Shift process control method, controller, system and pure electric vehicle

Abstract

The application discloses a gear shifting process control method, a controller, a system and a pure electric vehicle. The method comprises the following steps: in the neutral stage, a speed control mode sent by an automatic transmission control device is acquired; based on the speed control mode, a target motor speed is acquired; based on the target motor speed, a driving motor is controlled to enter a high-speed control stage; in the high-speed control stage, the driving motor is iteratively controlled for speed regulation by using a first calibration speed and a first limit torque; if a speed difference between an actual motor speed in the high-speed control stage and the target motor speed reaches a set speed difference, the driving motor is controlled to enter a low-speed control stage; in the low-speed control stage, a second calibration speed and a second limit torque are used to replace the first calibration speed and the first limit torque respectively, and the driving motor is iteratively controlled for speed regulation until the gear shifting is completed.

Description

Technical Field

[0001] This application relates to the field of pure electric vehicle technology, and in particular to a shift process control method, controller, system and pure electric vehicle. Background Technology

[0002] Currently, there are various types of vehicles on the market, including gasoline-powered cars, hybrid cars, and pure electric cars. Gasoline-powered cars primarily utilize multi-speed transmissions and clutches to drive the vehicle. Pure electric cars, as low-emission and high-efficiency new energy vehicles, differ from gasoline-powered cars in that they eliminate the multi-speed transmission and clutch mechanism. Instead, they use an automatic transmission system to control two-speed shifting, relying on the drive motor's speed regulation function to synchronize the motor speed with the speed of the next gear during shifting.

[0003] As we all know, the shifting process of a pure electric vehicle needs to ensure the smoothness of the entire vehicle during gear shifts. If the shifting process is not well controlled, it will cause shifting jerks, grinding, and other problems, which will greatly reduce the smoothness and comfort of the entire vehicle.

[0004] Therefore, how to effectively control the gear shifting process of pure electric vehicles and ensure the smoothness of the entire vehicle is an urgent problem to be solved. Summary of the Invention

[0005] This invention provides a shifting process control method, controller, system, and pure electric vehicle. It employs iterative control based on different calibration parameters according to the speed difference at different speed regulation stages to solve or partially solve the technical problem of pure electric vehicles failing to guarantee overall vehicle smoothness during shifting. It can effectively improve the motor speed response time and increase motor response efficiency in the early stage of speed regulation, and effectively stabilize the motor speed in the later stage of speed regulation, thereby avoiding shifting jerks, failures, and other situations. This ensures the overall smoothness and success rate of the pure electric vehicle during shifting and extends the service life of the transmission hardware.

[0006] A first aspect of the present invention discloses a shifting process control method applied to a pure electric vehicle, the method comprising:

[0007] During the neutral phase, the speed control mode sent by the automatic transmission control device is obtained;

[0008] Based on the speed control mode, the target motor speed is obtained;

[0009] Based on the target motor speed, the drive motor is controlled to enter the speed enhancement stage; in the speed enhancement stage, the drive motor is iteratively controlled to adjust its speed using a first calibrated speed and a first limiting torque.

[0010] If the speed difference between the actual motor speed under high speed and the target motor speed reaches the set speed difference, the drive motor is controlled to enter the weak speed adjustment stage; in the weak speed adjustment stage, the second rated speed and the second limiting torque are used to replace the first rated speed and the first limiting torque respectively, and the drive motor is continuously iteratively controlled to adjust the speed until the gear is engaged; the second rated speed is less than the first rated speed, and the second limiting torque is less than the first limiting torque.

[0011] Preferably, prior to the neutral phase, the method further includes:

[0012] During the torque reduction phase, the vehicle controller receives control commands based on the target gear and executes corresponding torque reduction operations.

[0013] During the disengagement phase, when the torque is reduced to the target range, the system receives the torque control mode sent by the automatic transmission control device and performs the disengagement operation according to the first torque control command 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.

[0014] Preferably, 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 motor torque calculated by the vehicle controller based on the battery capacity, used to prevent overcharging or over-discharging of the battery;

[0015] The iterative control of the drive motor using a first calibrated speed and a first limiting torque for speed adjustment specifically includes:

[0016] The speed of the drive motor is adjusted by iterative control using the first speed proportional parameter and the first speed integral parameter, and the torque of the drive motor is limited by the first limiting torque.

[0017] Preferably, after the speed difference between the actual motor speed under the specified acceleration and the target motor speed reaches a set speed difference, the method further includes:

[0018] The shifting process and control mode of the automatic transmission control device are detected.

[0019] If the shift process quantity is set to 4 and the control mode is speed control mode, the drive motor is controlled to enter the weak speed regulation stage.

[0020] Preferably, 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.

[0021] The process of replacing the first calibrated speed and the first limited torque with the second calibrated speed and the second limited torque respectively, and continuously iteratively controlling the drive motor to adjust the speed until gear engagement is completed, specifically includes:

[0022] The first speed proportional parameter, the first speed integral parameter, and the first speed limiting torque are replaced by the second speed proportional parameter, the first speed integral parameter, and the first speed limiting torque, respectively, and the drive motor is continuously iteratively controlled to adjust its speed until gear engagement is completed; wherein, the second speed limiting torque is the allowable torque of the motor calculated by the automatic transmission control device based on the torque required for gear engagement, and is used to prevent excessive torque from causing gear engagement failure.

[0023] Preferably, after the gear shift is completed, the method further includes:

[0024] The system receives the torque control mode sent by the automatic transmission control device and switches from the speed control mode to the torque control mode.

[0025] Preferably, after the method further includes replacing the first calibrated speed and the first limiting torque with the second calibrated speed and the second limiting torque respectively, and continuously iteratively controlling the drive motor to adjust the speed until gear engagement is completed, the method further includes:

[0026] During the torque-increasing phase, the system receives the 0-torque mode and actual gear position from the automatic transmission control device.

[0027] Based on the 0 torque mode and the actual gear position, the control torque is increased by the vehicle controller. The 0 torque mode is used to indicate that the control body is switched from the automatic transmission control device to the vehicle controller.

[0028] A second aspect of the present invention discloses a shift process controller for use in a pure electric vehicle, the shift process controller comprising:

[0029] The first acquisition module is used to acquire the speed control mode sent by the automatic transmission control device during the neutral phase.

[0030] The second acquisition module is used to acquire the target motor speed based on the speed control mode;

[0031] The first control module is used to control the drive motor to enter the speed enhancement stage based on the target motor speed; in the speed enhancement stage, the drive motor is iteratively controlled to adjust the speed using a first calibrated speed and a first limiting torque;

[0032] The second control module is used to control the drive motor to enter a weak speed adjustment stage if the speed difference between the actual motor speed under the high-speed condition and the target motor speed reaches a set speed difference; in the weak speed adjustment 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 iteratively controlled to adjust the speed until the gear engagement is completed; the second calibrated speed is less than the first calibrated speed, and the second limited torque is less than the first limited torque.

[0033] A third aspect of the present invention discloses a shift process control system for use in a pure electric vehicle. The shift process control system includes a shift process controller and an automatic transmission control device. The shift process controller is used to implement shift control through the shift control method described above.

[0034] In a fourth aspect, the present invention discloses a pure electric vehicle that achieves shift control through the shift control method described above.

[0035] Through one or more technical solutions of the present invention, the present invention has the following beneficial effects or advantages:

[0036] In this invention, the speed control mode sent by the automatic transmission control device is used as the trigger mechanism to execute the speed regulation of the drive motor. 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 speed difference are used for iterative control in different speed regulation stages. This effectively improves the motor speed response time and motor response efficiency in the early stage of speed regulation, and effectively stabilizes the motor speed in the later stage of speed regulation. This avoids situations such as gear shifting jerks and failures, ensuring the smoothness and success rate of the pure electric vehicle during gear shifting, and extending the service life of the pure electric vehicle's transmission hardware.

[0037] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and in order to make the above and other objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described below. Attached Figure Description

[0038] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings.

[0039] In the attached diagram:

[0040] Figure 1A schematic diagram of a shift process control method according to an embodiment of the present invention is shown;

[0041] Figure 2 A schematic diagram of the structure of a shift process controller according to an embodiment of the present invention is shown;

[0042] Figure 3 A schematic diagram of a shift process control system according to an embodiment of the present invention is shown. Detailed Implementation

[0043] Exemplary embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this invention will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0044] This invention discloses a shifting process control method applied to pure electric vehicles. It mainly targets the shifting process control of two-speed transmissions in pure electric vehicles, thereby effectively ensuring the smoothness and success rate of the entire vehicle during shifting and extending the service life of the transmission hardware.

[0045] See Figure 1 This is a schematic diagram of the shifting process control method disclosed in an embodiment of the present invention. The shifting process control method disclosed in an embodiment of the present invention includes the following steps:

[0046] S101, in neutral mode, acquires the speed control mode sent by the automatic transmission control device.

[0047] S102, based on the speed control mode, obtains the target motor speed.

[0048] S103, based on the target motor speed, controls the drive motor to enter the speed enhancement stage; in the speed enhancement stage, the drive motor is iteratively controlled to adjust the speed using the first calibrated speed and the first limiting torque.

[0049] S104, if the speed difference between the actual motor speed under high speed and the target motor speed reaches the set speed difference, control the drive motor to enter the weak speed adjustment stage; in the weak speed adjustment stage, the second rated speed and the second limiting torque are used to replace the first rated speed and the first limiting torque respectively, and the drive motor is continuously iterated to adjust the speed until the gear is engaged; the second rated speed is less than the first rated speed, and the second limiting torque is less than the first limiting torque.

[0050] In this scheme, the speed control mode sent by the automatic transmission control device is used as the trigger mechanism to execute the speed regulation of the drive motor. 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. This can effectively improve the motor speed response time and motor response efficiency in the early stage of speed regulation, and effectively stabilize the motor speed in the later stage of speed regulation. This avoids situations such as gear shifting jerks and failures, ensuring the smoothness and success rate of the pure electric vehicle during gear shifting, and extending the service life of the transmission hardware of the pure electric vehicle.

[0051] Specifically, the gear shifting process of a pure electric vehicle comprises five control stages: torque reduction stage, disengagement stage, neutral stage, gear engagement stage, and torque increase stage. Furthermore, the speed control of the drive motor during gear shifting is achieved through the interaction of the vehicle controller, automatic transmission control device, and gear shifting process controller. See the structural diagram of these three components. Figure 3 In this embodiment of the invention, the gear shifting process controller is exemplified as a motor controller, applied to a pure electric vehicle. To facilitate explanation and clarification of the embodiments of the invention, the process control logic of the invention is described below according to the aforementioned five control stages.

[0052] Before performing the operations related to the neutral phase of S101, there are also operations related to the torque reduction phase and the disengagement phase, as follows:

[0053] During the torque reduction phase, the motor controller receives control commands from the vehicle controller based on the target gear and executes corresponding torque reduction operations. Specifically, the motor controller is controlled by the vehicle controller to execute corresponding torque reduction operations during the torque reduction phase. The control commands based on the target gear guide the motor controller to perform the torque reduction and zeroing operation. Therefore, when the motor controller receives the control commands sent by the vehicle controller, it executes the corresponding torque reduction operation, gradually reducing the torque to the set range.

[0054] During the disengagement phase, when the torque is reduced to the target range, the motor controller, under the control of the automatic transmission control unit, performs the corresponding disengagement operation. Specifically, it receives the torque control mode sent by the automatic transmission control unit and performs the disengagement operation according to the first torque control command carried in the torque control mode. The torque control mode indicates that the control entity has switched from the vehicle controller to the automatic transmission control unit. When the motor controller receives the torque control mode sent by the automatic transmission control unit, it prioritizes processing the control command from the automatic transmission control unit and performs the disengagement operation with zero torque as the target.

[0055] The disengagement phase is when the motor controller switches control over the main control unit. Since smooth shifting cannot be guaranteed under the control of the vehicle controller, the main control unit is switched from the vehicle controller to the automatic transmission control device. This allows for subsequent adjustments to the drive motor speed to accommodate the shifting operation, effectively improving the motor's speed response time and efficiency in the early stages of speed regulation. In the later stages, it effectively stabilizes the motor speed, preventing shifting jerks and failures, and ensuring smooth and successful shifting.

[0056] Specifically, the switching condition is that the motor controller receives either torque control mode or speed control mode from the automatic transmission control device. When the motor controller receives either of these control modes, it will prioritize processing the relevant control commands from the automatic transmission control device.

[0057] During the neutral phase, the motor controller adjusts the speed of the drive motor to facilitate subsequent gear engagement. To ensure effective reduction of motor speed response time and improve motor efficiency during the initial speed adjustment phase, in the implementation of S101, the speed control mode sent by the automatic transmission control device is acquired, and the priority of the automatic transmission control device's control power is adjusted according to the speed control mode, ensuring that the automatic transmission control device has a higher priority than the vehicle controller.

[0058] During the implementation of S102, the speed control mode carries the 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 can be triggered.

[0059] During the implementation of S103, the motor controller, under the control of the automatic transmission control device, regulates the drive motor to accelerate. This acceleration phase, belonging to the neutral phase, is used to adjust the drive motor speed during neutral, ensuring the speed adjustment time is within a set time threshold. This allows for a rapid increase in the drive motor speed within the set time threshold, ensuring the speed difference between the actual and target motor speeds reaches the set speed difference within that threshold. The set time threshold is determined and output by the vehicle controller based on the vehicle model. For example, with a set speed difference of 400 rpm, the set time threshold is typically 200 milliseconds. It's important to note that the set speed difference and set time threshold differ between different vehicle models.

[0060] 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 based on the battery capacity, which is used to prevent overcharging or over-discharging of the battery.

[0061] Therefore, during the acceleration phase, the drive motor is iteratively controlled using the first speed proportional parameter and the first speed integral parameter to adjust its speed, thereby rapidly reducing the speed difference between the drive motor and the target motor, effectively shortening the motor speed response time and improving the motor's response efficiency.

[0062] Furthermore, due to the high response speed required during the acceleration phase, a large torque is needed. If the torque exceeds the control limit, it will cause overcharging or over-discharging of the battery. Therefore, based on the speed adjustment time meeting the set time threshold, the torque of the drive motor is limited by a first limiting torque. That is, the output torque of the motor controller is limited by the first limiting torque, so that the torque of the drive motor is completed within the first limiting torque. The first limiting torque is the allowable torque of the motor calculated by the vehicle controller based on the battery capacity, which can prevent overcharging or over-discharging of the battery.

[0063] For the motor controller, during the gear shifting phase, if the speed difference between the actual motor speed under the high-speed setting and the target motor speed reaches the set speed difference, the drive motor is controlled to enter the low-speed adjustment phase, and the relevant control commands of the automatic transmission control device are continuously prioritized.

[0064] In one optional implementation, the switching conditions between the high-speed acceleration phase and the low-speed adjustment phase are: the shift process quantity of the automatic transmission control device is set to 4, and the control mode of the automatic transmission control device is speed control mode. If the motor controller detects the above conditions, it can control the drive motor to switch from the high-speed acceleration phase to the low-speed adjustment phase. Specifically, the motor controller detects the shift process quantity setting and control mode of the automatic transmission control device; if the shift process quantity is set to 4 and the control mode is speed control mode, it controls the drive motor to enter the low-speed adjustment phase.

[0065] The weak speed adjustment stage belongs to the gear engagement stage. It's used to weaken the speed of the drive motor after the speed difference between the actual motor speed and the target motor speed reaches the set speed difference. This brings the speed difference between the actual and target motor speeds close to zero, facilitating gear engagement. It's important to note that during the weak speed adjustment stage, the motor controller still uses speed control, not torque control. This is because using torque control during gear engagement (e.g., a torque control command of 0 torque) would cause the motor speed to fluctuate significantly, potentially leading to gear engagement failure or jerking. To avoid these issues and ensure smooth and successful gear engagement, speed control is still used.

[0066] Since the response speed requirement of the motor controller is not high during the weak speed adjustment phase, and only the motor controller is required to stabilize the actual speed of the motor, in the implementation of S104, the second calibrated speed is used instead of the first calibrated speed, and the drive motor is continuously iteratively controlled to adjust the speed until the gear engagement is completed. The second calibrated speed is lower than the first calibrated speed, allowing the motor controller to iteratively control the drive motor at a smaller calibrated speed, ensuring smooth gear engagement.

[0067] Specifically, the second calibrated speed includes a second proportional speed parameter and a second integral speed parameter based on the speed difference; the second proportional speed parameter is smaller than the first proportional speed parameter, and the second integral speed parameter is smaller than the first integral speed parameter. Therefore, the second proportional speed parameter and the second integral speed parameter are used to replace the first proportional speed parameter and the first integral speed parameter, respectively, and the drive motor is continuously iteratively controlled to adjust the speed until gear engagement is completed. This stabilizes the motor speed during the weak speed adjustment phase, thereby ensuring smooth gear engagement and a high success rate, and extending the service life of the transmission hardware.

[0068] Furthermore, during the low-speed adjustment phase, the motor torque should not be too high when engaging gears, otherwise it may easily lead to engagement failure. Therefore, to ensure successful engagement, the second limiting torque is less than the first limiting torque to guarantee the success rate of gear engagement. Specifically, the second limiting torque is used to replace the first limiting torque, and the drive motor is continuously iteratively controlled to adjust its speed until gear engagement is completed. The second limiting torque is the allowable torque of the motor calculated by the automatic transmission control device based on the torque required for gear engagement, used to prevent excessive torque from causing engagement failure.

[0069] Furthermore, after shifting gears, the system receives the torque control mode from the automatic transmission control device and switches from speed control mode to torque control mode, ensuring that the drive motor quickly returns to torque control mode after shifting gears.

[0070] After gear engagement, the torque-increasing phase begins. During this phase, the control mechanism of the motor controller switches from the automatic transmission control unit to the vehicle controller. Specifically, during this phase, the motor controller receives the 0-torque mode and the actual gear position from the automatic transmission control unit. The 0-torque mode indicates that the control mechanism has switched from the automatic transmission control unit to the vehicle controller; the automatic transmission control unit sends the 0-torque mode to withdraw control of the motor controller. The actual gear position is used for updating the motor controller's settings.

[0071] For the motor controller, based on the 0 torque mode and the actual gear position, it receives the control torque boost from the vehicle controller. Specifically, it updates the actual gear position to the target gear position and receives the control torque boost from the vehicle controller.

[0072] The above describes the process control logic for the five control stages of the gear shifting process control of electric vehicles. By implementing improvements in each of the five control stages, the overall smoothness and success rate of the pure electric vehicle during gear shifting can be guaranteed, and the service life of the pure electric vehicle's transmission hardware can be extended.

[0073] Based on the same inventive concept, the following embodiments describe a shift process controller applied to a pure electric vehicle. See Figure 2 The gear shift controller includes:

[0074] The first acquisition module 201 is used to acquire the speed control mode sent by the automatic transmission control device during the neutral phase.

[0075] The second acquisition module 202 is used to acquire the target motor speed based on the speed control mode;

[0076] The first control module 203 is used to control the drive motor to enter the speed enhancement stage based on the target motor speed; in the speed enhancement stage, the drive motor is iteratively controlled to adjust the speed using the first calibrated speed and the first limiting torque;

[0077] The second control module 204 is used to control the drive motor to enter a weak speed adjustment stage if the speed difference between the actual motor speed under the high speed and the target motor speed reaches a set speed difference; in the weak speed adjustment 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 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 limited torque is less than the first limited torque.

[0078] Based on the same inventive concept, the following embodiments describe a shift process control system applied to a pure electric vehicle. (See attached image.) Figure 3 The shift process control system includes: a shift process controller, an automatic transmission control unit (TCU), and a vehicle control unit (PDCU). The shift process controller is used to implement shift control through the shift control method described in one or more of the foregoing embodiments. In this embodiment of the invention, the shift process controller is exemplified as a motor control unit (MCU).

[0079] Specifically, the gear shifting process of a pure electric vehicle comprises five control stages: torque reduction stage, disengagement stage, neutral stage, gear engagement stage, and torque increase stage. Furthermore, the speed control of the drive motor during gear shifting is achieved through the interaction of the vehicle controller (PDCU), the automatic transmission control unit (TCU), and the motor controller (MCU).

[0080] During the torque reduction phase, the vehicle control unit (PDCU) primarily controls the 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 a torque reduction reset operation. The torque mode contains control commands for the torque reduction reset. The MCU receives the control commands from the PDCU based on the target gear and executes the corresponding torque reduction operation. The transmission control unit (TCU) monitors the real-time torque reduction value from the MCU. During this phase, the shift process parameter of the TCU is set to 1.

[0081] During the disengagement phase, the automatic transmission control unit (TCU) acquires control of the motor controller (MCU) from the vehicle controller (PDCU), and the TCU's shift process parameter is set to 2. Specifically, the TCU includes three modes: torque control mode, speed control mode, and zero torque mode. Torque control mode indicates that the control entity switches from the vehicle controller (PDCU) to the TCU, guiding the MCU to adjust the drive motor with torque as a reference. Speed ​​control mode guides the MCU to adjust the drive motor with speed as a reference. Zero torque mode exits control of the MCU, transferring control back to the vehicle controller (PDCU).

[0082] Specifically, the automatic transmission control unit (TCU) monitors the real-time torque reduction value of the motor controller (MCU). When the torque reduction reaches the target range, the TCU sends a torque control mode to the MCU, gaining control of the MCU and thus controlling it to perform a disengagement operation. Upon receiving the torque control mode from the TCU, the MCU prioritizes processing the TCU's control commands. Specifically, it performs the disengagement operation according to the first torque control command carried in the torque control mode. This first torque control command guides the MCU to perform the disengagement operation at zero torque.

[0083] After disengaging from gear, the vehicle enters neutral.

[0084] In the neutral phase of this embodiment, the motor controller MCU needs to adjust the speed of the drive motor to bring it close to the target motor speed in order to complete the gear engagement operation. To ensure effective reduction of motor speed response time and improve motor efficiency during the initial speed adjustment phase, the automatic transmission control unit (TCU) sends a speed mode command to the motor controller MCU during the neutral phase, prioritizing control of the MCU. During this process, the shift process parameter of the TCU is set to 3. The speed command 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 reducing the motor speed response time and improving motor efficiency.

[0085] 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. The acceleration phase belongs to the neutral phase and is used to accelerate the drive motor during the neutral phase, keeping the speed adjustment time within a set time threshold. This allows for a rapid increase in the drive motor speed within the set time threshold, ensuring that the speed difference between the actual motor speed and the target motor speed reaches the set speed difference within the set time threshold. An example set time threshold is 0.5 seconds, but this is not a limitation.

[0086] During the acceleration phase, the drive motor is iteratively controlled using a first calibrated speed and a first limiting torque for speed adjustment. The first calibrated speed includes a first proportional speed parameter and a first integral speed parameter based on the speed difference. Therefore, iteratively controlling the drive motor using the first proportional speed parameter and the first integral speed parameter enables the drive motor to quickly reduce the speed difference between itself and the target motor, thereby effectively shortening the motor's speed response time and improving its responsiveness.

[0087] Furthermore, due to the high response speed required during the acceleration phase, a large torque is needed. If the torque exceeds the control limit, it will cause overcharging or over-discharging of the battery. Therefore, based on meeting the set time threshold for speed regulation, it is necessary to use a first limiting torque to limit the torque of the drive motor. That is, the output torque of the motor controller MCU is limited by the first limiting torque, so that the torque of the drive motor is completed within the first limiting torque. The first limiting torque is the allowable torque of the motor calculated by the vehicle controller PDCU based on the battery capacity, which can prevent overcharging or over-discharging of the battery.

[0088] Furthermore, the automatic transmission control unit (TCU) monitors in real time whether the actual motor speed and the target motor speed at the set speed difference have reached the set speed difference. If so, the control enters the gear shifting stage and continuously sends speed mode commands to the motor controller (MCU). The speed command is to calculate the actual motor speed based on the vehicle speed. During this process, the shifting process parameter of the automatic transmission control unit (TCU) is set to 4.

[0089] For the motor controller MCU, during the gear shifting phase, if the speed difference between the actual motor speed under high speed and the target motor speed reaches the set speed difference, the drive motor is controlled to enter the low speed adjustment phase.

[0090] In one optional implementation, the switching conditions between the high-speed and low-speed adjustment stages are: the shift process quantity of the automatic transmission control unit (TCU) is set to 4, and the control mode of the TCU is set to speed control mode. If the motor controller MCU detects the above conditions, it can control the drive motor to switch from the high-speed stage to the low-speed adjustment stage. Specifically, the motor controller MCU detects the shift process quantity of the TCU and the control mode; if the shift process quantity is set to 4 and the control mode is speed control mode, it controls the drive motor to enter the low-speed adjustment stage.

[0091] The weak speed adjustment phase belongs to the gear engagement phase. It's used to weaken the speed of the drive motor after the speed difference between the actual motor speed and the target motor speed reaches the set speed difference. This brings the actual motor speed and the target motor speed close to zero, facilitating gear engagement. It's important to note that during the weak speed adjustment phase, the motor controller MCU still uses speed control, not torque control. This is because using torque control during gear engagement (e.g., a torque control command of 0 torque) would cause the motor speed to fluctuate significantly, potentially leading to gear engagement failure or jerking. To avoid these issues and ensure smooth and successful gear engagement, speed control is still used.

[0092] Since the response speed requirement of the motor controller MCU is not high during the weak speed adjustment phase, and only requires the MCU to stabilize the actual motor speed, a second calibrated speed is used instead of the first calibrated speed, and the drive motor is continuously iteratively controlled to adjust its speed until gear engagement is completed. The second calibrated speed is lower than the first calibrated speed, allowing the motor controller MCU to iteratively control the drive motor at a smaller calibrated speed, ensuring smooth gear engagement. The second calibrated speed includes a second proportional parameter and a second integral parameter based on the speed difference; the second proportional parameter is lower than the first proportional parameter, and the second integral parameter is lower than the first integral parameter. Therefore, by using the second proportional parameter and the second integral parameter to replace the first proportional parameter and the first integral parameter respectively, and continuously iteratively controlling the drive motor to adjust its speed until gear engagement is completed, smooth gear engagement and a high success rate are ensured, and the service life of the transmission hardware is extended.

[0093] Furthermore, during the low-speed adjustment phase, the motor torque should not be too high when engaging gears, otherwise it may easily lead to engagement failure. Therefore, to ensure successful engagement, the second limiting torque is less than the first limiting torque to guarantee the success rate of gear engagement. Specifically, the second limiting torque and the first limiting torque are used to iteratively control the drive motor for speed adjustment until gear engagement is completed. The second limiting torque is the allowable torque of the motor calculated by the automatic transmission control unit (TCU) based on the torque required for gear engagement, and is used to prevent excessive torque from causing gear engagement failure.

[0094] In one alternative implementation, the target motor speed of the automatic transmission control unit (TCU) during gear engagement can be finely adjusted according to the actual vehicle speed, thereby making gear shifting smoother.

[0095] When the speed difference between the actual motor speed and the target motor speed approaches zero, the motor controller MCU executes the gear shifting operation. After gear shifting is completed, it receives the torque control mode 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 gear shifting. At this time, the shifting process parameter of the automatic transmission control unit (TCU) is set to 4.

[0096] After gear engagement, the torque increase phase begins. During this phase, the vehicle control unit (PDCU) gains control and controls the motor controller (MCU). Specifically, the automatic transmission control unit (TCU) sends a 0-torque mode and the actual gear position to the MCU. The 0-torque mode indicates that the control entity has switched from the TCU to the PDCU; the TCU sends this mode to relinquish control of the MCU. During this process, the TCU's shift parameter is set to 5. The actual gear position is used for updating the MCU.

[0097] For the motor controller MCU, it receives the 0 torque mode and actual gear position from the automatic transmission control unit (TCU); based on the 0 torque mode and actual gear position, it receives the control torque increase from the vehicle control unit (PDCU). Specifically, it updates the actual gear position to the target gear position; when the vehicle control unit (PDCU) detects that the actual gear position is the target gear, it updates the torque command and can then take over control of the motor controller MCU. For the motor controller MCU, it receives the control torque increase from the vehicle control unit (PDCU) based on the 0 torque mode.

[0098] Based on the same inventive concept, the following embodiments describe a pure electric vehicle that achieves shift control through the shift control method described in one or more of the foregoing embodiments.

[0099] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0100] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A shifting process control method, applied to a pure electric vehicle, characterized in that, The method includes: During the neutral phase, the speed control mode sent by the automatic transmission control device is obtained; Based on the speed control mode, the target motor speed is obtained; Based on the target motor speed, the drive motor is controlled to enter the speed enhancement stage; in the speed enhancement stage, the drive motor is iteratively controlled to adjust its speed using a first calibrated speed and a first limiting torque; 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 based on the battery capacity, used to prevent overcharging or over-discharging of the battery; If the speed difference between the actual motor speed under high speed and the target motor speed reaches the set speed difference, the drive motor is controlled to enter a weak speed adjustment phase. In the weak speed adjustment phase, the first calibrated speed and the first limited torque are replaced by the second calibrated speed and the first limited torque, respectively, and the drive motor is continuously iteratively controlled to adjust the speed until the gear engagement is completed. The second calibrated speed is less than the first calibrated speed, and the second limited torque is less than the first limited torque. 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.

2. The method as described in claim 1, characterized in that, Prior to the neutral phase, the method further includes: During the torque reduction phase, the vehicle controller receives control commands based on the target gear and executes corresponding torque reduction operations. During the disengagement phase, when the torque is reduced to the target range, the system receives the torque control mode sent by the automatic transmission control device and performs the disengagement operation according to the first torque control command 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.

3. The method as described in claim 1, characterized in that, The iterative control of the drive motor using a first calibrated speed and a first limiting torque for speed adjustment specifically includes: The speed of the drive motor is adjusted by iterative control using the first speed proportional parameter and the first speed integral parameter, and the torque of the drive motor is limited by the first limiting torque.

4. The method as described in claim 3, characterized in that, If the speed difference between the actual motor speed under the specified acceleration and the target motor speed reaches a set speed difference, the method further includes: The shifting process and control mode of the automatic transmission control device are detected. If the shift process quantity is set to 4 and the control mode is speed control mode, the drive motor is controlled to enter the weak speed regulation stage.

5. The method as described in claim 1, characterized in that, The process of replacing the first calibrated speed and the first limited torque with the second calibrated speed and the second limited torque respectively, and continuously iteratively controlling the drive motor to adjust the speed until gear engagement is completed, specifically includes: The first speed proportional parameter, the first speed integral parameter, and the first speed limiting torque are replaced by the second speed proportional parameter, the first speed integral parameter, and the first speed limiting torque, respectively, and the drive motor is continuously iteratively controlled to adjust its speed until gear engagement is completed; wherein, the second speed limiting torque is the allowable torque of the motor calculated by the automatic transmission control device based on the torque required for gear engagement, and is used to prevent excessive torque from causing gear engagement failure.

6. The method as described in claim 5, characterized in that, After the gear shift is completed, the method further includes: The system receives the torque control mode sent by the automatic transmission control device and switches from the speed control mode to the torque control mode.

7. The method as described in claim 6, characterized in that, The method further includes: replacing the first calibrated speed and the first limited torque with the second calibrated speed and the second limited torque respectively, and continuously iteratively controlling the drive motor to adjust the speed until gear engagement is completed. During the torque-increasing phase, the system receives the 0-torque mode and actual gear position from the automatic transmission control device. Based on the 0 torque mode and the actual gear position, the control torque is increased by the vehicle controller. The 0 torque mode is used to indicate that the control body is switched from the automatic transmission control device to the vehicle controller.

8. A gear shifting process controller, applied to a pure electric vehicle, characterized in that, The shift process controller includes: The first acquisition module is used to acquire the speed control mode sent by the automatic transmission control device during the neutral phase. The second acquisition module is used to acquire the target motor speed based on the speed control mode; The first control module is used to control the drive motor to enter the speed enhancement stage based on the target motor speed; in the speed enhancement stage, the drive motor is iteratively controlled to adjust the speed using a first calibrated speed and a first limiting torque; 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, used to prevent overcharging or over-discharging of the battery; The second control module is used to control the drive motor to enter a weak speed adjustment phase when the speed difference between the actual motor speed under the specified speed and the target motor speed reaches a set speed difference. In the weak speed adjustment phase, the first calibrated speed and the first limited torque are replaced by a second calibrated speed and a second limited torque, respectively, and the drive motor is continuously iteratively controlled to adjust the speed until gear engagement is completed. The second calibrated speed is less than the first calibrated speed, and the second limited torque is less than the first limited torque. The second calibrated speed includes a second proportional speed parameter and a second integral speed parameter based on the speed difference. The second proportional speed parameter is less than the first proportional speed parameter, and the second integral speed parameter is less than the first integral speed parameter.

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

10. A pure electric vehicle, characterized in that, Gear shifting control is achieved by the gear shifting process control method as described in any one of claims 1-7.

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