A two-gear shifting control method, system and vehicle controller for an electric vehicle

Abstract

The application provides a two-gear shifting control method and system for an electric vehicle and a vehicle controller, and the method comprises the following steps: acquiring the current vehicle speed and the current gear and shifting line of the front axle and the rear axle of the vehicle; determining the shifting axle and the target gear according to the current vehicle speed and the current gear and shifting line of the front axle and the rear axle; determining the torque distribution ratio of the front axle and the rear axle according to the current torque of the shifting axle and the front axle and the rear axle; controlling the adjustment of the torque of the shifting axle to the target torque allowed for shifting according to the torque distribution ratio, and transferring the part of the torque to the other non-shifting axle; and controlling the shifting of the shifting axle according to the target gear. The control method can ensure the power performance in the shifting process by transferring the torque of the shifting axle to the other axle before the single-axle shifting and by sequentially shifting the front axle transmission and the rear axle transmission in the double-transmission architecture of the front axle and the rear axle. The torque of the shifting axle can be transferred to the other axle in the shifting process, and the power is not interrupted in the shifting process in the single-transmission architecture.

Description

Technical Field

[0001] This invention belongs to the field of electric vehicle control technology, and specifically relates to a two-gear shifting control method, system and vehicle controller for electric vehicles. Background Technology

[0002] Currently, most mass-produced pure electric vehicles use a single-gear fixed-ratio transmission. This solution is easy to develop and can basically meet the requirements of small and medium-sized pure electric vehicles. However, the single-gear transmission solution requires high motor torque and a wide speed range, and cannot effectively control the motor's operating state. Compared with existing technologies, two-gear transmissions can improve the vehicle's power at low speeds and its economy at high speeds, and effectively control the motor's operating state. As a result, they are gradually being adopted by new pure electric vehicles.

[0003] However, most existing two-speed transmissions are based on single-transmission configurations. For multi-motor four-wheel drive vehicles, each axle is equipped with a two-speed transmission, and the control involves the alternating shifting and torque transfer process of the front and rear axle transmissions, making the control method more complex. Most existing technical solutions are based on a single-transmission two-speed transmission architecture or a single-ratio architecture of dual transmissions on the front and rear axles, but their focus is on the driving mode rather than the shifting strategy. Therefore, there is an urgent need for a shifting control method for electric vehicles to solve the above problems. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the purpose of this invention is to provide a two-speed shifting control method, system and vehicle controller for electric vehicles, so as to solve the problem that most existing two-speed transmissions are based on single-transmission configurations. For multi-motor four-wheel drive vehicles, each axle is equipped with a two-speed transmission, and the control involves the alternating shifting and torque transfer process of the front and rear axle transmissions, making the control method more complex.

[0005] To achieve the above and other related objectives, this invention proposes a two-gear shifting control method for electric vehicles, comprising:

[0006] Get the current vehicle speed and the current gear and shift line of the front and rear axles;

[0007] The shift shaft and target gear are determined based on the current vehicle speed and the current gear and shift line of the front axle and the rear axle;

[0008] The torque distribution ratio of the front axle and the rear axle is adjusted based on the shift shaft and the current torque of the front axle and the rear axle;

[0009] The torque of the shift shaft is adjusted to the target torque that allows shifting according to the torque distribution ratio, and this portion of the torque is transferred to another non-shift shaft;

[0010] The shift shaft is controlled to shift gears according to the target gear position.

[0011] In one embodiment of the present invention, when there is only one transmission among the front axle and the rear axle, the step of determining the shift shaft and the target gear based on the current vehicle speed and the current gear and shift line of the front axle and the rear axle includes:

[0012] The transmission shaft in the front axle and the rear axle is used as the shift shaft, and the target gear is determined based on the current vehicle speed and the current gear and shift line of the front axle and the rear axle.

[0013] In one embodiment of the present invention, when there is a transmission on each of the front axle and the rear axle, the step of determining the shift shaft and the target gear based on the current vehicle speed and the current gear and shift line of the front axle and the rear axle includes:

[0014] Based on the current vehicle speed and the current gear and shift line of the front axle and the rear axle, determine whether the front axle and the rear axle have a request to shift up or down;

[0015] When only one of the front axle and the rear axle has a shift request, the axle with the shift request will be designated as the shift axle.

[0016] When both the front axle and the rear axle have upshift / downshift requests, the shift shaft is determined based on the current torque of the front axle and the rear axle, wherein the one with the lower current torque value between the front axle and the rear axle is selected as the shift shaft.

[0017] In one embodiment of the present invention, when there is a transmission on both the front axle and the rear axle, the step of controlling the shift shaft to shift gears according to the target gear position further includes:

[0018] Determine whether the shift shaft has successfully shifted gears;

[0019] After the shift shaft completes the shift, it is determined whether there is a request to shift up or down among the front axle and the rear axle that has not shifted. The front axle and the rear axle that have not shifted are designated as the new shift shaft, and the process returns to the step of adjusting the torque distribution ratio of the front axle and the rear axle based on the current torque and the shift shaft.

[0020] In one embodiment of the present invention, the method further includes: if the torque of the shift shaft does not reach the target torque within a preset time, the shifting process is stopped and a torque transfer timeout fault is indicated.

[0021] In one embodiment of the present invention, the method further includes: if the shift shaft fails to shift to the target gear within a preset time, the shifting process is stopped and a shifting timeout fault is indicated; if the shift shaft shifts to the target gear within the preset time, the shifting is completed.

[0022] In one embodiment of the present invention, the method further includes: after the shift shaft completes shifting, acquiring a shift shaft shift completion signal, and controlling the restoration of torque of the front axle and the rear axle based on the shift completion signal.

[0023] In one embodiment of the present invention, the method further includes the following steps before obtaining the current vehicle speed, the current gear position of the front axle and the rear axle of the vehicle, the shift line, and the current torque:

[0024] Obtain vehicle information and determine whether the basic conditions for shifting are met or whether there are conditions that prohibit shifting based on the vehicle information;

[0025] If the basic conditions for shifting are not met or there are conditions that prohibit shifting, then shifting is not allowed in the current state of the vehicle.

[0026] If the basic conditions for shifting are met and there are no conditions prohibiting shifting, then proceed to the step of obtaining the current vehicle speed and the current gear and shift line of the front and rear axles of the vehicle.

[0027] This invention also proposes a two-speed shifting control system for electric vehicles, comprising:

[0028] The information acquisition module is used to acquire the current vehicle speed and the current gear and shift line of the front and rear axles of the vehicle;

[0029] The shift shaft determination module is used to determine the shift shaft and target gear based on the current vehicle speed and the current gear and shift line of the front axle and the rear axle;

[0030] The torque distribution module is used to adjust the torque distribution based on the shift shaft and the current torque of the front and rear axles.

[0031] The torque distribution ratio between the front axle and the rear axle; and the control and adjustment of the torque of the shift shaft to the target torque that allows shifting based on the torque distribution ratio, and the transfer of this portion of the torque to another non-shift shaft;

[0032] The shift module is used to control the shift shaft to shift gears according to the target gear.

[0033] The present invention also proposes a vehicle controller for performing the steps of implementing the two-gear shifting control method for electric vehicles as described in any of the above embodiments.

[0034] This invention proposes a two-gear shifting control method, system, and vehicle controller for electric vehicles. The control method can determine the target gears for the front and rear axles that satisfy both economy and power requirements based on the shift line or specific gear requirements. For a dual-transmission architecture with one transmission on each axle, the method performs sequential shifting of the front and rear axles during gear changes, transferring torque from the shift shaft to the other axle before shifting on a single axle, thus ensuring power during shifting. Furthermore, for a single-transmission architecture, the method can transfer torque from the shift shaft to the other axle during shifting, ensuring uninterrupted power during the shift. This control method can also coordinate the vehicle's overall status and fault conditions during shifting, ensuring driving safety and drivability. Attached Figure Description

[0035] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 This is a schematic flowchart of a two-gear shifting control method for electric vehicles provided in one embodiment of the present invention;

[0037] Figure 2 This is a schematic diagram of a process for determining whether a gear shift is possible according to an embodiment of the present invention;

[0038] Figure 3 This is a schematic diagram of the process for determining the shift shaft according to an embodiment of the present invention;

[0039] Figure 4 This is a structural block diagram of a two-gear shifting control system for electric vehicles provided in one embodiment of the present invention. Detailed Implementation

[0040] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0041] It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of the present invention. Therefore, the drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0042] Please see Figure 1 As shown, Figure 1 This is a flowchart illustrating a two-speed shifting control method for electric vehicles provided in one embodiment of the present invention. The present invention proposes a two-speed shifting control method, system, and vehicle controller for electric vehicles to address the problem that most existing two-speed transmissions are based on single-transmission configurations. For multi-motor four-wheel drive vehicles, each axle is equipped with a two-speed transmission, and the control involves the alternating shifting and torque transfer processes of the front and rear axles, making the control method more complex. Specifically, the two-speed shifting control method for electric vehicles includes the following steps:

[0043] S1. Obtain the current vehicle speed and the current gear and shift line of the front and rear axles of the vehicle; it should be noted that the shift line is determined based on the motor efficiency diagram, the motor external characteristic curve, the transmission speed ratio and efficiency to meet the requirements of power and economy. For example, the shift line can be pre-stored in the vehicle controller and directly read and used when needed.

[0044] Please see Figure 1 and Figure 2 As shown, Figure 2 This is a schematic diagram of a process for determining whether a gear shift is possible according to an embodiment of the present invention. In this embodiment, before the steps of obtaining the current vehicle speed, the current gear of the front axle and the rear axle of the vehicle, the shift line, and the current torque, the following steps are included:

[0045] S11. Obtain vehicle information and determine whether the basic conditions for shifting are met or whether there are conditions that prohibit shifting based on the vehicle information.

[0046] If the basic conditions for shifting gears are not met or there are conditions that prohibit shifting gears, then shifting gears is not allowed in the current state of the vehicle.

[0047] S13. If the basic conditions for shifting are met and there are no conditions prohibiting shifting, proceed to the step of obtaining the current vehicle speed and the current gear and shift line of the front and rear axles of the vehicle.

[0048] For example, shifting gears is prohibited when the vehicle is in reverse gear; shifting gears is prohibited when the steering wheel angle of the vehicle is greater than a certain value, or when shifting gears would interfere with the vehicle's stability; and shifting gears is prohibited in the current driving cycle if a shifting fault has been reported.

[0049] S2. Determine the shift shaft and target gear based on the current vehicle speed and the current gear and shift line of the front axle and the rear axle; for example, when the demand is low vehicle speed and high torque, select the D1 gear with a larger gear ratio to ensure acceleration power; at high vehicle speed, shift to D2 gear to ensure that the vehicle speed is not limited by the maximum speed of D1 gear, while ensuring power; when the vehicle speed is high and the torque demand is low, keep D2 gear to meet the economy of high-speed constant speed driving.

[0050] S3. Adjust the torque distribution ratio of the front axle and the rear axle according to the shift shaft and the current torque of the front axle and the rear axle; for example, when one of the front axle and the rear axle is determined to be the shift shaft, adjust the torque distribution ratio of the front axle and the rear axle according to the current torque of the front axle and the rear axle.

[0051] S4. Based on the torque distribution ratio, the torque of the shift shaft is adjusted to the target torque that allows shifting, and this portion of the torque is transferred to another non-shifting shaft. For example, after adjusting the torque distribution ratio, the controller sends the target torque of the front and rear axle motors to the actuator. By adjusting the torque distribution ratio of the front and rear axles, the torque of the shaft used as the shift shaft is gradually transitioned to a torque lower than the allowable shifting torque, and the reduced torque is transferred to another non-shifting shaft to ensure that power is not lost during the torque transfer process. At this time, the shift activation flag is 0. It should be noted that the method also includes: if the torque of the shift shaft does not reach the target torque within a preset time, the shifting process is stopped and a torque transfer timeout fault is indicated. For example, if the torque of the shift shaft does not fall below the allowable shifting torque within a predetermined time, it is determined that the torque transfer has timed out, the shifting process is stopped and a torque transfer timeout fault is indicated, and the shift shaft returns to its initial state, with the torque gradually restored.

[0052] S5. Control the shift shaft to shift gears according to the target gear position; for example, after the torque transfer between the shift shaft and another shaft is completed, the shift shaft enters the shifting state. The controller sends the target gear to the actuator according to the shift shaft's upshift / downshift request. The actuator performs the shift according to the target gear and feeds back the shift result to the controller. During this process, the shift activation flag is 1. It should be noted that the method also includes: if the shift shaft does not shift to the target gear within a preset time, the shifting process is stopped and a shift timeout fault is indicated; if the shift shaft shifts to the target gear within the preset time, the shift is completed; for example, it is determined whether the shift shaft has successfully shifted within a specified time. If the target gear and the current gear are the same within the specified time, the shift is successful; if they are not the same, the shift fails, the shifting process is stopped, and the shift shaft returns to its initial state. For example, when a certain shaft has a shift request and the shift torque transfer is complete, a shift command has been sent to the transmission. However, if the transmission remains in the shifting state for a certain period of time, a shift timeout fault is output for that shaft, and the shift state returns to the initial shift state. The controller does not send a shift command for that shaft. At this time, if the shaft is not in neutral (N) gear, the torque of that shaft gradually recovers.

[0053] Please see Figure 1 As shown, in this embodiment, when there is only one transmission among the front axle and the rear axle, the step of determining the shift shaft and target gear based on the current vehicle speed and the current gear and shift line of the front axle and the rear axle includes:

[0054] The transmission shaft in the front axle and the rear axle is used as the shift shaft, and the target gear is determined based on the current vehicle speed and the current gear and shift line of the front axle and the rear axle.

[0055] Please see Figure 1 and Figure 3 As shown, Figure 3 This is a schematic flowchart illustrating the process of determining a shift shaft according to an embodiment of the present invention. In this embodiment, when there is one transmission on each of the front axle and the rear axle, the step of determining the shift shaft and the target gear based on the current vehicle speed and the current gear and shift line of the front axle and the rear axle includes:

[0056] S21. Determine whether the front axle and the rear axle have a request to shift gears based on the current vehicle speed and the current gear and shift line of the front axle and the rear axle;

[0057] S22. When only one of the front axle and the rear axle has a shift request, the axle with the shift request is designated as the shift axle.

[0058] S23. When both the front axle and the rear axle have upshift / downshift requests, the shift shaft is determined based on the current torque of the front axle and the rear axle, wherein the one with the lower current torque value between the front axle and the rear axle is taken as the shift shaft.

[0059] In this embodiment, the method further includes: determining whether the transmission of the front axle and / or the rear axle has a shifting fault; if so, shifting is not performed. The shifting fault includes torque transfer timeout fault, shifting timeout fault, and shifting failure fault. When a certain axle has a shifting request and enters the shifting torque transfer process, if its torque transfer does not reach the target torque for a certain period of time, a torque transfer timeout fault for that axle is output. When a certain axle has a shifting request and the shifting torque transfer is complete, and a shifting command has been sent to the transmission, but the transmission remains in a shifting state for a certain period of time, a shifting timeout fault for that axle is output. When a certain transmission reports that a shift is complete, but the current actual gear is inconsistent with the target gear, a shifting failure fault is output.

[0060] It should be noted that when there is no upshift or downshift request on the front or rear axle, the shift state is in the initial shift state. At this time, the shift state activation flag is 0, the target gear of the front and rear axle transmissions remains the current gear, and the front and rear axle torque distribution ratio remains the torque distribution ratio calculated by the current four-wheel drive function.

[0061] In Embodiment 1, when there is only one transmission on the front axle and the rear axle and there is a request to shift gears, the control method is as described in steps S1 to S5 above. In this case, the axle with the transmission is used as the shift axle, and after the shift axle completes shifting, a shift completion signal is obtained, and the torque of the front axle and the rear axle is restored according to the shift completion signal. For example, after the controller receives the shift completion signal, it controls the restoration of the torque of the front axle and the rear axle, and at this time, the shift activation flag is 0.

[0062] In Embodiment 2, when there is one transmission on each of the front axle and the rear axle, the step of controlling the shift shaft to shift gears according to the target gear position further includes:

[0063] Determine whether the shift shaft has successfully shifted gears;

[0064] After the shift shaft completes the shift, it is determined whether there is a request to shift up or down among the front axle and the rear axle that has not shifted. If so, the front axle and the rear axle that have not shifted are designated as the new shift shaft, and the process returns to the step of determining the torque distribution ratio of the front axle and the rear axle based on the current torque and the shift shaft.

[0065] For example, if either the current axle or the rear axle requests a shift, the axle with the shift request is designated as the first shift axle, and the other axle as the second shift axle. If both the current axle and the rear axle have shift requests, the axle with the lower current torque value is designated as the first shift axle, and the other axle as the second shift axle. The first shift axle is used first for the shift. After the first shift axle completes its shift, it is checked again whether the second shift axle has a shift request. If it does, the second shift axle is designated as the new shift axle, and the process returns to the step of adjusting the torque distribution ratio of the front and rear axles based on the current torque and the shift axle. Furthermore, after the second shift axle completes its shift, a shift completion signal is obtained, and the torque of the front and rear axles is restored based on this signal. For example, after receiving the second shift axle's shift completion signal, the controller restores the torque of the front and rear axles; at this time, the shift activation flag is 0.

[0066] Please see Figure 1 and Figure 4 As shown, Figure 4 This is a structural block diagram of a two-gear shifting control system for an electric vehicle provided in one embodiment of the present invention. This embodiment provides a two-gear shifting control system for an electric vehicle, which corresponds one-to-one with the two-gear shifting control method for the electric vehicle in the above embodiments. The two-gear shifting control system 100 includes an information acquisition module 10, a shift shaft determination module 20, a torque distribution module 30, and a shifting module 40. Detailed descriptions of each functional module are as follows:

[0067] The information acquisition module 10 is used to acquire the current vehicle speed and the current gear and shift line of the front and rear axles of the vehicle;

[0068] The shift shaft determination module 20 is used to determine the shift shaft and target gear based on the current vehicle speed and the current gear and shift line of the front axle and the rear axle. For example, when there is only one transmission on the front axle and the rear axle, the axle with the transmission is used as the shift shaft, and the target gear is determined based on the current vehicle speed and the current gear and shift line of the front axle and the rear axle. When there is one transmission on each of the front axle and the rear axle, if only one axle has a shift request, the axle with the shift request is used as the shift shaft; if both the front axle and the rear axle have shift requests, the axle with the lower current torque value is used as the shift shaft.

[0069] The torque distribution module 30 is used to adjust the torque distribution ratio of the front axle and the rear axle based on the current torque of the shift shaft and the front and rear axles. For example, when one of the front axle and the rear axle is determined to be the shift shaft, the torque distribution ratio of the front axle and the rear axle is adjusted based on the current torque of the front and rear axles. The torque distribution module 30 is also used to control and adjust the torque of the shift shaft to the target torque that allows shifting based on the torque distribution ratio, and transfer this portion of the torque to another non-shift shaft. For example, after adjusting the torque distribution ratio, the controller sends the target torque of the front and rear axle motors to the actuator, and by adjusting the front and rear axle torque distribution ratio, the torque of the shaft that is used as the shift shaft is gradually transitioned to a torque lower than that that allows shifting, and the reduced torque is transferred to another shaft.

[0070] The shift module 40 is used to control the shift shaft to shift gears according to the target gear. For example, when the torque transfer between the shift shaft and another shaft is completed, the shift shaft enters the shift state. The controller sends the target gear to the actuator according to the shift shaft's upshift / downshift request, and the actuator performs the shift according to the target gear.

[0071] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is used as an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above.

[0072] The present invention also proposes a vehicle controller, which is used to execute the steps of implementing the two-gear shifting control method for electric vehicles described in the above embodiments.

[0073] This invention proposes a two-gear shifting control method, system, and vehicle controller for electric vehicles. The control method can determine the target gears for the front and rear axles that satisfy both economy and power requirements based on the shift line or specific gear requirements. For a dual-transmission architecture with one transmission on each axle, the method performs sequential shifting of the front and rear axles during gear changes, transferring torque from the shift shaft to the other axle before shifting on a single axle, thus ensuring power during shifting. Furthermore, for a single-transmission architecture, the method can transfer torque from the shift shaft to the other axle during shifting, ensuring uninterrupted power during the shift. This control method can also coordinate the vehicle's overall status and fault conditions during shifting, ensuring driving safety and drivability.

[0074] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

[0075] Apart from the technical features described in the specification, the other technical features are known to those skilled in the art. To highlight the innovative features of this invention, the other technical features will not be described in detail here.

Claims

1. A two-gear shifting control method for an electric vehicle, characterized in that, include: Get the current vehicle speed and the current gear and shift line of the front and rear axles; The shift shaft and target gear are determined based on the current vehicle speed and the current gear and shift line of the front axle and the rear axle; The torque distribution ratio of the front axle and the rear axle is adjusted based on the shift shaft and the current torque of the front axle and the rear axle; The torque of the shift shaft is adjusted to the target torque that allows shifting according to the torque distribution ratio, and this portion of the torque is transferred to another non-shift shaft; The shift shaft is controlled to shift gears according to the target gear position; Where there is only one transmission between the front axle and the rear axle, the step of determining the shift shaft and target gear based on the current vehicle speed and the current gear and shift line of the front axle and the rear axle includes: The transmission is used as the shift shaft between the front axle and the rear axle, and the target gear is determined based on the current vehicle speed and the current gear and shift line of the front axle and the rear axle. When there is one transmission on each of the front axle and the rear axle, the step of determining the shift shaft and the target gear based on the current vehicle speed and the current gear and shift line of the front axle and the rear axle includes: Based on the current vehicle speed and the current gear and shift line of the front axle and the rear axle, determine whether the front axle and the rear axle have a request to shift up or down; When only one of the front axle and the rear axle has a shift request, the axle with the shift request will be designated as the shift axle. When both the front axle and the rear axle have upshift / downshift requests, the shift shaft is determined based on the current torque of the front axle and the rear axle, wherein the one with the lower current torque value between the front axle and the rear axle is selected as the shift shaft.

2. The two-gear shifting control method for electric vehicles according to claim 1, characterized in that, When there is one transmission on each of the front axle and the rear axle, the step of controlling the shift shaft to shift gears according to the target gear position further includes: Determine whether the shift shaft has successfully shifted gears; After the shift shaft completes the shift, it is determined whether there is a request to shift up or down among the front axle and the rear axle that has not shifted. The front axle and the rear axle that have not shifted are designated as the new shift shaft, and the process returns to the step of adjusting the torque distribution ratio of the front axle and the rear axle based on the current torque and the shift shaft.

3. The two-gear shifting control method for electric vehicles according to claim 1, characterized in that, The method further includes: if the torque of the shift shaft does not reach the target torque within a preset time, the shifting process is stopped and a torque transfer timeout fault is indicated.

4. The two-gear shifting control method for electric vehicles according to claim 1, characterized in that, The method further includes: if the shift shaft fails to shift to the target gear within a preset time, the shifting process is stopped and a shift timeout fault is indicated; if the shift shaft shifts to the target gear within the preset time, the shifting is completed.

5. The two-gear shifting control method for electric vehicles according to claim 4, characterized in that, The method further includes: after the shift shaft completes shifting, acquiring a shift completion signal of the shift shaft, and controlling the restoration of torque of the front axle and the rear axle based on the shift completion signal.

6. The two-gear shifting control method for electric vehicles according to claim 1, characterized in that, Before obtaining the current vehicle speed, the current gear position of the front and rear axles, the shift line, and the current torque, the following steps are also included: Obtain vehicle information and determine whether the basic conditions for shifting are met or whether there are conditions that prohibit shifting based on the vehicle information; If the basic conditions for shifting are not met or there are conditions that prohibit shifting, then shifting is not allowed in the current state of the vehicle. If the basic conditions for shifting are met and there are no conditions prohibiting shifting, then proceed to the step of obtaining the current vehicle speed and the current gear and shift line of the front and rear axles of the vehicle.

7. A two-speed shifting control system for an electric vehicle, characterized in that, include: The information acquisition module is used to acquire the current vehicle speed and the current gear and shift line of the front and rear axles of the vehicle; The shift shaft determination module is used to determine the shift shaft and target gear based on the current vehicle speed and the current gear and shift line of the front axle and the rear axle; A torque distribution module is used to adjust the torque distribution ratio between the front axle and the rear axle based on the shift shaft and the current torque of the front axle and the rear axle. And based on the torque distribution ratio, control and adjust the torque of the shift shaft to the target torque that allows shifting, and transfer that portion of the torque to another non-shift shaft; The shift module is used to control the shift shaft to shift gears according to the target gear position; Where there is only one transmission between the front axle and the rear axle, the step of determining the shift shaft and target gear based on the current vehicle speed and the current gear and shift line of the front axle and the rear axle includes: The transmission is used as the shift shaft between the front axle and the rear axle, and the target gear is determined based on the current vehicle speed and the current gear and shift line of the front axle and the rear axle. When there is one transmission on each of the front axle and the rear axle, the step of determining the shift shaft and the target gear based on the current vehicle speed and the current gear and shift line of the front axle and the rear axle includes: Based on the current vehicle speed and the current gear and shift line of the front axle and the rear axle, determine whether the front axle and the rear axle have a request to shift up or down; When only one of the front axle and the rear axle has a shift request, the axle with the shift request will be designated as the shift axle. When both the front axle and the rear axle have upshift / downshift requests, the shift shaft is determined based on the current torque of the front axle and the rear axle, wherein the one with the lower current torque value between the front axle and the rear axle is selected as the shift shaft.

8. A vehicle controller, characterized in that, The vehicle controller is used to perform the steps of implementing the electric vehicle two-gear shift control method as described in any one of claims 1 to 6.

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