Electric vehicle anti-rolling control method and system based on a motor controller

Abstract

The present invention discloses an anti-rolling control method and system for an electric vehicle based on a motor controller. When the vehicle is running, vehicle parameters are detected in real time, and it is judged whether the vehicle enters the anti-rolling mode according to the vehicle parameters. If the vehicle enters the anti-rolling mode, it is judged whether the number of times of entering the anti-rolling mode reaches the set number of times. If the set number of times is reached, a fault alarm is prompted and the vehicle is controlled to enter the standby mode. If the set number of times is not reached, the motor torque is accumulated until the vehicle does not roll backward, and then it is judged again whether the vehicle enters the anti-rolling mode. When the vehicle enters the anti-rolling mode, the present invention makes the vehicle exit the rolling state by increasing the torque. Both the anti-rolling mode and the normal operation mode are torque modes, and there are no unnecessary problems caused by mode switching. After the number of times of entering the anti-rolling mode continuously accumulates and exceeds the set number of times, the anti-rolling system reports an anti-rolling fault and stops running, preventing damage to the motor caused by entering the anti-rolling mode for a long time.

Description

Technical Field

[0001] The present invention belongs to the technical field of automobiles, and particularly relates to an anti-rolling control method and system for electric vehicles based on a motor controller. Background Art

[0002] In recent years, new energy vehicles have become the main direction of the global automotive industry's transformation and development and an important engine for promoting the sustainable growth of the world economy. On the other hand, in the context of global energy shortage, it is necessary to increase the R & D efforts for electric vehicles. With the increasing popularity of electric vehicles, people have higher and higher requirements for their safety technology issues and driving comfort. Among them, the anti-rolling function is a key concern item. However, the current research on the anti-rolling function of electric vehicles is still relatively lagging, mostly staying on the existing technologies of traditional vehicles. Vehicles with imperfect functions seriously affect the driving experience of drivers, also increase the difficulty of starting on slopes of electric vehicles, and increase the accident rate of vehicle starting.

[0003] When parking and starting on slopes, if the motor is used for slope holding, the motor will keep working and consuming energy, reducing the driving range, and the motor will be blocked for a long time when holding the slope. When an electric vehicle holds the slope, the driver needs to take mechanical braking. However, since it takes a certain amount of time for the driver to release the brake and then step on the accelerator for the motor to generate power output to make the vehicle move forward, the electric vehicle is very likely to roll back during this period. In the prior art, the anti-rolling of pure electric vehicles usually relies on an inclination sensor to detect the slope inclination, which will increase the hardware cost. Therefore, it is necessary to improve the existing technology to solve the deficiencies of the existing technology. Summary of the Invention

[0004] The purpose of the present invention is to solve the deficiencies existing in the above background art, and provide an anti-rolling control method and system for electric vehicles based on a motor controller, which can avoid entering the anti-rolling mode for a long time and thus damage the motor.

[0005] The technical solution adopted by the present invention is: an anti-rolling control method for an electric vehicle based on a motor controller, which real-time detects vehicle parameters during vehicle driving, judges whether the vehicle enters the anti-rolling mode according to the vehicle parameters. If it enters the anti-rolling mode, the time interval t between two adjacent times of entering the anti-rolling mode is detected.

[0006] If the time interval t is less than the first set time t0, the number of times n of entering the anti-rolling mode is incremented by one, and then it is judged whether the number of times n of entering the anti-rolling mode reaches the set number N. If the time interval t is greater than or equal to the first set time t0, the motor torque is accumulated until the vehicle does not roll back, and then it is judged again whether it enters the anti-rolling mode.

[0007] If the set number of times is reached, a fault alarm is prompted and the vehicle is controlled to enter the standby mode; if the set number of times is not reached, the motor torque is controlled to accumulate until the vehicle does not roll back, and then it is judged again whether to enter the anti-rollback mode. The set number of times is 3 - 5 times, preferably 3 times or 4 times.

[0008] Further, when the following conditions are met simultaneously, it is confirmed to enter the anti-rollback mode:

[0009] a. The brake signal is 0; b. The motor speed is greater than |±10| rpm; c. The vehicle speed direction is inconsistent with the gear direction.

[0010] Further, the time interval between two adjacent entries into the anti-rollback mode refers to the time interval between the moment of the last exit from the anti-rollback mode and the moment of the current entry into the anti-rollback mode.

[0011] Further, when the time interval is greater than or equal to the first set time, the number of times of entering the anti-rollback mode is cleared first, and then the motor torque is controlled to accumulate.

[0012] Further, the torque accumulation means increasing the set torque on the basis of the current torque, and the set torque is obtained by looking up the table according to the current speed.

[0013] Further, when it is detected that the vehicle speed is greater than or equal to zero or the vehicle speed direction is consistent with the gear direction, it is judged that the vehicle does not roll back, otherwise it is judged that the vehicle rolls back.

[0014] Furthermore, after the vehicle does not roll back, wait for the second set time t2 and then judge again whether to enter the anti-rollback mode. The second set time is 3 - 5 s, preferably 3 s or 4 s.

[0015] An anti-rollback control system for an electric vehicle based on a motor controller, including

[0016] A vehicle control module for obtaining vehicle parameters in real time;

[0017] A motor controller for judging whether the vehicle enters the anti-rollback mode according to the vehicle parameters. If it enters the anti-rollback mode, the time interval between two adjacent entries into the anti-rollback mode is detected;

[0018] If the time interval is less than the first set time, the number of times of entering the anti-rollback mode is incremented by one, and then it is judged whether the number of times of entering the anti-rollback mode reaches the set number of times; if the time interval is greater than or equal to the first set time, the motor torque is controlled to accumulate until the vehicle does not roll back, and then it is judged again whether to enter the anti-rollback mode;

[0019] If the set number of times is reached, a fault alarm is prompted and the vehicle is controlled to enter the standby mode; if the set number of times is not reached, the motor torque is controlled to accumulate until the vehicle does not roll back, and then it is judged again whether to enter the anti-rollback mode.

[0020] Furthermore, when the following conditions are simultaneously met, it is confirmed that the anti-sliding mode is entered:

[0021] a. The brake signal is 0; b. The motor speed is greater than |±10| rpm; c. The vehicle speed direction is inconsistent with the gear direction.

[0022] Furthermore, when it is detected that the vehicle speed is greater than or equal to zero or the vehicle speed direction is consistent with the gear direction, it is determined that there is no anti-sliding, otherwise it is determined that there is anti-sliding.

[0023] The beneficial effects of the present invention are as follows:

[0024] When the vehicle enters the anti-sliding mode according to the present invention, the vehicle is made to exit the anti-sliding by increasing the torque, so that both the anti-sliding mode and the normal operation mode are torque modes, and there are no unnecessary problems caused by mode switching; after entering the anti-sliding mode, a look-up table is performed according to the current speed to calculate the step size of torque accumulation. The content of the look-up table is calibrated based on actual vehicle tests to obtain data, and the given value of torque is obtained through this step size, avoiding the jitter of the vehicle system caused by accidentally entering the anti-sliding mode; if the system enters the anti-sliding mode, it is first determined that when the time interval between two adjacent entries into the anti-sliding mode is less than the first set time, the number of times of entering the anti-sliding mode is accumulated. When the accumulation exceeds three times, the anti-sliding system reports an anti-sliding fault and stops running, entering the standby mode to turn off all PWMs, preventing damage to the motor due to long-term entry into the anti-sliding mode; when the cumulative number is less than three times, regardless of the throttle opening, the torque command value is increased until the vehicle speed is greater than or equal to zero or the vehicle speed direction is consistent with the gear direction. After there is no more anti-sliding, it is considered qualified. After the anti-sliding is qualified, the anti-sliding timing stage is entered. After timing to the second set time, the mode is judged again. If the set time is not reached, it stays in the anti-sliding mode. This first set time is the time reserved for the driver to operate the vehicle. Description of the Drawings

[0025] Figure 1 It is a principle block diagram of the control system of the present invention.

[0026] Figure 2 It is a flowchart of the control method of the present invention. Detailed Embodiments

[0027] The following further describes the detailed embodiments of the present invention in conjunction with the drawings. It should be noted here that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation to the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0028] As Figure 1 shown, the present invention provides an anti-sliding control system for an electric vehicle based on a motor controller, including

[0029] The vehicle control module VCU is used to obtain vehicle parameters in real time. Specifically, it obtains the current gear signal, vehicle speed magnitude and direction, throttle opening and other parameters of the whole vehicle through the vehicle CAN communication network, and sends these parameters to the motor controller.

[0030] The motor controller is used to judge whether the whole vehicle is in the anti-rollback mode according to the current gear signal, brake signal, vehicle speed magnitude and direction. If it is not in the anti-rollback mode, it is normal vehicle control. It judges whether the system meets the torque mode and standby mode conditions. If the system is in the standby mode, all controllers are turned off; if the system enters the torque mode, a torque command is given normally according to the throttle opening to control the vehicle to travel; if the system enters the anti-rollback mode, it is determined that when the time interval between two adjacent entries into the anti-rollback mode is less than the first set time, the number of times of entering the anti-rollback mode is accumulated. When the time interval is greater than or equal to the first set time, the torque command is directly increased; when the accumulation exceeds three times, the anti-rollback system reports an anti-rollback fault and stops running, and enters the standby mode to turn off all PWMs, preventing damage to the motor due to long-term entry into the anti-rollback mode; when the accumulation times are less than three times, regardless of the throttle opening, the torque command value starts to increase until the vehicle speed is greater than or equal to zero or the vehicle speed direction is the same as the gear direction. After no more rollback, it is considered up to standard. After the anti-rollback reaches the standard, the anti-rollback time t1 is timed, and the torque at this time is kept unchanged. After the t1 timing reaches the second set time t2, the mode is judged again. If the set time is not reached, it stays in the anti-rollback mode (that is, the vehicle control under the corresponding torque is maintained). The first set time is the time reserved for the driver to operate the vehicle.

[0031] Based on the above electric vehicle anti-rollback control system, the present invention also provides an electric vehicle anti-rollback control method based on the motor controller, as Figure 2 shown, including the following steps:

[0032] Step 1, when the vehicle is running, the vehicle controller VCU detects vehicle parameters in real time and sends them to the motor controller. The vehicle parameters include gear signal, brake signal, vehicle speed magnitude and direction, and throttle opening.

[0033] Step 2, the motor controller judges whether to enter the anti-rollback mode according to the received gear signal, brake signal, vehicle speed magnitude and direction. When the brake signal is 0, the vehicle speed is greater than |±10| rpm and the vehicle speed direction is inconsistent with the gear direction, it is judged to enter the anti-rollback mode, and this time is the current moment of entering the anti-rollback mode; when the vehicle speed is zero or the vehicle speed direction is the same as the gear direction, the system is in the standby mode, and all PWMs are turned off. Turning off the PWMs is to let the controller reduce unnecessary energy consumption; under other conditions, it enters the torque mode, gives a torque command normally according to the throttle opening, controls the vehicle to run, and monitors the rollback state again.

[0034] Step 3, when the judgment result is to enter the anti-slip mode, detect the time interval t between two adjacent entries into the anti-slip mode. This time interval refers to the time interval between the moment of the last exit from the anti-slip mode and the current moment of entering the anti-slip mode. If the time interval is within the range of the first set time t0, increment the number of times of entering the anti-slip mode by one, and judge the cumulative number of times of entering the anti-slip mode. When the cumulative number reaches three times, the system reports a fault and locks into the standby mode, reminding the driver to step on the brake or the accelerator. When entering the standby mode, turn off all PWMs, preventing damage to the motor caused by long-term entry into the anti-slip mode. When the cumulative number is less than three times, increment the torque setting by one, and then further judge whether the vehicle is slipping. If the conclusion is that the vehicle is slipping, continue to increment the torque setting based on the current torque, incrementing once per function interruption period. The incremented torque value is obtained by looking up the table according to the rotational speed until the vehicle speed is greater than or equal to zero or the vehicle speed direction is the same as the gear direction, determining that the vehicle is no longer slipping and the torque is no longer incremented. After maintaining this torque for the second set time t2, exit the anti-slip mode and re-detect whether to enter the anti-slip mode. The second set time is 3 - 5 s, preferably 3 s or 4 s; use the moment when the current second set time is reached as the moment of the last exit from the anti-slip mode in the next judgment of the time interval.

[0035] Step 4, if the interval time exceeds the first set time t0, clear the number of times of entering the anti-slip mode without incrementing the number of times, which can avoid slipping caused by road conditions. Then increment the torque setting by one, and then further judge whether the vehicle is slipping. If the conclusion is that the vehicle is slipping, continue to increment the torque setting based on the current torque, incrementing once per function interruption period. The incremented torque value is obtained by looking up the table according to the rotational speed until the vehicle speed is greater than or equal to zero or the vehicle speed direction is the same as the gear direction, determining that the vehicle is no longer slipping and the torque is no longer incremented. After maintaining this torque for the second set time, exit the anti-slip mode and re-detect whether to enter the anti-slip mode. The number of times of entering the anti-slip mode does not increment when the interval time exceeds the first set time t0, which can avoid slipping caused by road conditions. In this embodiment, the method for increasing the torque of the present invention is as follows: once entering the anti-slip mode, calculate the step size of torque increment through looking up the table with the current speed, and the given torque size can be obtained through this step size.

[0036] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered by the protection scope of the present invention. The content not described in detail in this specification belongs to the prior art well-known to those skilled in the art.

Claims

1. An anti-rollback control method for an electric vehicle based on a motor controller, characterized in that: During vehicle driving, vehicle parameters are detected in real time. According to the vehicle parameters, it is judged whether the vehicle enters the anti-rollback mode. If it enters the anti-rollback mode, the time interval between two adjacent entries into the anti-rollback mode is detected. If the time interval is less than the first set time, the number of times of entering the anti-rollback mode is incremented by one, and then it is judged whether the number of times of entering the anti-rollback mode reaches the set number; if the time interval is greater than or equal to the first set time, the motor torque is accumulated until the vehicle does not roll back, and then it is judged again whether to enter the anti-rollback mode. If the set number is reached, a fault alarm is prompted, and the vehicle is controlled to enter the standby mode; if the set number is not reached, the motor torque is accumulated until the vehicle does not roll back, and then it is judged again whether to enter the anti-rollback mode. The time interval between two adjacent entries into the anti-rollback mode refers to the time interval between the moment of the last exit from the anti-rollback mode and the moment of the current entry into the anti-rollback mode. When the time interval is greater than or equal to the first set time, the number of times of entering the anti-rollback mode is cleared first, and then the motor torque is accumulated.

2. The anti-rolling control method for an electric vehicle based on a motor controller according to claim 1, wherein: When the following conditions are met simultaneously, it is judged to enter the anti-rollback mode: a. The brake signal is 0; b. The motor speed is greater than |±10| rpm; c. The vehicle speed direction is inconsistent with the gear direction.

3. The electric vehicle anti-rollback control method based on a motor controller according to claim 1, wherein: The torque accumulation means adding a set torque to the current torque.

4. The anti-rolling control method for an electric vehicle based on a motor controller according to claim 1, characterized in that: When it is detected that the vehicle speed is greater than or equal to zero or the vehicle speed direction is consistent with the gear direction, it is judged that the vehicle does not roll back, otherwise it is judged that the vehicle rolls back.

5. The electric vehicle anti-rollback control method based on a motor controller according to claim 1, wherein: After the vehicle does not roll back, wait for the second set time and then judge again whether to enter the anti-rollback mode.

6. An anti-rolling-back control system for an electric vehicle based on a motor controller, characterized in that: Including A vehicle control module for obtaining vehicle parameters in real time; A motor controller for judging whether the vehicle enters the anti-rollback mode according to the vehicle parameters. If it enters the anti-rollback mode, the time interval between two adjacent entries into the anti-rollback mode is detected. If the time interval is less than the first set time, the number of times of entering the anti-rollback mode is incremented by one, and then it is judged whether the number of times of entering the anti-rollback mode reaches the set number; if the time interval is greater than or equal to the first set time, the motor torque is accumulated until the vehicle does not roll back, and then it is judged again whether to enter the anti-rollback mode. If the set number is reached, a fault alarm is prompted, and the vehicle is controlled to enter the standby mode; if the set number is not reached, the motor torque is accumulated until the vehicle does not roll back, and then it is judged again whether to enter the anti-rollback mode. The time interval between two adjacent entries into the anti-rollback mode refers to the time interval between the moment of the last exit from the anti-rollback mode and the moment of the current entry into the anti-rollback mode. When the time interval is greater than or equal to the first set time, the number of times of entering the anti-rollback mode is cleared first, and then the motor torque is accumulated.

7. The anti-rolling control system for an electric vehicle based on a motor controller according to claim 6, characterized in that: When the following conditions are met simultaneously, it is confirmed to enter the anti-rollback mode: a. The brake signal is 0; b. The motor speed is greater than |±10| rpm; c. The vehicle speed direction is inconsistent with the gear direction.

8. The electric vehicle anti-rollback control method based on a motor controller according to claim 6, characterized in that: When it is detected that the vehicle speed is greater than or equal to zero or the vehicle speed direction is consistent with the gear direction, it is judged that the vehicle does not roll back, otherwise it is judged that the vehicle rolls back.

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