A vehicle brake energy recovery control method and system

Abstract

The application provides a vehicle brake energy recovery control method and system, which comprises the following steps: calculating a maximum recovery torque value corresponding to a wheel end system inside a hybrid vehicle in real time; calculating a generated coasting energy recovery torque and a driving motor power generation torque of the hybrid vehicle in real time during operation, and calculating a corresponding brake energy recovery available electric power according to the maximum recovery torque value, the coasting energy recovery torque and the driving motor power generation torque in real time; calculating a maximum electric brake recovery capability limit and a maximum generator power generation capability limit corresponding to the hybrid vehicle based on a preset rule in real time; limiting a brake energy recovery request torque and a generator request torque calculated corresponding to the hybrid vehicle according to the maximum electric brake recovery capability limit and the maximum generator power generation capability limit to complete corresponding brake energy recovery control. The application can solve the problem of overcharging or overdischarging of a brake recovery battery pack, improve brake recovery efficiency, reduce vehicle energy consumption, improve vehicle cruising range, and improve user experience.

Description

Technical Field

[0001] This invention relates to the field of automotive technology, and in particular to a method and system for controlling regenerative braking energy in vehicles. Background Technology

[0002] With the advancement of technology and the rapid development of productivity, automobiles have become widespread in people's daily lives and have become an indispensable means of transportation, greatly facilitating people's lives.

[0003] Existing pure electric and hybrid vehicles are equipped with regenerative braking. Specifically, existing regenerative braking works by feeding back electrical energy when the driver presses the brake pedal, thus saving energy. When the electric braking power is insufficient to meet the vehicle's braking requirements, mechanical braking is used to ensure the overall braking effect. In pure electric vehicles, the regenerative braking system only involves the battery pack and drive motor. When the driver applies the brakes, the energy distribution during regenerative braking is completed by limiting the regenerative power of the drive motor based on the available power of the battery pack. However, in hybrid vehicles, the actual charging and discharging power of the battery pack is determined by both the drive motor and the generator. The drive motor is not only related to the torque required by the driver, but also includes the condition where the engine generates electricity for the battery pack through the drive motor. Therefore, coordinating the energy distribution among the engine, drive motor, generator, and electric braking torque becomes a key issue in hybrid energy recovery. Because the generator, engine, and drive motor work together in hybrid vehicles, the engine can charge the battery through the generator or the battery pack through the drive motor. In these two conditions, the available power of electric braking and the power of the battery pack are not equal. If the battery pack power is used to be equal to the available power of electric braking, it will lead to problems such as overcharging or over-discharging of the battery. Summary of the Invention

[0004] Based on this, the purpose of this invention is to provide a vehicle braking energy recovery control method and system to solve the problem that existing hybrid vehicles may cause overcharging or over-discharging of the battery pack if braking energy recovery is completed by making the available power of electric braking equal to the available power of the battery pack. Because the generator, engine and drive motor of the hybrid vehicle work together, the engine can charge the battery through the generator or the battery pack through the drive motor. Under these two operating conditions, the available power of electric braking and the power of the battery pack are not equal. If the battery pack power is made equal to the available power of electric braking, it will lead to the problem of battery overcharging or over-discharging.

[0005] The first aspect of the present invention proposes:

[0006] A method for controlling regenerative braking energy in a vehicle, wherein the method includes:

[0007] When the hybrid vehicle is detected to be in operation in real time, the maximum recovery torque value corresponding to the wheel-end system inside the hybrid vehicle is calculated in real time.

[0008] The system calculates in real time the coasting energy recovery torque and the drive motor generation torque generated by the hybrid vehicle during operation, and calculates the corresponding available electric power for braking energy recovery based on the maximum recovery torque value, the coasting energy recovery torque, and the drive motor generation torque.

[0009] The maximum limit of electric braking recovery and the maximum power generation limit of the generator corresponding to the hybrid vehicle are calculated in real time based on preset rules.

[0010] Based on the maximum capacity limit of electric regenerative braking and the maximum power generation capacity limit of the generator, the calculated regenerative braking torque and generator torque corresponding to the hybrid vehicle are limited to complete the corresponding regenerative braking control.

[0011] The beneficial effects of this invention are:

[0012] Key Point 1: Energy management of regenerative braking is based on the available power of the battery pack, wheel-end slip torque, and drive motor generating torque (engine part). The maximum wheel-end torque allowed for electric braking recovery in electric braking mode is calculated, and the request to perform electric braking must be within this limit.

[0013] Key Point 2: The regenerative braking strategy adopts a wheel-end priority principle to improve the overall vehicle drivability. When the available power of the battery pack is low, priority is given to ensuring the wheel-end regenerative torque and reducing the generator output. This achieves the following: under braking conditions, as the braking opening increases, the regenerative braking energy increases while the generator output decreases. When the regenerative braking power equals the available power of the battery pack, the generator output is zero.

[0014] Furthermore, the method also includes:

[0015] Design a throttle, vehicle speed, and coasting energy recovery torque mapping table, and calculate the current coasting energy recovery torque based on the throttle and vehicle speed mapping table.

[0016] The method further includes:

[0017] When the hybrid vehicle is detected to be in a driving state in real time, the actual wheel end torque corresponding to the hybrid vehicle is calculated in real time. The actual wheel end torque is equal to the actual output torque of the clutch multiplied by the gear ratio and the value of the drive motor torque multiplied by the motor gear ratio.

[0018] Furthermore, during the operation of the hybrid vehicle, the corresponding brake energy recovery value is displayed in real time on the instrument panel of the hybrid vehicle, and the brake energy recovery value changes dynamically.

[0019] The second aspect of the present invention proposes:

[0020] A vehicle regenerative braking energy control system, wherein the system includes:

[0021] The detection module is used to calculate the maximum recovery torque value corresponding to the wheel-end system inside the hybrid vehicle in real time when the hybrid vehicle is detected to be in operation.

[0022] The first processing module is used to calculate in real time the coasting energy recovery torque and the drive motor generating torque generated by the hybrid vehicle during operation, and to calculate the corresponding braking energy recovery available electric power in real time based on the maximum recovery torque value, the coasting energy recovery torque and the drive motor generating torque.

[0023] The second processing module is used to calculate in real time the maximum limit of electric braking recovery capacity and the maximum power generation capacity limit of the generator corresponding to the hybrid vehicle based on preset rules.

[0024] The third processing module is used to calibrate the clutch, gearbox and engine inside the vehicle based on the judgment result, and to test the driving performance of the vehicle in real time based on the drive wheel end of the engine.

[0025] Furthermore, the method also includes:

[0026] The throttle-to-vehicle speed mapping table is brought up, and the coasting energy recovery torque is calculated based on the throttle-to-vehicle speed mapping table.

[0027] Furthermore, the method also includes:

[0028] When the hybrid vehicle is detected to be in a driving state in real time, the actual wheel end torque corresponding to the hybrid vehicle is calculated in real time. The actual wheel end torque is equal to the actual output torque of the clutch multiplied by the gear ratio and the value of the drive motor torque multiplied by the motor gear ratio.

[0029] Furthermore, based on the maximum capacity limit of electric braking recovery and the maximum power generation capacity limit of the generator, the braking energy recovery request torque and the generator request torque calculated corresponding to the hybrid vehicle are limited to complete the corresponding braking energy recovery control.

[0030] The third aspect of the present invention proposes:

[0031] A computer includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor, when executing the computer program, implements the vehicle regenerative braking energy control method as described above.

[0032] The fourth aspect of the present invention proposes:

[0033] A readable storage medium having a computer program stored thereon, wherein the program, when executed by a processor, implements the vehicle regenerative braking energy control method as described above.

[0034] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0035] Figure 1 A flowchart of a vehicle regenerative braking energy control method provided in the first embodiment of the present invention;

[0036] Figure 2 A schematic diagram of the vehicle braking energy recovery control method provided in the second embodiment of the present invention;

[0037] Figure 3 This is a schematic diagram illustrating an implementation of the vehicle regenerative braking energy control method provided in the second embodiment of the present invention;

[0038] Figure 4 This is a structural block diagram of a vehicle regenerative braking energy control system provided in the third embodiment of the present invention.

[0039] The following detailed description, in conjunction with the accompanying drawings, will further illustrate the present invention. Detailed Implementation

[0040] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Several embodiments of the invention are illustrated in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

[0041] It should be noted that when a component is said to be "fixed to" another component, it can be directly on the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0042] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0043] Please see Figure 1 The image shows a vehicle regenerative braking energy control method provided in the first embodiment of the present invention. The vehicle regenerative braking energy control method provided in this embodiment can accurately and effectively calculate the regenerative braking energy value, ensure that the battery pack is not overcharged or over-discharged, reduce the energy consumption of the whole vehicle, and correspondingly improve the driving range of the whole vehicle while improving the user experience.

[0044] Specifically, this embodiment provides:

[0045] A method for controlling regenerative braking energy in vehicles specifically includes the following steps:

[0046] Step S10: When the hybrid vehicle is detected to be in operation in real time, the maximum recovery torque value corresponding to the wheel-end system inside the hybrid vehicle is calculated in real time.

[0047] Step S20: Calculate in real time the coasting energy recovery torque and the drive motor generating torque generated by the hybrid vehicle during operation, and calculate the corresponding braking energy recovery available electric power in real time based on the maximum recovery torque value, the coasting energy recovery torque and the drive motor generating torque.

[0048] Step S30: Calculate in real time the maximum limit of electric braking recovery and the maximum power generation limit of the generator corresponding to the hybrid vehicle based on preset rules.

[0049] Step S40: Based on the maximum capacity limit of electric braking recovery and the maximum power generation capacity limit of the generator, limit the braking energy recovery request torque and the generator request torque calculated corresponding to the hybrid vehicle to complete the corresponding braking energy recovery control.

[0050] Second Embodiment

[0051] Please see Figures 2 to 3 The overall approach provided in this embodiment is as follows:

[0052] 1. Calculate the maximum recovered torque value of the wheel-end system. The maximum recovered torque value is the same for both series and parallel modes, which is equal to the maximum charging power of the battery * 9550 / wheel speed.

[0053] 2. Calculate the coasting energy recovery torque by referring to a table based on throttle and vehicle speed;

[0054] 3. The actual torque at the wheel end is calculated as follows: the actual output torque of the clutch multiplied by the current gear ratio, plus the torque of the drive motor multiplied by the motor gear ratio.

[0055] 4. Calculate the drive motor's generating torque (from the engine's generator). Subtract the drive motor's torque from the actual wheel-end torque.

[0056] 5. Calculate the maximum capacity limit of electric braking recovery. Based on the maximum recovery torque value of the wheel-end system, calculate the wheel-end torque during coasting recovery, and the wheel-end torque generated by the drive motor (the part of the engine that generates electricity for the drive motor).

[0057] 6. Calculate the maximum generating capacity limit of the generator. Calculate the maximum generating capacity limit of the generator based on the available power of the battery pack and the current actual available power of the drive motor.

[0058] Vehicle strategy implementation:

[0059] 1. During driving, the driver releases the accelerator and then applies the brake. When the accelerator is released, the vehicle is in a coasting state. When the vehicle is in series or pure electric mode, the drive motor torque equals the wheel-end coasting torque, and the drive motor's generating torque (engine part) is 0. When the vehicle is in parallel mode, the drive motor torque equals the wheel-end coasting torque plus the drive motor's generating torque (engine part).

[0060] 2. After applying the brakes, the electric brakes begin to request negative regenerative torque. The available electric brake torque is equal to the system's maximum recovery torque minus the coasting recovery torque minus the drive motor's regenerative torque (engine part). The negative torque requested by the electric brakes must be limited to the range of available electric brake torque.

[0061] 3. Energy distribution principle after braking: Based on the available power of the battery pack, it is preferentially allocated to the drive motor. The generator dynamically adjusts its allowable charging torque according to the actual power of the drive motor and the available power of the battery pack, so as to ensure that the actual power used by the battery pack is within its own available power range.

[0062] Please see Figure 4 The third embodiment of the present invention provides:

[0063] A vehicle regenerative braking energy control system, wherein the system includes:

[0064] The detection module is used to calculate the maximum recovery torque value corresponding to the wheel-end system inside the hybrid vehicle in real time when the hybrid vehicle is detected to be in operation.

[0065] The first processing module is used to calculate in real time the coasting energy recovery torque and the drive motor generating torque generated by the hybrid vehicle during operation, and to calculate the corresponding braking energy recovery available electric power in real time based on the maximum recovery torque value, the coasting energy recovery torque and the drive motor generating torque.

[0066] The second processing module is used to calculate in real time the maximum limit of electric braking recovery capacity and the maximum power generation capacity limit of the generator corresponding to the hybrid vehicle based on preset rules.

[0067] The third processing module, based on the maximum capacity limit of electric braking recovery and the maximum power generation capacity limit of the generator, limits the braking energy recovery request torque and the generator request torque calculated corresponding to the hybrid vehicle to complete the corresponding braking energy recovery control.

[0068] The fourth embodiment of the present invention provides a computer, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the vehicle regenerative braking energy control method as described above.

[0069] The fifth embodiment of the present invention provides a readable storage medium having a computer program stored thereon, wherein the program, when executed by a processor, implements the vehicle braking energy recovery control method as described above.

[0070] In summary, the vehicle regenerative braking energy control method and system provided in the above embodiments of the present invention can solve the problem of overcharging or over-discharging of the regenerative braking battery pack, and can improve the efficiency of regenerative braking, reduce the energy consumption of the whole vehicle, and increase the driving range of the whole vehicle.

[0071] It should be noted that the above modules can be functional modules or program modules, and can be implemented through software or hardware. For modules implemented through hardware, the above modules can reside in the same processor; or the above modules can be located in different processors in any combination.

[0072] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device.

[0073] More specific examples of computer-readable media (a non-exhaustive list) include: electrical connections (electronic devices) having one or more wires, portable computer disk drives (magnetic devices), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Furthermore, computer-readable media can even be paper or other suitable media on which the program can be printed, since the program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in computer memory.

[0074] It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0075] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0076] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. A method for controlling regenerative braking energy in vehicles, characterized in that, The method includes: When the hybrid vehicle is detected to be in operation in real time, the maximum recovery torque value corresponding to the wheel-end system inside the hybrid vehicle is calculated in real time. The system calculates in real time the coasting energy recovery torque and the drive motor generation torque generated by the hybrid vehicle during operation, and calculates the corresponding available electric power for braking energy recovery based on the maximum recovery torque value, the coasting energy recovery torque, and the drive motor generation torque. The maximum limit of electric braking recovery and the maximum power generation limit of the generator corresponding to the hybrid vehicle are calculated in real time based on preset rules. Based on the maximum capacity limit of electric regenerative braking and the maximum power generation capacity limit of the generator, the calculated regenerative braking torque and generator torque corresponding to the hybrid vehicle are limited to complete the corresponding regenerative braking control. The method further includes: Design a mapping table for throttle, vehicle speed, and coasting energy recovery torque, and calculate the current coasting energy recovery torque based on the throttle and vehicle speed mapping table. During the operation of the hybrid vehicle, the maximum limit torque for brake energy recovery is calculated based on the maximum torque recovered by the system, the current coasting energy recovery torque, the actual torque at the wheel end, and the actual torque of the drive motor.

2. The vehicle braking regenerative energy control method according to claim 1, characterized in that: The method further includes: When the hybrid vehicle is detected to be in series mode or parallel mode in real time, the maximum regenerative torque value of the hybrid vehicle is equal to the maximum charging power of the battery pack multiplied by 9550 and divided by the wheel speed.

3. The vehicle braking regenerative energy control method according to claim 1, characterized in that: The method further includes: When the hybrid vehicle is detected to be in a driving state in real time, the actual wheel end torque corresponding to the hybrid vehicle is calculated in real time. The actual wheel end torque is equal to the actual output torque of the clutch multiplied by the gear ratio and the value of the drive motor torque multiplied by the motor gear ratio.

4. A vehicle regenerative braking energy control system, characterized in that, The system for implementing the vehicle regenerative braking energy control method as described in any one of claims 1 to 3 includes: The detection module is used to calculate the maximum recovery torque value corresponding to the wheel-end system inside the hybrid vehicle in real time when the hybrid vehicle is detected to be in operation. The first processing module is used to calculate in real time the coasting energy recovery torque and the drive motor generating torque generated by the hybrid vehicle during operation, and to calculate the corresponding braking energy recovery available electric power in real time based on the maximum recovery torque value, the coasting energy recovery torque and the drive motor generating torque. The second processing module is used to calculate in real time the maximum limit of electric braking recovery capacity and the maximum power generation capacity limit of the generator corresponding to the hybrid vehicle based on preset rules. The third processing module is used to limit the braking energy recovery request torque and the generator request torque calculated corresponding to the hybrid vehicle based on the maximum electric braking recovery capacity limit and the maximum generator power generation capacity limit to complete the corresponding braking energy recovery control.

5. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the vehicle regenerative braking energy control method as described in any one of claims 1 to 3.

6. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the vehicle braking energy recovery control method as described in any one of claims 1 to 3.

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