Anti-lock control method and control system for energy recovery driving wheel of new energy vehicle

Abstract

The invention relates to the technical field of vehicle control methods, in particular to an energy recovery driving wheel anti-lock control method and system of a new energy vehicle. When a brake pedal is stepped down, whether braking energy recovery needs to be quitted or not is judged based on the slip rate of the current driving wheel; if yes, braking energy recovery is quitted, and the braking torque is compensated; whether sliding energy recovery needs to be quitted or not is judged based on the slip rate of the current driving wheel; if yes, sliding energy recovery is quitted; when the sliding energy recovery completely exits and the brake pedal is not released, whether the ABS function needs to be activated or not is judged based on the slip rate of the current driving wheel; if yes, activating the ABS function. The control method is simple, through the mode of quitting energy recovery in stages, the situation that the locking trend is uncontrollable after the slip rate rises too much is avoided, the problem of forward shifting caused by deceleration loss generated by quitting sliding energy recovery in advance is avoided as much as possible, the smoothness of the vehicle is improved, and working noise is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle control methods, and specifically refers to an anti-lock control method and control system for the energy recovery drive wheels of new energy vehicles. Background Art

[0002] The application of coasting energy recovery and braking energy recovery in new energy vehicles can generally achieve a recovery deceleration of more than 0.3g for the whole vehicle, greatly reducing the intervention of friction braking and significantly improving the endurance of the whole vehicle. However, when the coasting energy recovery and braking energy recovery are simultaneously superimposed on the drive shaft, there will be a phenomenon of axle load transfer when the rear-wheel drive vehicle decelerates. When lightly braking on a wet and slippery public road with low adhesion, a small wheel-side hydraulic braking force will trigger the ABS function. During the operation of the ABS, the wheel-side pressure adjustment is prone to cause fluctuations in deceleration and lateral yaw of the vehicle, and at the same time, working noise will be generated, which is likely to cause complaints from users.

[0003] In the prior art, when the wheel anti-lock slip ratio rises, the brake controller recognizes a tendency of wheel lock-up, and sends a torque increase request to the motor controller after PID calculation. However, since the motor sends the energy recovery negative torque to the brake controller through the CAN bus, the brake control obtains the wheel speed and the energy recovery negative torque, performs arithmetic processing, and then sends a torque increase request to the motor controller to request torque reduction. The torque link is relatively long, and the real-time performance of the control is poor, resulting in the inability to quickly suppress the slip ratio of the wheel, and the slip ratio further rises to trigger the ABS function. At the same time, a large and rapid torque reduction is likely to cause a sense of deceleration loss.

[0004] Currently, some manufacturers have also noticed this problem. For example, in the Chinese invention patent application named "A Control Method for Automotive Energy Recovery, a Vehicle Controller and an Electric Vehicle", a control method for automotive energy recovery is proposed. The method includes: receiving the slip ratio of each wheel sent by the anti-lock braking system; comparing the slip ratio of each wheel with a preset value to obtain a comparison result; and controlling the energy recovery system to exit the enabled state or maintain the enabled state according to the comparison result. This method can indeed avoid the problem that the anti-lock braking system is triggered due to the intervention of energy recovery to a certain extent, and can also reduce the impact of energy recovery on the vehicle. However, this method is relatively simple. In actual application, the energy recovery system includes two aspects, braking energy recovery and coasting energy recovery. Once it is determined that the energy recovery system needs to be exited, both the braking energy recovery and the coasting energy recovery will exit. For the vehicle, the deceleration will suddenly become smaller, giving the occupants the feeling that the vehicle suddenly jerks forward, seriously affecting the driving experience. Moreover, this control strategy does not elaborate on the control method of the energy recovery control system, and there are problems such as the inability to quickly suppress the slip ratio resulting in the triggering of the ABS function and the slip ratio exiting too quickly resulting in deceleration fluctuations. Summary of the Invention

[0005] The purpose of this application is to solve the deficiencies in the above-mentioned background technology and provide an anti-lock control method and control system for the energy recovery driving wheels of new energy vehicles.

[0006] The technical solution of this application is as follows: An anti-lock control method for the energy recovery driving wheels of new energy vehicles, including: when the brake pedal is depressed, based on the slip rate of the current driving wheel to determine whether to exit the braking energy recovery; if it is determined that the braking energy recovery needs to be exited, then exit the braking energy recovery and compensate the braking torque; when the braking energy recovery is exited and the brake pedal is not released, based on the slip rate of the current driving wheel to determine whether to exit the coasting energy recovery; if it is determined that the coasting energy recovery needs to be exited, then exit the coasting energy recovery; when the coasting energy recovery is completely exited and the brake pedal is not released, based on the slip rate of the current driving wheel to determine whether to activate the ABS function; when it is determined that the ABS function needs to be activated, activate the ABS function.

[0007] According to the anti-lock control method for the energy recovery driving wheels of new energy vehicles provided by this application, the method for determining whether to exit the braking energy recovery based on the slip rate of the current driving wheel includes: comparing the slip rate of the current driving wheel with a first preset threshold, if the slip rate of the current driving wheel is greater than the first preset threshold, then it is determined that the braking energy recovery needs to be exited; if the slip rate of the current driving wheel is not greater than the first preset threshold, then it is determined that the braking energy recovery does not need to be exited.

[0008] According to the anti-lock control method for the energy recovery driving wheels of new energy vehicles provided by this application, the method for determining whether to exit the coasting energy recovery based on the slip rate of the current driving wheel includes: comparing the slip rate of the current driving wheel with a second preset threshold, if the slip rate of the current driving wheel is greater than the second preset threshold, then it is determined that the coasting energy recovery needs to be exited; if the slip rate of the current driving wheel is not greater than the second preset threshold, then it is determined that the coasting energy recovery does not need to be exited; the second preset threshold is greater than the first preset threshold.

[0009] According to the anti-lock control method for the energy recovery driving wheels of new energy vehicles provided by this application, the method for determining whether to activate the ABS function based on the slip rate of the current driving wheel includes: comparing the slip rate of the current driving wheel with a third preset threshold, if the slip rate of the current driving wheel is greater than the third preset threshold, then it is determined that the ABS function needs to be activated; if the slip rate of the current driving wheel is not greater than the third preset threshold, then it is determined that the ABS function does not need to be activated; the third preset threshold is greater than the second preset threshold.

[0010] According to an anti-lock control method for an energy recovery driving wheel of a new energy vehicle provided by the present application, the method for compensating the braking torque includes: when the braking energy recovery exits, controlling the braking hydraulic pressure according to the reduction of the braking energy recovery capacity value to compensate the braking torque so that the braking torque remains unchanged.

[0011] According to an anti-lock control method for an energy recovery driving wheel of a new energy vehicle provided by the present application, the first preset threshold is 3% - 5%, the second preset threshold is 6% - 8%, and the third preset threshold is 10% - 12%.

[0012] The present application also relates to an anti-lock control system for an energy recovery driving wheel of a new energy vehicle. The control system operates according to any one of the above anti-lock control methods for an energy recovery driving wheel of a new energy vehicle, and includes: A slip ratio acquisition module, which is used to acquire the slip ratios of four wheels in real time; A first judgment module, which is used to judge whether it is necessary to exit the braking energy recovery based on the current driving wheel slip ratio acquired by the slip ratio acquisition module after the brake pedal is depressed; A braking energy recovery control module, which is used to control the exit of the braking energy recovery when the first judgment module judges that it is necessary to exit the braking energy recovery; A second judgment module, which is used to judge whether it is necessary to exit the coasting energy recovery based on the current driving wheel slip ratio when the braking energy recovery exits and the brake pedal is not released; A coasting energy recovery control module, which is used to control the exit of the coasting energy recovery when the second judgment module judges that it is necessary to exit the coasting energy recovery; A third judgment module, which is used to judge whether it is necessary to activate the ABS function based on the current driving wheel slip ratio when the coasting energy recovery completely exits and the brake pedal is not released; An ABS control module, which is used to activate the ABS function when the third judgment module judges that it is necessary to activate the ABS function.

[0013] According to an anti-lock control system for an energy recovery driving wheel of a new energy vehicle provided by the present application, the first judgment module is used to compare the current driving wheel slip ratio with the first preset threshold after the brake pedal is depressed, and make a judgment that it is necessary to exit the braking energy recovery when the current driving wheel slip ratio is greater than the first preset threshold, and make a judgment that it is not necessary to exit the braking energy recovery when the current driving wheel slip ratio is not greater than the first preset threshold.

[0014] According to an anti-lock control system for the energy recovery drive wheels of a new energy vehicle provided by the present application, the second judgment module is used to compare the slip rate of the current drive wheel with a second preset threshold when the braking energy recovery exits and the brake pedal is not released, and make a judgment that it is necessary to exit the coasting energy recovery when the slip rate of the current drive wheel is greater than the second preset threshold, and make a judgment that it is not necessary to exit the coasting energy recovery when the slip rate of the current drive wheel is not greater than the second preset threshold; the second preset threshold is greater than the first preset threshold.

[0015] According to an anti-lock control system for the energy recovery drive wheels of a new energy vehicle provided by the present application, the third judgment module is used to compare the slip rate of the current drive wheel with a third preset threshold when the coasting energy recovery completely exits and the brake pedal is not released, and make a judgment that it is necessary to activate the ABS function when the slip rate of the current drive wheel is greater than the third preset threshold, and make a judgment that it is not necessary to activate the ABS function when the slip rate of the current drive wheel is not greater than the third preset threshold; the third preset threshold is greater than the second preset threshold.

[0016] According to an anti-lock control system for the energy recovery drive wheels of a new energy vehicle provided by the present application, it further includes a braking torque compensation module; the braking torque compensation module is used to control the braking hydraulic pressure according to the reduction of the braking energy recovery ability value when the braking energy recovery exits, so as to compensate the braking torque and keep the braking torque unchanged.

[0017] The advantages of the present application are as follows: 1. The present application proposes an anti-lock control method for the energy recovery drive wheels of a new energy vehicle, which performs the exit of energy recovery and anti-lock control by judging the slip rate of the drive wheels; in the first stage, the rise of the slip rate of the drive wheels can be inhibited by the exit of the braking energy recovery; if the rise of the slip rate of the drive wheels still cannot be inhibited after the braking energy recovery exits, it can be further inhibited by the exit of the coasting energy recovery, that is, the control in the second stage; in the third stage, if the rise of the slip rate of the drive wheels still cannot be inhibited, the ABS system is activated again; by phased withdrawal of energy recovery, it is possible to avoid the uncontrollable locking trend after the slip rate rises too much, and at the same time, as much as possible, avoid the loss of deceleration and forward jerk caused by the premature exit of the coasting energy recovery, and avoid the problems of vehicle ride comfort and working noise caused by the easy triggering of the ABS on wet roads, so as to improve the user experience; 2. The control method in the first stage of the present application is very simple. By comparing the slip rate of the current drive wheel with the first preset threshold, it is possible to judge whether it is necessary to exit the braking energy recovery. The exit of the braking energy recovery is easy to operate, simple to control, and has a rapid response, and can quickly inhibit the rise of the slip rate; 3. In the second stage, the present application compares the current driving wheel slip rate with the second preset threshold value to determine whether it is necessary to exit the coasting energy recovery. This step is superimposed on the first stage. The exit of the coasting energy recovery further suppresses the increase in the driving wheel slip rate. The exit of the energy recovery is carried out in stages in conjunction with the exit of the braking energy recovery, making the exit of the energy recovery smoother, reducing the occurrence of setbacks and forward rushing, and greatly improving the user experience; 4. In the third stage, the present application can judge whether the ABS function needs to be activated by comparing the current driving wheel slip rate with the third preset threshold value. At this time, energy recovery has been completely withdrawn. If the slip rate is still at a high level, it proves that the current vehicle is at great risk of slipping. Therefore, slipping is avoided by activating the ABS function, thereby improving the safety of the entire driving; 5. After the braking energy recovery is exited, in order to avoid the problem of forward movement caused by the sudden decrease in deceleration caused by the exit of the braking energy recovery, the present application compensates for the braking force during the exit of the braking energy recovery to maintain a smooth change of the braking force, thereby greatly improving the user's driving experience; 6. This application defines the first preset threshold, the second preset threshold, and the third preset threshold, so that in actual control, accurate control can be performed by referring to the above values; 7. The present application also provides a control system. The control system of the present application is operated based on the control method of the present application. The constructed control system can be integrated into the control system of the automobile, so that the control system can control the new energy vehicle according to the corresponding control method, ensuring that the vehicle can exit energy recovery in stages, avoiding uncontrollable locking trend after the slip rate increases too much, and avoiding deceleration loss and forward rush caused by premature exit of gliding energy recovery as much as possible. By exiting energy recovery in advance, the vehicle's smoothness and working noise problems caused by ABS being easily triggered on slippery roads can be avoided, thereby improving the user experience.

[0018] The control method of the present application is simple. It avoids the uncontrollable locking trend after the slip rate increases too much by exiting the energy recovery in stages, and avoids the forward rushing problem caused by the loss of deceleration caused by premature exit of the sliding energy recovery as much as possible. Early exit of the energy recovery avoids the smoothness and working noise problems of the vehicle caused by the easy triggering of ABS on slippery roads, thereby greatly improving the user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 : A schematic diagram of the control flow of the energy recovery driving wheel anti-lock control method of the new energy vehicle of the present application; Figure 2 : Schematic diagram of an embodiment of the energy recovery drive wheel anti-lock control method for the new energy vehicle of the present application. DETAILED DESCRIPTION

[0020] Embodiments of the present application will be described in detail below, where the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to explain the present application, but should not be construed as limiting the present application.

[0021] In the description of the present application, it should be understood that the orientation or positional relationships indicated by the terms "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationships shown in the accompanying drawings. These are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present application.

[0022] In addition, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present application, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0023] The present application will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0024] The present application relates to an anti-lock control method for the energy recovery drive wheels of a new energy vehicle. The control method of the present application controls the energy recovery control and anti-lock system of the new energy vehicle. The control method of the present application constructs three stages. In the first stage, the rise of the drive wheel slip ratio can be inhibited by withdrawing the braking energy recovery. If the rise of the drive wheel slip ratio still cannot be inhibited after the braking energy recovery is withdrawn, it can be further inhibited by withdrawing the coasting energy recovery, that is, the control in the second stage; in the third stage, if the rise of the drive wheel slip ratio still cannot be inhibited, the ABS system is activated again. By withdrawing the energy recovery in stages, the problem that the anti-lock trend becomes uncontrollable after the slip ratio rises too much is avoided. At the same time, the forward rush phenomenon caused by the loss of deceleration due to the premature withdrawal of the coasting energy recovery is avoided as much as possible. By withdrawing the energy recovery in advance, the problems of vehicle ride comfort and working noise caused by the easy triggering of the ABS on wet and slippery roads are avoided, greatly improving the user experience.

[0025] Specifically, as Figure 1 shown, an anti-lock control method for the energy recovery drive wheels of a new energy vehicle according to the present application can be carried out according to the following steps: S0. The program starts. It is judged whether the brake pedal is in the process of being depressed. If so, go to S1; otherwise, return to S0. Whether the brake pedal is in the process of being depressed can be monitored by the sensor of the brake pedal. When it is monitored that the brake pedal is in the process of being depressed, a braking effect will occur, and then brake energy recovery and coasting energy recovery may occur. Therefore, whether the brake pedal is in the process of being depressed is a prerequisite for the entire control method. S1. Based on the slip ratio of the current driving wheel, it is judged whether it is necessary to exit the brake energy recovery. If so, go to S2; otherwise, return to S0. The motor controller is directly connected to the wheel speed sensor through a hard wire to supply power to the wheel speed sensor and collect signals, obtain the wheel speed signals of the four wheels of the vehicle to calculate the reference wheel speed of the vehicle, and calculate the slip ratio of the current driving wheel. If the slip ratio of the current driving wheel is too large, if the increase in the slip ratio is not suppressed in time, it is very likely to cause the activation of the ABS. Therefore, it is necessary to control the further increase in the slip ratio, and the purpose of suppressing the increase in the slip ratio can be achieved by controlling the exit of the brake energy recovery. If the slip ratio of the current driving wheel is appropriate, the exit of the brake energy recovery can be not carried out. S2. If it is judged that it is necessary to exit the brake energy recovery, exit the brake energy recovery and compensate the braking torque. The motor controller controls the exit of the brake energy recovery. At the same time, the wire-controlled brake controller controls the brake hydraulic pressure to compensate the braking torque. In order to quickly suppress the increase in the slip ratio, the motor controller directly controls the exit of the brake energy recovery, which is equivalent to no longer braking through the brake energy recovery system. However, if the brake energy recovery is completely exited, the braking force of the braking system will be reduced. In terms of the driving situation, the deceleration of the vehicle is reduced, and the problem of forward jerk may occur. Therefore, to solve this technical problem, the present application compensates the braking torque through the wire-controlled brake controller. S3. When the brake energy recovery is exited and the brake pedal is not released, based on the slip ratio of the current driving wheel, it is judged whether it is necessary to exit the coasting energy recovery. If so, go to S4; otherwise, return to S2. When the brake energy recovery has been exited, continue to collect the state information of the brake pedal. If the pedal is not released, it proves that the brake pedal is still in the depressed state at this time, and there is still a braking requirement, and it is necessary to further judge the slip ratio of the current driving wheel. If the slip ratio of the current driving wheel is too large, if the increase in the slip ratio is not suppressed in time, it is very likely to cause the activation of the ABS. Therefore, it is necessary to further control the increase in the slip ratio, and the purpose of suppressing the increase in the slip ratio can be achieved by controlling the exit of the coasting energy recovery. If the slip ratio of the current driving wheel is appropriate, the exit of the coasting energy recovery can be not carried out. S4. If it is determined that the coasting energy recovery needs to be exited, then exit the coasting energy recovery; The motor controller exits the coasting energy recovery through PID control. Generally, the deceleration corresponding to the coasting energy recovery is relatively small, smaller than that of the braking energy recovery. Therefore, no compensation for the braking torque is required after the coasting energy recovery is exited. Of course, if a relatively large deceleration is set for the coasting energy recovery, such as 0.15g, and at this time the coasting energy recovery exits quickly and completely, there will be a loss of deceleration, and the subjective feeling is that the vehicle jerks forward or the deceleration fluctuates. At this time, it is necessary to gradually exit the coasting energy recovery through PID control according to the current driving wheel slip ratio; when the driving wheel slip ratio is controllable, only partially exit the coasting energy recovery; S5. When the coasting energy recovery is completely exited and the brake pedal is not released, judge whether it is necessary to activate the ABS function based on the current driving wheel slip ratio. If so, enter S6; otherwise, return to S4; If the coasting energy recovery is not completely exited, and at this time the current driving wheel slip ratio still has a tendency to exceed the set threshold, it can be suppressed by completely exiting the coasting energy recovery; if the coasting energy recovery is completely exited, and at this time the brake pedal is still in the depressed state and not released, it proves that there is still a braking demand, and the energy recovery has exited, so only the ABS can be activated for control; S6. When it is determined that the ABS function needs to be activated, activate the ABS function.

[0026] In some embodiments of the present application, this embodiment optimizes the above step S2. Specifically, the method for judging whether it is necessary to exit the braking energy recovery based on the current driving wheel slip ratio is: compare the current driving wheel slip ratio with a first preset threshold. If the current driving wheel slip ratio is greater than the first preset threshold, it is judged that the braking energy recovery needs to be exited; if the current driving wheel slip ratio is not greater than the first preset threshold, it is judged that the braking energy recovery does not need to be exited.

[0027] The first preset threshold is 3% - 5%. In actual application, it is not limited to this value and can be set according to actual needs.

[0028] The deceleration corresponding to the braking energy recovery is relatively large. If it is judged that the braking energy recovery is exited and then the braking energy recovery is exited quickly, in terms of the driving situation, there will be a problem that the deceleration decreases and the vehicle jerks forward. To avoid this situation, in this embodiment, during the process of exiting the braking energy recovery, the braking torque will be compensated to solve this technical problem.

[0029] When the braking energy recovery exits, the braking hydraulics is controlled according to the reduction of the braking energy recovery ability value to compensate for the braking torque so that the braking torque remains unchanged. The motor controller sends the braking energy recovery torque ability value to the braking controller. After the braking controller obtains the reduction of the electric motor braking energy recovery torque ability value, it calculates the reduction value of the four-wheel hydraulic braking to compensate for the reduction of the drive wheel energy recovery. Then, the braking controller compensates the braking torque according to this reduction value, and generally maintains the braking torque unchanged before and after the braking energy recovery exits.

[0030] Compared with the method of only performing energy recovery braking through a single axis for the front-wheel drive and rear-wheel drive in this embodiment, this method changes the torque distribution between the front and rear axles, reduces the braking torque of the drive wheels, and suppresses the slip rate of the drive wheels. At the same time, due to the exit of the braking energy recovery, after compensating the hydraulic braking torque, the problem of the reduction of the vehicle deceleration is avoided, the stability of the vehicle is ensured, and the risk of the further increase of the slip rate causing the exit of the coasting energy recovery or the activation of the ABS is reduced. Therefore, in this embodiment, the braking energy recovery is directly exited completely without adopting the PID regulation method to control the braking energy recovery. The braking energy recovery exits very quickly, the whole vehicle runs very smoothly, the regulation is simple, and the control effect on the slip rate of the drive wheels is very good.

[0031] In some other embodiments of the present application, this embodiment optimizes the above step S3. Specifically, the method for judging whether to exit the coasting energy recovery based on the current slip rate of the drive wheels is as follows: compare the current slip rate of the drive wheels with a second preset threshold. If the current slip rate of the drive wheels is greater than the second preset threshold, it is judged that the coasting energy recovery needs to be exited; if the current slip rate of the drive wheels is not greater than the second preset threshold, it is judged that the coasting energy recovery does not need to be exited; the second preset threshold is greater than the first preset threshold.

[0032] The second preset threshold of this embodiment is 6% - 8%. In actual application, it is not limited to this value and can be set according to actual needs.

[0033] The motor controller exits the coasting energy recovery through PID control. The coasting energy recovery is carried out gradually, and the exit method of the braking energy recovery is different. During the coasting energy recovery process, there is no need to compensate for the braking torque.

[0034] In a further embodiment of the present application, this embodiment optimizes the above step S5. Specifically, the method for judging whether to activate the ABS function based on the current slip rate of the drive wheels is as follows: compare the current slip rate of the drive wheels with a third preset threshold. If the current slip rate of the drive wheels is greater than the third preset threshold, it is judged that the ABS function needs to be activated; if the current slip rate of the drive wheels is not greater than the third preset threshold, it is judged that the ABS function does not need to be activated; the third preset threshold is greater than the second preset threshold.

[0035] The third preset threshold is 10% - 12%. In actual application, it is not limited to this value and can be set according to actual requirements. After both the braking energy recovery and the coasting energy recovery are exited, the braking force distribution between the front and rear wheels is distributed according to the specifications of the front and rear brakes. At this time, when the brake pedal is deeply depressed for a large-intensity braking, the hydraulic braking force will cause the slip ratio to rise. When it exceeds the third preset slip ratio, the deceleration is relatively large at this time, and the ABS is normally activated to prevent the wheels from locking.

[0036] When the control method of the present application is actually applied: as Figure 2 shown, at time t0, the accelerator pedal is released, and the coasting energy recovery intervenes and the negative torque of the drive wheels gradually increases; at time t1, the driver starts to depress the brake pedal, the pedal stroke gradually increases, the brake controller requests the motor controller to perform braking energy recovery, and the intervention of the braking energy recovery causes the total energy recovery to increase. The coasting energy recovery of the drive wheels is superimposed on the braking energy recovery, and the slip ratio rises; at time t2, the motor controller monitors that the slip ratio of the drive wheels reaches the preset first preset threshold, and the motor controller controls the braking energy recovery to exit, and the brake controller compensates the braking hydraulic pressure to meet the target deceleration of the vehicle; as the brake pedal stroke continues to increase, the hydraulic braking force of the four wheels continues to increase, and the coasting energy recovery is superimposed on the hydraulic braking of the four wheels. At time t3, the motor controller monitors that the slip ratio of the drive wheels reaches the preset second preset threshold, and the motor controller controls the coasting energy recovery to exit through PID regulation; after both the coasting energy recovery and the braking energy recovery are exited, as the brake pedal is further depressed, the hydraulic braking of the four wheels continues to increase. At time t4, the brake controller monitors that the slip ratio of the drive wheels reaches the preset third preset threshold, and controls the activation of the ABS function to adjust the wheel-side pressure to prevent the wheels from locking.

[0037] In addition, the present application also provides an anti-lock braking control system for the energy recovery drive wheels of a new energy vehicle, including a slip ratio acquisition module, a first judgment module, a braking energy recovery control module, a second judgment module, a coasting energy recovery control module, a third judgment module, and an ABS control module: The slip ratio acquisition module is used to collect the slip ratios of the four wheels in real time. The motor controller is directly connected to the wheel speed sensor through a hard wire, and the motor controller directly obtains the wheel speed signal to calculate the reference wheel speed of the vehicle, and obtains the slip ratio of the drive wheel based on the wheel speed; The first judgment module is used to judge whether to exit the braking energy recovery based on the current slip ratio of the drive wheel collected by the slip ratio acquisition module after the brake pedal is depressed; The braking energy recovery control module is used to control the exit of the braking energy recovery when the first judgment module judges that the braking energy recovery needs to be exited; The second judgment module is used to judge whether to exit the coasting energy recovery based on the current slip ratio of the drive wheel when the braking energy recovery has exited and the brake pedal has not been released; The coasting energy recovery control module is used to control the exit of the coasting energy recovery when the second judgment module judges that the coasting energy recovery needs to be exited; The third judgment module is used to judge whether to activate the ABS function based on the current slip ratio of the drive wheel when the coasting energy recovery has completely exited and the brake pedal has not been released; The ABS control module is used to activate the ABS function when the third judgment module judges that the ABS function needs to be activated.

[0038] Among them, the first judgment module is used to compare the current slip ratio of the drive wheel with a first preset threshold after the brake pedal is depressed, and make a judgment that the braking energy recovery needs to be exited when the current slip ratio of the drive wheel is greater than the first preset threshold, and make a judgment that the braking energy recovery does not need to be exited when the current slip ratio of the drive wheel is not greater than the first preset threshold.

[0039] The second judgment module is used to compare the current slip ratio of the drive wheel with a second preset threshold when the braking energy recovery has exited and the brake pedal has not been released, and make a judgment that the coasting energy recovery needs to be exited when the current slip ratio of the drive wheel is greater than the second preset threshold, and make a judgment that the coasting energy recovery does not need to be exited when the current slip ratio of the drive wheel is not greater than the second preset threshold; The second preset threshold is greater than the first preset threshold.

[0040] The third judgment module is used to compare the current slip ratio of the drive wheel with a third preset threshold when the coasting energy recovery has completely exited and the brake pedal has not been released, and make a judgment that the ABS function needs to be activated when the current slip ratio of the drive wheel is greater than the third preset threshold, and make a judgment that the ABS function does not need to be activated when the current slip ratio of the drive wheel is not greater than the third preset threshold; The third preset threshold is greater than the second preset threshold.

[0041] It further includes a braking torque compensation module; the braking torque compensation module is used to control the braking hydraulic pressure according to the reduction of the braking energy recovery capacity value when the braking energy recovery exits, so as to compensate the braking torque and keep the braking torque unchanged.

[0042] The above shows and describes the basic principle, main features and advantages of the present application. Those skilled in the art should understand that the present application is not limited by the above embodiments. The above embodiments and the descriptions in the specification only illustrate the principle of the present application. Without departing from the spirit and scope of the present application, the present application will have various changes and improvements, and these changes and improvements all fall within the scope of the present application claimed. The scope of protection claimed by the present application is defined by the appended claims and their equivalents.

Claims

1. A method for controlling the energy recovery driving wheel anti-lock braking of a new energy vehicle, characterized in that: include: When the brake pedal is depressed, the system determines whether to exit the braking energy recovery function based on the current slip rate of the driving wheels. If it is determined that the braking energy recovery needs to be exited, the braking energy recovery is exited and the braking torque is compensated; when the braking energy recovery is exited and the brake pedal is not released, it is determined whether the coasting energy recovery needs to be exited based on the current slip rate of the driving wheel; If it is determined that the coasting energy recovery needs to be exited, then the coasting energy recovery is exited; when the coasting energy recovery is completely exited and the brake pedal is not released, it is determined whether the ABS function needs to be activated based on the current slip rate of the driving wheel; when it is determined that the ABS function needs to be activated, the ABS function is activated.

2. The energy recovery driving wheel anti-lock control method of a new energy vehicle as claimed in claim 1, characterized in that: The method for determining whether it is necessary to exit braking energy recovery based on the slip rate of the current driving wheel comprises: comparing the slip rate of the current driving wheel with a first preset threshold value; if the slip rate of the current driving wheel is greater than the first preset threshold value, determining that it is necessary to exit braking energy recovery; if the slip rate of the current driving wheel is not greater than the first preset threshold value, determining that it is not necessary to exit braking energy recovery.

3. The energy recovery driving wheel anti-lock control method of a new energy vehicle as claimed in claim 2, characterized in that: The method for determining whether it is necessary to exit coasting energy recovery based on the slip rate of the current driving wheel comprises: comparing the slip rate of the current driving wheel with a second preset threshold value; if the slip rate of the current driving wheel is greater than the second preset threshold value, determining that it is necessary to exit coasting energy recovery; if the slip rate of the current driving wheel is not greater than the second preset threshold value, determining that it is not necessary to exit coasting energy recovery; and the second preset threshold value is greater than the first preset threshold value.

4. The energy recovery driving wheel anti-lock control method of a new energy vehicle as claimed in claim 3, characterized in that: The method for determining whether the ABS function needs to be activated based on the slip rate of the current driving wheel includes: comparing the slip rate of the current driving wheel with a third preset threshold value; if the slip rate of the current driving wheel is greater than the third preset threshold value, determining that the ABS function needs to be activated; if the slip rate of the current driving wheel is not greater than the third preset threshold value, determining that the ABS function does not need to be activated; and the third preset threshold value is greater than the second preset threshold value.

5. The energy recovery driving wheel anti-lock control method of a new energy vehicle as claimed in claim 1, characterized in that: The method for compensating the braking torque comprises: when the braking energy recovery is exited, the braking hydraulic pressure is controlled according to the reduction of the braking energy recovery capacity value to compensate the braking torque so as to keep the braking torque unchanged.

6. The energy recovery driving wheel anti-lock control method of a new energy vehicle as claimed in claim 4, characterized in that: The first preset threshold is 3%~5%, the second preset threshold is 6%~8%, and the third preset threshold is 10%~12%.

7. An energy recovery driving wheel anti-lock braking control system for a new energy vehicle, characterized in that: The control system is operated according to any one of the energy recovery driving wheel anti-lock control methods for new energy vehicles as claimed in claims 1 to 6, including: A slip rate acquisition module, which is used to acquire the slip rates of four wheels in real time; A first judgment module, the first judgment module is used to judge whether it is necessary to exit the braking energy recovery based on the current driving wheel slip rate collected by the slip rate collection module after the brake pedal is stepped on; A braking energy recovery control module, the braking energy recovery control module is used to control the braking energy recovery to exit when the first judgment module determines that the braking energy recovery needs to be exited; A second judgment module, the second judgment module is used to judge whether it is necessary to exit the coasting energy recovery based on the current slip rate of the driving wheel when the braking energy recovery is exited and the brake pedal is not released; A coasting energy recovery control module, the coasting energy recovery control module is used to control the coasting energy recovery to exit when the second judgment module determines that the coasting energy recovery needs to be exited; a third judgment module, the third judgment module being used to judge whether the ABS function needs to be activated based on the slip rate of the current driving wheel when the coasting energy recovery is completely exited and the brake pedal is not released; The ABS control module is used to activate the ABS function when the third judgment module determines that the ABS function needs to be activated.

8. The energy recovery driving wheel anti-lock braking control system of a new energy vehicle as claimed in claim 7, characterized in that: The first judgment module is used to compare the current driving wheel slip rate with a first preset threshold after the brake pedal is pressed, and to make a judgment on the need to exit braking energy recovery when the current driving wheel slip rate is greater than the first preset threshold, and to make a judgment on the need to exit braking energy recovery when the current driving wheel slip rate is not greater than the first preset threshold.

9. The energy recovery driving wheel anti-lock braking control system of a new energy vehicle as claimed in claim 8, characterized in that: The second judgment module is used to compare the slip rate of the current driving wheel with a second preset threshold when the braking energy recovery is exited and the brake pedal is not released, and to make a judgment that the coasting energy recovery needs to be exited when the slip rate of the current driving wheel is greater than the second preset threshold, and to make a judgment that the coasting energy recovery does not need to be exited when the slip rate of the current driving wheel is not greater than the second preset threshold; the second preset threshold is greater than the first preset threshold.

10. The energy recovery driving wheel anti-lock braking control system of a new energy vehicle as claimed in claim 9, characterized in that: The third judgment module is used for comparing the slip rate of the current driving wheel with a third preset threshold when the coasting energy recovery is completely exited and the brake pedal is not released, and making a judgment that the ABS function needs to be activated when the slip rate of the current driving wheel is greater than the third preset threshold, and making a judgment that the ABS function does not need to be activated when the slip rate of the current driving wheel is not greater than the third preset threshold; the third preset threshold is greater than the second preset threshold.

11. The energy recovery driving wheel anti-lock braking control system of a new energy vehicle as claimed in claim 7, characterized in that: It also includes a braking torque compensation module; the braking torque compensation module is used to control the braking hydraulic pressure to compensate the braking torque so as to maintain the braking torque unchanged according to the reduction of the braking energy recovery capacity value when the braking energy recovery is exited.

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