CN-121993592-A - Gear shifting control method and system for electric commercial vehicle, medium and electric commercial vehicle

CN121993592ACN 121993592 ACN121993592 ACN 121993592ACN-121993592-A

Abstract

The invention discloses a gear shifting control method, a gear shifting control system, a medium and an electric commercial vehicle, wherein the method comprises the steps of determining a target driving axle to be controlled if the electric commercial vehicle is detected to be in an emergency braking working condition, controlling to reduce the torque of the target driving axle and place a corresponding gear shifting hub in neutral gear by referring to the speed of the electric commercial vehicle, wherein the target driving axle is any driving axle in double driving axles of the electric commercial vehicle, placing the corresponding gear shifting hub in neutral gear to indicate that a driving motor of the target driving axle is switched from a torque control mode to a rotating speed control mode, judging whether the target driving axle performs dynamic gear shifting or static gear shifting according to the rotating speed of an output shaft in the rotating speed control mode, determining the corresponding target rotating speed, controlling the driving motor of the target driving axle to perform speed regulation according to the target rotating speed, judging whether the driving motor of the target driving axle meets the corresponding gear shifting synchronous condition, and if so, shifting the corresponding gear shifting hub of the target driving axle is shifted from the neutral gear to the target gear.

Inventors

LI YONG
ZENG WEI
CHEN LONG
LI SHICHENG
XIA LEI

Assignees

东风汽车集团股份有限公司

Dates

Publication Date: 20260508
Application Date: 20260302

Claims (10)

1. A shift control method of an electric commercial vehicle, the method comprising: if the electric commercial vehicle is detected to be in an emergency braking working condition, determining a target drive axle to be controlled, reducing the torque of the target drive axle and placing a corresponding gear shifting hub in a neutral gear by referring to the vehicle speed control of the electric commercial vehicle, wherein the target drive axle is any one of the double drive axles of the electric commercial vehicle; in the rotating speed control mode, judging whether the target drive axle executes dynamic gear shifting or static gear shifting according to the rotating speed of an output shaft, and determining the corresponding target rotating speed; Controlling a driving motor of the target driving axle to regulate speed according to the target rotating speed, and judging whether the driving motor of the target driving axle meets corresponding gear shifting synchronous conditions or not; and if so, shifting the gear shifting hub corresponding to the target drive axle from the neutral gear to a target gear.
2. The method according to claim 1, wherein if the electric commercial vehicle is detected to be in an emergency braking condition, determining the target drive axle to be controlled specifically includes: if the electric commercial vehicle is detected to be in an emergency braking working condition, detecting whether a mid-bridge gear shifting action in-place signal exists or not; If not, determining that the middle bridge is the target drive bridge; And if yes, determining the rear axle as the target drive axle.
3. The method of claim 1, wherein said controlling the reduction of the target drive axle torque and placing the corresponding shift hub in neutral with reference to the vehicle speed of the electric utility vehicle, comprises: monitoring the actual speed of the electric commercial vehicle; if the actual vehicle speed is reduced to a set vehicle speed calibration value, controlling to reduce the target drive axle torque; and if the target drive axle torque is reduced to a set torque value, placing a gear shifting hub corresponding to the target drive axle in the neutral gear.
4. The method according to claim 1, wherein the determining, according to the rotation speed of the output shaft, whether the target drive axle performs dynamic shift or static shift specifically includes: If the absolute value of the rotation speed of the output shaft is below the set rotation speed and is not 0, the target drive axle executes the dynamic gear shifting; And if the rotating speed of the output shaft is 0, the target drive axle executes the static gear shifting.
5. The method of claim 4, wherein if the target transaxle performs the dynamic shift, the determining the corresponding target rotational speed specifically includes: Determining a target rotating speed according to n target.1 =n base.1 +Δn 1 ×k 1 ; The dynamic gear shifting device comprises a dynamic gear shifting device, a motor speed compensation coefficient, a motor direction coefficient, a motor speed compensation coefficient and a motor speed compensation coefficient, wherein n target.1 is used for representing a target rotating speed corresponding to the dynamic gear shifting device, n base.1 is used for representing a basic rotating speed corresponding to the dynamic gear shifting device, n base.1 =n output ×i target ,n output is used for representing a value of an output shaft rotating speed, i target is used for representing a transmission ratio of the target gear shifting device, delta n 1 is used for representing a motor rotating speed compensation coefficient corresponding to the dynamic gear shifting device, a brake pedal stroke and gradient signal table look-up is referred to obtain, k 1 is used for representing a motor direction coefficient corresponding to the dynamic gear shifting device, and is referred to the direction of the output shaft rotating speed, if the direction of the output shaft rotating speed is a positive direction, k 1 =1, and if the direction of the output shaft rotating speed is a negative direction, k 1 = -1; if the target drive axle executes the static gear shifting, the determining the corresponding target rotation speed specifically includes: determining a target rotating speed corresponding to the static gear shifting according to n target.2 =n base.2 ×k 2 ; Wherein n target.2 represents the target rotation speed corresponding to the static gear shift, n base.2 represents the basic rotation speed corresponding to the static gear shift, the reference motor temperature is obtained, k 2 represents the motor direction coefficient corresponding to the static gear shift, and the motor direction coefficient of the last period is determined.
6. The method of claim 1, wherein prior to said controlling the drive motor of the target drive axle to speed in accordance with the target rotational speed, the method further comprises: And adjusting a corresponding torque limit value according to the target rotating speed, wherein the torque limit value of the dynamic gear shift is larger than the torque limit value of the static gear shift.
7. The method according to claim 1, wherein the shift synchronization condition is specifically a shift synchronization condition corresponding to the dynamic shift or a shift synchronization condition corresponding to the static shift; The gear shifting synchronization condition corresponding to the dynamic gear shifting is that the speed difference value between the actual motor speed of the driving motor of the target driving axle and the target speed is in a preset speed difference section, the change rate of the speed difference value of the actual motor speed and the target speed is smaller than or equal to a first change rate, and the first set delay time is delayed, wherein the preset speed difference section is set by referring to the speed difference of the target gear transmission ratio and the combining teeth; The gear shifting synchronization condition corresponding to the static gear shifting is that a rotating speed difference value between an actual rotating speed of a motor of a driving motor of the target driving axle and the target rotating speed is lower than a set rotating speed difference, the changing rate of the rotating speed difference value of the actual rotating speed and the target rotating speed is lower than or equal to a second changing rate, and a second set delay time is delayed, wherein the set rotating speed difference value is lower than the minimum value of the preset rotating speed difference section, and the second changing rate is lower than the first changing rate.
8. A shift control system for an electric utility vehicle, the system comprising: The system comprises a first control module, a second control module, a third control module and a fourth control module, wherein the first control module is used for determining a target drive axle to be controlled if the electric commercial vehicle is detected to be in an emergency braking working condition, reducing the torque of the target drive axle and placing a corresponding gear shifting hub in a neutral gear according to the vehicle speed control of the electric commercial vehicle, wherein the target drive axle is any one of the double drive axles of the electric commercial vehicle; The judging module is used for judging whether the target drive axle executes dynamic gear shifting or static gear shifting according to the rotation speed of the output shaft in the rotation speed control mode, and determining the corresponding target rotation speed; The second control module is used for controlling the driving motor of the target driving axle to regulate the speed according to the target rotating speed and judging whether the driving motor of the target driving axle meets the corresponding gear shifting synchronization condition or not; And the switching module is used for switching the gear shifting hub corresponding to the target drive axle from the neutral gear to the target gear if the gear shifting hub is satisfied.
9. A computer readable storage medium, on which a computer program is stored, characterized in that the program, when being executed by a processor, implements the steps of the method according to any one of claims 1-7.
10. An electric utility vehicle comprising a memory, a processor and a computer program stored on the memory and executable on the processor, characterized in that the processor implements the steps of the method of any of claims 1-7 when the program is executed by the processor.

Description

Gear shifting control method and system for electric commercial vehicle, medium and electric commercial vehicle Technical Field The invention relates to the technical field of new energy vehicles, in particular to a gear shifting control method and system of an electric commercial vehicle, a medium and the electric commercial vehicle. Background Under the dual driving of the rapid iteration of the global new energy automobile industry and the green transformation in the commercial vehicle field, the electric commercial vehicle continuously climbs the market demand by virtue of the core advantages of low emission and high economy. In order to meet the power output requirements of the electric commercial vehicle under the complex working conditions such as heavy load, climbing and the like, the power configuration of the double-bridge double-motor becomes the main technical choice of the electric commercial vehicle, and the structure drives the middle bridge and the rear bridge respectively through the double-motor, so that the power performance and the bearing capacity of the whole vehicle can be effectively improved. Meanwhile, the electric commercial vehicle is suitable for a heavy load carrying and conveying scene, and a gear shifting mechanism is generally designed with a large speed ratio so as to realize large torque output at a low rotating speed and ensure running stability and bearing efficiency. However, in the special working condition of emergency braking, the electric commercial vehicle faces the outstanding technical bottleneck that the emergency braking requires the vehicle to be dynamically and quickly transited to a stop state in a short time, the high speed ratio design of the electric commercial vehicle can cause rapid change of the rotating speed of an output shaft, the fluctuation range and the speed of the rotating speed are obviously higher than those of the conventional running working condition, the independent driving characteristic of the double-bridge double-motor further increases the control difficulty of the rotating speed synchronization in the gear shifting process, the rotating speeds of the driving motor and the gear shifting mechanism are difficult to be quickly matched, impact and interference are easy to generate in the gear meshing process, finally gear shifting failure or gear tooth striking phenomenon frequently occurs, the driving safety and the gear shifting smoothness are influenced, the abrasion of parts of a gearbox is further increased, and the service life of the whole vehicle is shortened. Disclosure of Invention In order to solve or partially solve the technical problem that the electric commercial vehicle causes gear shifting failure or gear tooth striking phenomenon frequently due to the structure of a double-bridge double motor, the invention provides a gear shifting control method, a gear shifting control system, a gear shifting control medium and an electric commercial vehicle of the electric commercial vehicle, and the technical scheme is that when the electric commercial vehicle is braked in an emergency, a target drive axle is dynamically determined to avoid electric control command conflict and gear overload caused by double-bridge synchronous gear shifting, and then the speed is combined with accurate control of torque reduction and neutral gear switching, so that the drive motor is stably switched to a rotating speed mode under no-load constraint; and finally, through closed loop judgment of gear shifting synchronous conditions, gear shifting actions are executed after the complete matching of the rotating speeds is ensured, gear meshing impact and abrasion are reduced from the root, the failure rate and gear striking risk of emergency braking gear shifting under a double-bridge double-motor structure are effectively reduced, and gear shifting safety, smoothness and system reliability are remarkably improved. To solve the above technical problems, according to a first aspect of the present invention, a shift control method for an electric commercial vehicle is disclosed, the method comprising: if the electric commercial vehicle is detected to be in an emergency braking working condition, determining a target drive axle to be controlled, reducing the torque of the target drive axle and placing a corresponding gear shifting hub in a neutral gear by referring to the vehicle speed control of the electric commercial vehicle, wherein the target drive axle is any one of the double drive axles of the electric commercial vehicle; in the rotating speed control mode, judging whether the target drive axle executes dynamic gear shifting or static gear shifting according to the rotating speed of an output shaft, and determining the corresponding target rotating speed; Controlling a driving motor of the target driving axle to regulate speed according to the target rotating speed, and judging whether the driving motor of the target driving axle meets corresponding