Braking energy recovery control system and method self-adaptive to road surfaces with different adhesion coefficients

Abstract

The invention provides a braking energy recovery control system and method adaptive to road surfaces with different adhesion coefficients. The method comprises the following steps: acquiring an initial braking demand torque; brake feedback required torque under the current working condition is obtained; the magnitude relation between the current pedal opening value and the pedal opening limit value is judged, and under the conditions that the pedal opening value is lower than the pedal opening limit value and rear wheels are locked, an instruction is sent to a motor controller through a vehicle control unit for adjustment, so that the negative torque of a motor is continuously reduced, the rear wheels are not locked and drifted, and the safety performance of the whole vehicle can be improved; and on a road surface with a high adhesion coefficient, relatively high braking energy recovery strength can be provided, and the endurance mileage of the whole vehicle is improved. The problems that in the prior art, a whole vehicle decelerates only through negative torque of motor force, energy recovery torque is large, rear wheels are locked, and the vehicle drifts are solved; and if the torque for recovering the braking energy is reduced, the endurance mileage of the new energy vehicle type is influenced.

Description

Technical Field

[0001] The present invention relates to the field of vehicle technology, and in particular to a braking energy recovery control system and method for adaptively controlling roads with different adhesion coefficients. Background Art

[0002] In order to increase the cruising range, new energy vehicles use brake energy recovery to charge the battery. At present, the brake energy recovery technology based on ABS cannot automatically identify the ground adhesion coefficient and can only rely on the driver's active intervention. When the driver brakes on low-adhesion roads such as rain and snow, the pedal opening is low, and the front / rear axle cannot be mechanically adjusted. The vehicle only relies on the negative torque of the motor to slow down. The large energy recovery torque causes the rear wheels to lock and the vehicle to drift. If the torque of the brake energy recovery is reduced, the cruising range of new energy vehicles will be affected. Summary of the invention

[0003] The present application provides a braking energy recovery control system and method that is adaptive to roads with different adhesion coefficients, in order to solve the technical problems existing in the related art that the whole vehicle is decelerated only by the negative torque of the motor force, the energy recovery torque is large, causing the rear wheels to lock, and the vehicle to skid; if the braking energy recovery torque is reduced, the cruising range of the new energy vehicle model is affected.

[0004] According to one aspect of an embodiment of the present application, a braking energy recovery control method for adaptively controlling roads with different adhesion coefficients is provided, comprising:

[0005] Get the initial braking torque T Brk ;

[0006] Obtain the braking energy recovery compensation coefficient k1 and the slope compensation coefficient k2 to obtain the braking feedback required torque T under the current working condition Regn =T Brk *k1*k2;

[0007] Setting a pedal opening limit, obtaining a current pedal opening value, and determining a magnitude relationship between the current pedal opening value and the pedal opening limit;

[0008] If the current pedal opening value is ≥ the pedal opening limit value, and the ABS is detected to be inactive, the brake feedback required torque T is sent via the CAN line. Regn To the motor controller;

[0009] If the current pedal opening value is less than the pedal opening limit value, and the ABS is detected to be activated, the ABS is controlled to exit, and the execution torque T is sent through the CAN line. Regn*0.8 is given to the motor controller, the adjusted pedal opening value is obtained and recorded as the current pedal opening value, and the relationship between the current pedal opening value and the pedal opening limit value is determined again until the current pedal opening value ≥ the pedal opening limit value.

[0010] As an optional implementation, the method further includes: obtaining the current vehicle speed and the current brake pedal opening by initializing the vehicle power-on; obtaining the initial braking demand torque T according to the current vehicle speed and the current brake pedal opening by looking up a table. Brk .

[0011] As an optional implementation, it also includes: the VCU obtains the output torque and motor speed of the driving motor in real time, and calculates the vehicle mass m according to the driving force balance formula.

[0012] As an optional implementation, it also includes: obtaining the braking energy recovery compensation coefficient k1 by looking up a table according to the vehicle mass m.

[0013] As an optional implementation, the method further includes: acquiring a ramp angle, and obtaining the ramp compensation coefficient k2 by looking up a table according to the ramp angle.

[0014] As an optional implementation, it also includes: the pedal opening limit is determined according to the brake pedal idle travel and whether the front / rear axle mechanical brake is involved.

[0015] As an optional implementation, it also includes: when the current pedal opening value ≥ the pedal opening limit value and ABS activation is detected, exiting brake energy recovery.

[0016] As an optional implementation, the method further includes: if the current pedal opening value is less than the pedal opening limit value and it is detected that the ABS is not activated, sending the brake feedback required torque T through the CAN line Regn to the motor controller.

[0017] According to another aspect of the embodiment of the present application, a braking energy recovery control system that is adaptive to roads with different adhesion coefficients is also provided, including a vehicle controller, the vehicle controller including an information acquisition module and a judgment module, the information acquisition module is used to obtain information transmitted by the electronic control equipment of each component; the judgment module is used to judge the size relationship between the current pedal opening value and the pedal opening limit value.

[0018] Furthermore, the information acquisition module includes a CAN line for transmitting information, the CAN line includes an identification module, a receiving module and a transmission module, the CAN line is electrically connected to various electronic control devices in the car, the receiving module is used to receive information transmitted by various electronic control devices, the identification module is used to identify the source of information and the direction in which the information needs to be transmitted, and the transmission module is used to transmit the identified information to the designated electronic control device.

[0019] In an embodiment of the present application, a braking energy recovery control method for adaptively adjusting the road surface with different adhesion coefficients is provided, comprising: obtaining an initial braking demand torque T Brk ; Obtain the braking energy recovery compensation coefficient k1 and the slope compensation coefficient k2, and obtain the braking feedback required torque T under the current working condition Regn =T Brk *k1*k2; set the pedal opening limit, obtain the current pedal opening value, and determine the relationship between the current pedal opening value and the pedal opening limit; if the current pedal opening value ≥ the pedal opening limit, and it is detected that ABS is not activated, send the brake feedback demand torque T through the CAN line Regn to the motor controller; if the current pedal opening value is less than the pedal opening limit value, and the ABS is detected to be activated, the ABS is controlled to exit, and the execution torque T is sent through the CAN line. Regn *0.8 to the motor controller, obtain the adjusted pedal opening value and record it as the current pedal opening value, and judge the size relationship between the current pedal opening value and the pedal opening limit value again, until the current pedal opening value ≥ the pedal opening limit value. The problem that the existing vehicle only relies on the negative torque of the motor to slow down, the energy recovery torque is large, causing the rear wheels to lock, and the vehicle to drift; if the torque of the braking energy recovery is reduced, the cruising range of the new energy vehicle is affected. When the pedal opening is lower than the pedal opening limit value and the rear wheels are locked, the vehicle controller (VCU) sends instructions to the motor controller to adjust it, continuously reduce the negative torque of the motor, so that the rear wheels do not lock and drift, which can improve the safety performance of the vehicle; on high adhesion coefficient roads, it can provide a greater braking energy recovery intensity and improve the cruising range of the vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0022] Figure 1 It is a schematic flow chart of a braking energy recovery control method for adaptively controlling roads with different adhesion coefficients provided in an embodiment of the present application;

[0023] Figure 2 It is a structural block diagram of a vehicle controller provided according to an embodiment of the present application.

[0024] List of parts and reference numerals:

[0025] 1. Vehicle controller, 11. Judgment module, 12. Information acquisition module, 121. Identification module, 122. Receiving module, 123. Transmission module. DETAILED DESCRIPTION

[0026] In order to enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of this application.

[0027] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0028] In order to increase the cruising range, new energy vehicles use brake energy recovery to charge the battery. At present, the brake energy recovery technology based on ABS cannot automatically identify the ground adhesion coefficient and can only rely on the driver's active intervention. When the driver brakes on low-adhesion roads such as rain and snow, the pedal opening is low, and the front / rear axle cannot be mechanically adjusted. The vehicle only relies on the negative torque of the motor to slow down. The large energy recovery torque causes the rear wheels to lock and the vehicle to drift. If the torque of the brake energy recovery is reduced, the cruising range of new energy vehicles will be affected.

[0029] like Figure 1 As shown, the embodiment of the present application provides a braking energy recovery control method for adaptively controlling roads with different adhesion coefficients, including:

[0030] S1: Get the initial braking torque T Brk ;

[0031] S2: Obtain the braking energy recovery compensation coefficient k1 and the slope compensation coefficient k2 to obtain the braking feedback required torque T under the current working condition Regn =T Brk *k1*k2;

[0032] S3: setting a pedal opening limit, obtaining a current pedal opening value, and determining a magnitude relationship between the current pedal opening value and the pedal opening limit;

[0033] S4: If the current pedal opening value is ≥ the pedal opening limit value, and it is detected that the ABS is not activated, the brake feedback required torque T is sent via the CAN line. Regn To the motor controller;

[0034] S5: If the current pedal opening value is less than the pedal opening limit value and the ABS is detected to be activated, the ABS is controlled to exit and the execution torque T is sent through the CAN line. Regn *0.8 is given to the motor controller, the adjusted pedal opening value is obtained and recorded as the current pedal opening value, and the relationship between the current pedal opening value and the pedal opening limit value is determined again until the current pedal opening value ≥ the pedal opening limit value.

[0035] This application solves the problem that the existing technology only relies on the negative torque of the motor to slow down, and the energy recovery torque is large, causing the rear wheels to lock and the vehicle to drift; if the torque of the braking energy recovery is reduced, the cruising range of the new energy vehicle will be affected. When the pedal opening is lower than the pedal opening limit and the rear wheels are locked, the vehicle controller 1 (VCU) sends instructions to the motor controller to adjust, continuously reduce the negative torque of the motor, so that the rear wheels do not lock and drift, which can improve the safety performance of the vehicle, and provide a greater braking energy recovery intensity on high adhesion coefficient roads, thereby increasing the cruising range of the vehicle.

[0036] As an optional implementation, it also includes: through vehicle power-on initialization, the vehicle controller 1 (VCU) obtains the current vehicle speed and the current brake pedal opening; and obtains the initial braking demand torque by looking up the table according to the current vehicle speed and the current brake pedal opening.

[0037] As an optional implementation, it also includes: the VCU obtains the output torque and motor speed of the driving motor in real time, and calculates the vehicle mass m according to the driving force balance formula.

[0038] As an optional implementation, it also includes: obtaining the braking energy recovery compensation coefficient k1 by looking up a table according to the vehicle mass m.

[0039] As an optional implementation, the method further includes: acquiring a ramp angle, and obtaining the ramp compensation coefficient k2 by looking up a table according to the ramp angle.

[0040] As an optional implementation, it also includes: the pedal opening limit is determined according to the brake pedal idle travel and whether the front / rear axle mechanical brake is involved.

[0041] As an optional implementation, it also includes: when the current pedal opening value ≥ the pedal opening limit value and ABS activation is detected, exiting brake energy recovery.

[0042] As an optional implementation, the method further includes: if the current pedal opening value is less than the pedal opening limit value and it is detected that the ABS is not activated, sending the brake feedback required torque T through the CAN line Regn to the motor controller.

[0043] According to another aspect of the embodiment of the present application, a braking energy recovery control system that is adaptive to different adhesion coefficient roads is also provided, such as Figure 2 As shown, it includes a vehicle controller 1, which includes an information acquisition module 12 and a judgment module 11. The information acquisition module 12 is used to obtain information transmitted by the electronic control equipment of each component; the judgment module 11 is used to judge the size relationship between the current pedal opening value and the pedal opening limit value.

[0044] Furthermore, the information acquisition module 12 includes a CAN line for transmitting information, and the CAN line includes an identification module 121, a receiving module 122 and a transmission module 123. The CAN line is electrically connected to various electronic control devices in the car. The receiving module 122 is used to receive information transmitted by various electronic control devices. The identification module 121 is used to identify the source of information and the direction in which the information needs to be transmitted. The transmission module 123 is used to transmit the identified information to the designated electronic control device.

[0045] The serial numbers of the above-mentioned embodiments of the present application are for description only and do not represent the advantages or disadvantages of the embodiments.

[0046] If the integrated units in the above embodiments are implemented in the form of software functional units and sold or used as independent products, they can be stored in the above computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for enabling one or more electronic devices (such as personal computers, servers, or network devices) to perform all or part of the steps of the methods described in the various embodiments of the present application.

[0047] In the above embodiments of the present application, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, please refer to the relevant description of other embodiments.

[0048] In the several embodiments provided in the present application, it should be understood that the disclosed client can be implemented in other ways. Among them, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of units or modules, which can be electrical or other forms.

[0049] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution provided in this embodiment.

[0050] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0051] In the above embodiments of the present application, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, please refer to the relevant description of other embodiments.

[0052] The above is only a preferred implementation of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A braking energy recovery control method for adaptively adapting to different adhesion coefficient roads, characterized in that: include: Get the initial braking torque T Brk ; Obtain the braking energy recovery compensation coefficient k1 and the slope compensation coefficient k2 to obtain the braking feedback required torque T under the current working condition Regn =T Brk *k1*k2; Setting a pedal opening limit, obtaining a current pedal opening value, and determining a magnitude relationship between the current pedal opening value and the pedal opening limit; If the current pedal opening value is ≥ the pedal opening limit value, and the ABS is detected to be inactive, the brake feedback required torque T is sent via the CAN line. Regn To the motor controller; If the current pedal opening value is less than the pedal opening limit value, and the ABS is detected to be activated, the ABS is controlled to exit, and the execution torque T is sent through the CAN line. Regn *0.8 is given to the motor controller, the adjusted pedal opening value is obtained and recorded as the current pedal opening value, and the relationship between the current pedal opening value and the pedal opening limit value is determined again until the current pedal opening value ≥ the pedal opening limit value.

2. The braking energy recovery control method for adaptively adjusting to different adhesion coefficient roads according to claim 1, characterized in that: Also includes: Through vehicle power-on initialization, the vehicle controller (VCU) obtains the current vehicle speed and the current brake pedal opening; the initial braking demand torque T is obtained by looking up the table according to the current vehicle speed and the current brake pedal opening. Brk .

3. The braking energy recovery control method for adaptively adjusting the road surface with different adhesion coefficients according to claim 1, characterized in that: Also includes: The VCU obtains the output torque and speed of the drive motor in real time, and calculates the vehicle mass m based on the driving force balance formula.

4. The braking energy recovery control method for adaptively adjusting the road surface with different adhesion coefficients according to claim 3 is characterized in that: Also includes: The braking energy recovery compensation coefficient k1 is obtained by looking up the table according to the vehicle mass m.

5. The braking energy recovery control method for adaptively adjusting to different adhesion coefficient roads according to claim 1, characterized in that: Also includes: The ramp angle is obtained, and the ramp compensation coefficient k2 is obtained by looking up a table according to the ramp angle.

6. The braking energy recovery control method for adaptively adjusting to different adhesion coefficient roads according to claim 1, characterized in that: Also includes: The pedal opening limit is determined according to the idle travel of the brake pedal and whether the front / rear axle mechanical brake is involved.

7. The braking energy recovery control method for adaptively adjusting to different adhesion coefficient roads according to claim 1, characterized in that: Also includes: When the current pedal opening value ≥ the pedal opening limit value and ABS activation is detected, brake energy recovery is exited.

8. The braking energy recovery control method for adaptively adjusting the road surface with different adhesion coefficients according to claim 1, characterized in that: Also includes: If the current pedal opening value is less than the pedal opening limit value and the ABS is detected to be inactive, the brake feedback required torque T is sent via the CAN line. Regn to the motor controller.

9. The braking energy recovery control system that is adaptive to different adhesion coefficient roads is characterized by: It includes a vehicle controller, which includes an information acquisition module and a judgment module. The information acquisition module is used to obtain information transmitted by the electronic control equipment of each component; the judgment module is used to judge the size relationship between the current pedal opening value and the pedal opening limit value.

10. The braking energy recovery control system according to claim 9, which is self-adaptive to roads with different adhesion coefficients, characterized in that: The information acquisition module includes a CAN line for transmitting information, and the CAN line includes an identification module, a receiving module and a transmission module. The CAN line is electrically connected to various electronic control devices in the car. The receiving module is used to receive information transmitted by various electronic control devices. The identification module is used to identify the source of information and the direction in which the information needs to be transmitted. The transmission module is used to transmit the identified information to the designated electronic control device.

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