Vehicle brake energy recovery control method and device and vehicle

Abstract

The application provides a vehicle brake energy recovery control method, device and vehicle. When the vehicle is in a brake energy recovery state, the method responds to a received gear reduction request of a transmission, and then controls a power system to perform brake energy recovery according to a brake energy recovery request value sent by a chassis system. Further, current gear information of the transmission in the gear reduction process is obtained, wheel end torque is determined based on the current gear information and a current input shaft torque, and then a brake energy recovery execution value is determined according to the wheel end torque, which is sent to the chassis system to make the chassis system feedback an execution result. The execution value is determined based on actual gear shifting process information of the transmission, the accuracy of the execution value fed back to the chassis system is ensured, the problem that the brake energy recovery function is reported as an error and disabled in the prior art is solved, and normal operation of the function is ensured.

Description

Vehicle braking energy recovery control methods, devices and vehicles Technical Field

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

[0002] Current new energy vehicles are generally equipped with CRBS (Cooperative Regenerative Brake Systems), an electro-hydraulic coordinated energy recovery device, to ensure smooth deceleration during braking. Simultaneously, the regenerative braking function can increase the driving range of new energy vehicles. Furthermore, most new energy vehicles are also equipped with a transmission. During gear shifting, the transmission requests a certain target torque from the vehicle to allow the transmission input shaft to quickly reach the target speed, thus achieving both rapid gear shifting and ensuring smoothness.

[0003] When downshifting occurs during the regenerative braking phase, the transmission shifts from the current gear to the target gear. Currently, before the transmission shifts to the target gear, the torque calculation at the wheels is inaccurate, leading to errors in the torque execution value of the regenerative braking feedback. This causes the regenerative braking function to frequently report errors and become disabled, affecting the vehicle's driving range. Summary of the Invention

[0004] In view of this, the purpose of this application is to propose a vehicle braking energy recovery control method, device and vehicle, which solves the problem of braking energy recovery function error and disabling caused by vehicle downshifting interference in the braking energy recovery process in the prior art, and ensures the normal operation of braking energy recovery function.

[0005] To achieve the above objectives, this application provides a vehicle braking energy recovery control method, applied to a vehicle controller, comprising:

[0006] When the vehicle is in the regenerative braking state, it responds to the downshift request received by the transmission and controls the powertrain to perform regenerative braking based on the regenerative braking request value sent by the chassis system.

[0007] The current gear information of the transmission during downshifting is obtained, and the wheel-end torque of the vehicle is determined based on the current gear information and the current input shaft torque of the transmission.

[0008] The braking energy recovery execution value is determined based on the wheel end torque, and the braking energy recovery execution value is sent to the chassis system so that the chassis system can provide feedback on the execution result based on the braking energy recovery execution value.

[0009] Optionally, determining the wheel-end torque of the vehicle based on the current gear information and the current input shaft torque of the transmission includes:

[0010] Based on the current gear information, determine the current hydraulic pressure value corresponding to each clutch in the transmission;

[0011] Based on the current hydraulic value corresponding to each clutch, the current transmission coefficient corresponding to the current hydraulic value is queried in a preset first calibration table, wherein the preset first calibration table is used to describe the correspondence between each hydraulic value and each transmission coefficient;

[0012] The wheel-end torque of the vehicle is determined based on the current input shaft torque of the transmission and each of the current transmission coefficients.

[0013] Optionally, determining the wheel-end torque of the vehicle based on the current input shaft torque of the transmission and each of the current transmission coefficients includes:

[0014] The output torque of each clutch is determined based on the current input shaft torque of the transmission and each current transmission coefficient, and the output shaft torque of the transmission is determined based on the output torque of each clutch.

[0015] Obtain the final drive ratio of the vehicle, and determine the wheel-end torque of the vehicle based on the output shaft torque and the final drive ratio.

[0016] Optionally, determining the output shaft torque of the transmission based on the output torque of each of the clutches includes:

[0017] The sum of the output torques of each of the clutches is taken as the initial output shaft torque of the transmission;

[0018] The moment of inertia and angular acceleration of the drive shaft in the vehicle are obtained, and the loss torque of the drive shaft is determined based on the moment of inertia and the angular acceleration.

[0019] The difference between the initial output shaft torque and the lost torque is determined as the output shaft torque.

[0020] Optionally, determining the regenerative braking value based on the wheel-end torque includes:

[0021] The current vehicle speed is obtained, and the corresponding current coasting energy recovery torque is queried in a preset second calibration table based on the current vehicle speed. The preset second calibration table is used to describe the correspondence between each vehicle speed and each coasting energy recovery torque.

[0022] The braking energy recovery execution value is determined based on the difference between the wheel-end torque and the current coasting energy recovery torque.

[0023] Optionally, determining the braking energy recovery execution value based on the difference between the wheel-end torque and the current coasting energy recovery torque includes:

[0024] The difference between the wheel-end torque and the current coasting energy recovery torque is taken as the actual value of braking energy recovery;

[0025] If the actual value of the regenerative braking energy is greater than the requested value of the regenerative braking energy, then the requested value of the regenerative braking energy is determined as the regenerative braking energy execution value; if the actual value of the regenerative braking energy is less than or equal to the requested value of the regenerative braking energy, then the actual value of the regenerative braking energy is determined as the regenerative braking energy execution value.

[0026] Optionally, before controlling the powertrain to perform brake energy recovery based on the brake energy recovery request value sent by the chassis system, the method further includes:

[0027] The maximum regenerative braking energy of the vehicle is determined based on the maximum allowable charging capacity of the vehicle's battery and the maximum power generation capacity of the vehicle's motor.

[0028] The maximum value of brake energy recovery is sent to the chassis system so that the chassis system determines a brake energy recovery request value based on the maximum value of brake energy recovery, wherein the brake energy recovery request value does not exceed the maximum value of brake energy recovery.

[0029] For the same purpose, this application also provides a vehicle braking energy recovery control method, applied to a chassis system, comprising:

[0030] Receive the regenerative braking execution value sent by the vehicle controller;

[0031] If the difference between the regenerative braking execution value and the regenerative braking return request value exceeds a preset threshold, an execution failure result is sent to the vehicle controller, and the regenerative braking function of the vehicle is turned off.

[0032] For the same purpose, this application also provides a vehicle braking energy recovery control device, comprising:

[0033] The regenerative braking module is used to respond to the downshift request received by the transmission when the vehicle is in the regenerative braking state, and to control the powertrain to perform regenerative braking based on the regenerative braking request value sent by the chassis system.

[0034] The determination module is used to obtain the current gear information of the transmission during downshifting, and determine the wheel end torque of the vehicle based on the current gear information and the current input shaft torque of the transmission.

[0035] The sending module is used to determine the braking energy recovery execution value based on the wheel end torque, and send the braking energy recovery execution value to the chassis system so that the chassis system can provide feedback on the execution result based on the braking energy recovery execution value.

[0036] For the same purpose, this application also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the method provided in any embodiment of this application.

[0037] For the same purpose, this application also provides a non-transitory computer-readable storage medium storing computer instructions for causing a computer to perform the methods provided in any embodiment of this application.

[0038] For the same purpose, this application also provides a vehicle including the electronic equipment provided in any embodiment of this application.

[0039] As can be seen from the above, the vehicle braking energy recovery control method provided in this application responds to the downshift request received by the transmission when the vehicle is in braking energy recovery state. Then, based on the braking energy recovery request value sent by the chassis system, it controls the power system to perform braking energy recovery. Furthermore, it obtains the current gear information of the transmission during downshifting, determines the wheel-end torque based on this information and the current input shaft torque, and then determines the braking energy recovery execution value based on the wheel-end torque, sending it to the chassis system so that the chassis system can provide feedback on the execution result. This method determines the wheel-end torque based on the transmission's structural information during downshifting to obtain the braking energy recovery execution value, realizing the determination of the execution value based on the actual transmission shifting process information. This ensures the accuracy of the execution value fed back to the chassis system, solves the problem of incorrect execution value calculation caused by vehicle downshifting interference in the braking energy recovery process in the prior art, and further solves the problem of the chassis system reporting errors and disabling the braking energy recovery function, ensuring the normal operation of the braking energy recovery function. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in this application or related technologies, the drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 is a flowchart of a vehicle braking energy recovery control method provided in an embodiment of this application;

[0042] Figure 2 is a flowchart of a vehicle braking energy recovery control method provided in an embodiment of this application;

[0043] Figure 3 is a framework diagram of a vehicle braking energy recovery control system provided in an embodiment of this application;

[0044] Figure 4 is a flowchart illustrating the execution process of the vehicle braking energy recovery control system provided in an embodiment of this application;

[0045] Figure 5 is a structural schematic diagram of a vehicle braking energy recovery control device provided in an embodiment of this application;

[0046] Figure 6 is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Detailed Implementation

[0047] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with specific embodiments and the accompanying drawings.

[0048] It should be noted that, unless otherwise defined, the technical or scientific terms used in the embodiments of this application should have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "first," "second," and similar terms used in the embodiments of this application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are only used to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0049] Before introducing the vehicle braking energy recovery control method provided in the embodiments of this application, the technical problem to be solved is described first. In the prior art, when a downshift occurs during the braking energy recovery stage, the vehicle will prioritize responding to the transmission's torque increase request, and then further respond to the braking energy recovery torque request. The wheel-end torque of the whole vehicle is calculated by multiplying the engine / motor by the speed ratio (transmission speed ratio, final drive ratio, etc.). During the shifting process, the transmission is shifting from the current gear to the target gear. The actual power transmission does not have a fixed speed ratio. Currently, before the transmission shifts to the target gear, the whole vehicle uses the speed ratio of the current gear. This leads to inaccurate calculation of the wheel-end torque of the whole vehicle during the shifting process, which in turn leads to errors in the torque execution value of the braking energy recovery feedback. The difference between this value and the torque request value is large, causing the braking energy recovery function to frequently report errors and be disabled, affecting the vehicle's driving range.

[0050] Therefore, in order to solve the above problems, this application provides a vehicle braking energy recovery control method, which determines the wheel end torque of the vehicle by using the current gear information during the downshifting process of the transmission, and then obtains the braking energy recovery execution value, thus ensuring the accuracy of the braking energy recovery execution value.

[0051] Figure 1 is a flowchart of a vehicle brake energy recovery control method provided in an embodiment of this application. This method is applied to the vehicle controller, specifically, it is applicable when the vehicle controller, based on a brake energy recovery request value sent by the chassis system, controls the powertrain to perform brake energy recovery, and then feeds back a brake energy recovery execution value to the chassis system, so that the chassis system can determine the execution result based on the brake energy recovery request value and the brake energy recovery execution value. This vehicle brake energy recovery control method can be executed by a vehicle brake energy recovery control device, which can be integrated into the vehicle controller through hardware and / or software. As shown in Figure 1, the vehicle brake energy recovery control method includes the following steps:

[0052] S110. When the vehicle is in the braking energy recovery state, respond to the received downshift request from the transmission, and control the power system to perform braking energy recovery based on the braking energy recovery request value sent by the chassis system.

[0053] The regenerative braking state can be a state in which excess energy released during vehicle braking is converted into electrical energy and stored in the battery. For example, when the brake pedal is detected to be triggered, it can be determined that the regenerative braking function is activated, and thus the vehicle is in a regenerative braking state.

[0054] Specifically, when the vehicle is in regenerative braking mode, if a downshift request is detected from the transmission, the system will respond to the downshift request first. This downshift request can be a request for the transmission to shift from the current gear to a target gear, where the gear ratio of the target gear is lower than that of the current gear.

[0055] In this embodiment, the transmission can determine whether a downshift is needed based on the vehicle's current speed and brake pedal opening. For example, the transmission can determine that a downshift is needed when the current speed is decreasing and the brake pedal opening is greater than zero. If a downshift is needed, the transmission can determine the target torque based on the clutch engagement conditions in the target gear. The target torque can be the torque value that the transmission's input shaft is expected to adjust to. Then, a downshift request is generated based on the target torque and sent to the vehicle controller.

[0056] It should be noted that when the transmission detects a downshifting demand, it sends a downshifting request to the vehicle controller to request the target torque. The purpose of this is that since the transmission's downshifting request requires switching to the target gear, and the gear ratio of the target gear is lower than that of the current gear, in order to ensure the smoothness of the vehicle during the shift, that is, to prevent a sudden change in the wheel torque, the transmission requests the target torque from the vehicle controller. This target torque is usually greater than the current input shaft torque, so as to increase the input shaft torque and thus avoid sudden changes in wheel torque caused by the reduction in gear ratio.

[0057] After receiving a downshift request from the transmission, the vehicle controller can use torque arbitration to prioritize responding to the target torque in the downshift request, among the received downshift request and regenerative braking request values. Specifically, the vehicle controller can send the target torque in the downshift request to the vehicle's powertrain, which then adjusts the input shaft torque of the transmission. The powertrain consists of an engine and an electric motor.

[0058] Furthermore, the vehicle controller responds to the regenerative braking request value sent by the chassis system. Specifically, the vehicle controller can send the regenerative braking request value to the powertrain system, which will then execute the request. The regenerative braking request value can be the wheel-end torque value requested for regenerative braking, which can be calculated by the CRBS device in the chassis system based on the brake pedal opening.

[0059] In this embodiment, in order to ensure that the braking energy recovery request value received by the vehicle controller from the chassis system does not exceed the maximum power generation of the motor and the maximum allowable charging capacity of the battery, the maximum braking energy recovery value can also be sent to the chassis system before receiving the braking energy recovery request value.

[0060] For example, optionally, before controlling the powertrain to perform brake energy recovery based on the brake energy recovery request value sent by the chassis system, the method further includes: determining the maximum value of brake energy recovery for the vehicle based on the maximum allowable charging amount of the vehicle's battery and the maximum power generation of the vehicle's motor; sending the maximum value of brake energy recovery to the chassis system so that the chassis system determines the brake energy recovery request value based on the maximum value of brake energy recovery, wherein the brake energy recovery request value does not exceed the maximum value of brake energy recovery.

[0061] The maximum value of regenerative braking can be the maximum feasible value for regenerative braking. Specifically, the maximum value of regenerative braking can be the minimum value between the maximum allowable charge of the battery and the maximum power generation of the vehicle's control unit. The vehicle controller can convert the minimum value between the maximum allowable charge and the maximum power generation into wheel-end torque to obtain the maximum value of regenerative braking.

[0062] Furthermore, the vehicle controller can send the maximum regenerative braking value to the chassis system, ensuring that the regenerative braking request value determined by the chassis system does not exceed this maximum value. This implementation avoids situations where the regenerative braking request value is too high, preventing the powertrain from fully executing the function and causing errors or disabling of the regenerative braking function in the chassis system.

[0063] S120: Obtain the current gear information of the transmission during downshifting, and determine the wheel-end torque of the vehicle based on the current gear information and the current input shaft torque of the transmission.

[0064] The current gear information describes the current state of the components inside the transmission that perform gear shifting, such as the position of the gears or the hydraulic pressure of each clutch. Specifically, sensors installed inside the transmission can collect the current gear information during the process of shifting from the current gear to the target gear.

[0065] In this embodiment, the purpose of obtaining the current gear information during downshifting is that the transmission does not have a fixed speed ratio during downshifting. If a fixed speed ratio is used to calculate the wheel-end torque, the calculated wheel-end torque will be incorrect. Therefore, in this embodiment, the wheel-end torque is calculated by using the current gear information, which can ensure the accuracy of the calculated wheel-end torque, so that it can be used as the real wheel-end torque for subsequent calculation of the braking energy recovery execution value.

[0066] For example, the gear position in the current gear information can be used to find the current transmission coefficient corresponding to the gear position in a pre-calibrated transmission coefficient table, and then the wheel end torque can be calculated using the current transmission coefficient and the current input shaft torque of the transmission.

[0067] In one specific implementation, determining the wheel-end torque of the vehicle based on the current gear information and the current input shaft torque of the transmission includes: determining the current hydraulic value corresponding to each clutch in the transmission based on the current gear information; querying the current transmission coefficient corresponding to the current hydraulic value in a preset first calibration table based on the current hydraulic value of each clutch, wherein the preset first calibration table is used to describe the correspondence between each hydraulic value and each transmission coefficient; and determining the wheel-end torque of the vehicle based on the current input shaft torque of the transmission and each current transmission coefficient.

[0068] Specifically, the current transmission coefficient corresponding to the current hydraulic pressure value of each clutch in the current gear information can be found in the preset first calibration table. The current transmission coefficient represents the ratio of the torque after clutch transmission to the torque before transmission. Furthermore, after obtaining the current transmission coefficients of all clutches, the wheel end torque can be calculated using the current input shaft torque.

[0069] For example, the current input shaft torque can be multiplied by each current transmission coefficient, and the sum of the results can be used as the wheel end torque. For instance, if there are 2 clutches, and the current transmission coefficients obtained by looking up the preset first calibration table include 0.8 and 0.6, and the current input shaft torque is 160N, then the wheel end torque can be determined to be 160×0.8+160*0.6=224N.

[0070] By presetting the first calibration table, the current transmission coefficient of each clutch in the transmission can be accurately determined, thereby accurately determining the wheel-end torque and ensuring the accuracy of subsequent calculations of the braking energy recovery execution value.

[0071] In this embodiment, considering that in some scenarios, the output shaft torque of the transmission needs to be obtained by passing through the final drive ratio to obtain the wheel end torque, the wheel end torque of the vehicle can also be calculated by combining the final drive ratio.

[0072] In one alternative implementation, determining the wheel-end torque of the vehicle based on the current input shaft torque of the transmission and each current transmission coefficient includes: determining the output torque of each clutch based on the current input shaft torque and each current transmission coefficient, and determining the output shaft torque of the transmission based on the output torque of each clutch; obtaining the final drive ratio of the vehicle, and determining the wheel-end torque of the vehicle based on the output shaft torque and the final drive ratio.

[0073] That is, the product of the current input shaft torque and the current transmission coefficient can be used as the clutch output torque. Furthermore, the sum of the output torques of all clutches is used as the transmission output shaft torque. The product of the output shaft torque and the final drive ratio is used as the wheel-end torque of the vehicle. Through this implementation, the wheel-end torque considering the vehicle's final drive ratio can be determined, further improving the accuracy of the wheel-end torque.

[0074] In addition, considering that there is a certain amount of loss when the drive shaft transmits all the output torque of the clutches to the output end of the transmission, in order to further improve the accuracy of the output shaft torque of the transmission, the torque loss of the drive shaft can also be considered in the process of calculating the output shaft torque.

[0075] For example, optionally, the output shaft torque of the transmission is determined based on the output torque of each clutch, including: using the sum of the output torques of each clutch as the initial output shaft torque of the transmission; obtaining the moment of inertia and angular acceleration of the drive shaft in the vehicle, and determining the loss torque of the drive shaft based on the moment of inertia and angular acceleration; and determining the difference between the initial output shaft torque and the loss torque as the output shaft torque.

[0076] The driveshaft can be a structure used to transmit the output torque of the clutch to the output shaft of the transmission. Specifically, a sensor installed on the driveshaft can collect the rotational speed of the driveshaft. The collected rotational speed can then be used to determine the moment of inertia and angular acceleration of the driveshaft. The vehicle controller can then use the product of the moment of inertia and angular acceleration as the loss torque of the driveshaft. Furthermore, the difference between the initial output shaft torque and the loss torque is used as the output shaft torque of the transmission.

[0077] Through the above implementation method, the output shaft torque of the transmission can be accurately determined considering the transmission shaft loss, further improving the accuracy of the output shaft torque.

[0078] S130. Determine the braking energy recovery execution value based on the wheel end torque, and send the braking energy recovery execution value to the chassis system so that the chassis system can provide feedback on the execution result based on the braking energy recovery execution value.

[0079] Specifically, the vehicle controller can use the wheel-end torque as the braking energy recovery execution value, or it can consider that the wheel-end torque contains the current coasting energy recovery torque, and use the difference between the wheel-end torque and the current coasting energy recovery torque as the braking energy recovery execution value. The braking energy recovery execution value can be the vehicle wheel-end torque value executed for braking energy recovery.

[0080] In one specific implementation, determining the braking energy recovery execution value based on wheel-end torque includes: obtaining the vehicle's current speed; querying the corresponding current coasting energy recovery torque in a preset second calibration table based on the current vehicle speed, wherein the preset second calibration table is used to describe the correspondence between each vehicle speed and each coasting energy recovery torque; and determining the braking energy recovery execution value based on the difference between the wheel-end torque and the current coasting energy recovery torque.

[0081] That is, the vehicle controller can obtain the current vehicle speed through the vehicle speed sensor, and then look up the current coasting energy recovery torque corresponding to the current vehicle speed in the preset second calibration table, and then use the difference between the wheel end torque and the current coasting energy recovery torque as the braking energy recovery execution value.

[0082] In the above implementation, the current coasting energy recovery torque is determined by presetting a second calibration table, and the coasting energy recovery torque is taken into account to obtain a more accurate braking energy recovery execution value.

[0083] Furthermore, the vehicle controller can feed back the regenerative braking execution value to the chassis system. The chassis system is equipped with a CRBS (Regenerative Braking System) device. The CRBS device in the chassis system can determine the execution result of regenerative braking based on the difference between the regenerative braking execution value and the regenerative braking request value, i.e., whether the execution was successful. The chassis system then feeds this result back to the vehicle controller. If the execution result is a failure, the vehicle controller can display a regenerative braking failure message on the vehicle's infotainment system to alert the user that the regenerative braking function has malfunctioned and vehicle repair is recommended.

[0084] In this embodiment, considering the possibility that the regenerative braking execution value is greater than the regenerative braking request value, for example, due to vehicle bus communication delays, the regenerative braking execution value fed back by the vehicle controller at the current moment may be based on the regenerative braking request value from the previous moment. Since the regenerative braking request value from the previous moment is greater than the regenerative braking request value from the current moment, the fed-back regenerative braking execution value at the current moment is greater than the regenerative braking request value. In this case, it indicates that the powertrain has fully executed the regenerative braking request value, meaning the regenerative braking execution is successful. If the vehicle controller still sends the regenerative braking execution value to the chassis system, the chassis system will calculate a significant difference between the execution value and the request value, thus disabling the regenerative braking function.

[0085] Therefore, to avoid the above situation, when the difference between the wheel-end torque and the current coasting energy recovery torque is large, the braking energy recovery request value can be fed back to the chassis system to avoid false alarms and disabling of the function.

[0086] In one optional implementation, determining the braking energy recovery execution value based on the difference between the wheel-end torque and the current coasting energy recovery torque includes: taking the difference between the wheel-end torque and the current coasting energy recovery torque as the actual braking energy recovery value; if the actual braking energy recovery value is greater than the braking energy recovery request value, then the braking energy recovery request value is determined as the braking energy recovery execution value; if the actual braking energy recovery value is less than or equal to the braking energy recovery request value, then the actual braking energy recovery value is determined as the braking energy recovery execution value.

[0087] That is, first calculate the difference between the wheel end torque and the current coasting energy recovery torque to obtain the actual value of braking energy recovery. If the actual value of braking energy recovery is greater than the braking energy recovery request value, the braking energy recovery request value is fed back as the braking energy recovery execution value; otherwise, the actual value of braking energy recovery is fed back as the braking energy recovery execution value.

[0088] The above implementation method avoids the situation where, when the execution value for regenerative braking is greater than the requested value, i.e., when regenerative braking is successfully executed, a large execution value is directly fed back, leading to false error reports and disabling of the function.

[0089] It should be noted that the regenerative braking torque is generally a negative value. In the embodiments of this application, the above-mentioned regenerative braking request value, regenerative braking execution value, and regenerative braking actual value can all be understood as the absolute value of the value.

[0090] The vehicle regenerative braking control method provided in this application responds to a downshift request from the transmission when the vehicle is in regenerative braking mode. Based on the regenerative braking request value sent by the chassis system, the powertrain system is controlled to perform regenerative braking. Furthermore, the current gear information of the transmission during downshifting is obtained. Based on this current gear information and the current input shaft torque, the wheel-end torque is determined, and then the regenerative braking execution value is determined based on the wheel-end torque. This value is then sent to the chassis system so that the chassis system can provide feedback on the execution result. This method determines the wheel-end torque based on the transmission's structural information during downshifting to obtain the regenerative braking execution value. This achieves the determination of the execution value based on the actual structure of the transmission, ensuring the accuracy of the execution value fed back to the chassis system. It solves the problem of calculation errors in the execution value caused by vehicle downshifting interference in the regenerative braking process in the prior art, thereby solving the problem of the chassis system reporting errors and disabling the regenerative braking function, and ensuring the normal operation of the regenerative braking function.

[0091] Figure 2 is a flowchart of a vehicle brake energy recovery control method provided in an embodiment of this application. This method is applied to the vehicle's chassis system. Specifically, it is applicable to the chassis system receiving the brake energy recovery execution value fed back by the vehicle controller after sending a brake energy recovery request value, thereby determining the execution result of the vehicle's brake energy recovery and whether to disable the vehicle's brake energy recovery function. As shown in Figure 2, the vehicle brake energy recovery control method includes the following steps:

[0092] S220: Receives the brake energy recovery execution value sent by the vehicle controller.

[0093] Specifically, after the chassis system sends a brake energy recovery request value to the vehicle controller, it can obtain the brake energy recovery execution value fed back by the vehicle controller.

[0094] S230. If the difference between the brake energy recovery execution value and the brake energy return request value exceeds a preset threshold, the execution result of execution failure is sent to the vehicle controller, and the vehicle's brake energy recovery function is turned off.

[0095] The preset threshold can be a pre-defined allowable error between the executed value and the requested value of regenerative braking. Specifically, the chassis system calculates the difference between the executed value and the requested value of regenerative braking. If the difference exceeds the preset threshold, it indicates that the regenerative braking has failed. The system can then report the failure to the vehicle controller and disable the vehicle's regenerative braking function to ensure vehicle safety.

[0096] The vehicle regenerative braking control method provided in this application involves the chassis system receiving the regenerative braking execution value sent by the vehicle controller, judging the difference between the request value and the execution value to determine whether the vehicle's regenerative braking has been successfully executed. If the execution fails, it indicates that the power system has not successfully executed regenerative braking, which affects the braking performance of the vehicle. At this time, the chassis system can turn off the vehicle's regenerative braking function to ensure the safety of the vehicle during braking.

[0097] For example, as shown in Figure 3, which is a framework diagram of a vehicle braking energy recovery control system provided in an embodiment of this application, the system includes a vehicle controller, a chassis system, a transmission, and a powertrain. Specifically, the chassis system is used to calculate the braking energy recovery request value and detect the execution status of braking energy recovery. The transmission is used to calculate the target torque that the powertrain needs to respond to during downshifting based on the transmission's input shaft speed and the target gear's speed, and to send the powertrain structure information (i.e., current gear information) during downshifting to the vehicle controller. The powertrain is used to respond to the torque value sent by the vehicle controller. The vehicle controller is used to receive information sent by the chassis system and the transmission, calculate and feedback the braking energy recovery execution value, and prioritize responding to the target torque in the downshift request sent by the transmission through torque arbitration.

[0098] Referring to Figure 4, which is a flowchart illustrating the execution process of the vehicle brake energy recovery control system provided in this embodiment, the vehicle controller first determines that the vehicle is in a brake energy recovery state when it detects that the brake pedal has been triggered. Further, when the transmission detects a downshift demand, it calculates the target torque and generates a downshift request, which is then sent to the vehicle controller. Upon detecting the downshift request, the vehicle controller controls the powertrain to prioritize responding to the target torque. Further, the vehicle controller controls the powertrain to respond to the brake energy recovery request value. Specifically, the vehicle controller can first calculate the maximum brake energy recovery value and send it to the chassis system, thereby obtaining a brake energy recovery request value calculated by the chassis system based on the brake pedal depth (i.e., opening degree), which does not exceed the maximum brake energy recovery value.

[0099] Furthermore, the vehicle controller calculates the regenerative braking execution value based on the current gear information sent by the transmission and feeds it back to the chassis system. If the difference between the execution value and the requested value is greater than a preset threshold, the chassis system reports a successful execution result; otherwise, the chassis system reports a failed execution result and disables the regenerative braking function.

[0100] This system can determine the execution value based on the actual structure of the transmission, ensuring the accuracy of the execution value fed back to the chassis system. It solves the problem of incorrect execution value calculation caused by vehicle downshifting interference in the braking energy recovery process in the prior art, and ensures the normal operation of the braking energy recovery function.

[0101] It should be noted that the method in this embodiment can be executed by a single device, such as a computer or server. The method can also be applied in a distributed scenario, where multiple devices cooperate to complete the task. In such a distributed scenario, one of these devices may execute only one or more steps of the method in this embodiment, and the multiple devices will interact with each other to complete the method described.

[0102] It should be noted that the above description describes some embodiments of this application. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be performed in a different order than that shown in the above embodiments and still achieve the desired result. Furthermore, the processes depicted in the drawings do not necessarily require a specific or sequential order to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0103] Based on the same inventive concept, and corresponding to any of the methods in the above embodiments, this application also provides a vehicle braking energy recovery control device. Figure 5 is a schematic diagram of the structure of a vehicle braking energy recovery control device provided in an embodiment of this application. Referring to Figure 5, the vehicle braking energy recovery control device includes a recovery module 510, a determination module 520, and a sending module 530.

[0104] The recovery module 510 is used to respond to the downshift request received by the transmission when the vehicle is in the braking energy recovery state, and to control the power system to perform braking energy recovery based on the braking energy recovery request value sent by the chassis system.

[0105] The determining module 520 is used to obtain the current gear information of the transmission during downshifting, and determine the wheel end torque of the vehicle based on the current gear information and the current input shaft torque of the transmission.

[0106] The sending module 530 is used to determine the braking energy recovery execution value based on the wheel end torque, and send the braking energy recovery execution value to the chassis system so that the chassis system can provide feedback on the execution result based on the braking energy recovery execution value.

[0107] Optionally, the determining module 520 includes a hydraulic value determining unit, a transmission coefficient determining unit, and a torque determining unit, wherein;

[0108] The hydraulic value determination unit is used to determine the current hydraulic value corresponding to each clutch in the transmission based on the current gear information.

[0109] The transmission coefficient determination unit is used to look up the current transmission coefficient corresponding to the current hydraulic value in a preset first calibration table according to the current hydraulic value corresponding to each clutch. The preset first calibration table is used to describe the correspondence between each hydraulic value and each transmission coefficient.

[0110] A torque determination unit is used to determine the wheel-end torque of the vehicle based on the current input shaft torque of the transmission and each of the current transmission coefficients.

[0111] Optionally, the torque determination unit is specifically used for:

[0112] The output torque of each clutch is determined based on the current input shaft torque of the transmission and each current transmission coefficient, and the output shaft torque of the transmission is determined based on the output torque of each clutch; the final drive ratio of the vehicle is obtained, and the wheel-end torque of the vehicle is determined based on the output shaft torque and the final drive ratio.

[0113] Optionally, the torque determination unit is further configured to use the sum of the output torques of each of the clutches as the initial output shaft torque of the transmission; obtain the moment of inertia and angular acceleration of the drive shaft in the vehicle, and determine the loss torque of the drive shaft based on the moment of inertia and the angular acceleration; and determine the difference between the initial output shaft torque and the loss torque as the output shaft torque.

[0114] Optionally, the sending module 530 is specifically used for:

[0115] The current vehicle speed is obtained, and the corresponding current coasting energy recovery torque is queried from a preset second calibration table based on the current vehicle speed. The preset second calibration table is used to describe the correspondence between each vehicle speed and each coasting energy recovery torque. The braking energy recovery execution value is determined based on the difference between the wheel end torque and the current coasting energy recovery torque.

[0116] Optionally, the sending module 530 is further configured to use the difference between the wheel end torque and the current coasting energy recovery torque as the actual value of braking energy recovery; if the actual value of braking energy recovery is greater than the braking energy recovery request value, then the braking energy recovery request value is determined as the braking energy recovery execution value; if the actual value of braking energy recovery is less than or equal to the braking energy recovery request value, then the actual value of braking energy recovery is determined as the braking energy recovery execution value.

[0117] Optionally, the device further includes a capacity calculation module for determining the maximum value of regenerative braking energy of the vehicle based on the maximum allowable charging capacity of the vehicle's battery and the maximum power generation capacity of the vehicle's motor; and sending the maximum value of regenerative braking energy to the chassis system so that the chassis system determines a regenerative braking energy request value based on the maximum value of regenerative braking energy, wherein the regenerative braking energy request value does not exceed the maximum value of regenerative braking energy.

[0118] For ease of description, the above devices are described in terms of function, divided into various modules. Of course, in implementing this application, the functions of each module can be implemented in one or more software and / or hardware.

[0119] The apparatus described above is used to implement the corresponding vehicle braking energy recovery control method in any of the foregoing embodiments, and has the beneficial effects of the corresponding method embodiments, which will not be repeated here.

[0120] Based on the same inventive concept, corresponding to the methods of any of the above embodiments, this application also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the vehicle braking energy recovery control method described in any of the above embodiments.

[0121] Figure 6 is a schematic diagram of an electronic device provided in an embodiment of this application. It illustrates a more specific hardware structure of the electronic device provided in this embodiment. The device may include: a processor 1010, a memory 1020, an input / output interface 1030, a communication interface 1040, and a bus 1050. The processor 1010, memory 1020, input / output interface 1030, and communication interface 1040 are interconnected internally via the bus 1050.

[0122] The processor 1010 can be implemented using a general-purpose CPU (Central Processing Unit), microprocessor, application-specific integrated circuit (ASIC), or one or more integrated circuits, and is used to execute relevant programs to implement the technical solutions provided in the embodiments of this specification.

[0123] The memory 1020 can be implemented in the form of ROM (Read Only Memory), RAM (Random Access Memory), static storage device, dynamic storage device, etc. The memory 1020 can store the operating system and other applications. When the technical solutions provided in the embodiments of this specification are implemented by software or firmware, the relevant program code is stored in the memory 1020 and is called and executed by the processor 1010.

[0124] The input / output interface 1030 is used to connect input / output modules to realize information input and output. Input / output modules can be configured as components within the device (not shown in the figure) or externally connected to the device to provide corresponding functions. Input devices may include keyboards, mice, touchscreens, microphones, various sensors, etc., while output devices may include displays, speakers, vibrators, indicator lights, etc.

[0125] The communication interface 1040 is used to connect a communication module (not shown in the figure) to enable communication between this device and other devices. The communication module can communicate via wired means (such as USB, Ethernet cable, etc.) or wireless means (such as mobile network, WIFI, Bluetooth, etc.).

[0126] Bus 1050 includes a pathway for transmitting information between various components of the device, such as processor 1010, memory 1020, input / output interface 1030, and communication interface 1040.

[0127] It should be noted that although the above-described device only shows the processor 1010, memory 1020, input / output interface 1030, communication interface 1040, and bus 1050, in specific implementations, the device may also include other components necessary for normal operation. Furthermore, those skilled in the art will understand that the above-described device may only include the components necessary for implementing the embodiments of this specification, and not necessarily all the components shown in the figures.

[0128] The electronic devices described above are used to implement the corresponding vehicle braking energy recovery control methods in any of the foregoing embodiments, and have the beneficial effects of the corresponding method embodiments, which will not be repeated here.

[0129] Based on the same inventive concept, corresponding to any of the above-described embodiments, this application also provides a vehicle that includes the aforementioned electronic equipment.

[0130] Based on the same inventive concept, corresponding to the methods of any of the above embodiments, this application also provides a non-transitory computer-readable storage medium storing computer instructions for causing the computer to execute the vehicle braking energy recovery control method as described in any of the above embodiments.

[0131] The computer-readable medium of this embodiment includes permanent and non-permanent, removable and non-removable media, and information storage can be implemented by any method or technology. Information can be computer-readable instructions, data structures, program modules, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic magnetic disk storage or other magnetic storage devices, or any other non-transfer medium that can be used to store information accessible by a computing device.

[0132] The computer instructions stored in the storage medium of the above embodiments are used to cause the computer to execute the vehicle braking energy recovery control method as described in any of the above embodiments, and have the beneficial effects of the corresponding method embodiments, which will not be repeated here.

[0133] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of this application (including the claims) is limited to these examples; within the framework of this application, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of the embodiments of this application as described above, which are not provided in the details for the sake of brevity.

[0134] Additionally, to simplify the description and discussion, and to avoid obscuring the embodiments of this application, the well-known power / ground connections to integrated circuit (IC) chips and other components may or may not be shown in the provided drawings. Furthermore, the apparatus may be shown in block diagram form to avoid obscuring the embodiments of this application, and this also takes into account the fact that the details of the implementation of these block diagram apparatuses are highly dependent on the platform on which the embodiments of this application will be implemented (i.e., these details should be fully understood by those skilled in the art). While specific details (e.g., circuits) have been set forth to describe exemplary embodiments of this application, it will be apparent to those skilled in the art that the embodiments of this application can be implemented without these specific details or with variations thereof. Therefore, these descriptions should be considered illustrative rather than restrictive.

[0135] Although this application has been described in conjunction with specific embodiments thereof, many substitutions, modifications, and variations of these embodiments will be apparent to those skilled in the art from the foregoing description. For example, other memory architectures (e.g., dynamic RAM (DRAM)) may be used with the embodiments discussed.

[0136] The embodiments of this application are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the embodiments of this application should be included within the protection scope of this application.

Claims

1. A method for controlling vehicle braking energy recovery, characterized in that, This system, applied to a vehicle controller, includes: responding to a received downshift request from the transmission when the vehicle is in a regenerative braking state, and controlling the powertrain to perform regenerative braking based on a regenerative braking request value sent by the chassis system, wherein priority is given to responding to the target torque in the downshift request, and then responding to the regenerative braking request value; acquiring the current gear information of the transmission during the downshifting process, determining the wheel-end torque of the vehicle based on the current gear information and the current input shaft torque of the transmission, wherein the current gear information describes the current state of the components performing gear shifting inside the transmission during the process of adjusting from the current gear to the target gear, and the current gear information includes the position of the gears or the hydraulic pressure value of each clutch; determining a regenerative braking execution value based on the wheel-end torque, and sending the regenerative braking execution value to the chassis system so that the chassis system can provide feedback on the execution result based on the regenerative braking execution value.

2. The method according to claim 1, characterized in that, The step of determining the wheel-end torque of the vehicle based on the current gear information and the current input shaft torque of the transmission includes: determining the current hydraulic pressure value corresponding to each clutch in the transmission based on the current gear information; querying the current transmission coefficient corresponding to the current hydraulic pressure value in a preset first calibration table based on the current hydraulic pressure value of each clutch, wherein the preset first calibration table is used to describe the correspondence between each hydraulic pressure value and each transmission coefficient; and determining the wheel-end torque of the vehicle based on the current input shaft torque of the transmission and each current transmission coefficient.

3. The method according to claim 2, characterized in that, The step of determining the wheel-end torque of the vehicle based on the current input shaft torque of the transmission and each of the current transmission coefficients includes: determining the output torque of each clutch based on the current input shaft torque of the transmission and each of the current transmission coefficients; determining the output shaft torque of the transmission based on the output torque of each of the clutches; obtaining the final drive ratio of the vehicle; and determining the wheel-end torque of the vehicle based on the output shaft torque and the final drive ratio.

4. The method according to claim 3, characterized in that, The step of determining the output shaft torque of the transmission based on the output torque of each clutch includes: using the sum of the output torques of each clutch as the initial output shaft torque of the transmission; obtaining the moment of inertia and angular acceleration of the drive shaft in the vehicle, and determining the loss torque of the drive shaft based on the moment of inertia and the angular acceleration; and determining the difference between the initial output shaft torque and the loss torque as the output shaft torque.

5. The method according to claim 1, characterized in that, The step of determining the regenerative braking value based on the wheel-end torque includes: obtaining the current vehicle speed; querying the corresponding current coasting energy recovery torque in a preset second calibration table based on the current vehicle speed, wherein the preset second calibration table is used to describe the correspondence between each vehicle speed and each coasting energy recovery torque; and determining the regenerative braking value based on the difference between the wheel-end torque and the current coasting energy recovery torque.

6. The method according to claim 5, characterized in that, The step of determining the braking energy recovery execution value based on the difference between the wheel-end torque and the current coasting energy recovery torque includes: taking the difference between the wheel-end torque and the current coasting energy recovery torque as the actual braking energy recovery value; if the actual braking energy recovery value is greater than the braking energy recovery request value, then the braking energy recovery request value is determined as the braking energy recovery execution value; if the actual braking energy recovery value is less than or equal to the braking energy recovery request value, then the actual braking energy recovery value is determined as the braking energy recovery execution value.

7. The method according to claim 1, characterized in that, Before controlling the powertrain to perform brake energy recovery based on the brake energy recovery request value sent by the chassis system, the method further includes: determining the maximum brake energy recovery value of the vehicle based on the maximum allowable charging capacity of the vehicle's battery and the maximum power generation capacity of the vehicle's motor; sending the maximum brake energy recovery value to the chassis system so that the chassis system determines the brake energy recovery request value based on the maximum brake energy recovery value, wherein the brake energy recovery request value does not exceed the maximum brake energy recovery value.

8. A method for controlling vehicle braking energy recovery, characterized in that, The method is applied to a chassis system and includes: receiving a brake energy recovery execution value sent by a vehicle controller, wherein the vehicle controller is used to execute the steps of the vehicle brake energy recovery control method as described in any one of claims 1 to 7; if the difference between the brake energy recovery execution value and the brake energy recovery request value exceeds a preset threshold, then sending an execution failure result to the vehicle controller and disabling the vehicle's brake energy recovery function.

9. A vehicle braking energy recovery control device, characterized in that, include: The regeneration module is used to respond to a downshift request from the transmission when the vehicle is in a regenerative braking state, and to control the powertrain to perform regenerative braking based on the regenerative braking request value sent by the chassis system. Priority is given to responding to the target torque in the downshift request, and then responding to the regenerative braking request value. The determination module is used to acquire the current gear information of the transmission during downshifting, and to determine the wheel-end torque of the vehicle based on the current gear information and the current input shaft torque of the transmission. The current gear information describes the current state of the components performing gear shifting within the transmission during the shift from the current gear to the target gear, and includes the position of the gears or the hydraulic pressure values ​​of each clutch. The sending module is used to determine the regenerative braking execution value based on the wheel-end torque, and to send the regenerative braking execution value to the chassis system so that the chassis system can provide feedback on the execution result based on the regenerative braking execution value.

10. A vehicle, characterized in that, Includes the vehicle braking energy recovery control device as described in claim 9.

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