CN116638976A - Control method and system for sliding energy recovery - Google Patents

Abstract

The invention provides a control method and system for sliding energy recovery and a vehicle, and belongs to the technical field of energy recovery. The method comprises the following steps: acquiring a current slip rate of the vehicle in a sliding state; when the current slip rate is larger than a preset value, activating an ABS function of the vehicle and adjusting the recovery torque to a preset recovery torque; continuously acquiring the current slip rate, and adjusting the recovery torque from the preset recovery torque to a second recovery torque when the current slip rate is larger than a preset value; after the current slip rate is smaller than a preset value, adjusting the recovery torque from the second recovery torque to a first recovery torque and judging whether a torque recovery request is smaller than an energy recovery request or not; when the torque recovery request is less than the energy recovery request, then the above steps are repeated. The invention solves the problems that in the prior art, the vehicle generates a bump when the sliding energy is recovered, so that the vehicle slides unevenly, and uncomfortable feeling is brought to a driver.

Description

A control method and system for coasting energy recovery

technical field

The invention relates to the technical field of energy recovery, in particular to a control method and system for coasting energy recovery.

Background technique

New energy vehicles are generally designed with a coasting energy recovery function. Its functional safety logic requires that when the anti-lock brake ABS (Antilock Brake System, anti-lock brake system) is activated, the coasting energy recovery function needs to exit to ensure vehicle safety; after the slip rate recovers and the ABS exits, Coasting energy recovery resumes normal operation.

The design logic commonly adopted at present is that the exit and reactivation of coasting energy recovery are only judged according to the activation state of ABS, that is, when ABS is activated, coasting energy recovery immediately exits; ABS exits work, and coasting energy recovery activates again. This will cause the sliding recovery function to repeatedly enter and exit until the driver has other inputs or the vehicle speed drops to the idling speed. The vehicle will show continuous ups and downs, which will bring discomfort to the driver and even affect safety.

Contents of the invention

An object of the present invention is to provide a control method, system, and vehicle for energy recovery from coasting, so as to solve the problem of the vehicle in the prior art when recovering energy from coasting, which causes the vehicle to coast unevenly and brings discomfort to the driver. The problem.

In particular, the present invention provides a method for controlling recovery of taxiing energy, including the following steps:

Obtain the current slip rate of the vehicle in the coasting state;

When the current slip ratio is greater than a preset value, activate the ABS function of the vehicle and adjust the regenerative torque to a preset regenerative torque;

Continue to obtain the current slip ratio, and adjust the recovery torque from the preset recovery torque to a second recovery torque when the current slip rate is greater than a preset value;

After the current slip ratio is less than a preset value, adjusting the recovery torque from the second recovery torque to the first recovery torque and judging whether the torque recovery request is smaller than the energy recovery request;

When the torque recovery request is smaller than the energy recovery request, the above steps are repeated.

Further, after the step of activating the ABS function of the vehicle and adjusting the regenerative torque to the preset regenerative torque when the current slip ratio is greater than a preset value, the step further includes:

Continue to acquire the current slip ratio, adjust the recovery torque from the preset recovery torque to the first recovery torque when the current slip rate is less than the preset value, and judge the torque recovery request Is it smaller than the energy recovery request;

When the torque recovery request is smaller than the energy recovery request, continue to obtain the current slip ratio to repeat the above steps.

Further, when the torque recovery request is greater than the energy recovery request, the loop is exited.

Further, when the recovery torque is the first recovery torque, if the slip ratio is greater than the preset value, the recovery torque is adjusted from the first recovery torque to the second recovery torque.

Further, the first recovery torque is the current recovery torque plus a calibrated recovery torque.

Further, the second recovery torque is the current recovery torque minus a calibrated recovery torque.

The present invention also discloses a control system for recovery of coasting energy, which includes a control device, the control device includes a memory and a processor, and a control program is stored in the memory, and when the control program is executed by the processor, it is used to Realize the control method described above.

The present invention also discloses a vehicle, which includes the above-mentioned control system for coasting energy recovery.

The present invention keeps the slip rate of the vehicle below the preset value by actively adjusting the recovery torque of the vehicle, thus avoiding the occurrence of secondary and multiple wheel locks. By withdrawing from the recycling strategy, the present invention actively avoids the problem of continuous wheel locking on low-adhesion roads from the source, and improves safety and comfort.

In addition, the present invention replaces the function of directly exiting the recovery by continuously adjusting the recovery torque, which not only avoids the problem of continuous setbacks, but also maximizes the economic contribution of recovery. Compared with balancing economy and smoothness by changing the recovery intensity and maximum torque of the sliding energy, the present invention does not change the design value of the recovery of the sliding energy, and guarantees the economic goal to the greatest extent.

Furthermore, compared with reducing the intensity of frustration caused by continuous withdrawal and activation by changing the energy recovery intensity and maximum torque of the coasting, the present invention fundamentally solves the problem of multiple consecutive frustrations.

Those skilled in the art will be more aware of the above and other objects, advantages and features of the present invention according to the following detailed description of specific embodiments of the present invention in conjunction with the accompanying drawings.

Description of drawings

Hereinafter, some specific embodiments of the present invention will be described in detail by way of illustration and not limitation with reference to the accompanying drawings. The same reference numerals in the drawings designate the same or similar parts or parts. Those skilled in the art will appreciate that the drawings are not necessarily drawn to scale. In the attached picture:

Fig. 1 is a flow chart of a control method according to an embodiment of the present invention;

Fig. 2 is a logic control diagram of a control method according to an embodiment of the present invention;

Detailed ways

New energy vehicles are generally designed with a coasting energy recovery function. Its functional safety logic requires that when the anti-lock brake ABS is activated, the coasting energy recovery function needs to exit to ensure vehicle safety; after the slip rate recovers and the ABS exits, the coasting energy recovery resumes normal operation. The design logic commonly adopted at present is that the exit and reactivation of coasting energy recovery are only judged according to the activation state of ABS, that is, when ABS is activated, coasting energy recovery immediately exits; after ABS is out of work, coasting energy recovery is activated again.

Energy recovery under the general strategy will repeatedly enter and exit until the driver has other inputs or the vehicle speed drops to idling speed, "energy recovery activation → ABS activation → energy recovery exit → ABS exit → energy recovery activation". The vehicle shows continuous ups and downs and unevenness, which brings discomfort to the driver and even affects safety. Due to the recovery of sliding energy, the motor generates braking torque on the driving wheels. Therefore, when the vehicle passes by sliding and lightly braking on a road with a low adhesion coefficient, the regenerative braking torque acting on the driving wheels is greater than or equal to that of the ground. When the braking torque is provided, the wheel slip rate increases and reaches the ABS activation threshold to activate the ABS function.

According to the safety design logic, the coasting energy recovery function should immediately exit at this time to avoid vehicle instability caused by wheel lock. And when the coasting recovery torque falls to a certain value (the torque acting on the wheel is less than the ground braking torque) or completely exits (the torque is 0), the wheel slip rate is lower than the ABS activation threshold, and the ABS function exits. The coasting energy recovery function is reactivated and the recovery torque is increased to the set value.

At this time, if the vehicle is still gliding on the low-adhesion road surface, the excessive torque of the gliding recovery will still cause the activation of the ABS, the gliding recovery exits, the ABS exits, and the gliding recovery is activated again. The speed is lost, and the deceleration increases again when the recovery is activated), which brings discomfort to the driver and even affects safety.

In one embodiment, as shown in Fig. 1 and Fig. 2, the present invention provides a method for controlling recovery of taxiing energy, comprising the following steps:

S1. Obtain the current slip rate of the vehicle in the coasting state;

S2. When the current slip ratio is greater than a preset value, activate the ABS function of the vehicle and adjust the recovery torque to the preset recovery torque;

S3. Continue to acquire the current slip ratio, and adjust the recovery torque from the preset recovery torque to the second recovery torque when the current slip rate is greater than the preset value;

S4. After the current slip ratio is less than the preset value, adjust the recovery torque from the second recovery torque to the first recovery torque and judge whether the torque recovery request is smaller than the energy recovery request;

S5. When the torque recovery request is smaller than the energy recovery request, repeat the above steps.

Specifically, as shown in Figure 1 and Figure 2, when the vehicle is in a sliding state, if the current slip rate of the vehicle is greater than the preset value, it means that the vehicle needs ABS to intervene to prevent the vehicle from having an accident. The regenerative torque needs to be adjusted. That is, adjust the current recovery torque to the preset recovery torque, and make the vehicle perform energy recovery under the preset recovery torque instead of exiting energy recovery. When the vehicle is at the preset recovery torque, the current slip rate of the vehicle is continuously obtained and judged Whether the current slip ratio is less than a preset value, if not, adjust the regenerative torque of the vehicle from the preset regenerative torque to the first regenerative torque, so that the vehicle performs energy recovery in the first regenerative torque state; at the current slip ratio When it is less than the preset value, adjust the vehicle from the current first regenerative torque to the second regenerative torque, and judge whether the torque regenerative request is smaller than the energy regenerative request, if so, it means that the vehicle can still perform energy regenerative, thus repeating the above steps ; If not, it means that the vehicle has not met the energy recovery condition, so the energy recovery of the vehicle is ended.

In this embodiment, by actively adjusting the regenerative torque of the vehicle, the slip ratio of the vehicle is kept below the preset value, thereby avoiding the occurrence of secondary and multiple wheel locks. That is, the strategy of withdrawing from recycling after the ABS is activated, the present invention actively avoids the problem of continuous wheel locking on low-adhesion roads from the source, and improves safety and comfort.

In addition, the present invention replaces the function of directly exiting the recovery by continuously adjusting the recovery torque, which not only avoids the problem of continuous setbacks, but also maximizes the economic contribution of recovery. Compared with balancing economy and smoothness by changing the recovery intensity and maximum torque of the sliding energy, the present invention does not change the design value of the recovery of the sliding energy, and guarantees the economic goal to the greatest extent.

Furthermore, compared with reducing the intensity of frustration caused by continuous withdrawal and activation by changing the energy recovery intensity and maximum torque of the coasting, the present invention fundamentally solves the problem of multiple consecutive frustrations.

In one embodiment, as shown in FIG. 1 and FIG. 2 , the method for controlling recovery of coasting energy further includes the following steps:

S2. When the current slip ratio is greater than a preset value, activate the ABS function of the vehicle and adjust the recovery torque to the preset recovery torque;

S3', continue to obtain the current slip ratio, and when the current slip ratio is less than the preset value, adjust the recovery torque from the preset recovery torque to the first recovery torque, and determine whether the torque recovery request is smaller than the energy recovery request;

S5. When the torque recovery request is smaller than the energy recovery request, continue to obtain the current slip ratio to repeat the steps.

Specifically, when the vehicle is in a coasting state and the ABS is activated, at this time, the regenerative torque of the vehicle is adjusted to the preset regenerative torque to regenerate the energy of the vehicle, and the current slip ratio of the vehicle is continuously obtained, and the current slip ratio is judged. Whether the slip ratio is less than a preset value, if so, adjust the regenerative torque of the vehicle from the preset regenerative torque to the second regenerative torque, so that the vehicle performs energy recovery in the second regenerative torque state.

In this embodiment, by actively adjusting the regenerative torque of the vehicle, the slip ratio of the vehicle is kept below the preset value, thereby avoiding the occurrence of secondary and multiple wheel locks. That is, the strategy of withdrawing from recycling after the ABS is activated, the present invention actively avoids the problem of continuous wheel locking on low-adhesion roads from the source, and improves safety and comfort.

In addition, the present invention replaces the function of directly exiting the recovery by continuously adjusting the recovery torque, which not only avoids the problem of continuous setbacks, but also maximizes the economic contribution of recovery. Compared with balancing economy and smoothness by changing the recovery intensity and maximum torque of the sliding energy, the present invention does not change the design value of the recovery of the sliding energy, and guarantees the economic goal to the greatest extent.

Furthermore, compared with reducing the intensity of frustration caused by continuous withdrawal and activation by changing the energy recovery intensity and maximum torque of the coasting, the present invention fundamentally solves the problem of multiple consecutive frustrations.

In one embodiment, as shown in FIG. 1 and FIG. 2 , the recovery torque is switched between the first recovery torque and the second recovery torque according to the magnitude of the slip ratio. Wherein, the first recovery torque is the current recovery torque plus the calibration torque; the second recovery torque is the current recovery torque minus the calibration torque, and the calibration torque is determined by the car factory through experiments based on different types of vehicles.

Specifically, when the vehicle is in energy recovery mode and the ABS is activated, the energy recovery system does not perform an exit operation at this time, but adjusts the current recovery torque to the first recovery torque or the second recovery torque, so that The vehicle does not affect the energy recovery system when the ABS is executed, so there is no need to exit the energy recovery work.

Of course, the first regenerative torque and the second regenerative torque can be exchanged with each other, and can also be adjusted according to the design requirements of different vehicles, which is not limited to the situation described herein.

In this embodiment, after the driver releases the accelerator pedal and the energy recovery works, such as the road condition changes and the ABS is activated, the energy recovery does not perform an exit operation at this time, but adjusts the recovery torque through torque control (setting value min or 0). Continue to monitor the wheel slip rate. If the ABS is triggered, continue to request a smaller recovery torque or 0; if the ABS is not triggered, increase the recovery torque by a certain amount based on the current recovery torque, and then continue to monitor the wheel slip rate. Until the torque increases to the maximum torque designed for recovery strength.

In addition, by avoiding the alternate operation/exit of ABS and recuperation, it not only solves the problem of continuous bumping and roughness of the vehicle, but also further ensures the economy of the energy recuperation function through real-time monitoring and adjusting the recuperation torque to maximize.

The present invention also discloses a control system for recovery of coasting energy, which includes a control device, the control device includes a memory and a processor, and a control program is stored in the memory, and when the control program is executed by the processor, it is used to Realize the control method described above.

The present invention also discloses a vehicle, which includes the above-mentioned control system for coasting energy recovery.

So far, those skilled in the art should appreciate that, although a number of exemplary embodiments of the present invention have been shown and described in detail herein, without departing from the spirit and scope of the present invention, the disclosed embodiments of the present invention can still be used. Many other variations or modifications consistent with the principles of the invention are directly identified or derived from the content. Accordingly, the scope of the present invention should be understood and deemed to cover all such other variations or modifications.

Claims (8)

1. A control method for coasting energy recovery, characterized in that, comprising the following steps: Obtain the current slip rate of the vehicle in the coasting state; When the current slip ratio is greater than a preset value, activate the ABS function of the vehicle and adjust the regenerative torque to a preset regenerative torque; Continue to obtain the current slip ratio, and adjust the recovery torque from the preset recovery torque to a second recovery torque when the current slip rate is greater than a preset value; After the current slip ratio is less than a preset value, adjusting the recovery torque from the second recovery torque to the first recovery torque and judging whether the torque recovery request is smaller than the energy recovery request; When the torque recovery request is smaller than the energy recovery request, the above steps are repeated. 2. The control method according to claim 1, characterized in that, when the current slip ratio is greater than a preset value, the step of activating the ABS function of the vehicle and adjusting the regenerative torque to a preset regenerative torque After that also include: Continue to acquire the current slip ratio, adjust the recovery torque from the preset recovery torque to the first recovery torque when the current slip rate is less than the preset value, and judge the torque recovery request Is it smaller than the energy recovery request; When the torque recovery request is smaller than the energy recovery request, continue to obtain the current slip ratio to repeat the above steps. 3. The control method according to claim 2, wherein when the torque recovery request is greater than the energy recovery request, the loop is exited. 4. The control method according to claim 1, wherein when the recovery torque is the first recovery torque, if the slip ratio is greater than the preset value, the recovery torque is changed from the The first recuperation torque is adjusted to the second recuperation torque. 5. The control method according to claim 1, wherein the first regenerative torque is the current regenerative torque plus a calibrated regenerative torque. 6. The control method according to claim 1, wherein the second regenerative torque is the current regenerative torque minus a calibrated regenerative torque. 7. A control system for coasting energy recovery, characterized in that it includes a control device, the control device includes a memory and a processor, a control program is stored in the memory, and the control program is used when executed by the processor To realize the control method according to any one of claims 1-6. 8. A vehicle, characterized in that the vehicle comprises the control system for coasting energy recovery as claimed in claim 7.