A method, device, and vehicle for regenerative braking shift control of a multi-speed electric drive axle.

Abstract

This invention belongs to the field of mechanical transmission technology, specifically providing a method, device, and vehicle for controlling regenerative braking shifting of a multi-speed electric drive axle. The method includes the following steps: calculating the required torque for regenerative braking of the electric drive axle; using the calculated required torque as a control signal for the vehicle's braking system, controlling the braking system to increase the corresponding braking torque while simultaneously reducing the regenerative braking torque of the electric drive axle to zero; determining the target gear of the electric drive axle; switching the electric drive axle from the current gear to the target gear; increasing the regenerative braking torque of the electric drive axle from zero to the calculated required torque, while simultaneously reducing the braking torque of the braking system to the same torque as the required torque for regenerative braking of the electric drive axle, thus completing the shift. This helps reduce braking force fluctuations, improves braking safety, and also helps reduce vehicle acceleration fluctuations, improving driving comfort.

Description

Technical Field

[0001] This invention relates to the field of mechanical transmission technology, specifically to a method, device, and vehicle for controlling the regenerative braking shift of a multi-speed electric drive axle. Background Technology

[0002] Regenerative braking is one of the advantages of electric drive systems. It aims to reduce the heat loss during braking. During operation, it generates resistance in the moving vehicle, thereby achieving the braking effect. The recovered mechanical energy is stored in the form of chemical energy, hydraulic energy, etc., for the vehicle to use next time, which helps to improve the vehicle's braking safety and energy economy.

[0003] Current research on regenerative braking systems primarily focuses on improving braking safety, comfort, and energy recovery efficiency. The research mainly focuses on single-speed electric drive systems for passenger vehicles, with limited research on regenerative braking systems for multi-speed electric drive systems.

[0004] In recent years, with the development of electric drive technology for passenger vehicles, commercial vehicles have gradually entered the era of electric drive. The electric drive axle is one of the feasible routes for electric drive in commercial vehicles, generally featuring a multi-motor, multi-gear configuration. The multi-gear configuration of the electric drive axle provides more operational possibilities for regenerative braking, but also presents challenges to its shifting process control. Therefore, how to control the shifting process of a multi-gear electric drive axle is a problem that needs to be solved. Summary of the Invention

[0005] To address the problem of controlling the shifting process of a multi-speed electric drive axle, this invention provides a method, device, and vehicle for controlling the regenerative braking shifting of a multi-speed electric drive axle.

[0006] In a first aspect, the present invention provides a multi-speed electric drive axle braking energy recovery shift control method, comprising the following steps:

[0007] Calculate the torque required for regenerative braking of the electric drive axle;

[0008] The calculated electric drive axle braking energy recovery torque is used as the control signal for the vehicle braking system, which controls the braking system to increase the corresponding braking torque, while simultaneously controlling the electric drive axle braking energy recovery torque to decrease to zero.

[0009] Determine the target gear position of the electric drive axle;

[0010] Switch the electric drive axle from the current gear to the target gear;

[0011] The electric drive axle's regenerative braking torque is increased from zero to the calculated regenerative braking torque required for the electric drive axle, while the braking torque of the braking system is reduced to the same torque as the regenerative braking torque required for the electric drive axle, thus completing the gear shift.

[0012] As a preferred embodiment of the technical solution of the present invention, the step of calculating the required torque for regenerative braking of the electric drive axle includes the following:

[0013] Obtain the regenerative braking torque of the electric drive axle in the current gear;

[0014] Obtain the vehicle's current braking torque and required braking torque;

[0015] The steps for calculating the required torque for regenerative braking of the electric drive axle include:

[0016] The required torque for regenerative braking of the electric drive axle is calculated based on the regenerative braking torque of the electric drive axle in the current gear, the vehicle's current braking torque, and the required braking torque.

[0017] As a preferred embodiment of the technical solution of the present invention, the formula for calculating the torque required for regenerative braking of the electric drive axle is as follows:

[0018] T R =T 0_R +(T i -T0)

[0019] Among them, T R To meet the torque requirements for regenerative braking of the electric drive axle, T 0_R T is the regenerative braking torque of the electric drive axle in the current gear. i T0 represents the vehicle's braking torque requirement, while T0 represents the vehicle's current braking torque.

[0020] As a preferred embodiment of the technical solution of the present invention, the step of obtaining the regenerative braking torque of the electric drive axle in the current gear includes:

[0021] Obtain the output speed of the electric drive axle, the current gear, and the current regenerative braking torque of the motor;

[0022] Obtain the speed ratio of each gear and the motor braking torque-speed characteristics;

[0023] Calculate the regenerative braking torque of the electric drive axle in the current gear based on the obtained information:

[0024]

[0025] Among them, T M n is the current energy recovery braking torque of the motor. W η is the output speed at the wheel end. i The speed ratio of the electric drive axle in i gear This refers to the transmission efficiency of the electric drive axle under the current gear, torque, and output speed conditions.

[0026] As a preferred embodiment of the technical solution of the present invention, the step of determining the target gear of the electric drive axle includes:

[0027] Configure the speed ratio of each gear of the electric drive axle and the motor braking torque-speed characteristics;

[0028] Obtain the vehicle's current braking torque and braking demand torque, electric drive axle output speed, current gear information, and the motor's current regenerative braking torque.

[0029] Based on the speed ratios of each gear of the configured electric drive axle and the braking torque-speed characteristics of the motor, a calculation model for the braking energy recovery torque range of the electric drive axle is established.

[0030] Based on the established calculation model of the electric drive axle braking energy recovery torque and the current output speed of the electric drive axle, the maximum braking energy recovery torque of the electric drive axle in each gear is calculated.

[0031] Based on the current braking torque and braking torque requirement of the vehicle, as well as the calculated maximum braking energy recovery torque of the electric drive axle in each gear, the target gear of the electric drive axle is determined.

[0032] As a preferred embodiment of the technical solution of the present invention, the target gear is determined as follows:

[0033] If n i <n max And T 0_R_max -T 0_R ≤T i -T0≤T i_R_max -T 0_R At that time, the target gear of the electric drive axle is gear i;

[0034] Otherwise, do not shift gears.

[0035] Where, n i n is the motor speed when the electric drive bridge is switched to gear i. max T represents the peak speed of the motor. 0_R_max and T i_R_max This is the maximum torque that the electric drive axle can achieve during regenerative braking in the current gear and in gear i.

[0036] As a preferred embodiment of the technical solution of the present invention, the step of determining the target gear of the electric drive axle based on the obtained current braking torque and braking torque demand of the vehicle and the calculated maximum braking energy recovery torque of the electric drive axle in each gear includes:

[0037] The target gear is sent as the shift control signal for regenerative braking of the electric drive axle.

[0038] Secondly, the present invention provides a multi-speed electric drive axle braking energy recovery shift control device, comprising a second calculation module, a first control module, a judgment module, an execution module, and a second control module.

[0039] The second calculation module is used to calculate the torque required for brake energy recovery of the electric drive axle.

[0040] The first control module is used to control the vehicle braking system to increase the corresponding braking torque by using the calculated electric drive axle braking energy recovery torque as the control signal for the vehicle braking system, while controlling the electric drive axle braking energy recovery torque to decrease to zero.

[0041] The judgment module is used to determine the target gear of the electric drive axle;

[0042] The execution module is used to switch the electric drive axle from the current gear to the target gear;

[0043] The second control module is used to increase the electric drive axle's regenerative braking torque from zero to the calculated electric drive axle's regenerative braking torque requirement, while simultaneously controlling the braking system's braking torque to decrease to the same torque as the electric drive axle's regenerative braking torque requirement, thus completing the gear shift.

[0044] As a preferred embodiment of the technical solution of the present invention, the device further includes a second acquisition module, used to acquire the vehicle's current braking torque and braking demand torque, the electric drive axle output speed, the current gear, and the motor's current braking energy recovery torque.

[0045] The second calculation module is used to calculate the required torque for the electric drive axle's braking energy recovery based on the electric drive axle's braking energy recovery torque in the current gear, the vehicle's current braking torque, and the required braking torque.

[0046] As a preferred embodiment of the technical solution of the present invention, the formula for calculating the torque required for regenerative braking of the electric drive axle is as follows:

[0047] T R =T 0_R +(T i -T0)

[0048] Among them, T R To meet the torque requirements for regenerative braking of the electric drive axle, T 0_R T is the regenerative braking torque of the electric drive axle in the current gear. i T0 represents the vehicle's braking torque requirement, while T0 represents the vehicle's current braking torque.

[0049] As a preferred embodiment of the technical solution of the present invention, the second acquisition module is specifically used to acquire the output speed of the electric drive axle, the current gear, and the current regenerative braking torque of the motor; acquire the speed ratio of each gear and the motor's braking torque-speed characteristics; and calculate the regenerative braking torque of the electric drive axle in the current gear based on the acquired information.

[0050]

[0051] Among them, T Mn is the current energy recovery braking torque of the motor. W η is the output speed at the wheel end. i This refers to the speed ratio of the electric drive axle in gear i. This refers to the transmission efficiency of the electric drive axle under the current gear, torque, and output speed conditions.

[0052] As a preferred embodiment of the technical solution of the present invention, the device further includes a configuration module, a model creation module, and a first calculation module;

[0053] The configuration module is used to configure the speed ratio of each gear of the electric drive axle and the motor braking torque-speed characteristics;

[0054] The second acquisition module is used to acquire the vehicle’s current braking torque and braking demand torque, electric drive axle output speed, current gear information and motor’s current braking energy recovery torque.

[0055] The model creation module is used to establish a calculation model for the range of braking energy recovery torque of the electric drive axle based on the configured speed ratios of each gear of the electric drive axle and the braking torque-speed characteristics of the motor.

[0056] The first calculation module is used to calculate the maximum regenerative braking torque of the electric drive axle in each gear based on the established electric drive axle regenerative braking torque calculation model and the current output speed of the electric drive axle.

[0057] The judgment module is used to determine the target gear of the electric drive axle based on the current braking torque and braking torque demand of the vehicle and the calculated maximum braking energy recovery torque of the electric drive axle in each gear.

[0058] As a preferred embodiment of the technical solution of the present invention, the target gear is determined as follows:

[0059] If n i <n max And T 0_R_max -T 0_R ≤T i -T0≤T i_R_max -T 0_R At that time, the target gear of the electric drive axle is gear i;

[0060] Otherwise, do not shift gears.

[0061] Where, n i n is the motor speed when the electric drive bridge is switched to gear i. max T represents the peak speed of the motor. 0_R_max and T i_R_max This is the maximum torque that the electric drive axle can achieve during regenerative braking in the current gear and in gear i.

[0062] As a preferred embodiment of the technical solution of the present invention, the device further includes an output module for sending a target gear position as a shift control signal for regenerative braking of the electric drive axle.

[0063] Thirdly, the present invention also provides a vehicle, the vehicle including the multi-speed electric drive axle brake energy recovery shift control device as described in the second aspect.

[0064] As can be seen from the above technical solutions, the present invention has the following advantages: It utilizes the change in braking force during vehicle wheel hub braking to compensate for the change in braking force caused by the torque reduction and increase / decrease of the motor braking torque during the shifting process of the electric drive axle, which helps reduce braking force fluctuations, improves braking safety, and also helps reduce vehicle acceleration fluctuations, improving driving comfort. Furthermore, the gear shifting during braking can utilize the different transmission ratios of different gears to coordinate the energy recovery braking torque of the motor, increasing the range of braking energy recovery torque and further improving vehicle braking performance, thus contributing to improved braking safety, comfort, and energy recovery rate. Finally, the method for determining the target gear for multi-gear electric drive axle braking energy recovery provided by the present invention uses the calculation of the braking energy recovery torque of each gear to determine the target gear, providing a feasible path for determining the target gear of multi-gear electric drive axles.

[0065] Furthermore, the design principle of this invention is reliable, the structure is simple, and it has a very wide range of application prospects.

[0066] Therefore, it is evident that the present invention has outstanding substantive features and significant progress compared with the prior art, and the beneficial effects of its implementation are also obvious. Attached Figure Description

[0067] 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, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0068] Figure 1 This is a schematic flowchart of a method according to an embodiment of the present invention.

[0069] Figure 2 A flowchart for determining the target gear for regenerative braking of a multi-speed electric drive axle.

[0070] Figure 3 This is a schematic block diagram of an apparatus according to an embodiment of the present invention.

[0071] Figure 4 This is a schematic diagram of torque changes during the braking energy recovery and shifting process of the multi-speed electric drive axle in an embodiment of the present invention. Detailed Implementation

[0072] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this invention.

[0073] like Figure 1 As shown in the figure, an embodiment of the present invention provides a method for controlling the regenerative braking shift of a multi-speed electric drive axle, comprising the following steps:

[0074] Step 1: Calculate the torque required for regenerative braking of the electric drive axle;

[0075] Step 2: Using the calculated electric drive axle braking energy recovery torque as the control signal for the vehicle braking system, control the braking system to increase the corresponding braking torque, while simultaneously controlling the electric drive axle braking energy recovery torque to decrease to zero.

[0076] Step 3: Determine the target gear of the electric drive axle;

[0077] Step 4: Shift the electric drive axle from the current gear to the target gear;

[0078] Step 5: Increase the regenerative braking torque of the electric drive axle from zero to the calculated regenerative braking torque required by the electric drive axle, while simultaneously controlling the braking torque of the braking system to decrease to the same torque as the regenerative braking torque required by the electric drive axle, thus completing the gear shift.

[0079] This invention provides a method for controlling regenerative braking shifting of a multi-speed electric drive axle. The multi-speed electric drive axle includes a motor, a multi-speed drive axle, a wheel hub braking system, and a controller. The method includes:

[0080] S100: Obtains the braking energy recovery torque requirement information of the electric drive axle and the current braking energy recovery torque information of the electric drive axle.

[0081] In the specific implementation process, the first acquisition module acquires the regenerative braking torque of the electric drive axle in the current gear, and the second acquisition module acquires the vehicle's current braking torque information and braking torque demand information. The regenerative braking torque demand information of the electric drive axle is calculated according to the following formula:

[0082] T R =T 0_R +(T i -T0)

[0083] Among them, T R To meet the torque requirements for regenerative braking of the electric drive axle, T 0_RT is the regenerative braking torque of the electric drive axle in the current gear. i T0 represents the vehicle's braking torque requirement, while T0 represents the vehicle's current braking torque information.

[0084] As a common method for obtaining vehicle braking torque, it is generally obtained by detecting the brake pedal travel. The current braking torque of the vehicle can be obtained from the travel of the brake pedal before the change in travel; the required braking torque can be obtained from the travel of the brake pedal after the change in travel, or it can be obtained from future road condition information obtained through predictive driving. The specific acquisition process will not be explained in detail in this embodiment.

[0085] The current regenerative braking torque information of the electric drive axle can be obtained through the output speed and current gear information of the electric drive axle obtained by the second acquisition module, the current regenerative braking torque information of the motor, and the speed ratios of each gear and the motor braking torque-speed characteristics configured by the configuration module. One feasible acquisition method is as follows:

[0086]

[0087] Among them, T M n is the current energy recovery braking torque of the motor. W η is the output speed at the wheel end. i This refers to the speed ratio of the electric drive axle in gear i. This refers to the transmission efficiency of the electric drive axle under the current gear, torque, and speed conditions.

[0088] In other words, the current regenerative braking torque information of the electric drive axle can be obtained by calculating the speed ratio of the current gear of the electric drive axle, the current regenerative braking torque of the motor, and the transmission efficiency under the current gear, torque, and speed conditions.

[0089] S200: The obtained electric drive axle braking energy recovery torque demand information is used as the control signal for the vehicle braking system, controlling the braking system to increase the corresponding braking torque, while controlling the electric drive axle braking energy recovery torque to decrease to zero.

[0090] In the specific implementation process, the braking torque increase process of the braking system and the braking energy recovery torque decrease process of the electric drive axle are carried out synchronously, and both satisfy the linear function of uniform increase and decrease.

[0091] For example, a feasible relationship between the electric drive axle braking energy recovery torque (referred to as motor braking torque in the figure), the vehicle braking system braking torque (referred to as wheel hub braking torque in the figure), and the total vehicle braking torque during a gear shifting process is as follows: Figure 4 As shown.

[0092] S300: Switches the electric drive axle from the current gear to the target gear.

[0093] S400: Increases the electric drive axle braking energy recovery torque from zero to the obtained electric drive axle braking energy recovery demand torque, while controlling the braking system braking torque to decrease to the same torque as the electric drive axle braking energy recovery demand torque.

[0094] S500: Gear shift complete.

[0095] Based on the following Figure 4 The gear shifting process in this embodiment is described in detail below:

[0096] During normal driving, the wheel hub braking torque from 0s to 1s is 2000Nm, the electric motor braking torque is 5000Nm, and the total braking torque of the vehicle is 7000Nm.

[0097] At this time, the controller receives the vehicle's braking torque demand information of 12000Nm and determines the target gear of the electric drive axle.

[0098] During the motor torque reduction and braking torque increase phase, starting from 1 second, the wheel hub braking torque increases from 2000Nm to 12000Nm within a time range of 0.4 seconds, while at the same time, the motor braking torque decreases from 5000Nm to 0Nm within the same time range; at this time, the electric drive axle has completed the gear shift preparation.

[0099] During the gear shifting phase, the shift is completed within a time range of 1.4s to 1.6s.

[0100] During the motor torque increase and braking torque decrease phase, starting from 1.6s, the motor braking torque increases from 0Nm to 10000Nm within a time range of 0.4s, while at the same time, the wheel hub braking torque decreases from 12000Nm to 2000Nm within the same time range.

[0101] The gear shift is now complete, and normal driving has commenced.

[0102] It is worth noting that, in the specific implementation process, if the maximum value of the electric drive axle's regenerative braking torque after gear shifting can meet the vehicle's braking torque requirements, then after the gear shift is completed, the vehicle's braking system's braking torque can be directly reduced to 0 Nm.

[0103] In some embodiments, such as Figure 2 As shown, the step of determining the target gear of the electric drive axle before the step of switching the electric drive axle from the current gear to the target gear in S300 includes:

[0104] S031: Configure the speed ratio of each gear of the electric drive axle and the motor braking torque-speed characteristics;

[0105] In this embodiment, the electric drive axle is a two-speed electric drive axle, with a first-speed gear ratio of 77 and a second-speed gear ratio of 26. In some embodiments, the motor braking torque-speed characteristic is a two-dimensional lookup table, which is configured to look up the range of motor braking energy recovery torque based on the motor's output speed.

[0106] For example, the braking torque-speed characteristics of the motor are represented by the two-dimensional lookup table shown in Table 1.

[0107] Table 1

[0108] Motor output speed / rpm 0 (0,1000] (1000,2000] (2000,3000] (3000,4000] (4000,5000] (5000,6000] Motor braking torque range / Nm 0 [0,350] [0,350] [0,350] [0,310] [0,248] [0,207] Motor output speed / rpm - (6000,7000] (7000,8000] (8000,9000] (9000,10000] (10000,11000] (11000,12000] Motor braking torque range / Nm - [0,177] [0,155] [0,138] [0,124] [0,113] [0,103]

[0109] S032: Obtain the vehicle's current braking torque and braking demand torque, electric drive axle output speed, current gear information and the motor's current regenerative braking torque;

[0110] In practice, the vehicle's braking torque is typically obtained by detecting the brake pedal travel. The vehicle's current braking torque can be obtained from the travel of the brake pedal before the change; the vehicle's required braking torque can be obtained from the travel of the brake pedal after the change, or it can be obtained from future road condition information acquired through predictive driving. The specific acquisition process will not be explained in detail in this embodiment.

[0111] The output speed and current gear information of the electric drive axle can be obtained through the built-in sensors of the electric drive axle, and the current regenerative braking torque information of the motor can be obtained through the motor controller.

[0112] For example, in this embodiment, the current braking torque is 7000 Nm, the braking torque demand information is 12000 Nm, the output speed of the electric drive axle is 154 rpm, the current gear is 2nd gear with a speed ratio of 26, and the current braking energy recovery torque of the motor is approximately 192 Nm.

[0113] S033: Based on the speed ratios of each gear of the configured electric drive axle and the braking torque-speed characteristics of the motor, establish a calculation model for the range of braking energy recovery torque of the electric drive axle.

[0114] In the specific implementation scope, the braking torque of the electric motor braking is calculated as: braking torque - speed characteristic × speed ratio / electric drive axle transmission efficiency, which represents the range of energy recovery torque for electric drive axle braking. Specifically:

[0115]

[0116] S034: Based on the established electric drive axle braking energy recovery torque calculation model and the current output speed of the electric drive axle, calculate the maximum braking energy recovery torque of the electric drive axle in each gear.

[0117] The transmission efficiency of the electric drive axle can be represented by a two-dimensional lookup table based on speed and torque at different gear positions. Specific examples will not be explained in detail in this embodiment.

[0118] For example, the regenerative braking torque of the electric drive axle in each gear is as follows:

[0119] In gear 1, with a speed ratio of 77, the motor input speed is 11858 rpm. Therefore, the range of the motor's regenerative braking torque is [0, 103]. At this time, the electric drive axle transmission efficiency is 75%, so the range of the regenerative braking torque is [0, 10712].

[0120] With gear 2 and a speed ratio of 26, the motor input speed is 4004 rpm. Therefore, the regenerative braking torque range of the motor is [0, 248]. At this time, the electric drive bridge transmission efficiency is 90%, so the regenerative braking torque range is [0, 7164].

[0121] S035: Based on the current braking torque and braking torque requirement of the vehicle and the calculated maximum braking energy recovery torque of the electric drive axle in each gear, determine the target gear of the electric drive axle.

[0122] The target gear is determined as follows:

[0123] If n i <n max And T 0_R_max -T 0_R ≤T i -T0≤T i_R_max -T 0_R At that time, the target gear of the electric drive axle is gear i;

[0124] Otherwise, do not shift gears.

[0125] Where, n i n is the motor speed when the electric drive bridge is switched to gear i. max T represents the peak speed of the motor. 0_R_max and T i_R_max This is the maximum torque that the electric drive axle can achieve during regenerative braking in the current gear and in gear i.

[0126] In the specific implementation process, the data obtained and calculated in steps S031 to S035 are substituted into the above formula:

[0127] The following conditions must be met: 11848rpm < 12000rpm and 7164-5000 ≤ 12000-7000 ≤ 10712-5000

[0128] Then switch to gear 1.

[0129] S036: Send the target gear as the shift control signal for regenerative braking of the electric drive axle; here, the target gear of the electric drive axle is 1st gear.

[0130] like Figure 3 As shown, this embodiment of the invention provides a multi-speed electric drive axle braking energy recovery shift control device, including a second calculation module, a first control module, a judgment module, an execution module, and a second control module;

[0131] The second calculation module is used to calculate the torque required for brake energy recovery of the electric drive axle.

[0132] The first control module is used to control the vehicle braking system to increase the corresponding braking torque by using the calculated electric drive axle braking energy recovery torque as the control signal for the vehicle braking system, while controlling the electric drive axle braking energy recovery torque to decrease to zero.

[0133] The judgment module is used to determine the target gear of the electric drive axle;

[0134] The execution module is used to switch the electric drive axle from the current gear to the target gear;

[0135] The second control module is used to increase the electric drive axle's regenerative braking torque from zero to the calculated electric drive axle's regenerative braking torque requirement, while simultaneously controlling the braking system's braking torque to decrease to the same torque as the electric drive axle's regenerative braking torque requirement, thus completing the gear shift.

[0136] This application provides a multi-speed electric drive axle brake energy recovery shift control device, including:

[0137] The first acquisition module is used to acquire the braking energy recovery torque demand information of the electric drive axle and the current braking energy recovery torque information of the electric drive axle.

[0138] In specific implementation, the multi-speed electric drive axle regenerative braking shift control device further includes a configuration module for configuring the speed ratios of each gear of the electric drive axle and the motor braking torque-speed characteristics; a second acquisition module for acquiring the vehicle's current braking torque and braking torque demand information, the electric drive axle's output speed and current gear information, and the motor's current regenerative braking torque information; a model creation module for establishing a calculation model for the electric drive axle's regenerative braking torque range based on the configured speed ratios of each gear of the electric drive axle and the motor braking torque-speed characteristics; a first calculation module for calculating the maximum regenerative braking torque of the electric drive axle in each gear based on the acquired vehicle's current braking torque information and braking torque demand information; and a judgment module for determining the target gear of the electric drive axle based on the calculated maximum regenerative braking torque of each gear.

[0139] It also includes a second calculation module, which is used to calculate the required torque for regenerating braking energy of the electric drive axle based on the electric drive axle's regenerative braking torque, the vehicle's current braking torque information, and the braking torque demand information.

[0140] The first control module is used to control the vehicle braking system by using the obtained electric drive axle braking energy recovery torque demand information as a control signal for the vehicle braking system, thereby controlling the braking system to increase the corresponding braking torque, and simultaneously controlling the electric drive axle braking energy recovery torque to decrease to zero.

[0141] An execution module is used to switch the electric drive axle from the current gear to the target gear.

[0142] The second control module is used to control the electric drive axle braking energy recovery torque to increase from zero to the obtained electric drive axle braking energy recovery demand torque, and at the same time control the braking system braking torque to decrease to the same torque as the electric drive axle braking energy recovery demand torque.

[0143] The device also includes an output module for sending the target gear as a shift control signal for regenerative braking of the electric drive axle.

[0144] This invention also provides a vehicle that includes a multi-speed electric drive axle brake energy recovery shift control device as described in the above embodiments.

[0145] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0146] The embodiments of the multi-speed electric drive axle brake energy recovery shift control device disclosed in this application belong to the same inventive concept as the multi-speed electric drive axle brake energy recovery shift control methods in the above embodiments. For details not described in detail in the embodiments of the multi-speed electric drive axle brake energy recovery shift control device, please refer to the embodiments of the above multi-speed electric drive axle brake energy recovery shift control methods.

[0147] The multi-speed electric drive axle regenerative braking shift control device comprises the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein. It can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of each example have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can implement the described functions using different methods for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0148] Those skilled in the art will understand that various aspects of the multi-speed electric drive axle regenerative braking shift control method can be implemented as a system, method, or program product. Therefore, various aspects of this disclosure can be specifically implemented in the following forms: a completely hardware implementation, a completely software implementation (including firmware, microcode, etc.), or a combination of hardware and software aspects, collectively referred to herein as a "circuit," "module," or "system."

[0149] Although the present invention has been described in detail with reference to the accompanying drawings and preferred embodiments, the invention is not limited thereto. Various equivalent modifications or substitutions can be made to the embodiments of the invention by those skilled in the art without departing from the spirit and essence of the invention, and such modifications or substitutions should all be within the scope of the invention. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the invention should also be covered within the protection scope of the invention. Therefore, the protection scope of the invention should be determined by the scope of the claims.

Claims

1. A method for controlling regenerative braking shifting in a multi-speed electric drive axle, characterized in that, Includes the following steps: Calculate the torque required for regenerative braking of the electric drive axle; The calculated electric drive axle braking energy recovery torque is used as the control signal for the vehicle braking system, which controls the braking system to increase the corresponding braking torque, while simultaneously controlling the electric drive axle braking energy recovery torque to decrease to zero. Determining the target gear of the electric drive axle involves: configuring the speed ratios of each gear of the electric drive axle and the motor braking torque-speed characteristics; obtaining the vehicle's current braking torque and braking demand torque, the electric drive axle's output speed, the current gear information, and the motor's current regenerative braking torque; establishing a calculation model for the electric drive axle's regenerative braking torque range based on the configured speed ratios of each gear and the motor's braking torque-speed characteristics; calculating the maximum regenerative braking torque of the electric drive axle in each gear based on the established calculation model and the electric drive axle's current output speed; and determining the target gear of the electric drive axle based on the obtained vehicle's current braking torque and braking torque demand, as well as the calculated maximum regenerative braking torque of the electric drive axle in each gear. Switch the electric drive axle from the current gear to the target gear; The electric drive axle's regenerative braking torque is increased from zero to the calculated regenerative braking torque required for the electric drive axle, while the braking torque of the braking system is reduced to the braking torque of the braking system before the corresponding increase in braking torque is controlled, thus completing the gear shift.

2. The multi-speed electric drive axle braking energy recovery shift control method according to claim 1, characterized in that, Before calculating the required torque for regenerative braking of the electric drive axle, the following steps are included: Obtain the regenerative braking torque of the electric drive axle in the current gear; Obtain the vehicle's current braking torque and required braking torque; The steps for calculating the required torque for regenerative braking of the electric drive axle include: The required torque for regenerative braking of the electric drive axle is calculated based on the regenerative braking torque of the electric drive axle in the current gear, the vehicle's current braking torque, and the required braking torque.

3. The multi-speed electric drive axle braking energy recovery shift control method according to claim 2, characterized in that, The formula for calculating the torque required for regenerative braking of the electric drive axle is as follows: in, The torque required for regenerative braking of the electric drive axle. The regenerative braking torque of the electric drive axle in the current gear. For the vehicle's braking torque requirements, This represents the vehicle's current braking torque.

4. The multi-speed electric drive axle braking energy recovery shift control method according to claim 3, characterized in that, The steps for obtaining the regenerative braking torque of the electric drive axle in the current gear include: Obtain the output speed of the electric drive axle, the current gear, and the current regenerative braking torque of the motor; Obtain the speed ratio of each gear and the motor braking torque-speed characteristics; Calculate the regenerative braking torque of the electric drive axle in the current gear based on the obtained information: in, This is the current energy recovery braking torque of the motor. The output speed at the wheel end, For electric drive bridge in The gear ratio when in gear, This refers to the transmission efficiency of the electric drive axle under the current gear, torque, and output speed conditions.

5. The multi-speed electric drive axle braking energy recovery shift control method according to claim 3, characterized in that, The target gear is determined as follows: like and At that time, the target gear of the electric drive axle is block; Otherwise, do not shift gears; in, Switching the electric drive bridge to Motor speed in gear, This represents the peak speed of the motor; and For the electric drive axle in the current gear and The maximum torque that can be achieved through regenerative braking when in gear.

6. The multi-speed electric drive axle braking energy recovery shift control method according to claim 1, characterized in that, Based on the obtained current braking torque and braking torque demand of the vehicle, and the calculated maximum regenerative braking torque of the electric drive axle in each gear, the step of determining the target gear of the electric drive axle includes: The target gear is sent as the shift control signal for regenerative braking of the electric drive axle.

7. A multi-speed electric drive axle braking energy recovery shift control device, characterized in that, It includes a second calculation module, a first control module, a judgment module, an execution module, and a second control module; The second calculation module is used to calculate the torque required for brake energy recovery of the electric drive axle. The first control module is used to control the vehicle braking system to increase the corresponding braking torque by using the calculated electric drive axle braking energy recovery torque as the control signal for the vehicle braking system, while controlling the electric drive axle braking energy recovery torque to decrease to zero. The judgment module is used to determine the target gear of the electric drive axle; The execution module is used to switch the electric drive axle from the current gear to the target gear; The second control module is used to increase the electric drive axle braking energy recovery torque from zero to the calculated electric drive axle braking energy recovery required torque, while controlling the braking torque of the braking system to decrease to the braking torque of the braking system before controlling the braking system to increase the corresponding braking torque, thus completing the gear shift. The device also includes a configuration module, a second acquisition module, a model creation module, and a first calculation module; The configuration module is used to configure the speed ratio of each gear of the electric drive axle and the motor braking torque-speed characteristics; The second acquisition module is used to acquire the vehicle’s current braking torque and braking demand torque, electric drive axle output speed, current gear information and motor’s current braking energy recovery torque. The model creation module is used to establish a calculation model for the range of regenerative braking torque of the electric drive axle based on the configured speed ratios of each gear of the electric drive axle and the braking torque-speed characteristics of the motor. The first calculation module is used to calculate the maximum regenerative braking torque of the electric drive axle in each gear based on the established electric drive axle regenerative braking torque calculation model and the current output speed of the electric drive axle. The judgment module is used to determine the target gear of the electric drive axle based on the current braking torque and braking torque demand of the vehicle and the calculated maximum braking energy recovery torque of the electric drive axle in each gear.

8. A vehicle, characterized in that, The vehicle includes the multi-speed electric drive axle brake energy recovery shift control device as described in claim 7.

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