CN115179773A - A wheel speed control method, device, storage medium, autopilot and vehicle - Google Patents

Abstract

The invention discloses a wheel speed control method, a wheel speed control device, a storage medium, an automatic pilot and a vehicle through an embodiment, and the technical problem that wheels of an electric vehicle are slipped or locked is solved by adopting wheel speed control; the embodiment of the invention shows that the related products such as the control method and the control device have very small rotating speed overshoot and steady state errors in the aspect of rotating speed control, the adjustment response is very quick, and the very effective rotating speed control effect is achieved; the relevant control process can adopt PID or PI control to carry out parameter synthesis, and is suitable for application scenes with driving resistance moment capable of being calibrated or estimated.

Description

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

technical field

The invention belongs to the technical field of intelligent vehicles, and in particular relates to a wheel speed control method, a device, a storage medium, an autopilot and a vehicle.

Background technique

On new energy vehicles directly driven by the motor, slippage or lockup is prone to occur. The main reason is that the torque characteristic curve of the motor is different from that of traditional fuel vehicles. At low speed, the motor can output a large torque, and when the road surface When insufficient grip is provided, the tires will skid.

The current mainstream solution is to use the electronic stability system ESP (Electronic Stability Program) to perform mechanical braking to control the wheel speed, or to give the motor torque command limit through ESP, and the motor outputs torque according to the command. No matter which method is adopted, there is a shortcoming of slow response time, and there is room for improvement.

The anti-skid and anti-lock control scheme usually estimates a reasonable target wheel speed according to the running state of the vehicle, and generally keeps the slip rate within 0.2; through the electric drive system, the motor speed is controlled near the above target speed, so as to achieve wheel anti-skid and anti-skid. hug. Since the vehicle speed is constantly changing, the target speed is also changing, which puts forward higher requirements for the speed control in this scenario.

SUMMARY OF THE INVENTION

The invention discloses a wheel speed control method, a device, a storage medium, an autopilot and a vehicle through the embodiments, and the wheel speed control is used to solve the technical problem of the wheel slipping or locking of the electric vehicle.

The control method includes a working condition collecting step, a slip judging step, and a following control step; in the working condition collecting step, the control system is initialized by acquiring working condition information; wherein, the working condition information includes vehicle speed, gear position or speed ratio.

Usually, the wheel is mechanically connected to the main shaft of the drive motor through a transmission system, and the mechanical properties of the drive motor are indirectly transmitted to the wheel end.

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 drive motor is not involved; at the same time, the upper-layer system torque command is used as the output torque command; the upper-layer system includes the vehicle controller and the motor. / or domain controller, the upper system sends torque commands 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 obtained.

Further, the following control step also includes a process of acquiring feedforward control parameters or using a feedforward signal to intervene; the feedforward control parameter or feedforward signal is used to act on the output value compensation of the output torque together with the rotational speed difference information; the feedforward process belongs to Part of the closed loop of the drive motor, which can improve the speed and accuracy of the response characteristics.

Further, the following control step may further include a process of obtaining the motor rotation speed V; wherein the motor rotation speed V is used to calculate the rotation speed difference to provide a further judgment basis for the following control step.

Further, the feedforward control parameters or feedforward signals may include drive system drag torque calibration data and/or estimated drive system drag torque obtained.

Specifically, the resistance torque of the drive system can be obtained according to the motor torque and rotational speed.

Further, the method of the present invention further includes a data refresh step, so that the relevant control system re-acquires relevant data and re-outputs relevant signals or data according to preset time intervals.

Specifically, the relevant data includes operating condition information, and the relevant signals or data include torque or torque control signals.

Specifically, the method and/or system disclosed in this embodiment of the method further includes a closed-loop control process of vehicle speed or wheel speed, and the control process adopts a PID controller and/or a PI controller to perform parameter synthesis. The transition process time and overshoot of the speed control are limited within the preset index range.

Further, the present invention also discloses a wheel speed control device through an embodiment, which includes a working condition acquisition unit, a slip determination unit, and a following control unit.

The working condition acquisition unit acquires working condition information, including vehicle speed, gear position or speed ratio; in the slip determination unit, if the motor speed is within the upper and lower speed limits, the torque control of the drive motor is not involved; at the same time, the upper The system torque command is used as the output torque command; the upper system includes the vehicle controller and/or the domain controller, and the upper system sends the torque command 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 obtained .

Further, a feedforward control parameter or a feedforward signal is obtained through the follow-up control unit, which is used to act together with the rotational speed difference information to compensate the output torque of the output torque.

Specifically, the following control unit obtains the motor speed V; the motor speed V is used to calculate the speed difference information.

The feedforward control parameter or feedforward signal includes the drive system resistance torque calibration data and/or the estimated drive system resistance torque obtained.

Further, by performing a data refresh process in the operating condition acquisition unit, the slip determination unit, and the follow-up control unit, the dynamic vehicle condition information and related disturbances can be followed-controlled or adapted.

The data refresh process re-acquires relevant data and re-outputs relevant signals or data according to preset time intervals, where the relevant data includes working condition information, and the relevant signals or data include torque or torque control signals.

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

Similarly, the product disclosed in the embodiment of the device also includes a closed-loop control system for vehicle speed or wheel speed, and the control process uses a PID controller and/or a PI controller to synthesize parameters. After reasonable selection of parameters, the transition of speed control can be made Process time and overshoot are limited to preset specifications.

Through microelectronic technology, the method disclosed in the present invention is solidified in a computer storage medium to form computer-readable instructions, so that the corresponding control method can be realized.

For autopilot or vehicle products in a specific field, by adopting the above methods and products, the same design ideas and rules can be implemented on special devices or vehicle products, and the specific process is unnecessary.

The embodiment of the present invention shows that the control method, device and other related products have very small speed overshoot and steady-state error in speed control, and the adjustment response is very fast, which plays a very effective speed control. By controlling the wheel speed Avoid the wheel slipping or locking.

It should be noted that similar terms such as "first" and "second" used in this article are only used to describe the constituent elements of the technical solution, and do not constitute a limitation on the technical solution, nor can they be interpreted as Indication or implication of the importance of the corresponding element; an element with words like "first", "second", etc., means that in the corresponding technical solution, the element includes at least one.

Description of drawings

In order to illustrate the technical solutions of the present invention more clearly, and to further understand the technical effects, technical features and purposes of the present invention, the present invention will be described in detail below with reference to the accompanying drawings. The examples are used to illustrate the technical solutions of the present invention, but do not limit the present invention.

The same reference numbers in the drawings represent the same parts, in particular:

1 is a schematic diagram of a control flow and signal distribution of a method, a device, and a related product according to an embodiment of the present invention,

2 is a schematic diagram of a first adjustment process according to an embodiment of the present invention;

3 is a schematic diagram of a second adjustment process according to an embodiment of the present invention;

4 is a schematic flowchart of an embodiment of the method of the present invention;

FIG. 5 is a schematic diagram of the composition structure and signal transmission according to an embodiment of the apparatus of the present invention.

in:

001-First lower limit speed (speed lower limit),

011-Condition collection unit,

022 - Slip Judgment Unit,

033 - Follow Control Unit,

111- Working condition collection steps,

123-Signal refresh step,

200-Condition information,

222 - Slip Judgment Step,

333 - follow control steps;

555 - Current RPM,

606 - RPM difference information,

707 - Feedforward signal,

777 - Feedforward control parameters,

999-Second upper limit speed (speed upper limit).

Detailed ways

The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. Of course, the specific embodiments described below are only for explaining the technical solutions of the present invention, rather than limiting the present invention. In addition, the parts described in the embodiments or the drawings are only examples of the relevant parts of the present invention, rather than the whole of the present invention.

As shown in FIG. 4 , an embodiment of the present invention discloses a wheel speed control method, which includes a working condition collection step 111 , a slip judgment step 222 , and a follow-up control step 333 .

As shown in FIG. 5 , the working condition collection step 111 acquires working condition information 200 , including vehicle speed, gear position or speed ratio.

Further, as shown in FIG. 4 , the slip judging step is used to determine the vehicle state corresponding to information such as vehicle speed and gear position, and select an appropriate driving method according to the vehicle state to avoid the wheels from slipping or locking.

Specifically, if the motor speed is within the range of the upper and lower speed limits, the torque control of the drive motor is not involved; at the same time, the upper-layer system torque command is used as the output torque command.

The upper-layer system includes a vehicle controller and/or a domain controller, and the upper-layer system sends a torque command to the motor controller; otherwise, if the motor speed exceeds the upper limit or is lower than the lower limit, the speed difference information 606 is obtained.

Further, as shown in FIG. 1 , following the control step 333 , it also includes acquiring the feedforward control parameters 777 or using the feedforward signal 707 to intervene.

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

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

Specifically, the feedforward control parameter 777 or the feedforward signal 707 includes the drive system resistance torque calibration data and/or the estimated drive system resistance torque obtained.

Further, the method as shown in FIG. 3 further includes a data refresh step 123; according to preset time intervals, re-acquire relevant data and re-output relevant signals or data; the relevant data includes working condition information 200; the relevant signals or data include torque or torque control signal.

Specifically, a PID controller and/or a PI controller can be used to control the vehicle speed or wheel speed for parameter synthesis; the adjustment process of the motor speed V555 includes a first adjustment process and a second adjustment process; wherein the first adjustment process corresponds to the vehicle Anti-skid, the second adjustment process corresponds to vehicle anti-lock braking.

Further, as shown in FIG. 5 , an embodiment of the present invention discloses a wheel speed control device, including a working condition acquisition unit 011 , a slip determination unit 022 , and a following control unit 033 .

Specifically, the working condition collection unit 011 obtains the working condition information 200, including vehicle speed, gear position or speed ratio; in the slip determination unit 022, if the motor speed is within the range of the upper and lower speed limits, the torque control of the drive motor is not involved; , the upper-layer system torque command is used as the output torque command; wherein, the upper-layer system includes the vehicle controller and/or the domain controller, and the upper-layer system sends the torque command to the motor controller; otherwise, if the motor speed exceeds the upper limit or is lower than the lower limit, obtain Speed difference information 606 .

Further, the slip determination unit 022 obtains the rotational speed difference information 606 ; the follow-up control unit 033 outputs a torque command and drives the motor according to the rotational speed difference information 606 .

Further, the follow-up control unit 033 obtains a feedforward control parameter 777 or a feedforward signal 707; the feedforward control parameter 777 or the feedforward signal 707 is used to act together with the rotational speed difference information 606 to compensate the output torque of the output torque.

Further, the motor speed V555 is obtained following the control unit 033 ; wherein, the motor speed V555 is used to calculate the speed difference information 606 .

Further, the feedforward control parameter 777 or the feedforward signal 707 includes the drive system resistance torque calibration data and/or the estimated drive system resistance torque obtained.

Further, the working condition collection unit 011, the slip determination unit 022, and the follow-up control unit 033 re-acquire relevant data and re-output relevant signals or data by executing the data refresh step 123 according to preset time intervals; wherein, the relevant data includes Operating condition information ( 200 ), related signals or data include torque or torque control signals.

Further, the control of vehicle speed or wheel speed adopts PID controller and/or PI controller to perform parameter synthesis.

For the computer storage medium, the autopilot, and the vehicle disclosed in the embodiments of the present invention, since the core processes or components adopt the same technical concept as the method or device of the present invention, they can also deal with the same technical problems and obtain the same technology The effect and its specific implementation steps are not repeated here.

It should be noted that the above embodiments are only to illustrate the technical solutions of the present invention more clearly. Those skilled in the art can understand that the embodiments of the present invention are not limited to the above contents, and obvious changes, substitutions or substitutions based on the above contents are made. , all do not exceed the scope covered by the technical solution of the present invention; without departing from the concept of the present invention, other embodiments will also fall within the scope of the present invention.

Claims (17)

1. a wheel speed control method, is characterized in that, comprises: Working condition collection step (111), slip judgment step (222), following control step (333); The working condition collecting step (111) acquires working condition information (200), where the working condition information (200) includes vehicle speed, gear position or speed ratio; In the slip judgment step (222), if the motor speed is within the range of the upper and lower speed limits, the torque control of the drive motor is not involved; at the same time, the upper-layer system torque command is used as the output torque command; wherein, the upper-layer system includes a whole The vehicle controller and/or the domain controller, the upper-layer system sends a torque command to the motor controller; otherwise, if the motor speed exceeds the upper limit or is lower than the lower limit, obtain the speed difference information (606); In the following control step ( 333 ), according to the rotational speed difference information ( 606 ), output a torque command and adjust or control the drive motor. 2. The method of claim 1, wherein: The following control step (333) further includes acquiring feedforward control parameters (777) or using a feedforward signal (707) to intervene; The operating condition information ( 200 ) further includes a first lower rotational speed limit ( 001 ) and a second upper rotational speed limit ( 999 ), the first lower rotational speed limit ( 001 ) and/or the second upper rotational speed limit ( 999 ) according to vehicle operation Environmental and/or vehicle inherent characteristics; The feedforward control parameter (777) or the feedforward signal (707) is used to act together with the rotational speed difference information (606) to compensate the output value of the output torque. 3. any method as claimed in claim 1 or 2, wherein: The following control step (333) further includes acquiring the motor speed V (555); The motor speed V (555) is used to calculate the speed difference. 4. The method of claim 3, wherein: The feedforward control parameter (777) or the feedforward signal (707) includes drive system drag torque calibration data and/or estimated and acquired drive system drag torque. 5. The method of claim 4, wherein: The resistance torque of the drive system is obtained from the motor torque and rotational speed. 6. any method as claimed in claim 1,2,4,5, also comprises: Data refresh step (123); The data refresh step (123) re-acquires relevant data and re-outputs relevant signals or data according to preset time intervals; The relevant data includes the operating condition information ( 200 ); the relevant signal or data includes a torque or torque control signal. 7. The method of claim 6, wherein: The control of the vehicle speed or wheel speed adopts PID controller and/or PI controller to perform parameter synthesis; 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. 8. A wheel speed control device, comprising: Working condition acquisition unit (011), slip determination unit (022), following control unit (033); The working condition collecting unit (011) acquires working condition information (200), where the working condition information (200) includes vehicle speed, gear position or speed ratio; In the slip determination unit (022), if the motor speed is within the range of the upper and lower speed limits, the torque control of the driving motor is not involved; at the same time, the upper-layer system torque command is used as the output torque command; wherein, the upper-layer system includes vehicle control The upper-layer system sends a torque command 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 obtained (606); The following control unit (033) outputs a torque command and drives the drive motor according to the rotational speed difference information (606). 9. The apparatus of claim 8, wherein: 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 to act together with the rotational speed difference information (606) to compensate the output value of the output torque. 10. The apparatus of claim 8 or 9, wherein: The following control unit (033) acquires the motor speed V (555); The motor speed V (555) is used to calculate the speed difference information (606). 11. The apparatus of claim 10, wherein: The feedforward control parameter (777) or the feedforward signal (707) includes drive system drag torque calibration data and/or estimated and acquired drive system drag torque. 12. The apparatus of claim 11, wherein: The resistance torque of the drive system is obtained from the motor torque and rotational speed. 13. The apparatus of any of claims 8, 9, 11, 12, wherein: The working condition acquisition unit (011), the slip determination unit (022), and the follow-up control unit (033) execute the data refresh step (123); The data refresh step (123) re-acquires relevant data and re-outputs relevant signals or data according to preset time intervals; the relevant data includes the working condition information (200); the relevant signals or data include torque or Torque control signal. 14. The apparatus of claim 13, wherein: The control of the vehicle speed or the wheel speed adopts a PID controller and/or a PI controller to perform parameter synthesis. 15. A computer storage medium comprising: A storage medium body for storing computer programs; The computer program, when executed by the microprocessor, implements any one of the control methods described in claims 1 to 7 . 16. An autopilot comprising: Any device as claimed in claims 8 to 14; and/or a storage medium as claimed in claim 15 . 17. A vehicle comprising: Any device as claimed in claims 8 to 14; and/or a storage medium as claimed in claim 15; and/or a pilot as claimed in claim 16 .

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