Vehicle speed limit control method and device and medium
By monitoring the motor speed in real time and combining it with PID and speed limit feedforward control, the speed limit torque is dynamically adjusted, which solves the problem of jerking and vibration when limiting the speed of commercial vehicles, and achieves faster and more accurate speed limit response and overall vehicle weight reduction.
Patent Information
- Application Number
- CN202610304473.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-03-13
- Publication Date
- 2026-05-15
AI Technical Summary
In the existing technology, the speed limiting strategy implemented by the motor controller causes commercial vehicles to experience a strong sense of jerking when the speed is limited, cannot dynamically respond to different speed limit requirements, and needs to frequently switch between high torque and zero torque, resulting in obvious vibration of the whole vehicle.
By monitoring the motor speed in real time, a combination of PID control and speed limit feedforward control is used to dynamically adjust the speed limit torque. The calibration coefficient is determined based on the average speed and the actual speed, so as to achieve accurate speed limit state recognition and smooth transition, avoiding frequent switching.
It achieves smooth speed limiting for commercial vehicles under various scenarios and operating conditions, reduces vehicle vibration, improves speed limiting response speed and accuracy, reduces costs, and avoids dependence on slope and load sensors.
Smart Images
Figure CN122034736A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of vehicle control technology, and in particular to a vehicle speed limit control method, device and medium. Background Technology
[0002] Speed limiting in commercial vehicles is a crucial safety feature that must meet vehicle regulations. This function can be implemented by either the vehicle controller or the motor controller. The advantages of implementing speed limiting via the motor controller are: faster response when limiting the vehicle speed; and higher control precision and smaller steady-state error because the motor controller directly controls the motor speed to achieve vehicle speed limiting.
[0003] Patent CN103895530 A discloses a speed limiting strategy implemented by a motor controller, specifically a strategy that utilizes the external characteristics of the motor to smooth torque within a set speed range. The shortcomings of this patent are: 1) This strategy causes a strong jerkiness in the vehicle, especially commercial vehicles, when speed is limited. This is because when the motor speed exceeds the set value, the motor controller immediately resets the output torque to zero. As the speed decreases after torque reset, the motor controller responds again to the torque command sent by the vehicle controller. For commercial vehicles, under heavy loads and high torque requirements, speed limiting causes frequent switching between high and zero torque, resulting in noticeable vehicle vibration; 2) It cannot dynamically respond to different speed limiting requirements. Because this strategy sets the thresholds N, N1, and N2 for speed limiting to fixed values, it cannot meet the needs of commercial vehicles with multiple scenarios and speed limiting commands. Summary of the Invention
[0004] The present invention aims to at least solve the aforementioned technical problems existing in the prior art. To this end, the first aspect of the present invention proposes a vehicle speed limit control method, the method comprising:
[0005] The motor speed is monitored in real time. When the actual speed is greater than the motor speed limit and the vehicle control mode is torque control mode, the motor speed value at multiple moments is continuously collected. The average speed is obtained based on the sliding motor speed value at multiple moments. The motor controller speed limit state is activated based on the average speed value.
[0006] If activated, the calibration coefficient is determined based on the motor speed limit value and the current actual speed.
[0007] The PID torque is determined by using PID control and combining the motor speed limit value with the current actual speed.
[0008] The limiting torque is determined based on the torque under the external characteristics of the motor and a first coefficient; the first coefficient is determined based on the vehicle operating conditions.
[0009] The feedforward output torque is obtained based on the limiting torque and the calibration coefficient;
[0010] The speed-limiting output torque is obtained based on the feedforward output torque and the PID torque, and the motor operation is controlled according to the speed-limiting output torque.
[0011] Optionally, determining whether to activate the motor controller speed limiting state based on the average rotational speed includes:
[0012] If the average rotational speed is greater than the motor speed limit, the speed limit state is activated.
[0013] If the average rotational speed is less than or equal to the motor speed limit value, the speed limit state is not activated.
[0014] Optionally, determining the calibration coefficient based on the motor speed limit value and the current actual speed includes:
[0015] If the current actual speed is greater than the motor speed limit, then the calibration coefficient is negative.
[0016] If the current actual speed is less than the motor speed limit, then the calibration coefficient is a positive number.
[0017] Optionally, the motor speed limit is determined based on the vehicle's maximum speed limit, the local speed limit, and the motor's maximum speed.
[0018] Optionally, obtaining the feedforward output torque based on the limiting torque and the calibration coefficient includes:
[0019] The feedforward output torque is obtained by multiplying the limiting torque by the calibration coefficient.
[0020] Optionally, it also includes:
[0021] If the vehicle is detected to have a braking intention or the required driving force is less than the driving force at the current speed limit, the speed limit control will be discontinued.
[0022] Optionally, it also includes:
[0023] If the vehicle control mode is non-torque control mode, exit speed limit control.
[0024] Optionally, it also includes:
[0025] When the vehicle control mode is torque control mode, the speed limit exit pre-enable is set to 0. If the speed limit output torque is less than the target torque issued by the vehicle controller, the speed limit exit pre-enable is judged, and the speed limit output torque at multiple times is continuously collected to obtain the first torque average value.
[0026] If the average value of the first torque is less than the target torque issued by the vehicle controller, the speed limit exit pre-enablement will be set from 0 to 1.
[0027] After the speed limit exit pre-enable is set to 1, the speed limit output torque is continuously collected at multiple times. If the average value of the second torque obtained is less than the target torque issued by the vehicle controller, the speed limit control is exited.
[0028] A second aspect of the present invention provides an electronic device comprising a processor and a memory, wherein the memory stores at least one instruction or at least one program, the at least one instruction or at least one program being loaded and executed by the processor to implement the vehicle speed limit control method as proposed in the first aspect.
[0029] A third aspect of the present invention provides a computer-readable storage medium storing at least one instruction or at least one program, wherein the at least one instruction or at least one program is loaded and executed by a processor to implement the vehicle speed limit control method as proposed in the first aspect.
[0030] The beneficial effects of a vehicle speed limiting control method, device, and medium are as follows: This application consists of three parts: speed limiting state recognition, speed limiting execution, and speed limiting control exit recognition. In the speed limiting state recognition part, the activation of the motor controller speed limiting state is determined by the motor speed limiting value and control mode, effectively solving the problem of random switching of the speed limiting activation state, enabling the motor controller to effectively and accurately identify the vehicle's speed limiting intention. After activating the speed limiting state, a control strategy combining speed limiting feedforward control and PID control is adopted, resulting in faster speed response and higher speed control accuracy during speed limiting. Furthermore, the feedforward control designed in this application dynamically compensates for the feedforward torque based on the speed difference, resulting in better suppression of speed overshoot during speed limiting. Due to the dual effects of feedforward control and PID control, this application can meet the speed limiting requirements of commercial vehicles under conditions of large gradient and load variations, better satisfying the usage needs of commercial vehicles in multiple scenarios and operating conditions. Furthermore, the feedforward torque of this application is dynamically adjusted based on the speed deviation, offering advantages such as fast and accurate speed limit adjustment. This application incorporates vehicle load information, including variations in vehicle weight and gradient, into the speed deviation, thus eliminating concerns about significant deviations in the feedforward torque calculation due to sensor malfunction. The speed limiting function in this application saves costs and reduces weight. The vehicle does not require gradient or load sensors; the speed limiting function can be implemented through the motor controller, eliminating the need for additional sensors and achieving cost and weight reduction. During speed limiting execution, the system identifies whether to exit speed limiting control based on the target torque and speed limit output torque issued by the vehicle controller, thereby accurately recognizing the vehicle's intention to exit speed limiting and smoothly exiting when speed limiting is no longer necessary. Attached Figure Description
[0031] Figure 1 A flowchart of a vehicle speed limit control method provided in an embodiment of the present invention;
[0032] Figure 2 This is a speed limit measurement diagram from an embodiment of the present invention;
[0033] Figure 3 This is a speed limit test diagram of the comparative scheme of the embodiment of the present invention. Detailed Implementation
[0034] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0035] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of embodiments of this disclosure, unless otherwise stated, "a plurality of" means two or more. Furthermore, the use of "based on" or "according to" implies openness and inclusiveness, because processes, steps, calculations, or other actions "based on" or "according to" one or more of the stated conditions or values may in practice be based on additional conditions or beyond the stated values.
[0036] This invention provides a vehicle speed limiting control method, applied to a motor controller, such as... Figure 1 As shown, the method may include the following steps:
[0037] Step 101: Monitor the motor speed in real time. When the actual speed is greater than the motor speed limit and the vehicle control mode is torque control mode, start continuously collecting the motor speed values at multiple moments. Obtain the average speed based on the sliding motor speed values at multiple moments. Determine whether to activate the motor controller speed limit state based on the average speed value. The motor speed limit value is the target speed limit value of the motor.
[0038] Specifically, the activation of the motor controller speed limiting state is determined by the motor speed limit value and the control mode. An array A is set up to store the motor speed when the speed is limited. This array can store M data points. When the motor speed is greater than the motor speed limit value and the vehicle control mode is torque control mode, the motor speed values at multiple times are continuously recorded and stored in the array. If the number of data points stored in the array is less than or equal to M, the speed data stored in the array are summed. Otherwise, the average of the data points stored in the array is calculated. In other words, when the number of speed data points stored in the array reaches M, the average of these M speed data points is obtained.
[0039] In one possible implementation, determining whether to activate the motor controller speed limiting state based on the average rotational speed includes:
[0040] If the average rotational speed is greater than the motor speed limit, the speed limit state is activated.
[0041] If the average rotational speed is less than or equal to the motor speed limit value, the speed limit state is not activated.
[0042] In this embodiment of the invention, it is determined whether the speed limit state has been entered. If the conditions for the motor controller to activate the active speed limit function are met, the motor controller is switched from torque control to speed limit control, that is, the speed limit state is activated.
[0043] Step 102: If activated, determine the calibration coefficient based on the motor speed limit value and the current actual speed.
[0044] In one possible implementation, the motor speed limit is determined based on the vehicle's maximum speed limit, the local speed limit, and the motor's maximum speed.
[0045] Specifically, this invention provides a method for speed limiting in commercial vehicles based on a motor controller. First, the vehicle controller calculates a motor speed limit request value based on the vehicle's maximum speed limit, local speed limits, and other regulatory speed limits, and sends this request value to the motor controller via the CAN network. Then, the motor controller references this request value and, combined with the motor's actual output capacity and speed limit requirements, obtains the motor speed limit value. Afterward, referring to parameters such as the motor control mode and motor speed, the motor controller performs an active speed limit activation determination. If speed limiting is activated, the motor controller completes the speed limiting and speed adjustment actions.
[0046] In one possible implementation, determining the calibration coefficient based on the motor speed limit value and the current actual speed includes:
[0047] If the current actual speed is greater than the motor speed limit, then the calibration coefficient is negative.
[0048] If the current actual speed is less than the motor speed limit, then the calibration coefficient is a positive number.
[0049] In this embodiment of the invention, speed limiting is achieved by first determining the deviation between the motor speed limit and the current actual speed, and then using a combination of PID control and speed limiting feedforward control to output the speed-limiting torque. To determine the feedforward output torque, an output reference coefficient is first calibrated based on the deviation between the motor speed limit and the current actual speed. In this embodiment, this coefficient is called the calibration coefficient. Specifically, if the actual speed is greater than the motor speed limit, a negative coefficient is calibrated for calculating the feedforward output torque; that is, the calibration coefficient determined here is negative. If the actual speed is less than the motor speed limit, a positive coefficient is calibrated for calculating the feedforward output torque; that is, the calibration coefficient here is positive. If the actual speed is equal to the motor speed limit, the calibration coefficient is zero.
[0050] Step 103: Use PID control and combine the motor speed limit value and the current actual speed to determine the PID torque.
[0051] The embodiments of the present invention use a combination of PID control and speed limit feedforward control to obtain the final torque. Therefore, it is also necessary to obtain the PID torque based on the difference between the motor speed limit value and the current actual speed.
[0052] Step 104: Determine the limiting torque based on the torque under the external characteristics of the motor and the first coefficient; the first coefficient is determined based on the vehicle operating conditions.
[0053] The torque under the external characteristics of a motor refers to the maximum operating torque that a motor can output under a specific DC voltage and at different operating speeds.
[0054] Specifically, the limiting torque is obtained by multiplying the torque under the external characteristics of the motor by the first coefficient.
[0055] Step 105: Obtain the feedforward output torque based on the limiting torque and the calibration coefficient.
[0056] In one possible implementation, obtaining the feedforward output torque based on the limiting torque and the calibration coefficient includes:
[0057] The feedforward output torque is obtained by multiplying the limiting torque by the calibration coefficient.
[0058] Step 106: Obtain the speed-limiting output torque based on the feedforward output torque and the PID torque, and control the motor operation according to the speed-limiting output torque.
[0059] Specifically, the sum of the feedforward output torque and the PID torque is used as the final output torque when the speed is limited. The final output torque when the speed is limited changes dynamically in real time according to the changes in vehicle operating conditions, so that the vehicle responds quickly when the speed is limited and the speed output is stable.
[0060] In one possible implementation, it also includes:
[0061] If the vehicle is detected to have a braking intention or the required driving force is less than the driving force at the current speed limit, the speed limit control will be discontinued.
[0062] Specifically, embodiments of the present invention determine whether to exit the speed limit state by recognizing the driver's intention.
[0063] In one possible implementation, it also includes:
[0064] If the vehicle control mode is non-torque control mode, exit speed limit control.
[0065] Specifically, exiting speed limit control here means changing the speed limit control status from active to inactive.
[0066] In one possible implementation, it also includes:
[0067] When the vehicle control mode is torque control mode, the speed limit exit pre-enable is set to 0. If the speed limit output torque is less than the target torque issued by the vehicle controller, the speed limit exit pre-enable is judged, and the speed limit output torque at multiple times is continuously collected to obtain the first torque average value.
[0068] If the average value of the first torque is less than the target torque issued by the vehicle controller, the speed limit exit pre-enablement will be set from 0 to 1.
[0069] After the speed limit exit pre-enable is set to 1, the speed limit output torque is continuously collected at multiple times. If the average value of the second torque obtained is less than the target torque issued by the vehicle controller, the speed limit control is exited.
[0070] Specifically, the system determines whether to exit speed-limited control based on the target torque and speed-limited output torque issued by the vehicle controller. After setting the speed-limited exit pre-enable to 0, an array B is set to store the speed-limited output torque. This array B can store N speed-limited output torque data points. If the speed-limited output torque is less than the target torque issued by the vehicle controller, multiple speed-limited output torques are continuously recorded and stored in the array. If the number of speed-limited output torque data points stored in the array is less than or equal to N, the stored speed-limited output torque data points are summed; otherwise, the average value of the stored data points is calculated. In other words, when the number of speed-limited output torque data points stored in the array is N, the average value of these N data points is obtained, which is the first torque average value. The first torque average value is the pre-enable judgment torque. If the pre-enable judgment torque is less than the target torque issued by the vehicle controller, the speed-limited exit pre-enable is set from 0 to 1. At the same time, array B is cleared to zero. After the speed limit exit pre-enable is set to 1, the speed limit output torque at multiple moments is collected again using the same method as the first torque average. The second torque average is obtained using the same method. If the second torque average is less than the target torque issued by the vehicle controller, the speed limit control is exited, that is, the speed limit state is changed to an inactive state; otherwise, the speed limit state remains active.
[0071] Reference Figure 2 ,in, Figure 2 The horizontal axis represents time, and the vertical axis of the orange line represents the speed limit status. The status unit is bit. The speed limit status takes the value 0 or 1, where 0 means that the speed limit control is not activated and 1 means that the speed limit control is activated. Figure 2 The blue lines in the diagram represent the speed limit command value (or motor speed limit value), and the vertical axis represents the speed in rpm. Figure 3 The magenta line in the graph represents the actual speed value at which the speed limit is applied, with the vertical axis representing the speed in rpm. To facilitate comparison and display, the graphs of the speed limit status, motor speed limit value, and actual speed value at which the speed limit is applied are placed on a single coordinate system. Due to software limitations, only the vertical axis of one graph can be displayed, hence this explanation.
[0072] Reference Figure 3 , Figure 3 This is a speed limit measurement diagram of the comparative scheme of the embodiments of the present invention. Figure 3 The corresponding solution, after determining that the motor speed is greater than the motor speed limit and the vehicle control mode is torque control mode, does not collect the motor speed values at multiple times or determine whether to activate the motor controller speed limit state based on the average speed value. Instead, it directly activates the motor controller speed limit state after determining that the motor speed is greater than the motor speed limit and the vehicle control mode is torque control mode. Figure 3 The speed limit status, motor speed limit value, actual speed value at which the speed limit is applied, and the speed limit status are all specified in the data. Figure 2 The units of the corresponding parameters are the same, so they will not be explained further. Figure 2Similarly, to facilitate comparison of the display effects, the graphs of the speed limit status, motor speed limit value, and actual speed value of the speed limit are placed in one coordinate system. Due to software limitations, only the vertical axis of one graph can be displayed, hence the explanation.
[0073] The embodiments of the present invention consist of three parts: speed limit state recognition, speed limit execution, and exit speed limit control recognition. In the speed limit state recognition part, the speed limit state of the motor controller is determined by the motor speed limit value and the control mode. This effectively solves the problem of random switching of the speed limit activation state, enabling the motor controller to effectively and accurately recognize the speed limit intention of the whole vehicle.
[0074] Based on the speed limit command, the embodiment of the present invention responds quickly to the speed limit command when the motor controller is in torque control mode, so that the motor speed changes rapidly and smoothly transitions to the target speed limit value; after entering the speed limit state, the motor controller can dynamically adjust the speed control accuracy and control stability during speed limit control according to the load change.
[0075] This invention employs a control strategy combining speed-limiting feedforward control and PID control, resulting in faster speed response and higher speed control accuracy during speed limiting. Furthermore, the feedforward control designed in this application dynamically compensates for the feedforward torque based on the speed difference, leading to better suppression of speed overshoot during speed limiting. Due to the dual effects of feedforward control and PID control, this invention can meet the speed-limiting requirements of commercial vehicles under conditions of large gradient and load variations, better satisfying the usage needs of commercial vehicles in multiple scenarios and operating conditions. In addition, the feedforward torque in this invention is dynamically adjusted based on the speed deviation, offering advantages such as fast speed limit adjustment and high accuracy. This invention reflects vehicle load information such as vehicle weight and gradient changes in the speed deviation, thus eliminating concerns about large deviations in the calculated feedforward torque value due to the failure of gradient and load sensors. The speed-limiting function in this invention saves costs and reduces weight. The vehicle does not require gradient or load sensors; the speed-limiting function can be achieved through the motor controller, eliminating the need for additional gradient and load sensors, thereby reducing overall vehicle costs and weight.
[0076] In the process of speed limiting execution, this embodiment of the invention identifies whether to exit speed limiting control based on the target torque and speed limiting output torque issued by the vehicle controller, thereby achieving accurate identification of the vehicle's intention to exit speed limiting and smooth exit when speed limiting is not required.
[0077] In another embodiment of the present invention, an electronic device is also provided, the electronic device including a processor and a memory, the memory storing at least one instruction or at least one program, the at least one instruction or at least one program being loaded and executed by the processor to implement the vehicle speed limit control method proposed in the embodiment of the present invention.
[0078] In another embodiment of the present invention, a computer-readable storage medium is also provided, wherein at least one instruction or at least one program is stored in the storage medium, and the at least one instruction or at least one program is loaded and executed by a processor to implement the vehicle speed limit control method proposed in the embodiment of the present invention.
[0079] The foregoing primarily describes the solutions provided by the embodiments of the present invention from the perspective of the device. It is understood that, in order to achieve the above functions, the device includes corresponding hardware structures and / or software modules for executing each function. Those skilled in the art should readily recognize that, in conjunction with the algorithmic steps of the various examples described in the embodiments disclosed herein, the present invention can be implemented in hardware or a combination of hardware and computer software. Whether a function is executed in hardware or by computer software driving hardware depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present invention.
[0080] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions within the technical scope disclosed in the present invention should be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.
Claims
1. A vehicle speed limiting control method, characterized in that, include: The motor speed is monitored in real time. When the actual speed is greater than the motor speed limit and the vehicle control mode is torque control mode, the motor speed value at multiple moments is continuously collected. The average speed is obtained based on the sliding motor speed value at multiple moments. The motor controller speed limit state is activated based on the average speed value. If activated, the calibration coefficient is determined based on the motor speed limit value and the current actual speed. The PID torque is determined by using PID control and combining the motor speed limit value with the current actual speed. The limiting torque is determined based on the torque under the external characteristics of the motor and a first coefficient; the first coefficient is determined based on the vehicle operating conditions. The feedforward output torque is obtained based on the limiting torque and the calibration coefficient; The speed-limiting output torque is obtained based on the feedforward output torque and the PID torque, and the motor operation is controlled according to the speed-limiting output torque.
2. The vehicle speed limit control method according to claim 1, characterized in that, The step of determining whether to activate the motor controller speed limiting state based on the average rotational speed includes: If the average rotational speed is greater than the motor speed limit, the speed limit state is activated. If the average rotational speed is less than or equal to the motor speed limit value, the speed limit state is not activated.
3. The vehicle speed limit control method according to claim 1, characterized in that, The step of determining the calibration coefficient based on the motor speed limit and the current actual speed includes: If the current actual speed is greater than the motor speed limit, then the calibration coefficient is negative. If the current actual speed is less than the motor speed limit, then the calibration coefficient is a positive number.
4. The vehicle speed limit control method according to claim 1, characterized in that, The motor speed limit is determined based on the vehicle's maximum speed limit, the local speed limit, and the motor's maximum speed.
5. The vehicle speed limit control method according to claim 1, characterized in that, The step of obtaining the feedforward output torque based on the limiting torque and the calibration coefficient includes: The feedforward output torque is obtained by multiplying the limiting torque by the calibration coefficient.
6. The vehicle speed limit control method according to claim 1, characterized in that, Also includes: If the vehicle is detected to have a braking intention or the required driving force is less than the driving force at the current speed limit, the speed limit control will be discontinued.
7. The vehicle speed limit control method according to claim 1, characterized in that, Also includes: If the vehicle control mode is non-torque control mode, exit speed limit control.
8. The vehicle speed limit control method according to claim 7, characterized in that, Also includes: When the vehicle control mode is torque control mode, the speed limit exit pre-enable is set to 0. If the speed limit output torque is less than the target torque issued by the vehicle controller, the speed limit exit pre-enable is judged, and the speed limit output torque at multiple times is continuously collected to obtain the first torque average value. If the average value of the first torque is less than the target torque issued by the vehicle controller, the speed limit exit pre-enablement will be set from 0 to 1. After the speed limit exit pre-enable is set to 1, the speed limit output torque is continuously collected at multiple times. If the average value of the second torque obtained is less than the target torque issued by the vehicle controller, the speed limit control is exited.
9. An electronic device, characterized in that, The electronic device includes a processor and a memory, the memory storing at least one instruction or at least one program, the at least one instruction or at least one program being loaded and executed by the processor to implement the vehicle speed limit control method as described in any one of claims 1-8.
10. A computer-readable storage medium, characterized in that, The storage medium stores at least one instruction or at least one program, which is loaded and executed by a processor to implement the vehicle speed limit control method as described in any one of claims 1-8.