is determined based on the difference between the actual motor torque and the wheel inertial torque; wherein the wheel inertial torque is obtained based on the wheel rotational inertia, wheel speed change rate, and tire radius of the target vehicle.

[0065] Optionally, the wheel adhesion calculation corresponds to the situation where the current required torque has not yet been adjusted based on the desired slip ratio, i.e., slip ratio control is not activated, or slip ratio control is activated but the profile is not established. Here, wheel adhesion = actual motor torque - wheel moment of inertia * wheel speed change rate / tire radius. Wheel inertial torque = wheel moment of inertia * wheel speed change rate / tire radius.

[0066] like Figure 3 As shown, during the smooth transition from actual wheel speed to dynamic wheel speed, the adhesion feedforward uses the previous value before the Profile is established and is not updated. If a calculation window for the feedforward adhesion force is set, the wheel adhesion force can be calculated using the average actual motor torque and average wheel inertial torque within the window period. Then, at the end of the window, the adhesion feedforward is updated for subsequent control processes. Subsequently, the adhesion feedforward remains unchanged until the end of the next Profile window period.

[0067] The formula for calculating the feedforward torque is as follows:

[0068] Feedforward torque = Average actual motor torque within the Profile window (i.e., average actual motor torque) - Wheel moment of inertia * Average rate of change of rotational speed within the Profile window / Tire radius. Average wheel adhesion = Wheel moment of inertia * Average rate of change of rotational speed within the Profile window / Tire radius.

[0069] In an exemplary embodiment, after updating the current demand torque using closed-loop control instructions generated based on the closed-loop demand torque to obtain the target demand torque, and controlling the target vehicle to drive according to the target demand torque, the actual speed of the target vehicle after driving according to the target demand can be further obtained; the actual slip ratio of the target vehicle can be determined based on the road conditions of the road where the target vehicle is located and the actual speed of the target vehicle; if it is determined that the difference between the actual slip ratio and the expected slip ratio is less than a preset difference, the actual slip ratio and the actual speed are sent to the target object, and it is determined whether to update the expected slip ratio based on the response information of the target object.

[0070] Optionally, for electric four-wheel drive vehicles, this application can introduce a wheel speed smoothing control strategy into the VMC controller, calculate the corresponding desired wheel speed with the desired slip rate as the target, use the smoothing control strategy to calculate the corresponding dynamic wheel speed in reverse, and then use the closed-loop demand torque generated by the dynamic wheel speed change rate to obtain a new demand torque by smoothing the feedforward torque and wheel adhesion during the control process. The new demand torque is then used to control the vehicle, thereby improving the vehicle's acceleration performance and stability on low-friction surfaces.

[0071] Furthermore, this application can also utilize Electronic Stability Program (ESP), Anti-lock Braking System (ABS), Vehicle Dynamics Control (VDC), and Adaptive Cruise Control (ACC) to assist in achieving autonomous driving. ESP can intervene when the vehicle is about to lose control, helping the driver restore vehicle stability by reducing torque or braking a specific wheel. ABS can prevent wheel lock-up during emergency braking by intermittently reducing and restoring braking pressure to maintain wheel traction while allowing the driver to maintain steering control during braking. VDC integrates data from multiple sensors and can optimize the vehicle's trajectory by coordinating the power and braking systems. Adaptive Cruise Control can also control vehicle speed by adjusting engine torque to maintain a safe distance from the vehicle ahead.

[0072] Obviously, the embodiments described above are merely some embodiments of this application, and not all embodiments. Through the above description of the implementation methods, those skilled in the art can clearly understand that the methods according to the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk), and includes several instructions to cause a terminal device (which may be a mobile phone, computer, server, or network device, etc.) to execute the methods of the various embodiments of this application.

[0073] This embodiment also provides a vehicle control device for implementing the above embodiments and preferred embodiments; details already described will not be repeated. As used below, the term "module" can refer to a combination of software and / or hardware that implements a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, hardware implementations, or a combination of software and hardware, are also possible and contemplated.

[0074] Figure 4 This is a structural block diagram of a vehicle control device according to an embodiment of this application. The device includes:

[0075] Module 42 is used to determine the current torque demand of the target vehicle during driving;

[0076] The acquisition module 44 is used to determine the expected slip ratio of the target vehicle based on the road conditions of the road where the target vehicle is located and the reference speed of the target vehicle, and to acquire the closed-loop required torque of the target vehicle under the expected slip ratio.

[0077] The control module 46 is used to update the current demand torque using a closed-loop control command generated based on the closed-loop demand torque, to obtain the target demand torque, and to control the target vehicle to drive according to the target demand torque.

[0078] Through the aforementioned device and this application, the current required torque of the target vehicle during its driving process is determined; the desired slip ratio of the target vehicle is determined based on the road conditions of the road where the target vehicle is located and the reference speed of the target vehicle, and the closed-loop required torque of the target vehicle under the desired slip ratio is obtained; the current required torque is updated using a closed-loop control command generated based on the closed-loop required torque to obtain the target required torque, and the target vehicle is controlled to drive according to the target required torque. In other words, this application obtains the corresponding closed-loop required torque based on the reference speed and the desired slip ratio, with the desired slip ratio as the target; then, a torque reduction command (i.e., a closed-loop control command) is generated based on the closed-loop required torque; the current required torque is replaced by the torque reduction command to obtain the latest required torque (i.e., the target required torque); the acceleration and speed of the vehicle can be controlled according to this latest required torque, achieving precise control of the wheel slip ratio, improving the stability of the vehicle's acceleration on low-friction surfaces, enhancing the dynamic performance of electric four-wheel drive vehicles driving on low-friction surfaces, solving the technical problem of poor vehicle control stability, and improving vehicle control stability.

[0079] In an exemplary embodiment, the acquisition module 44 is further configured to: acquire the current road surface adhesion coefficient corresponding to the road state; determine a first preset slip ratio corresponding to the current road surface adhesion coefficient, wherein multiple first preset slip ratios correspond to different vehicle speeds; determine the first preset slip ratio with a target vehicle speed among the multiple first preset slip ratios as a second preset slip ratio, and determine the second preset slip ratio as the desired slip ratio, wherein the target vehicle speed represents the reference vehicle speed of the target vehicle.

[0080] In an exemplary embodiment, the acquisition module 44 is further configured to: determine the desired wheel speed of the target vehicle based on the reference vehicle speed of the target vehicle and the desired slip ratio; and, if the difference between the current wheel speed of the target vehicle and the desired wheel speed is less than a preset value, perform closed-loop control on the current wheel speed of the target vehicle with the desired wheel speed as the closed-loop control target, and generate a first closed-loop demand torque.

[0081] In an exemplary embodiment, the acquisition module 44 is further configured to: determine the desired wheel speed of the target vehicle based on the reference vehicle speed of the target vehicle and the desired slip ratio; and, if the difference between the current wheel speed of the target vehicle and the desired wheel speed is greater than a preset value, perform closed-loop control on the current wheel speed of the target vehicle using the dynamic wheel speed of the target vehicle as the closed-loop control target, and generate a second closed-loop demand torque.

[0082] In an exemplary embodiment, the acquisition module 44 is further configured to: calculate the desired wheel speed using a piecewise function corresponding to the reference vehicle speed and the desired slip ratio, wherein the piecewise function is expressed as follows: desired wheel speed = 1 / (1-desired slip ratio) × 5kph, the reference vehicle speed < 5kph; desired wheel speed = 1 / (1-desired slip ratio) × the reference vehicle speed, the reference vehicle speed < 30kph; desired wheel speed = [1 / (1-desired slip ratio)-1] × 30kph + the reference vehicle speed, the reference vehicle speed > 5kph.

[0083] In an exemplary embodiment, the acquisition module 44 is further configured to: determine the dynamic wheel speed of the target vehicle before performing closed-loop control on the current wheel speed of the target vehicle with the dynamic wheel speed of the target vehicle as the closed-loop control target, including: generating a wheel speed smoothing curve describing the change of the target vehicle from the current wheel speed to the desired wheel speed according to a smoothing control strategy, wherein the curve parameters on the wheel speed smoothing curve represent the dynamic wheel speed, and different dynamic wheel speeds correspond to dynamic wheel speed change rates.

[0084] In an exemplary embodiment, the vehicle control device further includes a generation module for: before updating the current demand torque using a closed-loop control command generated based on the closed-loop demand torque to obtain a target demand torque, the method further includes: generating the closed-loop control command based on the closed-loop demand torque, including: calculating the feedforward torque required for the closed-loop control and calculating the wheel adhesion of the target vehicle during the closed-loop control process using a generated wheel speed smoothing curve; generating the closed-loop control command based on the sum of the closed-loop demand torque, the feedforward torque, and the wheel adhesion.

[0085] In an exemplary embodiment, the generation module is further configured to: obtain the average actual motor torque and average wheel adhesion of the target vehicle when performing closed-loop control using the generated wheel speed smoothing curve; and determine the feedforward torque based on the difference between the average actual motor torque and the average wheel adhesion.

[0086] In an exemplary embodiment, the generation module is further configured to calculate the wheel adhesion force by: when performing closed-loop control using a generated wheel speed smoothing curve, if it is determined that the difference between the current wheel speed of the target vehicle and the desired wheel speed is less than a preset value, then obtaining the actual motor torque and wheel inertial torque of the target vehicle; determining the wheel adhesion force based on the difference between the actual motor torque and the wheel inertial torque; wherein the wheel inertial torque is obtained based on the wheel rotational inertia, wheel speed change rate, and tire radius of the target vehicle.

[0087] In an exemplary embodiment, the control module 46 is further configured to: update the current demand torque using a closed-loop control command generated based on the closed-loop demand torque to obtain a target demand torque, and control the target vehicle to drive according to the target demand torque, and then obtain the actual speed of the target vehicle after driving according to the target demand; determine the actual slip ratio of the target vehicle based on the road condition of the road where the target vehicle is located and the actual speed of the target vehicle; and if the difference between the actual slip ratio and the expected slip ratio is less than a preset difference, send the actual slip ratio and the actual speed to the target object, and determine whether to update the expected slip ratio based on the response information of the target object.

[0088] Embodiments of this application also provide a computer-readable storage medium storing a computer program, wherein the computer program is configured to execute the steps in any of the above method embodiments when run.

[0089] Optionally, in this embodiment, the storage medium may be configured to store a computer program for performing the following steps:

[0090] S1, determine the current torque demand of the target vehicle during driving;

[0091] S2, Based on the road conditions of the road where the target vehicle is located and the reference speed of the target vehicle, determine the expected slip ratio of the target vehicle, and obtain the closed-loop required torque of the target vehicle under the expected slip ratio;

[0092] S3, update the current demand torque using the closed-loop control command generated based on the closed-loop demand torque to obtain the target demand torque, and control the target vehicle to drive according to the target demand torque.

[0093] In one exemplary embodiment, the aforementioned computer-readable storage medium may include, but is not limited to, various media capable of storing computer programs, such as a USB flash drive, read-only memory (ROM), random access memory (RAM), portable hard disk, magnetic disk, or optical disk.

[0094] Specific examples in this embodiment can be found in the examples described in the above embodiments and exemplary implementations, and will not be repeated here.

[0095] Embodiments of this application also provide an electronic device including a memory and a processor, wherein the memory stores a computer program and the processor is configured to run the computer program to perform the steps in any of the above method embodiments.

[0096] Optionally, in this embodiment, the processor can be configured to perform the following steps via a computer program:

[0097] S1, determine the current torque demand of the target vehicle during driving;

[0098] S2, Based on the road conditions of the road where the target vehicle is located and the reference speed of the target vehicle, determine the expected slip ratio of the target vehicle, and obtain the closed-loop required torque of the target vehicle under the expected slip ratio;

[0099] S3, update the current demand torque using the closed-loop control command generated based on the closed-loop demand torque to obtain the target demand torque, and control the target vehicle to drive according to the target demand torque.

[0100] In one exemplary embodiment, the electronic device may further include a transmission device and an input / output device, wherein the transmission device is connected to the processor and the input / output device is connected to the processor.

[0101] Embodiments of this application also provide a computer program product, which includes a computer program that, when executed by a processor, implements the steps in any of the above method embodiments.

[0102] Embodiments of this application also provide another computer program product, including a non-volatile computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps in any of the above method embodiments.

[0103] Embodiments of this application also provide a computer program that includes computer instructions stored in a computer-readable storage medium; a processor of a computer device reads the computer instructions from the computer-readable storage medium and executes the computer instructions, causing the computer device to perform the steps in any of the above method embodiments.

[0104] Specific examples in this embodiment can be found in the examples described in the above embodiments and exemplary implementations, and will not be repeated here.

[0105] Obviously, those skilled in the art should understand that the modules or steps of this application described above can be implemented using general-purpose computing devices. They can be centralized on a single computing device or distributed across a network of multiple computing devices. They can be implemented using computer-executable program code, and thus can be stored in a storage device for execution by a computing device. In some cases, the steps shown or described can be performed in a different order than those presented here, or they can be fabricated as separate integrated circuit modules, or multiple modules or steps can be fabricated as a single integrated circuit module. Thus, this application is not limited to any particular combination of hardware and software.

[0106] The above description is only a preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A vehicle control method, characterized in that, include: Determine the current torque demand of the target vehicle during its operation; Based on the road conditions of the road where the target vehicle is located and the current speed of the target vehicle, the expected slip ratio of the target vehicle is determined, and the closed-loop required torque of the target vehicle under the expected slip ratio is obtained. The current required torque is updated using closed-loop control instructions generated based on the closed-loop required torque to obtain the target required torque, and the target vehicle is controlled to drive according to the target required torque.

2. The method according to claim 1, characterized in that, Determining the desired slip ratio of the target vehicle based on the road conditions of the road where the target vehicle is located and the reference speed of the target vehicle includes: Obtain the current road surface adhesion coefficient corresponding to the road condition; A first preset slip ratio corresponding to the current road surface adhesion coefficient is determined, wherein multiple first preset slip ratios correspond to different vehicle speeds; The first preset slip ratio with the target vehicle speed among the plurality of first preset slip ratios is determined as the second preset slip ratio, and the second preset slip ratio is determined as the desired slip ratio, wherein the target vehicle speed represents the reference vehicle speed of the target vehicle.

3. The method according to claim 1, characterized in that, Obtaining the closed-loop torque requirement of the target vehicle at the desired slip ratio includes: The desired wheel speed of the target vehicle is determined based on the reference speed of the target vehicle and the desired slip ratio; If the difference between the current wheel speed of the target vehicle and the desired wheel speed is less than a preset value, the current wheel speed of the target vehicle is controlled in a closed loop with the desired wheel speed as the closed loop control target, and a first closed loop demand torque is generated.

4. The method according to claim 1, characterized in that, Obtaining the closed-loop torque requirement of the target vehicle at the desired slip ratio includes: The desired wheel speed of the target vehicle is determined based on the reference speed of the target vehicle and the desired slip ratio; If the difference between the current wheel speed and the desired wheel speed of the target vehicle is greater than a preset value, the dynamic wheel speed of the target vehicle is used as the closed-loop control target to perform closed-loop control on the current wheel speed of the target vehicle and generate a second closed-loop demand torque.

5. The method according to any one of claims 3 to 4, characterized in that, Determining the desired wheel speed of the target vehicle based on its reference speed and the desired slip ratio includes: The desired wheel speed is calculated using a piecewise function corresponding to the reference vehicle speed and the desired slip ratio, wherein the piecewise function is expressed as follows: Desired wheel speed = 1 / (1-desired slip ratio) × 5kph, where the reference vehicle speed is <5kph; Desired wheel speed = 1 / (1-desired slip ratio) × the reference vehicle speed, where the reference vehicle speed is <30kph; Expected wheel speed = [1 / (1-expected slip ratio) – 1] × 30 kph + the reference vehicle speed, wherein the reference vehicle speed is greater than 5 kph.

6. The method according to claim 4, characterized in that, Before performing closed-loop control on the current wheel speed of the target vehicle using its dynamic wheel speed as the closed-loop control target, the method further includes: determining the dynamic wheel speed of the target vehicle, including: A smooth wheel speed change curve is generated based on a smooth control strategy to describe the target vehicle's wheel speed change from the current wheel speed to the desired wheel speed. The curve parameters on the smooth wheel speed change curve represent the dynamic wheel speed, and different dynamic wheel speeds correspond to dynamic wheel speed change rates.

7. The method according to claim 4, characterized in that, Before updating the current demand torque using the closed-loop control command generated based on the closed-loop demand torque to obtain the target demand torque, the method further includes: The closed-loop control command is generated based on the closed-loop demand torque, including: During the closed-loop control process using the generated wheel speed smooth change curve, the feedforward torque required for the closed-loop control is calculated, as well as the wheel adhesion of the target vehicle is calculated. The closed-loop control command is generated based on the sum of the closed-loop required torque, the feedforward torque, and the wheel adhesion.

8. The method according to claim 7, characterized in that, Calculating the feedforward torque required for the closed-loop control includes: When using the generated wheel speed smooth change curve for closed-loop control, the average actual motor torque and average wheel adhesion of the target vehicle are obtained. The feedforward torque is determined based on the difference between the average actual motor torque and the average wheel adhesion.

9. The method according to claim 7, characterized in that, The wheel adhesion is calculated as follows: when using the generated wheel speed smooth change curve for closed-loop control, if it is determined that the difference between the current wheel speed of the target vehicle and the desired wheel speed is less than a preset value, then the actual motor torque and wheel inertial torque of the target vehicle are obtained. The wheel adhesion force is determined based on the difference between the actual torque of the motor and the wheel inertial torque; wherein the wheel inertial torque is obtained based on the wheel rotational inertia, wheel speed change rate, and tire radius of the target vehicle.

10. The method according to claim 1, characterized in that, After updating the current demand torque using closed-loop control commands generated based on the closed-loop demand torque to obtain the target demand torque, and controlling the target vehicle to drive according to the target demand torque, the method further includes: Obtain the actual speed of the target vehicle after it travels according to the target requirements; The actual slip ratio of the target vehicle is determined based on the road conditions of the road where the target vehicle is located and the actual speed of the target vehicle. If the difference between the actual slip ratio and the expected slip ratio is less than a preset difference, the actual slip ratio and the actual vehicle speed are sent to the target object, and the expected slip ratio is updated based on the response information of the target object.

11. A vehicle control device, characterized in that, include: The determination module is used to determine the current torque demand of the target vehicle during driving; The acquisition module is used to determine the expected slip ratio of the target vehicle based on the road conditions of the road where the target vehicle is located and the reference speed of the target vehicle, and to acquire the closed-loop required torque of the target vehicle under the expected slip ratio. The control module is used to update the current demand torque using closed-loop control commands generated based on the closed-loop demand torque, to obtain the target demand torque, and to control the target vehicle to drive according to the target demand torque.

12. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a stored program, wherein the program, when executed, performs the method of any one of claims 1 to 10.

13. An electronic device comprising a memory and a processor, characterized in that, The memory stores a computer program, and the processor is configured to execute the method of any one of claims 1 to 10 through the computer program.

14. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 10.

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