A wheel speed control method, device, storage medium, autopilot and vehicle

Abstract

The application discloses a wheel speed control method and device, a storage medium, an autopilot and a vehicle, and solves the technical problem of wheel slip or locking of an electric vehicle by using wheel speed control. According to the embodiment of the application, the control method and device and related products have very small speed overshoot and steady-state error in speed control, and the adjustment response is very rapid, thereby playing a very effective speed control role. The related control process can adopt PID or PI control for parameter synthesis, and is suitable for application scenarios in which the driving resistance torque can be calibrated or estimated.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of intelligent vehicles, and particularly relates to a wheel speed control method and device, a storage medium, an automatic driving instrument and a vehicle. BACKGROUND

[0002] On a new energy vehicle directly driven by a motor, slippage or locking easily occurs, and the main reason is that the torque characteristic curve of the motor is different from that of a traditional fuel vehicle. At low speed, the motor can output a large torque, and when the road cannot provide sufficient adhesion, the tire will slip.

[0003] The current mainstream solution is to use an electronic stability system ESP (Electronic Stability Program) to control the wheel speed by mechanical braking, or to give a motor torque instruction limit value through the ESP, and the motor outputs torque according to the instruction. No matter which method, there is a defect of slow response time, and there is room for improvement.

[0004] The anti-slip and anti-lock control scheme generally estimates a reasonable target wheel speed according to the vehicle operating state, and generally keeps the slip ratio within 0.2; the motor speed is controlled near the above-mentioned target speed through the electric drive system, so as to realize the wheel anti-slip and anti-lock. Since the vehicle speed is constantly changing, the target speed is also constantly changing, which puts higher requirements on the speed control in this scene. SUMMARY

[0005] The application discloses a wheel speed control method, device, storage medium, automatic driving instrument and vehicle through embodiments, and adopts wheel speed control to solve the technical problem of wheel slippage or locking of an electric vehicle.

[0006] The control method comprises a working condition acquisition step, a slip judgment step and a following control step; the control system is initialized by acquiring working condition information in the working condition acquisition step; wherein the working condition information comprises vehicle speed, gear or speed ratio.

[0007] Generally, the wheel is mechanically connected to the driving motor main shaft through a transmission system, and the mechanical characteristics of the driving motor are indirectly transmitted to the wheel end.

[0008] Further, in the slip judgment step, if the motor speed is within the upper and lower limits of the speed, the torque control of the driving motor is not intervened; at the same time, the upper system torque instruction is taken as the output torque instruction; the upper system comprises a vehicle controller and / or a domain controller, and the upper system sends the torque instruction to the motor controller; otherwise, if the motor speed exceeds the upper limit or is lower than the lower limit, the speed difference information is acquired.

[0009] Further, the following control step further comprises a process of obtaining a feedforward control parameter or a feedforward signal; the feedforward control parameter or the feedforward signal is used to compensate the output value of the output torque together with the speed difference information; the feedforward process belongs to the part of the closed loop of the driving motor, which can improve the speed and accuracy of the response characteristics.

[0010] Further, the following control step further comprises a process of obtaining a motor speed V; wherein the motor speed V is used to calculate the speed difference, and provide further basis for the following control step.

[0011] Further, the feedforward control parameter or the feedforward signal can include the driving system resistance torque calibration data and / or the estimated driving system resistance torque.

[0012] Specifically, the resistance torque of the driving system can be obtained according to the motor torque and the speed.

[0013] Further, the method of the present application further comprises a data refreshing step, so that the relevant control system reacquires the relevant data and reoutputs the relevant signals or data according to the preset time interval.

[0014] Specifically, the relevant data includes working condition information, and the relevant signals or data includes torque or torque control signal.

[0015] Specifically, the method and / or system disclosed by the embodiment of the present application further comprises a closed loop control process of vehicle speed or wheel speed, which uses PID controller and / or PI controller for parameter synthesis, and after reasonable selection of parameters, the transition process time and overshoot of the speed control can be limited within the preset index range.

[0016] Further, the present application further discloses a wheel speed control device through an embodiment.

[0017] The working condition acquisition unit acquires working condition information, and the working condition information includes vehicle speed, gear or speed ratio; in the slip judgment unit, if the motor speed is within the upper and lower limits of the speed, the torque control of the driving motor is not intervened; at the same time, the torque instruction of the upper system is taken as the output torque instruction; wherein the upper system includes the vehicle controller and / or the domain controller, and the upper system sends the torque instruction to the motor controller; otherwise, if the motor speed exceeds the upper limit or is lower than the lower limit, the speed difference information is acquired.

[0018] Further, the feedforward control parameter or the feedforward signal is obtained through the following control unit, which is used to compensate the output value of the output torque together with the speed difference information.

[0019] Specifically, the following control unit acquires the motor speed V; the motor speed V is used to calculate the speed difference information.

[0020] The feedforward control parameter or feedforward signal comprises driving system resistance torque calibration data and / or estimated driving system resistance torque.

[0021] Further, by executing the data refreshing process in the working condition acquisition unit, the slip judgment unit and the following control unit, the dynamic vehicle condition information and the related disturbance can be followed and controlled or adapted.

[0022] The data refreshing process reacquires the related data and reoutputs the related signal or data according to the preset time interval, the related data comprises the working condition information, and the related signal or data comprises the torque or the torque control signal.

[0023] Further, by applying a correction coefficient to the gear or speed ratio, the interference caused by the mechanical wear of the gear pair can be further compensated, and the correction coefficient can be obtained by experimental measurement or calculation.

[0024] Similarly, the product disclosed in the embodiment of the device also comprises a closed-loop control system of vehicle speed or wheel speed, the control process of which adopts a PID controller and / or a PI controller for parameter synthesis, and after reasonable selection of parameters, the transition process time and the overshoot of speed control can be limited within the preset index range.

[0025] The method disclosed in the present application is solidified in a computer storage medium by microelectronic technology to form computer-readable instructions, so that the corresponding control method can be realized.

[0026] For specific field automatic pilots or vehicle products, the same design idea and rules can be realized on special devices or vehicle products by using the above method and product, and the specific process is not described in detail.

[0027] As shown in the embodiment of the present application, the control method and device and related products have very small speed overshoot and steady-state error in speed control, and the adjustment response is very rapid, which plays a very effective speed control, and the wheel slip or lock is avoided by controlling the wheel speed.

[0028] It should be noted that the terms such as "first", "second" and the like used in the present text are only used for describing the technical solutions, and do not constitute a limitation on the technical solutions, nor can they be understood as an indication or suggestion of the importance of the corresponding elements; the elements with "first", "second" and the like indicate that at least one element is included in the corresponding technical solution. BRIEF DESCRIPTION OF DRAWINGS

[0029] For more clearly illustrating the technical scheme of the present application, and facilitating further understanding of the technical effects, technical features and purposes of the present application, the present application will be described in detail below with reference to the drawings, which constitute an integral part of the present description and serve to illustrate the technical scheme of the present application together with the embodiments of the present application, but do not constitute a limitation of the present application.

[0030] The same reference numerals in the drawings denote the same components, specifically:

[0031] Figure 1 For the control flow and signal distribution schematic diagram of the method, device and related products of the embodiments of the present application,

[0032] Figure 2 For the first adjustment process schematic diagram of the embodiments of the present application;

[0033] Figure 3 For the second adjustment process schematic diagram of the embodiments of the present application;

[0034] Figure 4 For the process schematic diagram of the method embodiments of the present application;

[0035] Figure 5 For the component structure and signal transmission schematic diagram of the device embodiments of the present application.

[0036] Among them:

[0037] 001 - first lower limit speed (lower limit of speed),

[0038] 011 - working condition acquisition unit,

[0039] 022 - slip determination unit, 033 - follow-up control unit,

[0040] 111 - working condition acquisition step,

[0041] 123 - signal refreshing step,

[0042] 200 - working condition information,

[0043] 222 - slip determination step,

[0044] 333 - follow-up control step;

[0045] 555 - current speed,

[0046] 606 - speed difference information,

[0047] 707 - feedforward signal,

[0048] 777 - feedforward control parameter,

[0049] 999 - second upper limit speed (upper limit of speed). DETAILED DESCRIPTION

[0050] The application will be further described in detail below in conjunction with the accompanying drawings and embodiments. Of course, the following specific embodiments described are only to explain the technical solutions of the application, but not to limit the application. In addition, the parts expressed in the embodiments or the accompanying drawings are only exemplified parts of the application, but not the whole of the application.

[0051] As shown in Figure 4 , the embodiment of the application discloses a wheel speed control method, including a working condition acquisition step 111, a slip judgment step 222, and a following control step 333.

[0052] As shown in Figure 5 , the working condition acquisition step 111 acquires working condition information 200, including vehicle speed, gear or speed ratio.

[0053] Further, as shown in Figure 4 , the slip judgment step is used to determine the vehicle state corresponding to the vehicle speed, gear and other information, and to select an appropriate driving method according to the state of the vehicle to avoid wheel slip or lock.

[0054] Specifically, if the motor speed is within the upper and lower limits of the speed range, the torque control of the driving motor is not intervened; at the same time, the upper system torque instruction is taken as the output torque instruction.

[0055] Wherein, the upper system includes a vehicle controller and / or a domain controller, and the upper system sends a torque instruction to the motor controller; on the contrary, if the motor speed exceeds the upper limit or is lower than the lower limit, the speed difference information 606 is acquired.

[0056] Further, as shown in Figure 1 , the following control step 333 further includes acquiring a feedforward control parameter 777 or using a feedforward signal 707 to intervene.

[0057] Specifically, the feedforward control parameter 777 or the feedforward signal 707 is used to compensate the output value of the output torque together with the speed difference information 606.

[0058] Further, the following control step 333 further includes acquiring a motor speed V555; wherein the motor speed V555 is used to calculate the speed difference.

[0059] Specifically, the feedforward control parameter 777 or the feedforward signal 707 includes driving system resistance torque calibration data and / or estimated driving system resistance torque.

[0060] Further, as shown in Figure 1The method further comprises a data refreshing step 123; according to a preset time interval, reacquiring relevant data and re-outputting relevant signals or data; the relevant data comprises working condition information 200; the relevant signals or data comprises torque or torque control signals.

[0061] Specifically, the control of the vehicle speed or the wheel speed can adopt parameter synthesis of a PID controller and / or a PI controller; the regulation process of the motor speed V555 comprises a first regulation process and a second regulation process; the first regulation process corresponds to vehicle anti-slip, and the second regulation process corresponds to vehicle anti-lock.

[0062] Further, as Figure 5 The embodiment of the present application discloses a wheel speed control device, comprising a working condition acquisition unit 011, a slip judgment unit 022 and a following control unit 033.

[0063] Specifically, the working condition acquisition unit 011 acquires working condition information 200, including vehicle speed, gear or speed ratio; in the slip judgment unit 022, if the motor speed is within the upper and lower limits of the speed range, the torque control of the driving motor is not intervened; at the same time, the torque instruction of the upper system is taken as the output torque instruction; wherein the upper system comprises a vehicle controller and / or a domain controller, and the upper system sends the torque instruction to the motor controller; on the contrary, if the motor speed exceeds the upper limit or is lower than the lower limit, the speed difference information 606 is acquired.

[0064] Further, the slip judgment unit 022 acquires the speed difference information 606; the following control unit 033 outputs the torque instruction and drives the motor according to the speed difference information 606.

[0065] Further, the following control unit 033 acquires the feedforward control parameter 777 or the feedforward signal 707; the feedforward control parameter 777 or the feedforward signal 707 is used for output value compensation of the output torque together with the speed difference information 606.

[0066] Further, the following control unit 033 acquires the motor speed V555; wherein the motor speed V555 is used for calculating the speed difference information 606.

[0067] Further, the feedforward control parameter 777 or the feedforward signal 707 comprises driving system resistance torque calibration data and / or estimated driving system resistance torque.

[0068] Further, the working condition acquisition unit 011, the slip judgment unit 022 and the following control unit 033 reacquire relevant data and re-output relevant signals or data according to a preset time interval by executing the data refreshing step 123; wherein the relevant data comprises working condition information (200), and the relevant signals or data comprises torque or torque control signals.

[0069] Further, the control of the vehicle speed or wheel speed adopts a PID controller and / or a PI controller for parameter synthesis.

[0070] For the computer storage medium, the autopilot and the vehicle disclosed in the embodiments of the present application, since the core process or the parts adopt the same technical concept as the method or the device of the present application, the same technical problems can be solved and the same technical effects can be achieved. The specific implementation steps are not described in detail.

[0071] It should be noted that the above embodiments are only for more clearly illustrating the technical solutions of the present application, and those skilled in the art can understand that the implementation manners of the present application are not limited to the above content. The obvious changes, replacements or substitutions based on the above content do not exceed the scope of the technical solutions of the present application. Other embodiments will also fall within the scope of the present application without departing from the concept of the present application.

Claims

1. A wheel speed control method, characterized in that, include: Working condition acquisition steps (111), slip judgment steps (222), and follow control steps (333); The operating condition acquisition step (111) acquires operating condition information (200), which includes vehicle speed, gear or speed ratio; Obtain the overall vehicle status, including the upper and lower limits of allowable wheel speeds after wheel slippage; In the slip determination step (222), if the motor speed is within the upper and lower speed limits, the torque control of the drive motor is not intervened; at the same time, the torque command of the upper system is used as the output torque command; wherein, the upper system includes the vehicle controller and / or the domain controller, and the upper system sends the torque command to the motor controller; conversely, if the motor speed exceeds the upper limit or is lower than the lower limit, the speed difference information is obtained (606). Acquire feedforward control parameters or feedforward signals; the feedforward control parameters or feedforward signals are used in conjunction with speed difference information to compensate for the output torque; the feedforward control parameters include drive system resistance torque calibration data and / or estimated drive system resistance torque. In the following control step (333), based on the speed difference information (606), a torque command is output and the drive motor is adjusted or controlled; It also includes a data refresh step (123); The data refresh step (123) reacquires relevant data and re-outputs relevant signals or data according to a preset time interval; The relevant data includes the operating condition information (200); the relevant signals or data include torque or torque control signals.

2. The method of claim 1, wherein: The following control step (333) further includes obtaining the motor speed V (555); The motor speed V (555) is used to calculate the speed difference.

3. The method of claim 1, wherein: The resistance torque of the drive system is obtained based on the motor torque and speed.

4. The method of claim 1, wherein: The control of vehicle speed or wheel speed is achieved by combining parameters using a PID controller and / or a PI controller. The adjustment process of the motor speed V (555) includes a first adjustment process and a second adjustment process; wherein, the first adjustment process corresponds to vehicle anti-skid and the second adjustment process corresponds to vehicle anti-lock braking.

5. A wheel speed control device, comprising: Operating condition acquisition unit (011), slip judgment unit (022), and follow control unit (033); The working condition acquisition unit (011) acquires working condition information (200), which includes vehicle speed, gear or speed ratio; and acquires the overall vehicle status, including the upper and lower limits of allowable wheel speed after wheel slippage. In the slip judgment unit (022), if the motor speed is within the upper and lower speed limits, the torque control of the drive motor is not intervened; at the same time, the torque command of the upper system is used as the output torque command; wherein, the upper system includes the vehicle controller and / or the domain controller, and the upper system sends the torque command to the motor controller; conversely, if the motor speed exceeds the upper limit or is lower than the lower limit, the speed difference information (606) is obtained. The following control unit (033) outputs a torque command and drives the drive motor according to the speed difference information (606); The follow control unit (033) acquires feedforward control parameters (777) or feedforward signals (707); The feedforward control parameter (777) or feedforward signal (707) is used in conjunction with the speed difference information (606) to compensate the output value of the output torque; the feedforward control parameter (777) or the feedforward signal (707) includes drive system resistance torque calibration data and / or estimated drive system resistance torque; The operating condition acquisition unit (011), the sliding judgment unit (022), and the follow control unit (033) executed the data refresh step (123); The data refresh step (123) reacquires relevant data and re-outputs relevant signals or data at preset time intervals; the relevant data includes the operating condition information (200); the relevant signals or data include torque or torque control signals.

6. The apparatus of claim 5, wherein: The follow control unit (033) acquires the motor speed V (555); The motor speed V (555) is used to calculate the speed difference information (606).

7. The apparatus of claim 5, wherein: The resistance torque of the drive system is obtained based on the motor torque and speed.

8. The apparatus of claim 5, wherein: The control of the vehicle speed or the wheel speed is achieved by combining parameters using a PID controller and / or a PI controller.

9. A computer storage medium, comprising: The storage medium itself used to store computer programs; When the computer program is executed by the microprocessor, it implements any of the control methods described in claims 1 to 4.

10. An autopilot, comprising: Any of the apparatuses as described in claims 5 to 8; And / or the storage medium as described in claim 9.

11. A vehicle comprising: Any of the apparatuses as described in claims 5 to 8; And / or the storage medium as described in claim 9; And / or the driving device as described in claim 10.

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