Gear shifting process control method, controller, system, and pure electric vehicle

Abstract

A gear shifting process control method, comprising: in a neutral gear stage, acquiring a rotating speed control mode sent by an automatic speed change control device; on the basis of the rotating speed control mode, acquiring a target motor rotating speed; on the basis of the target motor rotating speed, controlling a driving motor to enter a quick speed-adjustment stage; in the quick speed-adjustment stage, using a first calibrated rotating speed and first limiting torque to iteratively control the driving motor to carry out speed adjustment; if a rotating speed difference between an actual motor rotating speed under quick speed-adjustment and the target motor rotating speed reaches a set rotating speed difference, controlling the driving motor to enter a slow speed-adjustment stage; and in the slow speed-adjustment stage, using a second calibrated rotating speed and second limiting torque to respectively replace the first calibrated rotating speed and the first limiting torque, and continuously iteratively controlling the driving motor to carry out speed adjustment until gear engagement is completed. Further provided are a controller, a system, and a pure electric vehicle.

Description

A shift process control method, controller, system and pure electric vehicle

[0001] This application claims priority to Chinese patent application No. 202311289762.3 filed on September 28, 2023, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the technical field of pure electric vehicles, and in particular to a shifting process control method, controller, system and pure electric vehicle. Background Art

[0003] Currently, there are a variety of vehicle types on the market, including gasoline-powered vehicles, hybrid vehicles, and pure electric vehicles. The drive system of gasoline-powered vehicles primarily utilizes a multi-speed transmission and clutch to propel the vehicle. However, pure electric vehicles, as low-emission, high-efficiency new energy vehicles, differ from gasoline-powered vehicles in that they eliminate the multi-speed transmission and clutch. Instead, they utilize an automatic transmission system to control two-speed transmission shifts, relying on the drive motor's speed regulation to synchronize the motor speed with the speed of the next gear during the shift.

[0004] As we all know, the shifting process control of pure electric vehicles must ensure the smoothness of the entire vehicle. If the shifting process is not properly controlled, it will cause gear shifting jerks and gear clashing, which will greatly reduce the smoothness and comfort of the entire vehicle.

[0005] Therefore, how to effectively control the shifting process of pure electric vehicles and ensure the smoothness of the entire vehicle is an urgent problem that needs to be solved. Technical issues

[0006] The present application provides a gear shifting process control method, controller, system and pure electric vehicle, which adopts different calibration parameters based on speed difference for iterative control in different speed regulation stages to solve or partially solve the technical problem that pure electric vehicles cannot ensure the smoothness of the whole vehicle when shifting gears. It can effectively improve the motor speed response time and improve the motor reaction efficiency in the early stage of speed regulation, and can effectively stabilize the motor speed in the later stage of speed regulation, thereby avoiding gear shifting, failure and the like, ensuring the smoothness and success rate of the pure electric vehicle during the gear shifting process, and can extend the service life of the gearbox hardware of the pure electric vehicle. Technical Solutions

[0007] In a first aspect of the present application, a shift process control method is disclosed, which is applied to a pure electric vehicle. The method comprises:

[0008] In the neutral stage, obtaining the speed control mode sent by the automatic transmission control device;

[0009] Based on the speed control mode, obtaining a target motor speed;

[0010] Based on the target motor speed, controlling the drive motor to enter a strong acceleration phase; in the strong acceleration phase, iteratively controlling the drive motor to adjust its speed using a first calibrated speed and a first limited torque; and

[0011] If the speed difference between the actual motor speed under strong speed regulation and the target motor speed reaches the set speed difference, the drive motor is controlled to enter the weak speed regulation stage; in the weak speed regulation stage, the second calibrated speed and the second limit torque are used to replace the first calibrated speed and the first limit torque respectively, and the drive motor is continuously iteratively controlled to adjust the speed until the gear is engaged; the second calibrated speed is less than the first calibrated speed, and the second limit torque is less than the first limit torque.

[0012] Before the neutral phase, the method further includes:

[0013] In the torque reduction phase, the vehicle controller receives a control instruction based on the target gear position and performs a corresponding torque reduction operation; and

[0014] During the gear disengagement stage, when the torque is reduced to the target range, the torque control mode sent by the automatic transmission control device is received, and the gear disengagement operation is performed according to the first torque control instruction carried in the torque control mode; the torque control mode is used to indicate that the control subject is switched from the vehicle controller to the automatic transmission control device.

[0015] In one embodiment, the first calibrated speed includes a first speed proportional parameter and a first speed integral parameter based on the speed difference; the first limit torque is a motor allowable torque calculated by a vehicle controller according to battery capacity, and is used to prevent overcharging or over-discharging of the battery;

[0016] The iterative control of the drive motor to adjust the speed by using the first calibrated speed and the first limited torque specifically includes:

[0017] The first speed proportional parameter and the first speed integral parameter are used to iteratively control the drive motor to adjust its speed, and the first limiting torque is used to limit the torque of the drive motor.

[0018] In one embodiment, after the speed difference between the actual motor speed and the target motor speed under the high speed condition reaches a set speed difference, the method further includes:

[0019] detecting a shift process variable setting and a control mode of the automatic transmission control device; and

[0020] If the shift process variable is set to 4 and the control mode is the speed control mode, the drive motor is controlled to enter the weak speed regulation stage.

[0021] In one embodiment, the second calibrated speed includes a second speed proportional parameter and a second speed integral parameter based on the speed difference; the second speed proportional parameter is smaller than the first speed proportional parameter, and the second speed integral parameter is smaller than the first speed integral parameter;

[0022] The step of replacing the first calibrated speed and the first limited torque respectively with the second calibrated speed and the second limited torque, and continuously iteratively controlling the drive motor to adjust the speed until the gear shifting is completed, specifically includes:

[0023] The second speed proportional parameter, the second speed integral parameter, and the second limiting torque are used to replace the first speed proportional parameter, the first speed integral parameter, and the first limiting torque respectively, and the drive motor is continuously iteratively controlled to adjust the speed until the gear is engaged; wherein, the second limiting torque is the allowable torque of the motor calculated by the automatic speed control device based on the gear engagement requirement torque, and is used to prevent gear engagement failure caused by excessive torque.

[0024] In one embodiment, after the gear shifting is completed, the method further includes:

[0025] The torque control mode is received from the automatic speed control device, and the speed control mode is switched to the torque control mode.

[0026] In one embodiment, after replacing the first calibrated speed and the first limit torque respectively with the second calibrated speed and the second limit torque, and continuously iteratively controlling the drive motor to adjust the speed until the gear engagement is completed, the method further includes:

[0027] In the torque increase phase, receiving the 0 torque mode and the actual gear position sent by the automatic transmission control device; and

[0028] Based on the zero torque mode and the actual gear position, a control boost torque of a vehicle controller is received, wherein the zero torque mode is used to indicate that the control subject is switched from the automatic transmission control device to the vehicle controller.

[0029] In a second aspect of the present application, a shift process controller is disclosed, which is applied to a pure electric vehicle. The shift process controller includes:

[0030] A first acquisition module is used to acquire a speed control mode sent by the automatic transmission control device during a neutral phase;

[0031] A second acquisition module is used to acquire a target motor speed based on the speed control mode;

[0032] a first control module configured to control the drive motor to enter a strong acceleration phase based on the target motor speed; and in the strong acceleration phase, iteratively controlling the drive motor to adjust its speed using a first calibrated speed and a first limited torque; and

[0033] The second control module is used to control the drive motor to enter a weak speed regulation stage if the speed difference between the actual motor speed under strong acceleration and the target motor speed reaches a set speed difference; in the weak speed regulation stage, the first calibrated speed and the first limit torque are replaced by a second calibrated speed and a second limit torque respectively, and the drive motor is continuously iterated to control the speed until the gear is engaged; the second calibrated speed is less than the first calibrated speed, and the second limit torque is less than the first limit torque.

[0034] The third aspect of the present application discloses a gear shifting process control system, which is applied to a pure electric vehicle. The gear shifting process control system includes: a gear shifting process controller and an automatic speed control device; wherein, the gear shifting process controller is used to realize gear shifting control through the gear shifting control method as described above.

[0035] In a fourth aspect of the present application, a pure electric vehicle is disclosed, which implements shift control through the aforementioned shift control method. Beneficial effects

[0036] Through one or more technical solutions of this application, this application has the following beneficial effects or advantages:

[0037] In this application, the speed control mode sent by the automatic speed control device is used as a trigger mechanism to execute the speed regulation of the drive motor, and the speed regulation control of the drive motor is divided into a strong speed regulation stage and a weak speed regulation stage. Different calibration parameters based on the speed difference are used for iterative control in different speed regulation stages, so that the motor speed response time can be effectively improved in the early stage of speed regulation, and the motor reaction efficiency can be improved. In the later stage of speed regulation, the motor speed can be effectively stabilized, thereby avoiding gear shifting, failure, etc., ensuring the vehicle smoothness and success rate of pure electric vehicles during the gear shifting process, and extending the service life of the gearbox hardware of pure electric vehicles.

[0038] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present application. Throughout the accompanying drawings, the same reference numerals are used to denote the same components.

[0040] In the attached figure:

[0041] FIG1 is a schematic diagram showing a process of a shift process control method according to an embodiment of the present application;

[0042] FIG2 shows a schematic structural diagram of a shift process controller according to an embodiment of the present application;

[0043] FIG3 shows a schematic structural diagram of a shift process control system according to an embodiment of the present application. Modes for Carrying Out the Invention

[0044] The following describes exemplary embodiments of the present application in more detail with reference to the accompanying drawings. Although exemplary embodiments of the present application are shown in the accompanying drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present application and to fully convey the scope of the present application to those skilled in the art.

[0045] The present application discloses a shifting process control method, which is applied to pure electric vehicles and mainly controls the shifting process of the two-speed transmission of the pure electric vehicle, thereby effectively ensuring the smoothness and success rate of the whole vehicle during the shifting process of the pure electric vehicle, and can extend the service life of the transmission hardware of the pure electric vehicle.

[0046] 1 , which is a schematic diagram of a shift process control method disclosed in an embodiment of the present application, the shift process control method disclosed in an embodiment of the present application includes the following steps:

[0047] S101, in a neutral phase, obtaining a speed control mode sent by an automatic transmission control device.

[0048] S102: Obtain a target motor speed based on a speed control mode.

[0049] S103 , based on the target motor speed, controlling the drive motor to enter a strong acceleration stage; in the strong acceleration stage, iteratively controlling the drive motor to adjust its speed using a first calibrated speed and a first limited torque.

[0050] S104: If the speed difference between the actual motor speed and the target motor speed under strong acceleration reaches the set speed difference, the drive motor is controlled to enter the weak speed regulation stage; in the weak speed regulation stage, the first calibrated speed and the first limited torque are replaced by the second calibrated speed and the second limited torque respectively, and the drive motor is continuously iterated to adjust the speed until the gear is engaged; the second calibrated speed is less than the first calibrated speed, and the second limited torque is less than the first limited torque.

[0051] In this solution, the speed control mode transmitted by the automatic transmission control device is used as a trigger mechanism to execute the speed regulation of the drive motor. The speed regulation of the drive motor is divided into a strong speed regulation stage and a weak speed regulation stage. Different calibration parameters based on the speed difference are used for iterative control in different speed regulation stages. This effectively improves the motor speed response time and reaction efficiency in the early stage of speed regulation. In the later stage of speed regulation, the motor speed can be effectively stabilized to avoid gear shifting jerk and failure. This ensures the smoothness and success rate of the pure electric vehicle during the gear shift process, and can also extend the service life of the pure electric vehicle's gearbox hardware.

[0052] The shifting process of a pure electric vehicle consists of five control phases: torque reduction phase, gear shifting phase, neutral phase, gear engagement phase, and torque increase phase. Furthermore, the drive motor speed control during the shifting process is achieved through the interaction of the vehicle controller, the automatic transmission control device, and the shifting process controller. See Figure 3 for a schematic diagram of the three structures. In this embodiment of the present application, the shifting process controller is exemplified as a motor controller for use in a pure electric vehicle. To facilitate the description and explanation of the embodiments of the present application, the process control logic of the present application is described below according to the aforementioned five control phases.

[0053] Before executing the relevant operations of the neutral phase in S101, the relevant operations for the torque reduction phase and the gear shifting phase are also included, which are as follows:

[0054] During the torque reduction phase, the motor controller receives control instructions from the vehicle controller based on the target gear position and executes the corresponding torque reduction operation. Specifically, during this phase, the motor controller is controlled by the vehicle controller to execute the corresponding torque reduction operation. The control instructions based on the target gear position instruct the motor controller to execute the torque reduction and reset operation. Therefore, when the motor controller receives the control instructions from the vehicle controller, it executes the corresponding torque reduction operation, gradually reducing the torque to the set range.

[0055] During the gear shifting phase, when torque is reduced to the target range, the motor controller, under the control of the automatic transmission control device, executes the corresponding gear shifting operation. Specifically, it receives the torque control mode sent by the automatic transmission control device and performs the gear shifting operation according to the first torque control command contained in the torque control mode. The torque control mode indicates that the control subject has switched from the vehicle controller to the automatic transmission control device. When the motor controller receives the torque control mode sent by the automatic transmission control device, it prioritizes the control command from the automatic transmission control device and performs the gear shifting operation with zero torque as the target.

[0056] The shifting phase is when the motor controller switches control. Since smooth shifting cannot be guaranteed under the control of the vehicle controller, the control is switched from the vehicle controller to the automatic transmission control device. This allows the drive motor speed to be adjusted to accommodate the shifting operation through various means. This effectively improves the motor speed response time and reaction efficiency in the early stages of speed regulation. In the later stages of speed regulation, the motor speed can be effectively stabilized to avoid gear engagement jerks and failures, ensuring smooth shifting and a successful rate.

[0057] The switching condition is: the motor controller receives the torque control mode or speed control mode sent by the automatic speed control device. When the motor controller receives any of the above control modes, it will give priority to the relevant control instructions of the automatic speed control device.

[0058] During the neutral phase, the motor controller regulates the speed of the drive motor to facilitate subsequent gear shifting. To ensure effective speed response time and improved motor response efficiency during the initial phase of speed regulation, S101 acquires the speed control mode sent by the automatic transmission control device and adjusts the control priority of the automatic transmission control device based on the speed control mode, giving the automatic transmission control device a higher priority than the vehicle controller.

[0059] During the implementation of S102, the speed control mode includes a target motor speed. The target motor speed is the motor speed required to adjust the current gear to the target gear. Once the target motor speed is obtained, S103 is triggered.

[0060] During the implementation of S103, the motor controller is controlled by the automatic speed control device to control the drive motor to accelerate. Among them, the acceleration stage belongs to the neutral stage, which is used to adjust the speed of the drive motor in the neutral stage, so that the speed regulation time of the drive motor is controlled within the set time threshold, thereby quickly increasing the speed of the drive motor within the set time threshold, so that the speed difference between the actual motor speed of the drive motor and the target motor speed reaches the set speed difference within the set time threshold. The set time threshold is determined and output by the vehicle controller according to the vehicle model. Taking the set speed difference of 400 rpm as an example, the set time threshold example is 200 milliseconds. It is worth noting that the set speed difference and set time threshold are different for different vehicle models.

[0061] In the specific implementation process, the first calibrated speed includes a first speed proportional parameter and a first speed integral parameter based on the speed difference; the first limiting torque is the allowable torque of the motor calculated by the vehicle controller according to the battery capacity, which is used to prevent overcharging or over-discharging of the battery.

[0062] Therefore, in the strong acceleration stage, the first speed proportional parameter and the first speed integral parameter are used to iteratively control the drive motor to adjust the speed, so that the drive motor can quickly reduce the speed difference with the target motor speed, thereby effectively shortening the motor speed response time and improving the motor reaction efficiency.

[0063] In one embodiment, due to the rapid response speed during the acceleration phase, high torque is required. Exceeding the controllable torque limit could result in battery overcharge or over-discharge. Therefore, a first torque limit is used to limit the drive motor torque, provided that the acceleration time meets a set time threshold. Specifically, the first torque limit is used to limit the output torque of the motor controller, ensuring that the drive motor torque is maintained within the first torque limit. The first torque limit is the permissible motor torque calculated by the vehicle controller based on the battery capacity, thereby preventing battery overcharge or over-discharge.

[0064] For the motor controller, during the gear engagement phase, if the speed difference between the actual motor speed under strong acceleration and the target motor speed reaches the set speed difference, the drive motor is controlled to enter the weak speed regulation phase and the relevant control instructions of the automatic speed control device are continuously prioritized.

[0065] In one embodiment, the conditions for switching between the strong acceleration phase and the weak speed regulation phase are: the shift process variable of the automatic transmission control device is set to 4, and the control mode of the automatic transmission control device is the speed control mode. If the motor controller detects these conditions, it can control the drive motor to switch from the strong acceleration phase to the weak speed regulation phase. Specifically, the motor controller detects the shift process variable setting and control mode of the automatic transmission control device; if the shift process variable is set to 4 and the control mode is the speed control mode, the drive motor is controlled to enter the weak speed regulation phase.

[0066] The weak speed regulation stage belongs to the gear engagement stage. It is used to perform weak speed regulation on the drive motor after the speed difference between the actual motor speed and the target motor speed reaches the set speed difference, so that the speed difference between the actual motor speed and the target motor speed of the drive motor approaches 0, so as to facilitate the execution of the gear engagement operation. It is worth noting that in the weak speed regulation stage, the motor controller still adopts speed control instead of torque control. The reason is that the use of torque control in the gear engagement stage (for example, the torque control instruction is 0 torque control) will cause the motor speed to fall back and rise again, with large fluctuations, which may cause gear engagement failure or frustration accidents. In order to avoid the above accidents and ensure the smoothness and success rate of gear engagement, the speed control mode is still used.

[0067] Because the motor controller's response speed is not critical during the weak speed regulation phase, it is only required to stabilize the actual motor speed. During S104 , the first calibrated speed is replaced by the second calibrated speed, and the drive motor is continuously iteratively controlled to regulate speed until the gear is engaged. The second calibrated speed is lower than the first calibrated speed, enabling the motor controller to iteratively control the drive motor at the lower calibrated speed, ensuring smooth gear engagement.

[0068] The second calibrated speed includes a second speed proportional parameter and a second speed integral parameter based on the speed difference; the second speed proportional parameter is less than the first speed proportional parameter, and the second speed integral parameter is less than the first speed integral parameter. Therefore, the second speed proportional parameter and the second speed integral parameter are used to replace the first speed proportional parameter and the first speed integral parameter, respectively, and the drive motor is continuously iteratively controlled to adjust its speed until the gear is engaged. During the weak speed regulation phase, the motor speed is stabilized, ensuring smooth and successful gear engagement and extending the service life of the transmission hardware.

[0069] In one embodiment, during the weak speed regulation phase, the motor torque should not be excessive when engaging a gear, as this can easily cause gear engagement failure. Therefore, to ensure successful gear engagement, the second torque limit is set to be lower than the first torque limit, thereby ensuring a high gear engagement success rate. Specifically, the second torque limit replaces the first torque limit, and the drive motor speed is continuously and iteratively controlled until gear engagement is complete. The second torque limit is the motor's allowable torque calculated by the automatic transmission control device based on the gear engagement torque requirement. This is used to prevent gear engagement failure caused by excessive torque.

[0070] In one embodiment, after the gear is engaged, the torque control mode sent by the automatic transmission control device is received, and the speed control mode is switched to the torque control mode, which can ensure that the drive motor quickly returns to the torque control mode after the gear is engaged.

[0071] After gear engagement is complete, the torque ramp-up phase begins. During this phase, the motor controller switches from the automatic transmission control unit to the vehicle controller. Specifically, during this phase, the 0 torque mode and actual gear position are received from the automatic transmission control unit. The 0 torque mode indicates that the vehicle controller has switched control from the automatic transmission control unit. The automatic transmission control unit sends the 0 torque mode to exit control of the motor controller. The actual gear position is used to update the motor controller.

[0072] The motor controller receives the control boost torque from the vehicle controller based on the zero torque mode and the actual gear position. Specifically, the actual gear position is updated to the target gear position, and the control boost torque from the vehicle controller is received.

[0073] The above is the process control logic introduced in this application for the five control stages of electric vehicle shifting process control. By implementing improvements in the five control stages respectively, the overall smoothness and success rate of the pure electric vehicle during the shifting process can be guaranteed, and the service life of the pure electric vehicle's gearbox hardware can be extended.

[0074] Based on the same inventive concept, the following embodiment introduces a shift process controller applied to a pure electric vehicle. Referring to FIG. 2 , the shift process controller includes:

[0075] The first acquisition module 201 is used to acquire the speed control mode sent by the automatic transmission control device in the neutral stage;

[0076] A second acquisition module 202 is configured to acquire a target motor speed based on the speed control mode;

[0077] The first control module 203 is configured to control the drive motor to enter a strong acceleration phase based on the target motor speed; in the strong acceleration phase, iteratively controlling the drive motor to adjust its speed using a first calibrated speed and a first limited torque;

[0078] The second control module 204 is used to control the drive motor to enter a weak speed regulation stage if the speed difference between the actual motor speed under strong acceleration and the target motor speed reaches a set speed difference; in the weak speed regulation stage, the first calibrated speed and the first limit torque are replaced by a second calibrated speed and a second limit torque respectively, and the drive motor is continuously iterated to control the speed until the gear is engaged; the second calibrated speed is less than the first calibrated speed, and the second limit torque is less than the first limit torque.

[0079] Based on the same inventive concept, the following embodiment introduces a shift control system for a pure electric vehicle. Referring to Figure 3 , the shift control system includes a shift controller, an automatic transmission control unit (TCU), and a vehicle controller (PDCU). The shift controller is used to implement shift control using the shift control methods described in one or more of the aforementioned embodiments. In this embodiment, the shift controller is exemplified by a motor controller (MCU).

[0080] The shifting process for pure electric vehicles consists of five control phases: torque reduction, gear shifting, neutral, gear engagement, and torque increase. Furthermore, the drive motor speed control during the shifting process is achieved through interaction between the vehicle control unit (PDCU), the automatic transmission control unit (TCU), and the motor controller (MCU).

[0081] During the torque reduction phase, the vehicle control unit (PDCU) primarily controls torque reduction. Specifically, after the PDCU learns the target gear, it sends the target gear and torque mode to the motor control unit (MCU) to perform the torque reduction reset operation. The torque mode contains control instructions for torque reduction reset. The motor control unit (MCU) receives the control instructions based on the target gear from the PDCU and executes the corresponding torque reduction operation. The TCU monitors the real-time torque reduction value of the motor control unit (MCU). During this phase, the shift process variable of the automatic transmission control unit (TCU) is set to 1.

[0082] During the gear disengagement phase, the automatic transmission control unit TCU will obtain the control right of the motor controller MCU from the vehicle controller PDCU, and the gear shift process quantity of the TCU will be set to 2. Specifically, the automatic transmission control unit TCU includes three modes: torque control mode, speed control mode, and 0 torque mode. Among them, the torque control mode is used to indicate that the control subject is switched from the vehicle controller PDCU to the automatic transmission control unit TCU, and guides the motor controller MCU to adjust the drive motor with torque as a reference. The speed control mode is used to guide the motor controller MCU to adjust the drive motor with speed as a reference. The 0 torque mode is used to exit the control of the motor controller MCU and transfer the control right of the motor controller MCU to the vehicle controller PDCU.

[0083] The automatic transmission control unit (TCU) monitors the real-time torque reduction value of the motor controller MCU. When the torque is reduced to the target range, the automatic transmission control unit (TCU) sends a torque control mode to the motor controller MCU, obtains control of the motor controller MCU, and thus controls the motor controller MCU to perform the gear shifting operation. For the motor controller MCU, after receiving the torque control mode sent by the automatic transmission control unit (TCU), it will give priority to processing the control instructions of the automatic transmission control unit (TCU). Specifically, the gear shifting operation is performed according to the first torque control instruction carried in the torque control mode. The first torque control instruction is used to instruct the motor controller MCU to perform the gear shifting operation according to 0 torque.

[0084] After the block is removed, it enters the neutral phase.

[0085] In the neutral stage of this embodiment, the motor controller MCU needs to regulate the speed of the drive motor so that it and the target motor speed are close to 0 in order to complete the gear shifting operation. In order to ensure that the motor speed response time is effectively shortened in the early stage of speed regulation and the motor reaction efficiency is improved. In the neutral stage, the automatic speed control device TCU sends a speed mode to the motor controller MCU, and still gives priority to controlling the motor controller MCU. In this process, the shift process quantity of the automatic speed control device TCU is set to 3. The speed instruction is the target motor speed corresponding to the target gear, requiring the motor controller MCU to control the drive motor to respond quickly, thereby effectively shortening the motor speed response time and improving the motor reaction efficiency.

[0086] For the motor controller MCU, the speed control mode sent by the TCU is executed first. Specifically, the motor controller MCU executes steps S101 to S103 to control the drive motor to accelerate. Among them, the acceleration stage belongs to the neutral stage, which is used to accelerate the drive motor in the neutral stage, so that the speed regulation time of the drive motor is controlled within the set time threshold, and the speed of the drive motor can be quickly increased within the set time threshold, so that the speed difference between the actual motor speed of the drive motor and the target motor speed reaches the set speed difference within the set time threshold. The example of setting the time threshold is 0.5S, but it does not form a limitation.

[0087] During the strong acceleration phase, the drive motor is iteratively controlled using the first calibrated speed and the first torque limit for speed regulation. The first calibrated speed includes a first speed proportional parameter and a first speed integral parameter based on the speed difference. Therefore, using the first speed proportional parameter and the first speed integral parameter to iteratively control the drive motor for speed regulation allows the drive motor to quickly narrow the speed difference with the target motor speed, effectively shortening the motor speed response time and improving motor reaction efficiency.

[0088] In one embodiment, due to the rapid response speed during the acceleration phase and the high torque required, exceeding the controllable torque can cause battery overcharging or over-discharging. Therefore, based on the speed regulation time meeting a set time threshold, a first torque limit is used to limit the torque of the drive motor. Specifically, the first torque limit is used to limit the output torque of the motor controller MCU, ensuring that the drive motor torque is maintained within the first torque limit. The first torque limit is the allowable torque of the motor calculated by the vehicle control unit (PDCU) based on the battery capacity, which prevents battery overcharging or over-discharging.

[0089] In one embodiment, the automatic transmission control unit (TCU) monitors in real time whether the actual motor speed under heavy acceleration meets the target motor speed difference. If so, the vehicle enters the gear-engagement phase and continuously sends speed commands to the motor controller MCU. The speed command is calculated based on the actual motor speed according to the vehicle speed. During this process, the gear shift process indicator of the automatic transmission control unit (TCU) is set to 4.

[0090] For the motor controller MCU, during the gear engagement phase, if the speed difference between the actual motor speed under strong acceleration and the target motor speed reaches the set speed difference, the drive motor is controlled to enter the weak speed regulation phase.

[0091] In one embodiment, the conditions for switching between the strong acceleration stage and the weak speed regulation stage are: the shift process variable of the automatic transmission control unit (TCU) is set to 4, and the control mode of the automatic transmission control unit (TCU) is the speed control mode. If the motor controller (MCU) detects these conditions, it can control the drive motor to switch from the strong acceleration stage to the weak speed regulation stage. Specifically, the motor controller MCU detects the shift process variable setting and control mode of the automatic transmission control unit (TCU); if the shift process variable is set to 4 and the control mode is the speed control mode, the drive motor is controlled to enter the weak speed regulation stage.

[0092] The weak speed regulation stage belongs to the gear engagement stage. It is used to perform weak speed regulation on the drive motor after the speed difference between the actual motor speed and the target motor speed reaches the set speed difference, so that the actual motor speed and the target motor speed of the drive motor approach 0, so as to facilitate the execution of the gear engagement operation. It is worth noting that in the weak speed regulation stage, the motor controller MCU still adopts speed control instead of torque control. The reason is that the use of torque control in the gear engagement stage (for example, the torque control instruction is 0 torque control) will cause the motor speed to fall back and rise again, with large fluctuations, which may cause gear engagement failure or frustration accidents. In order to avoid the above accidents and ensure the smoothness and success rate of gear engagement, the speed control mode is still used.

[0093] Since the response speed requirement of the motor controller MCU is not high during the weak speed regulation stage, the motor controller MCU is only required to stabilize the actual speed of the motor. Therefore, the second calibrated speed is used to replace the first calibrated speed, and the drive motor is continuously iteratively controlled to adjust the speed until the gear is engaged. Among them, the second calibrated speed is smaller than the first calibrated speed, so that the motor controller MCU can iteratively control the drive motor according to the smaller calibrated speed to ensure the smoothness of the gear engagement. The second calibrated speed includes a second speed proportional parameter and a second speed integral parameter based on the speed difference; the second speed proportional parameter is smaller than the first speed proportional parameter, and the second speed integral parameter is smaller than the first speed integral parameter. Therefore, the second speed proportional parameter and the second speed integral parameter are used to replace the first speed proportional parameter and the first speed integral parameter respectively, and the drive motor is continuously iteratively controlled to adjust the speed until the gear is engaged, thereby ensuring the smoothness and success rate of the gear engagement and extending the service life of the gearbox hardware.

[0094] In one embodiment, during the weak speed regulation phase, the motor torque should not be excessive when engaging a gear, as this can easily cause gear engagement failure. Therefore, to ensure successful gear engagement, the second torque limit is set to be lower than the first torque limit, thereby ensuring a high gear engagement success rate. Specifically, the second torque limit is used to control the drive motor speed in an iterative manner until gear engagement is complete. The second torque limit is calculated by the automatic transmission control unit (TCU) based on the gear engagement request torque to prevent gear engagement failure caused by excessive torque.

[0095] In one embodiment, the target motor speed of the automatic transmission control unit TCU during the gear shifting phase can be fine-tuned according to the actual vehicle speed, thereby facilitating smoother gear shifting.

[0096] When the speed difference between the actual motor speed and the target motor speed approaches zero, the motor controller MCU initiates the gear shift operation. After the gear shift is complete, the motor controller receives a torque control mode signal from the automatic transmission control unit (TCU) and switches from speed control mode to torque control mode. This ensures that the drive motor quickly returns to torque control mode after the gear shift is complete. At this point, the gear shift process indicator in the automatic transmission control unit (TCU) is set to bit 4.

[0097] After the gear is engaged, the torque increase phase begins. During the torque increase phase, the vehicle controller PDCU obtains control rights and performs corresponding control on the motor controller MCU. Specifically, the automatic transmission control unit TCU sends the 0 torque mode and the actual gear position to the motor controller MCU. The 0 torque mode is used to indicate that the control subject is switched from the automatic transmission control unit TCU to the vehicle controller PDCU. The purpose of the automatic transmission control unit TCU sending the 0 torque mode is to exit the control of the motor controller MCU. During this process, the gear shift process quantity of the automatic transmission control unit TCU is set to 5. The actual gear position is used to update the motor controller MCU.

[0098] The motor controller MCU receives the zero torque mode and actual gear position from the automatic transmission control unit (TCU). Based on this zero torque mode and actual gear position, it receives the control boost torque from the vehicle control unit (PDCU). Specifically, the actual gear position is updated to the target gear position. When the PDCU detects that the actual gear position is the target gear position, it updates the torque command and takes over control of the motor controller MCU. The motor controller MCU receives the control boost torque from the PDCU based on the zero torque mode.

[0099] Based on the same inventive concept, the following embodiment introduces a pure electric vehicle, which implements shift control through the shift control method described in one or more of the aforementioned embodiments.

[0100] Although the optional embodiments of the present application have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the optional embodiments and all changes and modifications that fall within the scope of the present application.

[0101] Obviously, those skilled in the art may make various changes and modifications to this application without departing from the spirit and scope of this application. Thus, if these modifications and variations of this application fall within the scope of the claims of this application and their equivalents, this application is intended to include these modifications and variations.

Claims

1. A shifting process control method, applied to a pure electric vehicle, wherein: The method comprises: In the neutral stage, a speed control mode sent by an automatic speed control device is obtained; Based on the speed control mode, obtaining a target motor speed; Based on the target motor speed, controlling the drive motor to enter a strong acceleration stage; in the strong acceleration stage, iteratively controlling the drive motor to adjust the speed by using a first calibrated speed and a first limited torque; and If the speed difference between the actual motor speed under strong speed control and the target motor speed reaches the set speed difference, the drive motor is controlled to enter a weak speed regulation stage; in the weak speed regulation stage, the second calibrated speed and the second limiting torque are used to replace the first calibrated speed and the first limiting torque respectively, and the drive motor is continuously iterated to control the speed until the gear is engaged; the second calibrated speed is less than the first calibrated speed, and the second limiting torque is less than the first limiting torque.

2. The method of claim 1, wherein: Before the neutral phase, the method further includes: In the torque reduction stage, receiving the control instruction of the vehicle controller based on the target gear position to perform the corresponding torque reduction operation; and During the gear shifting stage, when the torque is reduced to the target range, the torque control mode sent by the automatic transmission control device is received, and the gear shifting operation is performed according to the first torque control instruction carried in the torque control mode; the torque control mode is used to characterize that the control subject is switched from the vehicle controller to the automatic transmission control device.

3. The method of claim 1, wherein: The first calibrated speed includes a first speed ratio parameter and a first speed integral parameter based on the speed difference; the first limiting torque is the motor allowable torque calculated by the vehicle controller according to the battery capacity, and is used to prevent overcharging or over-discharging of the battery; The iterative control of the driving motor to adjust the speed by using the first calibrated speed and the first limited torque specifically includes: The first speed proportional parameter and the first speed integral parameter are used to iteratively control the drive motor to adjust its speed, and the first limiting torque is used to limit the torque of the drive motor.

4. The method of claim 3, wherein: If the speed difference between the actual motor speed under the high speed condition and the target motor speed reaches the set speed difference, the method further includes: Detecting the shift process quantity setting and control mode of the automatic transmission control device; and If the gear shift process quantity is set to 4 and the control mode is the speed control mode, the drive motor is controlled to enter the weak speed regulation stage.

5. The method of claim 1, wherein: The second calibrated speed includes a second speed proportional parameter and a second speed integral parameter based on the speed difference; the second speed proportional parameter is smaller than the first speed proportional parameter, and the second speed integral parameter is smaller than the first speed integral parameter; The using of the second calibrated speed and the second limited torque to replace the first calibrated speed and the first limited torque respectively, and continuously iteratively controlling the drive motor to adjust the speed until the gear is engaged, specifically includes: The second speed proportion parameter, the second speed integral parameter and the second limiting torque are used to replace the first speed proportion parameter, the first speed integral parameter and the first limiting torque respectively, and the drive motor is continuously and iteratively controlled to adjust the speed until the gear is engaged; wherein the second limiting torque is the allowable torque of the motor calculated by the automatic speed control device according to the gear engagement requirement torque, and is used to prevent gear engagement failure due to excessive torque.

6. The method of claim 5, wherein: After the gear shifting is completed, the method further includes: The torque control mode sent by the automatic transmission control device is received, and the rotation speed control mode is switched to the torque control mode.

7. The method of claim 6, wherein: After the second calibrated speed and the second limited torque are used to replace the first calibrated speed and the first limited torque respectively, and the drive motor is continuously and iteratively controlled to adjust the speed until the gear is engaged, the method further includes: In the torque increase phase, receiving the zero torque mode and the actual gear position sent by the automatic transmission control device; and Based on the 0 torque mode and the actual gear position, a control boost torque of a vehicle controller is received, wherein the 0 torque mode is used to indicate that a control subject is switched from the automatic transmission control device to the vehicle controller.

8. A gear shift process controller, applied to a pure electric vehicle, wherein: The shift process controller comprises: A first acquisition module is used to acquire a speed control mode sent by an automatic speed control device in a neutral stage; A second acquisition module, used for acquiring a target motor speed based on the speed control mode; A first control module is configured to control the drive motor to enter a strong acceleration stage based on the target motor speed; in the strong acceleration stage, iteratively control the drive motor to adjust the speed by using a first calibrated speed and a first limited torque; and The second control module is used to control the drive motor to enter a weak speed regulation stage if the speed difference between the actual motor speed under strong acceleration and the target motor speed reaches a set speed difference; in the weak speed regulation stage, the second calibrated speed and the second limiting torque are used to replace the first calibrated speed and the first limiting torque respectively, and the drive motor is continuously iterated to control the speed until the gear is engaged; the second calibrated speed is less than the first calibrated speed, and the second limiting torque is less than the first limiting torque.

9. A gear shifting process control system, applied to a pure electric vehicle, wherein: The gear shift process control system includes: a gear shift process controller and an automatic speed control device; wherein, the gear shift process controller is used to realize gear shift control through the gear shift control method as described in any one of claims 1-7.

10. A pure electric vehicle, wherein: The gear shifting control is achieved by the gear shifting control method as described in any one of claims 1 to 7.

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