Brake energy recovery control method and device, storage medium and vehicle

Abstract

The application provides a brake energy recovery control method and device, a storage medium and a vehicle, and belongs to the technical field of vehicle control. In the case that the locking mechanism of a hydraulic torque converter is in a locked state and a brake pedal depression signal is received, working condition information of the vehicle is acquired. Whether the vehicle meets brake energy recovery limiting conditions can be determined based on the working condition information. In the case that the vehicle meets brake energy recovery limiting conditions, the vehicle negative torque capacity value is adjusted, so that the target brake energy recovery capacity value can reach the target torque when the locking mechanism meets the opening condition, the engine is effectively prevented from being damaged by the negative torque output by the drive motor, the sudden reduction of the vehicle brake deceleration is prevented, the braking performance of the vehicle is ensured, and the driving experience of the user is effectively improved.

Description

Technical Field

[0001] This application relates to the field of vehicle control technology, and in particular to a braking energy recovery control method, device, storage medium, and vehicle. Background Technology

[0002] With societal progress and development, environmental protection and the energy crisis are receiving increasing attention. Hybrid electric vehicles (HEVs) have become a key direction for the automotive industry due to their significant advantages in energy conservation and environmental protection. Improving their driving range is a crucial technological issue for HEVs. Regenerative braking converts the kinetic energy of vehicle braking into electrical energy and stores it in the vehicle's energy storage unit, thereby increasing driving range to some extent.

[0003] In current hybrid vehicles equipped with torque converters, when the driver applies the brake pedal, the drive motor outputs negative torque to recover braking energy. The torque converter controls its locking mechanism to open or close based on parameters such as the current vehicle speed. However, during the vehicle's regenerative braking process, if the torque converter's locking mechanism opens, the negative torque generated by the drive motor poses a risk of stalling the engine. Furthermore, because the connection between the pump impeller and turbine in the torque converter changes from rigid to flexible transmission, it also causes a sudden decrease in the vehicle's braking deceleration, affecting the vehicle's braking performance and the driver's experience. Summary of the Invention

[0004] This application provides a braking energy recovery control method, device, storage medium, and vehicle to solve the problem that, in the process of braking energy recovery in hybrid vehicles equipped with hydraulic torque converters, the locking mechanism of the hydraulic torque converter easily causes the drive motor to stall the engine and the braking deceleration to suddenly decrease.

[0005] To solve the above problems, this application adopts the following technical solution:

[0006] In a first aspect, embodiments of this application provide a braking energy recovery control method, the method comprising:

[0007] When the locking mechanism of the hydraulic torque converter is locked and a brake pedal depress signal is received, the vehicle's operating condition information is obtained;

[0008] Based on the aforementioned operating condition information, determine whether the vehicle meets the braking energy recovery limit conditions;

[0009] If the vehicle meets the braking energy recovery limit conditions, the negative torque capacity of the whole vehicle is adjusted to obtain the target braking energy recovery capacity value.

[0010] Based on the target regenerative braking capacity value, the drive motor is controlled to perform regenerative braking operation so that when the locking mechanism meets the opening condition, the target regenerative braking capacity value reaches the target torque; wherein, the drive motor is connected to the vehicle's engine.

[0011] In one embodiment of this application, the operating condition information includes the brake pedal opening and the transmission output shaft speed;

[0012] The step of determining whether the vehicle meets the braking energy regeneration limit conditions based on the aforementioned operating condition information includes:

[0013] Based on the brake pedal opening, determine the threshold for entering the restriction function;

[0014] The target speed difference is determined based on the difference between the output shaft speed of the transmission and the opening speed of the locking mechanism;

[0015] If the target speed difference is less than the threshold for entering the limiting function, the vehicle is determined to meet the braking energy recovery limiting condition.

[0016] In one embodiment of this application, the step of determining whether a vehicle meets the braking energy recovery limit conditions based on the operating condition information further includes:

[0017] Based on the brake pedal opening, a restriction function exit threshold is determined; wherein, the restriction function exit threshold is greater than the restriction function entry threshold;

[0018] If the target speed difference is detected to be less than the limit function entry threshold, and the target speed difference is greater than the limit function exit threshold, it is determined that the vehicle does not meet the braking energy recovery limit condition.

[0019] In one embodiment of this application, before the step of adjusting the negative torque capability value of the vehicle to obtain the target braking energy recovery capability value, the method further includes:

[0020] The negative torque capability value of the vehicle is determined based on the charging power of the power battery and the negative torque capability of the drive motor.

[0021] In one embodiment of this application, the step of adjusting the negative torque capability value of the vehicle to obtain a target braking energy recovery capability value includes:

[0022] The braking energy recovery capability limit is determined based on the rate of change between the transmission output shaft speed and the target speed difference.

[0023] The larger of the braking energy recovery capability limit value and the vehicle negative torque capability value is determined as the target braking energy recovery capability value.

[0024] In one embodiment of this application, the step of determining the braking energy recovery capability limit value based on the change rate of the transmission output shaft speed and the target speed difference includes:

[0025] The initial moment is determined when the vehicle meets the braking energy recovery limit condition. Based on the initial rate of change of the initial transmission output shaft speed and the target speed difference corresponding to the initial moment, the initial braking energy recovery capacity limit value is determined.

[0026] The braking energy recovery capability limit value is controlled to increase from the initial braking energy recovery capability limit value to the target torque; wherein, the braking energy recovery capability limit value is negatively correlated with the output shaft speed of the transmission, and the braking energy recovery capability limit value is positively correlated with the rate of change of the target speed difference.

[0027] In one embodiment of this application, the step of controlling the drive motor to perform regenerative braking operation based on the target regenerative braking capability value includes:

[0028] The target regenerative braking capacity value is sent to the braking system controller so that the braking system controller can determine the regenerative braking torque based on the target regenerative braking capacity value and the brake pedal opening.

[0029] The system receives the regenerative braking torque and controls the drive motor to perform regenerative braking operation according to the regenerative braking torque.

[0030] Secondly, based on the same inventive concept, embodiments of this application provide a braking energy recovery control device, the device comprising:

[0031] The acquisition module is used to acquire vehicle operating condition information when the locking mechanism of the hydraulic torque converter is locked and a brake pedal depress signal is received.

[0032] The determination module is used to determine whether the vehicle meets the braking energy recovery limit conditions based on the operating condition information.

[0033] The adjustment module is used to adjust the negative torque capacity value of the vehicle when the vehicle meets the braking energy recovery limit conditions, so as to obtain the target braking energy recovery capacity value.

[0034] A control module is used to control a drive motor to perform regenerative braking operation based on the target regenerative braking capacity value, so that the target regenerative braking capacity value reaches the target torque when the locking mechanism meets the opening condition; wherein the drive motor is connected to the engine of the vehicle.

[0035] In one embodiment of this application, the operating condition information includes brake pedal opening and transmission output shaft speed; the determining module includes:

[0036] The first threshold determination submodule is used to determine the threshold for restricting the function based on the brake pedal opening.

[0037] The target speed difference determination submodule is used to determine the target speed difference based on the difference between the output shaft speed of the transmission and the opening speed of the locking mechanism;

[0038] The first condition determination submodule is used to determine that the vehicle meets the braking energy recovery limitation condition when the target speed difference is less than the limiting function entry threshold.

[0039] In one embodiment of this application, the determining module further includes:

[0040] The second threshold determination submodule determines the restriction function exit threshold based on the brake pedal opening; wherein the restriction function exit threshold is greater than the restriction function entry threshold.

[0041] The second condition determination submodule is used to determine that the vehicle does not meet the braking energy recovery restriction condition when the target speed difference is detected to be less than the restriction function entry threshold and the target speed difference is greater than the restriction function exit threshold.

[0042] In one embodiment of this application, the braking energy recovery control device further includes:

[0043] The vehicle negative torque capability value determination module is used to determine the vehicle negative torque capability value based on the charging power of the power battery and the negative torque capability of the drive motor before adjusting the vehicle negative torque capability value to obtain the target braking energy recovery capability value.

[0044] In one embodiment of this application, the adjustment module includes:

[0045] The limit value determination submodule is used to determine the limit value of braking energy recovery capability based on the rate of change of the difference between the output shaft speed of the transmission and the target speed.

[0046] The capability value determination submodule is used to determine the larger of the braking energy recovery capability limit value and the vehicle negative torque capability value as the target braking energy recovery capability value.

[0047] In one embodiment of this application, the limit value determination submodule includes:

[0048] An initial limit value determination unit is used to determine the time when the vehicle meets the braking energy recovery limit condition as the initial time, and to determine the initial braking energy recovery capability limit value based on the initial rate of change of the initial transmission output shaft speed and the target speed difference corresponding to the initial time.

[0049] A limit control unit is used to control the increase of the braking energy recovery capability limit value from the initial braking energy recovery capability limit value to the target torque; wherein the braking energy recovery capability limit value is negatively correlated with the output shaft speed of the transmission, and the braking energy recovery capability limit value is positively correlated with the rate of change of the target speed difference.

[0050] In one embodiment of this application, the control module includes:

[0051] The capability value sending submodule is used to send the target braking energy recovery capability value to the braking system controller, so that the braking system controller can determine the braking energy recovery torque based on the target braking energy recovery capability value and the brake pedal opening.

[0052] The energy recovery control submodule is used to receive the braking energy recovery torque and control the drive motor to perform braking energy recovery operation according to the braking energy recovery torque.

[0053] Thirdly, based on the same inventive concept, embodiments of this application provide a storage medium storing machine-executable instructions, which, when executed by a processor, implement the braking energy recovery control method proposed in the first aspect of this application.

[0054] Fourthly, based on the same inventive concept, embodiments of this application provide a vehicle including a processor and a memory, wherein the memory stores machine-executable instructions that can be executed by the processor, and the processor is used to execute the machine-executable instructions to implement the braking energy recovery control method proposed in the first aspect of this application.

[0055] Compared with the prior art, this application has the following advantages:

[0056] This application provides a braking energy recovery control method. When the locking mechanism of the torque converter is locked and a brake pedal depress signal is received, the method acquires vehicle operating condition information. Based on this information, it determines whether the vehicle meets the braking energy recovery limit conditions. If the vehicle meets these conditions, the method adjusts the vehicle's negative torque capacity and, based on the adjusted target braking energy recovery capacity value, controls the drive motor to perform braking energy recovery operations. This ensures that when the locking mechanism opens, the target braking energy recovery capacity value reaches the target torque. By adjusting the vehicle's negative torque capacity value before the torque converter's locking mechanism opens, this application reduces the braking energy recovery intensity of the drive motor. This ensures that when the locking mechanism opens, the target braking energy recovery capacity value reaches the target torque, effectively preventing the negative torque output by the drive motor from stalling the engine and preventing a sudden decrease in vehicle braking deceleration, thereby ensuring vehicle braking performance and effectively improving the user's driving experience. Attached Figure Description

[0057] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0058] Figure 1 This is a flowchart of the steps of a braking energy recovery control method in one embodiment of this application.

[0059] Figure 2 This is a schematic diagram of the functional modules of a braking energy recovery control device according to an embodiment of this application.

[0060] Figure 3 This is a structural schematic diagram of a vehicle according to one embodiment of this application. Detailed Implementation

[0061] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0062] It should be noted that a hydraulic torque converter, also known as a "hydraulic torque converter," "turbo torque converter," or "hydrodynamic torque converter," is a hydraulic component mainly composed of a pump impeller, a turbine, a stator, and a locking mechanism (usually a lock-up clutch), using hydraulic oil as its working medium. The pump impeller is connected to the vehicle's engine, the turbine is connected to the transmission, and the locking mechanism has two operating states: open and locked.

[0063] In the open state, the turbine and pump impeller are separated. The engine drives the pump impeller to rotate, which in turn drives the turbine by agitating the hydraulic oil in the torque converter. The guide wheel, located between the pump impeller and turbine, is used to adjust the direction of the hydraulic oil. Because power is transmitted between the turbine and pump impeller via hydraulic oil, a soft connection between the engine and transmission is achieved, reducing the dynamic load on the transmission system, ensuring smooth vehicle starts, and increasing vehicle power through the speed difference between the pump impeller and turbine. However, when the speed difference between the pump impeller and turbine is approximately the same during vehicle operation, if hydraulic oil is still needed to drive the turbine, it would lead to higher energy consumption.

[0064] To reduce energy consumption, the locking mechanism can be locked when the vehicle is running at medium to high speeds. The torque converter locks the pump wheel and turbine through the locking mechanism, which rigidly connects the pump wheel and turbine. In this way, the pump wheel can directly transmit power to the turbine instead of through hydraulic oil, thus reducing energy consumption.

[0065] The inventors of this application have discovered that, for hybrid vehicles, the engine and drive motor work together as power sources to transmit torque to the torque converter. When a hybrid vehicle is performing regenerative braking, the vehicle is typically traveling at medium to high speeds. At this time, the locking mechanism of the torque converter is locked. However, during vehicle braking, when the vehicle speed decreases to a certain value, the locking mechanism of the torque converter will automatically disengage. Because the connection between the pump impeller and turbine of the torque converter changes from a rigid connection to a flexible transmission, the braking force from the ground cannot be effectively transmitted to the drive motor for regenerative braking. This makes it easy for the negative torque generated by the drive motor to stall the engine, and at the same time, it causes a sudden decrease in the vehicle's braking deceleration, thereby affecting the vehicle's braking performance and the user experience.

[0066] To address the issue that in current hybrid vehicles equipped with torque converters, the opening of the torque converter's lock-up mechanism during regenerative braking can easily lead to the drive motor stalling the engine and a sudden decrease in braking deceleration. This application aims to provide a regenerative braking control method that gradually reduces the intensity of regenerative braking by the drive motor. This effectively prevents the negative torque output from the drive motor from stalling the engine when the torque converter's lock-up mechanism opens, while also avoiding a sudden decrease in the vehicle's braking deceleration, thereby ensuring overall vehicle braking performance and improving the user experience.

[0067] Reference Figure 1 This application illustrates a braking energy recovery control method, which may include the following steps:

[0068] S101: Obtain vehicle operating condition information when the locking mechanism of the hydraulic torque converter is locked and a brake pedal depress signal is received.

[0069] It should be noted that the executing entity in this embodiment can be a computing service device with data processing, network communication, and program execution functions, or an electronic device with the above functions, such as a vehicle computer or in-vehicle computer. This embodiment will use a VCU (Vehicle Controller Unit) as the executing entity for description. It should also be noted that this embodiment does not impose specific restrictions on the executing entity of the vehicle.

[0070] In this embodiment, during vehicle operation, the VCU will acquire the working status information of the locking mechanism of the hydraulic torque converter in real time, specifically including the close (locked) state and the open (open) state. If the locking mechanism is detected to be in the locked state, it means that the vehicle is running at medium to high speed and the locking mechanism does not meet the opening conditions. At the same time, when the VCU detects the brake pedal being pressed, it means that the driver is performing a braking operation. At this time, the brake energy recovery function will be activated and the drive motor will be controlled to output negative torque to recover brake energy.

[0071] In this embodiment, since the locking mechanism of the torque converter usually switches from the locked state to the open state when the vehicle speed is low, in order not to affect the vehicle's regenerative braking at medium and high speeds, the VCU will acquire the vehicle's operating condition information and determine whether the regenerative braking function needs to be restricted based on the operating condition information.

[0072] S102: Based on operating condition information, determine whether the vehicle meets the braking energy recovery limit conditions.

[0073] In this embodiment, if the VCU detects that the vehicle does not meet the braking energy recovery limit conditions, it will control the drive motor to perform braking energy recovery operation according to the preset braking energy recovery strategy.

[0074] Specifically, in the preset regenerative braking strategy, the VCU will first calculate the vehicle's negative torque capability, which represents the maximum negative torque that the drive motor can output when performing regenerative braking. Then, based on the driver's brake pedal opening, it will calculate the driver's required braking force and determine the regenerative braking torque based on the vehicle's negative torque capability and the driver's required braking force. Finally, it will send the regenerative braking torque to the drive motor controller, so that the drive motor controller can control the drive motor to output negative torque according to the regenerative braking torque to perform the regenerative braking operation.

[0075] In this embodiment, during the vehicle's regenerative braking process, if the VCU detects that the vehicle meets the regenerative braking limit conditions, it will restrict the regenerative braking function to control the vehicle to gradually exit the regenerative braking function, that is, gradually reduce the intensity of the drive motor's regenerative braking. This prevents the negative torque output of the drive motor from stalling the engine and the sudden decrease in the vehicle's braking deceleration when the torque converter's locking mechanism opens, i.e., when the pump wheel and turbine of the torque converter change from rigid connection to flexible transmission.

[0076] In this embodiment, the VCU determines whether the vehicle meets the braking energy recovery limit conditions based on the operating condition information, so that the vehicle can maximize braking energy recovery at medium and high speeds to improve the vehicle's driving range; while at low speeds, by limiting the braking energy recovery function in advance, the state of the torque converter's lock-up mechanism can be prevented from changing, thus avoiding affecting the normal driving of the vehicle.

[0077] S103: When the vehicle meets the braking energy recovery limit conditions, adjust the negative torque capacity value of the whole vehicle to obtain the target braking energy recovery capacity value.

[0078] In practical implementation, the negative torque capability of the vehicle can be adjusted using various adjustment strategies. For example, if the vehicle meets the braking energy recovery limit conditions, the negative torque capability of the vehicle can be directly adjusted to the target torque; alternatively, the negative torque capability of the vehicle can be gradually adjusted to the target torque according to a certain gradient.

[0079] It should be noted that the target torque represents the maximum torque at which the drive motor will not stall the engine. Since the drive motor outputs negative torque during regenerative braking, this target torque is less than or equal to 0 N·m. It should be understood that when the target torque is 0 N·m, the vehicle will completely disengage from regenerative braking; when the target torque is less than 0 N·m, the drive motor will output the target torque to perform a smaller-scale regenerative braking effect. This target torque can be calibrated for different engine models to ensure that even if the full target torque is applied to the engine, it will not cause the engine to stall.

[0080] S104: Based on the target regenerative braking capacity value, control the drive motor to perform regenerative braking operation so that when the locking mechanism meets the opening condition, the target regenerative braking capacity value reaches the target torque; wherein, the drive motor is connected to the vehicle's engine.

[0081] In this embodiment, the VCU adjusts the vehicle's negative torque capability value in advance, so that when the locking mechanism meets the opening conditions, the target braking energy recovery capability value can be adjusted to the target torque.

[0082] It should be noted that during the adjustment of the vehicle's negative torque capacity, the VCU will control the braking mechanism to supplement the adjustment based on the adjustment range of the vehicle's negative torque capacity, so as to ensure that the vehicle's braking performance remains unchanged.

[0083] For example, the target torque can be set to 0 N·m. When the vehicle does not meet the regenerative braking limit, i.e., when regenerative braking is performed normally, the vehicle's negative torque capacity is -700 N·m. When the vehicle is detected to meet the regenerative braking limit, the vehicle's negative torque capacity will be limited, and the resulting target regenerative braking capacity will continuously increase. When the locking mechanism meets the opening condition, the target regenerative braking capacity will increase to 0 N·m, i.e., regenerative braking will be discontinued. As the target regenerative braking capacity increases, the braking force provided by the braking mechanism will also continuously increase, with the same increase as the target regenerative braking capacity. Thus, when the target regenerative braking capacity reaches 0 N·m, the braking force will increase by 700 N·m from the initial braking force.

[0084] In this embodiment, when the locking mechanism meets the opening condition, the locking mechanism will switch from the locked state to the open state. Specifically, when vehicle speed is used as the criterion, the opening condition can be: the vehicle's current speed is less than a vehicle threshold. That is, when the vehicle's current speed is detected to be less than the vehicle threshold, it is determined that the locking mechanism meets the opening condition.

[0085] It should be noted that since the vehicle's current speed corresponds to the transmission output shaft speed, when using speed as the criterion, the opening condition can also be: the transmission output shaft speed is less than the locking mechanism's opening speed; that is, when the transmission output shaft speed is detected to be less than the locking mechanism's opening speed, it is determined that the locking mechanism meets the opening condition.

[0086] This application embodiment determines whether the vehicle meets the braking energy recovery limit conditions based on operating condition information when the vehicle is performing braking energy recovery. When the vehicle does not meet the braking energy recovery limit conditions, braking energy recovery is performed according to the vehicle's negative torque capability value to maximize braking energy recovery and improve the vehicle's driving range. When the vehicle meets the braking energy recovery limit conditions, the braking energy recovery intensity of the drive motor is gradually reduced by adjusting the vehicle's negative torque capability value. This ensures that when the locking mechanism meets the opening conditions, the target braking energy recovery capability value can reach the target torque, effectively preventing the negative torque output by the drive motor from stalling the engine and preventing a sudden decrease in vehicle braking deceleration, thereby ensuring the vehicle's braking performance and effectively improving the user's driving experience.

[0087] In one feasible implementation, the operating condition information includes the brake pedal opening and the transmission output shaft speed, and S102 may specifically include the following sub-steps:

[0088] S102-1: Determine the threshold for limiting function entry based on brake pedal opening.

[0089] In this embodiment, the brake pedal opening reflects the driver's braking demand. A larger brake pedal opening indicates a stronger braking demand, and correspondingly, the vehicle speed and transmission output shaft speed decrease more rapidly. To ensure timely adjustment of the vehicle's negative torque capacity at different brake pedal openings, a first mapping table is pre-established to characterize different limiting function entry thresholds at different brake pedal openings. After obtaining the brake pedal opening, the corresponding limiting function entry threshold can be matched to the first mapping table. Specifically, a larger brake pedal opening corresponds to a larger limiting function entry threshold. This ensures that when the driver depresses the brake pedal deeply, the vehicle's negative torque capacity can be adjusted promptly, effectively preventing the drive motor from stalling the engine due to untimely adjustment.

[0090] S102-2: Determine the target speed difference based on the difference between the output shaft speed of the transmission and the opening speed of the locking mechanism.

[0091] In this embodiment, since the locking mechanism will meet the opening condition and switch from the locked state to the open state when the output shaft speed of the transmission decreases to the opening speed of the locking mechanism, the opening condition of the locking mechanism can be further equivalent to: the target speed difference is 0 rpm.

[0092] S102-3: If the target speed difference is less than the threshold for entering the limiting function, determine that the vehicle meets the braking energy recovery limiting conditions.

[0093] In this embodiment, the speed range from 0 rpm to the limit function entry threshold can be understood as the limit buffer zone. That is, when the target speed difference is less than the limit function entry threshold, it means that the vehicle has entered the limit buffer zone. Within the limit buffer zone, the intensity of the regenerative braking of the drive motor will be gradually reduced until the regenerative braking function is completely discontinued.

[0094] For example, the locking mechanism opening speed can be set to 300 rpm, the limiting function entry threshold can be set to 100 rpm, and the limiting buffer zone can be set to [0, 100), which is a front-closed and rear-open interval. That is, when the transmission output shaft speed is less than 400 rpm, the limiting function will be activated, and the intensity of the regenerative braking of the drive motor will be gradually reduced until the transmission output shaft speed reaches 300 rpm, that is, when the target speed difference is 0 rpm, the regenerative braking function will be completely deactivated, and the drive motor will no longer output negative torque.

[0095] In this embodiment, by setting a threshold for limiting the entry of the function, the regenerative braking function can be gradually deactivated before the torque converter lock-up mechanism is opened. Compared with directly deactivating the regenerative braking function, this can recover as much braking energy as possible while avoiding the phenomenon of the drive motor stalling the engine, thereby increasing the vehicle's driving range.

[0096] In one feasible implementation, S102 may further include the following sub-steps:

[0097] S102-4: Determine the threshold for exiting the restriction function based on the brake pedal opening.

[0098] In this embodiment, while setting the threshold for entering the restriction function, the threshold for exiting the restriction function will also be determined based on the brake pedal opening, so that the driver can release the restriction on the regenerative braking function after stopping the braking.

[0099] In a specific implementation, a second mapping table can be pre-established to characterize different limit function exit thresholds under different brake pedal openings. Then, after obtaining the brake pedal opening, the limit function exit threshold corresponding to the brake pedal opening can be matched in the second mapping table.

[0100] It should be noted that the exit threshold for restricted functions must also be greater than the entry threshold for restricted functions. This can effectively avoid frequent switching between activation and exit of restricted functions due to a single threshold.

[0101] S102-5: If the target speed difference is detected to be less than the limit function entry threshold, and the target speed difference is greater than the limit function exit threshold, it is determined that the vehicle does not meet the braking energy recovery limit conditions.

[0102] In this embodiment, since the restriction function exit threshold is greater than the restriction function entry threshold, after detecting that the target speed difference is less than the restriction function entry threshold, if the target speed difference is greater than or equal to the restriction function entry threshold, the restriction function will not exit. Instead, the restriction function will exit only when the target speed difference is greater than the restriction function exit threshold.

[0103] For example, the locking mechanism opening speed can be set to 300 rpm, the limiting function entry threshold can be set to 100 rpm, and the limiting function exit threshold can be set to 200 rpm. That is, when the transmission output shaft speed is less than 400 rpm, the limiting function will be activated; thereafter, when the vehicle stops braking and the transmission output shaft speed increases to 400 rpm, the limiting function will remain activated, and it will remain activated when the transmission output shaft speed fluctuates between 400 rpm and 500 rpm, until the transmission output shaft speed increases to 500 rpm, at which point it is determined that the vehicle does not meet the braking energy recovery limiting conditions, and the limiting function will then exit.

[0104] In this embodiment, by setting different limit function entry thresholds and limit function exit thresholds, the target speed difference is allowed to fluctuate between the limit function entry threshold and the limit function exit threshold, avoiding frequent jumps in the vehicle's negative torque caused by the limit function frequently switching between activation and deactivation, thus ensuring the user's driving experience.

[0105] In one feasible implementation, prior to S103, the braking energy recovery control method may further include the following steps:

[0106] S201: Determine the vehicle's negative torque capability value based on the charging power of the power battery and the negative torque capability of the drive motor.

[0107] It should be noted that the charging power of the power battery represents the maximum power that the power battery can currently charge. This charging power is related to parameters such as the current SOC (State of Charge, also known as remaining charge), operating temperature, and electrode materials of the power battery. On the other hand, the negative torque capability of the drive motor represents the maximum negative torque that the drive motor can output. This negative torque capability is related to parameters such as the speed of the drive motor.

[0108] In practice, the VCU will calculate the maximum rechargeable torque corresponding to the charging power based on the charging power of the power battery. When the negative torque capability of the drive motor is greater than the maximum rechargeable torque, the maximum rechargeable torque will be determined as the negative torque capability value of the whole vehicle; when the negative torque capability of the drive motor is less than or equal to the maximum rechargeable torque, the negative torque capability of the drive motor will be determined as the negative torque capability value of the whole vehicle.

[0109] In this embodiment, by calculating the vehicle's negative torque capability value based on the charging power of the power battery and the negative torque capability of the drive motor, the drive motor can be controlled to maximize braking energy recovery while ensuring the charging safety of the power battery.

[0110] In one feasible implementation, S103 may specifically include the following sub-steps:

[0111] S103-1: Determine the limit value of braking energy recovery capability based on the rate of change of the difference between the transmission output shaft speed and the target speed.

[0112] In this embodiment, in order to achieve a smooth change in the braking energy recovery capability limit value, and at the same time limit the vehicle's negative torque capability value to a suitable braking energy recovery capability limit value, the VCU will match the corresponding braking energy recovery capability limit value according to the rate of change of the difference between the transmission output shaft speed and the target speed.

[0113] Specifically, a third mapping table can be pre-established to characterize the different braking energy recovery capability limits corresponding to the rate of change of different target speed differences under different transmission output shaft speeds. Then, after obtaining the transmission output shaft speed and the rate of change, the corresponding braking energy recovery capability limit can be matched by looking up the table.

[0114] In a specific implementation, S103-1 may include the following sub-steps:

[0115] S103-1-1: Determine the initial time when the vehicle meets the braking energy recovery limit conditions, and determine the initial braking energy recovery capacity limit value based on the initial rate of change of the initial transmission output shaft speed and the target speed difference corresponding to the initial time.

[0116] In this embodiment, when the vehicle is detected to meet the braking energy recovery limit conditions, the initial braking energy recovery capacity limit value corresponding to the initial time will be determined based on the third mapping table.

[0117] S103-1-2: Control the increase of the braking energy recovery capacity limit value from the initial braking energy recovery capacity limit value to the target torque.

[0118] It should be noted that since the limit value for regenerative braking capacity is negative, the initial limit value is the minimum value when the limiting function is first activated. As the braking process proceeds, the limit value for regenerative braking capacity will gradually increase until it reaches the target torque.

[0119] In this embodiment, the limit value for regenerative braking capability is negatively correlated with the transmission output shaft speed. That is, the faster the transmission output shaft speed, the larger the limit value for regenerative braking capability will be. In this case, the VCU will adjust the vehicle's negative torque capability value more early. In addition, the limit value for regenerative braking capability is also positively correlated with the rate of change of the target speed difference. The rate of change of the target speed difference is equivalent to the rate of change of the transmission output shaft speed. That is, the faster the rate of change, the larger the limit value for regenerative braking capability will be, and the VCU will adjust the vehicle's negative torque capability value more early.

[0120] For example, if the rate of change of the target speed difference remains constant, the transmission output shaft speed will decrease linearly. Correspondingly, the limit value for regenerative braking will also increase linearly from the initial limit value to the target torque. For instance, if the target torque is 0 N·m and the initial limit value for regenerative braking is -500 N·m, the limit value for regenerative braking will increase as the transmission output shaft speed decreases, such as from -500 N·m to -400 N·m, -300 N·m, -200 N·m, -100 N·m, and 0 N·m. When it increases to 0 N·m, the regenerative braking function will completely deactivate, and the locking mechanism will also meet the opening conditions, switching from the locked state to the open state.

[0121] In this embodiment, by comprehensively considering the rate of change of the difference between the transmission output shaft speed and the target speed, the limit value of the regenerative braking capability can be smoothly increased to the target torque at a certain slope. Compared with directly increasing the limit value of the regenerative braking capability to the target torque, more braking energy can be recovered, and it is ensured that when the locking mechanism switches from the locked state to the open state, the drive motor will not stall the engine, nor will the vehicle's braking performance be affected.

[0122] S103-2: The larger of the braking energy recovery capacity limit value and the vehicle negative torque capacity value is determined as the target braking energy recovery capacity value.

[0123] In this embodiment, since the vehicle's negative torque capability is determined based on the charging power of the power battery and the negative torque capability of the drive motor, under certain operating conditions, the limit value of the regenerative braking capability may be less than the vehicle's negative torque capability value. For example, the limit value of the regenerative braking capability may be -1000 N·m, while the vehicle's negative torque capability value may be -700 N·m. In this case, the vehicle's negative torque capability value will be determined as the target regenerative braking capability value. When the limit value of the regenerative braking capability may be greater than or equal to the vehicle's negative torque capability value, the limit value of the regenerative braking capability will be determined as the target regenerative braking capability value.

[0124] In this embodiment, by determining the larger of the braking energy recovery capability limit value and the vehicle negative torque capability value as the target braking energy recovery capability value, the vehicle negative torque capability value can be effectively adjusted under various operating conditions, achieving a smooth transition from the braking energy recovery function to the opening of the hydraulic torque converter lock-up mechanism.

[0125] In one feasible implementation, the braking energy recovery control method may further include the following steps:

[0126] S301: Send the target regenerative braking capacity value to the braking system controller so that the braking system controller can determine the regenerative braking torque based on the target regenerative braking capacity value and the brake pedal opening.

[0127] In this embodiment, after obtaining the target regenerative braking capacity value, the VCU will send the target regenerative braking capacity value to the chassis's braking system controller. The braking system controller will calculate the driver's required braking force based on the driver's brake pedal opening and return the regenerative braking torque to the VCU based on the target regenerative braking capacity value and the driver's required braking force.

[0128] It should be noted that when the target regenerative braking capacity is greater than or equal to the driver's required braking force, the brake system controller will determine the driver's required braking force as the regenerative braking torque; when the target regenerative braking capacity is less than the driver's required braking force, the brake system controller will determine the target regenerative braking capacity as the regenerative braking torque, and determine the difference between the driver's required braking force and the target regenerative braking capacity as the target braking force, and control the braking mechanism to perform braking operation according to the target braking force to meet the vehicle's braking needs.

[0129] S302: Receives the regenerative braking torque and controls the drive motor to perform regenerative braking operation according to the regenerative braking torque.

[0130] In this embodiment, after receiving the regenerative braking torque sent by the braking system controller, the VCU generates a torque request containing the regenerative braking torque and sends the torque request to the drive motor controller. The drive motor controller then responds to the torque request by outputting a negative torque according to the regenerative braking torque of the drive motor to perform the regenerative braking operation.

[0131] Secondly, based on the same inventive concept, and referring to... Figure 2 This application provides a braking energy recovery control device 200, which includes:

[0132] The acquisition module 201 is used to acquire the vehicle's operating condition information when the locking mechanism of the hydraulic torque converter is in the locked state and a brake pedal depressing signal is received.

[0133] The determination module 202 is used to determine whether the vehicle meets the braking energy recovery limit conditions based on the operating condition information;

[0134] The adjustment module 203 is used to adjust the negative torque capacity value of the vehicle when the vehicle meets the braking energy recovery limit conditions, so as to obtain the target braking energy recovery capacity value.

[0135] The control module 204 is used to control the drive motor to perform brake energy recovery operation based on the target brake energy recovery capability value, so that the target brake energy recovery capability value reaches the target torque when the locking mechanism meets the opening condition; wherein, the drive motor is connected to the vehicle's engine.

[0136] In one embodiment of this application, the operating condition information includes the brake pedal opening and the transmission output shaft speed; the determination module 202 includes:

[0137] The first threshold determination submodule is used to determine the threshold for restricting the function entry based on the brake pedal opening.

[0138] The target speed difference determination submodule is used to determine the target speed difference based on the difference between the transmission output shaft speed and the locking mechanism opening speed;

[0139] The first condition determination submodule is used to determine whether the vehicle meets the braking energy recovery limit conditions when the target speed difference is less than the limit function entry threshold.

[0140] In one embodiment of this application, the determining module 202 further includes:

[0141] The second threshold determination submodule determines the restriction function exit threshold based on the brake pedal opening; wherein, the restriction function exit threshold is greater than the restriction function entry threshold.

[0142] The second condition determination submodule is used to determine that the vehicle does not meet the braking energy recovery limit conditions when the target speed difference is detected to be less than the limit function entry threshold and greater than the limit function exit threshold.

[0143] In one embodiment of this application, the braking energy recovery control device 200 further includes:

[0144] The vehicle negative torque capability determination module is used to determine the vehicle negative torque capability value based on the charging power of the power battery and the negative torque capability of the drive motor before adjusting the vehicle negative torque capability value to obtain the target braking energy recovery capability value.

[0145] In one embodiment of this application, the adjustment module 203 includes:

[0146] The limit value determination submodule is used to determine the limit value of braking energy recovery capability based on the rate of change of the difference between the transmission output shaft speed and the target speed.

[0147] The capability value determination submodule is used to determine the larger of the braking energy recovery capability limit value and the vehicle negative torque capability value as the target braking energy recovery capability value.

[0148] In one embodiment of this application, the limit value determination submodule includes:

[0149] The initial limit value determination unit is used to determine the time when the vehicle meets the braking energy recovery limit conditions as the initial time, and to determine the initial braking energy recovery capacity limit value based on the initial rate of change of the difference between the initial transmission output shaft speed and the target speed corresponding to the initial time.

[0150] The limit control unit is used to control the increase of the regenerative braking capacity limit from the initial regenerative braking capacity limit to the target torque; wherein, the regenerative braking capacity limit is negatively correlated with the transmission output shaft speed, and positively correlated with the rate of change of the regenerative braking capacity limit and the target speed difference.

[0151] In one embodiment of this application, the control module 204 includes:

[0152] The capability value sending submodule is used to send the target braking energy recovery capability value to the braking system controller, so that the braking system controller can determine the braking energy recovery torque based on the target braking energy recovery capability value and the brake pedal opening.

[0153] The energy recovery control submodule is used to receive the braking energy recovery torque and control the drive motor to perform braking energy recovery operation according to the braking energy recovery torque.

[0154] It should be noted that the specific implementation of the braking energy recovery control device 200 in this application embodiment refers to the specific implementation of the braking energy recovery control method proposed in the first aspect of the aforementioned application embodiment, and will not be repeated here.

[0155] Thirdly, based on the same inventive concept, embodiments of this application provide a storage medium storing machine-executable instructions, which, when executed by a processor, implement the braking energy recovery control method proposed in the first aspect of this application.

[0156] It should be noted that the specific implementation of the storage medium in the embodiments of this application refers to the specific implementation of the braking energy recovery control method proposed in the first aspect of this application, and will not be repeated here.

[0157] Fourthly, based on the same inventive concept, referring to Figure 3 This application provides a vehicle 300, including a processor 301 and a memory 302; the memory 302 stores machine-executable instructions that can be executed by the processor 301, and the processor 301 is used to execute the machine-executable instructions to implement the braking energy recovery control method proposed in the first aspect of this application.

[0158] It should be noted that the specific implementation of the vehicle 300 in this application embodiment refers to the specific implementation of the braking energy recovery control method proposed in the first aspect of this application, and will not be repeated here.

[0159] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, apparatus, or computer program products. Therefore, embodiments of the present invention can take the form of entirely hardware embodiments, entirely software embodiments, or embodiments combining software and hardware aspects. Furthermore, embodiments of the present invention can take the form of computer program products implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0160] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, terminal devices (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing terminal device to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing terminal device, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0161] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing terminal device to operate in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0162] These computer program instructions can also be loaded onto a computer or other programmable data processing terminal equipment, causing a series of operational steps to be performed on the computer or other programmable terminal equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable terminal equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0163] Although preferred embodiments of the present invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the embodiments of the present invention.

[0164] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or terminal device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or terminal device. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or terminal device that includes the element.

[0165] The above provides a detailed description of the braking energy recovery control method, device, storage medium, and vehicle provided by the present invention. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A method for controlling regenerative braking energy, characterized in that, The method includes: When the locking mechanism of the hydraulic torque converter is locked and a brake pedal depress signal is received, the vehicle's operating condition information is obtained; Based on the aforementioned operating condition information, determine whether the vehicle meets the braking energy recovery limit conditions; The negative torque capability value of the whole vehicle is determined based on the charging power of the power battery and the negative torque capability of the drive motor. When the vehicle meets the braking energy recovery limit conditions, the negative torque capacity of the whole vehicle is adjusted to obtain the target braking energy recovery capacity value. Based on the target regenerative braking capacity value, the drive motor is controlled to perform regenerative braking operation so that when the locking mechanism meets the opening condition, the target regenerative braking capacity value reaches the target torque; wherein, the drive motor is connected to the vehicle's engine; The operating condition information includes the brake pedal opening and the transmission output shaft speed; The step of determining whether the vehicle meets the braking energy regeneration limit conditions based on the aforementioned operating condition information includes: Based on the brake pedal opening, determine the threshold for entering the restriction function; The target speed difference is determined based on the difference between the output shaft speed of the transmission and the opening speed of the locking mechanism; If the target speed difference is less than the threshold for entering the limiting function, the vehicle is determined to meet the braking energy recovery limiting condition.

2. The braking energy recovery control method according to claim 1, characterized in that, The step of determining whether the vehicle meets the braking energy recovery limit conditions based on the aforementioned operating condition information further includes: Based on the brake pedal opening, a restriction function exit threshold is determined; wherein, the restriction function exit threshold is greater than the restriction function entry threshold; If the target speed difference is detected to be less than the limit function entry threshold, and the target speed difference is greater than the limit function exit threshold, it is determined that the vehicle does not meet the braking energy recovery limit condition.

3. The braking energy recovery control method according to claim 1, characterized in that, The steps for adjusting the overall vehicle's negative torque capacity to obtain the target regenerative braking capacity include: The braking energy recovery capability limit is determined based on the rate of change between the transmission output shaft speed and the target speed difference. The larger of the braking energy recovery capability limit value and the vehicle negative torque capability value is determined as the target braking energy recovery capability value.

4. The braking energy recovery control method according to claim 3, characterized in that, The step of determining the braking energy recovery capability limit based on the output shaft speed of the transmission and the rate of change of the target speed difference includes: The initial moment is determined when the vehicle meets the braking energy recovery limit condition. Based on the initial rate of change of the initial transmission output shaft speed and the target speed difference corresponding to the initial moment, the initial braking energy recovery capacity limit value is determined. The braking energy recovery capability limit value is controlled to increase from the initial braking energy recovery capability limit value to the target torque; wherein, the braking energy recovery capability limit value is negatively correlated with the output shaft speed of the transmission, and the braking energy recovery capability limit value is positively correlated with the rate of change of the target speed difference.

5. The braking energy recovery control method according to claim 1, characterized in that, The steps for controlling the drive motor to perform regenerative braking operation based on the target regenerative braking capability value include: The target regenerative braking capacity value is sent to the braking system controller so that the braking system controller can determine the regenerative braking torque based on the target regenerative braking capacity value and the brake pedal opening. The system receives the regenerative braking torque and controls the drive motor to perform regenerative braking operation according to the regenerative braking torque.

6. A braking energy recovery control device, characterized in that, The device includes: The acquisition module is used to acquire vehicle operating condition information when the locking mechanism of the hydraulic torque converter is locked and a brake pedal depress signal is received. The determination module is used to determine whether the vehicle meets the braking energy recovery limit conditions based on the operating condition information. The vehicle negative torque capability value determination module is used to determine the vehicle negative torque capability value based on the charging power of the power battery and the negative torque capability of the drive motor before adjusting the vehicle negative torque capability value to obtain the target braking energy recovery capability value. The adjustment module is used to adjust the negative torque capacity value of the vehicle when the vehicle meets the braking energy recovery limit conditions, so as to obtain the target braking energy recovery capacity value. A control module is used to control a drive motor to perform regenerative braking operation based on the target regenerative braking capacity value, so that the target regenerative braking capacity value reaches the target torque when the locking mechanism meets the opening condition; wherein the drive motor is connected to the vehicle's engine; The operating condition information includes brake pedal opening and transmission output shaft speed; the determining module includes: The first threshold determination submodule is used to determine the threshold for restricting the function based on the brake pedal opening. The target speed difference determination submodule is used to determine the target speed difference based on the difference between the output shaft speed of the transmission and the opening speed of the locking mechanism; The first condition determination submodule is used to determine that the vehicle meets the braking energy recovery limitation condition when the target speed difference is less than the limiting function entry threshold.

7. A storage medium, characterized in that, The storage medium stores machine-executable instructions, which, when executed by a processor, implement the braking energy recovery control method as described in any one of claims 1-5.

8. A vehicle, characterized in that, It includes a processor and a memory, the memory storing machine-executable instructions that can be executed by the processor, the processor executing the machine-executable instructions to implement the braking energy recovery control method as described in any one of claims 1-5.

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