A control method and system for coasting energy recovery
By actively adjusting the torque of the recuperation energy recovery system of new energy vehicles, the slip ratio is kept at a preset value, preventing wheel lock-up, solving the problems of uneven and jerky coasting, and improving safety and economy.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- ZHEJIANG GEELY HLDG GRP CO LTD
- Filing Date
- 2023-06-16
- Publication Date
- 2026-05-29
AI Technical Summary
In existing technologies, new energy vehicles frequently deactivate and reactivate ABS during recuperation while coasting, resulting in uneven coasting, causing discomfort to the driver and affecting safety.
By actively adjusting the vehicle's regenerative torque, the slip ratio is kept below a preset value to prevent wheel lock-up. The regenerative torque is continuously adjusted by switching between the preset and the first regenerative torque to avoid jerking and maintain the economy of the energy recovery function.
It effectively avoids the problem of continuous wheel lock-up on low-traction road surfaces, improving safety and comfort, while maximizing the economy of energy recovery and solving the problem of continuous jerking.
Smart Images
Figure CN116638976B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of energy recovery technology, and in particular to a control method and system for recovering energy during gliding. Background Technology
[0002] New energy vehicles are generally designed with coasting energy recovery function. Its functional safety logic requires that when the anti-lock braking system (ABS) is activated, the coasting energy recovery function needs to be deactivated to ensure vehicle safety; after the slip ratio recovers and the ABS deactivates, the coasting energy recovery function resumes normal operation.
[0003] The currently prevalent design logic determines the deactivation and reactivation of coasting energy recovery solely based on the activation status of the ABS. That is, when ABS is activated, coasting energy recovery immediately deactivates; when ABS deactivates, coasting energy recovery reactivates. This causes the coasting energy recovery function to repeatedly enter and exit until the driver provides other input or the vehicle speed drops to idle speed. This results in continuous, jerky, and uneven vehicle movement, causing discomfort for the driver and potentially compromising safety. Summary of the Invention
[0004] One objective of this invention is to provide a control method, system, and vehicle for coasting energy recovery, in order to solve the problem in the prior art where vehicles experience jerking during coasting energy recovery, resulting in uneven coasting and causing discomfort to the driver.
[0005] Specifically, the present invention provides a control method for recovering gliding energy, comprising the following steps:
[0006] Get the current slip ratio of the vehicle in the coasting state;
[0007] When the current slip ratio is greater than a preset value, the vehicle's ABS function is activated and the recovery torque is adjusted to the preset recovery torque;
[0008] Continue to acquire the current slip ratio, and when the current slip ratio is greater than a preset value, adjust the recovery torque from the preset recovery torque to a second recovery torque;
[0009] After the current slip ratio is less than a preset value, the recovery torque is adjusted from the second recovery torque to the first recovery torque, and it is determined whether the torque recovery request is less than the energy recovery request.
[0010] If the torque recovery request is less than the energy recovery request, the above steps are repeated.
[0011] Furthermore, after the step of activating the vehicle's ABS function and adjusting the regenerative torque to a preset regenerative torque when the current slip ratio is greater than a preset value, the method further includes:
[0012] Continue to acquire the current slip ratio. 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 less than the energy recovery request.
[0013] If the torque recovery request is less than the energy recovery request, the current slip ratio is obtained again to repeat the above steps.
[0014] Furthermore, if the torque recovery request exceeds the energy recovery request, the loop exits.
[0015] Furthermore, 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.
[0016] Furthermore, the first recovery torque is the current recovery torque plus the calibrated recovery torque.
[0017] Furthermore, the second recovery torque is the current recovery torque minus the calibrated recovery torque.
[0018] The present invention also discloses a control system for gliding energy recovery, including a control device, the control device including a memory and a processor, the memory storing a control program, the control program being executed by the processor to implement the control method described above.
[0019] The present invention also discloses a vehicle that includes a coasting energy recovery control system as described above.
[0020] This invention actively adjusts the vehicle's regenerative torque to keep the vehicle's slip ratio below a preset value, thereby avoiding secondary and multiple wheel lock-ups. Compared to strategies that exit regenerative braking after wheel lock-up occurs and ABS is activated, this invention proactively avoids continuous wheel lock-up on low-friction surfaces from the source, improving safety and comfort.
[0021] Furthermore, this invention replaces the direct withdrawal of the recovery function by continuously adjusting the recovery torque, which avoids continuous jerking issues and maximizes the economic contribution of recovery. Compared to balancing economy and smoothness by changing the intensity and maximum torque of coasting energy recovery, this invention does not change the design value of coasting energy recovery, thus ensuring the economic objective to the greatest extent.
[0022] Furthermore, compared to mitigating the jerking intensity caused by continuous disengagement and activation by changing the intensity of coasting energy recovery and the maximum torque, this invention fundamentally and completely solves the problem of multiple consecutive jerking.
[0023] The above and other objects, advantages and features of the present invention will become more apparent to those skilled in the art from the following detailed description of specific embodiments of the invention in conjunction with the accompanying drawings. Attached Figure Description
[0024] The following sections will describe some specific embodiments of the invention in a detailed manner by way of example and not limitation, with reference to the accompanying drawings. The same reference numerals in the drawings denote the same or similar parts or portions. Those skilled in the art should understand that these drawings are not necessarily drawn to scale. In the drawings:
[0025] Figure 1 This is a flowchart of a control method according to an embodiment of the present invention;
[0026] Figure 2 This is a logic control diagram of a control method according to an embodiment of the present invention; Detailed Implementation
[0027] New energy vehicles are generally designed with a coasting energy recovery function. Its functional safety logic requires that the coasting energy recovery function must be deactivated when the anti-lock braking system (ABS) is activated to ensure vehicle safety; and that coasting energy recovery resumes normal operation after the slip ratio recovers and the ABS deactivates. Currently, the commonly used design logic determines the deactivation and reactivation of coasting energy recovery solely based on the ABS activation status; that is, when ABS is activated, coasting energy recovery immediately deactivates; and after ABS deactivates, coasting energy recovery reactivates.
[0028] Under normal energy recovery strategies, the system repeatedly engages and disengages until the driver provides other input or the vehicle speed drops to idle speed: "Energy recovery activated → ABS activated → Energy recovery disengaged → ABS disengaged → Energy recovery activated." This results in continuous, jerky, and uneven driving, causing discomfort and potentially compromising safety. However, with coasting energy recovery, the motor generates braking torque on the drive wheels. Therefore, when the vehicle travels on a low-friction surface with light braking, if the regenerative braking torque acting on the drive wheels exceeds or equals the braking torque provided by the ground, the wheel slip ratio increases, reaching the ABS activation threshold and thus activating the ABS function.
[0029] According to safety design logic, the coasting energy recovery function should immediately deactivate at this point to avoid wheel lock-up and vehicle instability. However, when the coasting recovery torque drops to a certain value (the torque acting on the wheels is less than the ground braking torque) or completely deactivates (torque 0), the wheel slip ratio falls below the ABS activation threshold, the ABS function deactivates, and the coasting energy recovery function is reactivated, with the recovered torque increasing to the set value.
[0030] If the vehicle is still coasting on a low-traction surface, excessive coasting recovery torque will still cause ABS to activate, coasting recovery to disengage, ABS to disengage, coasting recovery to reactivate, and so on. The vehicle will exhibit continuous jerking and unevenness (recovery disengagement means loss of deceleration, recovery activation means increased deceleration), which will bring discomfort to the driver and even affect safety.
[0031] In one embodiment, such as Figure 1 and Figure 2 As shown, the present invention provides a control method for recovering gliding energy, comprising the following steps:
[0032] S1. Obtain the current slip ratio of the vehicle in the coasting state;
[0033] S2. When the current slip ratio is greater than the preset value, activate the vehicle's ABS function and adjust the recovery torque to the preset recovery torque;
[0034] S3. Continue to obtain the current slip ratio. When the current slip ratio is greater than the preset value, adjust the recovery torque from the preset recovery torque to the second recovery torque.
[0035] S4. When 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 determine whether the torque recovery request is less than the energy recovery request.
[0036] S5. If the torque recovery request is less than the energy recovery request, repeat the above steps.
[0037] Specifically, such as Figure 1 and Figure 2As shown, when a vehicle is coasting, if its current slip ratio is greater than a preset value, ABS intervention is required to prevent accidents. In this case, the energy recovery torque needs adjustment. Specifically, the current recovery torque is adjusted to a preset recovery torque, ensuring the vehicle recovers energy at that torque level rather than exiting energy recovery. While the vehicle is at the preset recovery torque, the current slip ratio is continuously monitored and checked against the preset value. If not, the recovery torque is adjusted from the preset torque to a first recovery torque, allowing energy recovery to occur at the first torque level. If the current slip ratio is less than the preset value, the torque is adjusted from the first to a second recovery torque, and the recovery torque request is checked against the energy recovery request. If so, energy recovery continues, and the process repeats. If not, the vehicle no longer meets the energy recovery conditions, and energy recovery ends.
[0038] In this embodiment, by actively adjusting the vehicle's recovery torque, the vehicle's slip ratio is kept below a preset value, thereby avoiding secondary and multiple wheel lock-up events. Compared to the strategy of disengaging recovery after wheel lock-up occurs and ABS is activated, this invention proactively avoids the problem of continuous wheel lock-up on low-friction surfaces from the source, improving safety and comfort.
[0039] Furthermore, this invention replaces the direct withdrawal of the recovery function by continuously adjusting the recovery torque, which avoids continuous jerking issues and maximizes the economic contribution of recovery. Compared to balancing economy and smoothness by changing the intensity and maximum torque of coasting energy recovery, this invention does not change the design value of coasting energy recovery, thus ensuring the economic objective to the greatest extent.
[0040] Furthermore, compared to mitigating the jerking intensity caused by continuous disengagement and activation by changing the intensity of coasting energy recovery and the maximum torque, this invention fundamentally and completely solves the problem of multiple consecutive jerking.
[0041] In one embodiment, such as Figure 1 and Figure 2 As shown, the control method for recovering gliding energy also includes the following steps:
[0042] S2. When the current slip ratio is greater than the preset value, activate the vehicle's ABS function and adjust the recovery torque to the preset recovery torque;
[0043] S3' Continue to obtain the current slip ratio. 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 less than the energy recovery request.
[0044] S5. If the torque recovery request is less than the energy recovery request, continue to obtain the current slip ratio and repeat the steps.
[0045] Specifically, when the vehicle is in a coasting state and the ABS is activated, the vehicle's regenerative torque is adjusted to a preset regenerative torque to recover energy from the vehicle. The vehicle's current slip ratio is continuously acquired, and it is determined whether the current slip ratio is less than a preset value. If so, the vehicle's regenerative torque is adjusted from the preset regenerative torque to a second regenerative torque, so that the vehicle can perform energy recovery under the second regenerative torque state.
[0046] In this embodiment, by actively adjusting the vehicle's recovery torque, the vehicle's slip ratio is kept below a preset value, thereby avoiding secondary and multiple wheel lock-up events. Compared to the strategy of disengaging recovery after wheel lock-up occurs and ABS is activated, this invention proactively avoids the problem of continuous wheel lock-up on low-friction surfaces from the source, improving safety and comfort.
[0047] Furthermore, this invention replaces the direct withdrawal of the recovery function by continuously adjusting the recovery torque, which avoids continuous jerking issues and maximizes the economic contribution of recovery. Compared to balancing economy and smoothness by changing the intensity and maximum torque of coasting energy recovery, this invention does not change the design value of coasting energy recovery, thus ensuring the economic objective to the greatest extent.
[0048] Furthermore, compared to mitigating the jerking intensity caused by continuous disengagement and activation by changing the intensity of coasting energy recovery and the maximum torque, this invention fundamentally and completely solves the problem of multiple consecutive jerking.
[0049] In one embodiment, such as Figure 1 and Figure 2 As shown, the recovery torque switches between a first recovery torque and a second recovery torque depending on the slip ratio. The first recovery torque is the current recovery torque plus a calibrated torque; the second recovery torque is the current recovery torque minus the calibrated torque, which is determined by the automaker through experiments for different types of vehicles.
[0050] Specifically, when the vehicle is in energy recovery mode and ABS is activated, the energy recovery system does not exit the operation. Instead, it adjusts the current recovery torque to the first or second recovery torque, so that the energy recovery system is not affected when the vehicle is performing ABS, and therefore does not need to exit the energy recovery operation.
[0051] Of course, the first and second recovery torques can be interchanged or adjusted according to the design requirements of different vehicles, and are not limited to the situation described in this article.
[0052] In this embodiment, after the driver releases the accelerator pedal and energy recovery is activated, if road conditions change and ABS is activated, energy recovery is not deactivated. Instead, the recovery torque is adjusted (set to a minimum or zero value) through torque control. Wheel slip ratio is continuously monitored. If ABS is triggered, a smaller recovery torque or zero is requested; if ABS is not triggered, the recovery torque is increased by a certain amount based on the current torque, and wheel slip ratio is monitored again until the torque increases to the maximum torque designed for the recovery intensity.
[0053] Furthermore, by avoiding the alternating operation / disengagement of ABS and regenerative braking, not only is the problem of continuous jerking and unevenness in the vehicle resolved, but the energy recovery function is also further guaranteed by maximizing the regenerative torque through real-time monitoring and adjustment.
[0054] The present invention also discloses a control system for gliding energy recovery, including a control device, the control device including a memory and a processor, the memory storing a control program, the control program being executed by the processor to implement the control method described above.
[0055] The present invention also discloses a vehicle that includes a coasting energy recovery control system as described above.
[0056] Therefore, those skilled in the art should recognize that although numerous exemplary embodiments of the present invention have been shown and described in detail herein, many other variations or modifications conforming to the principles of the present invention can be directly determined or derived from the disclosure of the present invention without departing from the spirit and scope of the invention. Thus, the scope of the present invention should be understood and construed as covering all such other variations or modifications.
Claims
1. A control method for recovering gliding energy, characterized in that, Includes the following steps: Get the current slip ratio of the vehicle in the coasting state; When the current slip ratio is greater than a preset value, the vehicle's ABS function is activated and the recovery torque is adjusted to the preset recovery torque; Continue to acquire the current slip ratio. When the acquired current slip ratio is greater than a preset value, adjust the recovery torque from the preset recovery torque to the second recovery torque. After the current slip ratio is less than a preset value, the recovery torque is adjusted from the second recovery torque to the first recovery torque, and it is determined whether the torque recovery request is less than the energy recovery request. If the torque recovery request is less than the energy recovery request, the above steps are repeated.
2. The control method according to claim 1, characterized in that, The step of activating the vehicle's ABS function and adjusting the regenerative torque to a preset regenerative torque when the current slip ratio is greater than a preset value further includes: Continue to acquire the current slip ratio. 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 less than the energy recovery request. If the torque recovery request is less than the energy recovery request, the current slip ratio is obtained again to repeat the above steps.
3. The control method according to claim 2, characterized in that, If the torque recovery request exceeds the energy recovery request, the loop exits.
4. The control method according to claim 1, characterized in that, 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.
5. The control method according to claim 1, characterized in that, The first recovery torque is the current recovery torque plus the calibrated recovery torque.
6. The control method according to claim 1, characterized in that, The second recovery torque is the current recovery torque minus the calibrated recovery torque.
7. A control system for recovering gliding energy, characterized in that, The device includes a control unit, which comprises a memory and a processor. The memory stores a control program, which, when executed by the processor, is used to implement the control method according to any one of claims 1-6.
8. A vehicle, characterized in that, The vehicle includes a coasting energy recovery control system as described in claim 7.