Gear shifting control method and electronic device for electric drive assembly with two-gear dual clutch transmission

Abstract

The application relates to the technical field of vehicle control, and provides a gear shifting control method of an electric drive assembly equipped with a two-gear double-clutch transmission and electronic equipment. The method comprises the following steps: acquiring vehicle operation data; calculating a target gear based on the vehicle operation data, and determining a gear shifting strategy type according to the target gear; calculating a clutch slip rotation speed according to the vehicle operation data; determining an electric drive system operation mode based on a driver demand torque, an actual output torque of a motor and the clutch slip rotation speed; determining a target gear shifting mode according to a vehicle speed and the electric drive system operation mode; performing PI operation on a clutch pump motor target duty cycle based on a clutch target torque and a clutch target pressure in the target gear shifting mode according to the target gear shifting mode; performing clutch control based on the clutch pump motor target duty cycle obtained through operation, and completing gear shifting. The method realizes power interruption-free gear shifting during gear ratio switching, guarantees power performance, is economical, and takes into account gear shifting smoothness and comfort.

Description

Technical Field

[0001] This application relates to the field of vehicle control technology, specifically to a shift control method and electronic equipment for an electric drive assembly equipped with a two-speed dual-clutch transmission. Background Technology

[0002] Currently, electric vehicles typically use a motor connected to a single-stage reducer to drive the wheels, with a fixed relationship between motor speed and vehicle speed. Due to the characteristics of the motor, the vehicle cannot simultaneously meet the demands of low-speed power and high-speed efficiency. An electric drive system equipped with a two-speed dual-clutch transmission can solve this problem. In this system, the drive motor output is mechanically connected to the dual-clutch input, with speed ratio changes occurring in between. The two clutch outputs are mechanically connected to the wheel drive mechanism at different speed ratios. Each clutch is powered by a separate clutch pump that drives hydraulic oil to establish pressure and control clutch torque. Specifically... Figure 1 As shown.

[0003] The electric drive assembly of a two-speed dual-clutch transmission operates at high gear ratios at low speeds to provide greater wheel-side torque; at high speeds, it operates at low gear ratios to reduce the drive motor speed, keeping it within its efficient speed range, and also further increasing the vehicle's top speed. Therefore, maintaining and switching between the two gears under different operating conditions requires corresponding software strategies to achieve a smooth shifting experience. However, the shift control strategies of existing electric drive assemblies equipped with two-speed dual-clutch transmissions cannot achieve smooth shifting, resulting in poor comfort. Summary of the Invention

[0004] In view of this, the present application provides a shift control method and electronic device for an electric drive assembly equipped with a two-speed dual-clutch transmission, which enables the drive motor to shift gears without power interruption when the speed ratio is switched, so that the electric drive system can ensure power and economy while also taking into account shift smoothness and comfort.

[0005] The first aspect of this application provides a shift control method for an electric drive assembly equipped with a two-speed dual-clutch transmission, including:

[0006] Obtain vehicle operation data;

[0007] The target gear is calculated based on the vehicle operation data, and the shift strategy type is determined based on the target gear.

[0008] Calculate the clutch slippage speed based on the vehicle operating data;

[0009] The operating mode of the electric drive system is determined based on the driver's required torque, the actual output torque of the motor, and the clutch slippage speed.

[0010] The target shift mode is determined based on the vehicle speed and the operating mode of the electric drive system;

[0011] Based on the target shift mode, the target duty cycle of the clutch pump motor is calculated using PI based on the target torque and target pressure of the clutch under the target shift mode. Clutch control is then performed based on the calculated target duty cycle of the clutch pump motor to complete the shift.

[0012] A second aspect of this application provides a shift control device for an electric drive assembly equipped with a two-speed dual-clutch transmission, comprising:

[0013] The data acquisition module is used to acquire vehicle operation data;

[0014] The shift strategy determination module is used to calculate the target gear based on the vehicle operation data and determine the shift strategy type based on the target gear.

[0015] The calculation module is used to calculate the clutch slippage speed based on the vehicle operating data;

[0016] The operating mode determination module is used to determine the operating mode of the electric drive system based on the driver's required torque, the actual output torque of the motor, and the clutch slippage speed.

[0017] The target shift mode determination module is used to determine the target shift mode based on the vehicle speed and the operating mode of the electric drive system.

[0018] The shift execution module is used to perform PI calculation on the target duty cycle of the clutch pump motor based on the target shift mode, according to the target torque and target pressure of the clutch in the target shift mode, and to perform clutch control based on the calculated target duty cycle of the clutch pump motor to complete the shift.

[0019] A third aspect of this application provides an electronic device including a processor, a memory, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the electronic device implements the shift control method for an electric drive assembly equipped with a two-speed dual-clutch transmission as provided in the first aspect of this application.

[0020] A fourth aspect of this application provides a computer program product including a computer program that, when run, causes the method described in the first aspect of this application to be performed.

[0021] The first aspect of this application provides a shift control method for an electric drive assembly equipped with a two-speed dual-clutch transmission, comprising: acquiring vehicle operating data; calculating a target gear based on the vehicle operating data; determining a shift strategy type based on the target gear; calculating the clutch slippage speed based on the vehicle operating data; determining an electric drive system operating mode based on the driver's required torque, the actual output torque of the motor, and the clutch slippage speed; determining a target shift mode based on the vehicle speed and the electric drive system operating mode; performing a PI calculation on a target duty cycle of the clutch pump motor based on the target shift mode and the target clutch torque and target clutch pressure under the target shift mode; and performing clutch control based on the calculated target duty cycle of the clutch pump motor to complete the shift. By acquiring vehicle operating data, calculating the target gear and shifting strategy, determining the slip speed and system operating mode, selecting the target shifting mode, and finally controlling the clutch pump motor duty cycle through precise PI calculation based on the clutch target parameters under the target mode, this framework clearly defines the core logic process for achieving uninterrupted and smooth shifting. It closely integrates signal acquisition, decision-making, and execution control, covering the entire process from intent recognition to power transmission control. This enables the drive motor to shift gears without power interruption when the speed ratio changes, ensuring that the electric drive system can guarantee power and economy while also taking into account shifting smoothness and comfort.

[0022] It is understood that the beneficial effects of the second to fourth aspects mentioned above can be found in the relevant descriptions in the first aspect mentioned above, and will not be repeated here. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a hardware structure diagram of an electric drive assembly equipped with a two-speed dual-clutch transmission;

[0025] Figure 2 This is a schematic flowchart of a shift control method for an electric drive assembly equipped with a two-speed dual-clutch transmission provided in an embodiment of this application;

[0026] Figure 3 This is a schematic flowchart of a shift control method for an electric drive assembly equipped with a two-speed dual-clutch transmission, provided in another embodiment of this application.

[0027] Figure 4 This is the control flow for each working state of the transmission in this application;

[0028] Figure 5 This is a schematic diagram of the power shift control strategy of this application;

[0029] Figure 6 This is a schematic diagram of the coasting upshift control strategy of this application;

[0030] Figure 7 This is a schematic diagram of the power downshift control strategy of this application;

[0031] Figure 8 This is a schematic diagram of the coasting downshift control strategy of this application;

[0032] Figure 9 This is a schematic diagram of the simulation test data of the drive assembly in this application;

[0033] Figure 10 This is a schematic diagram of the shift control device for an electric drive assembly equipped with a two-speed dual-clutch transmission provided in an embodiment of this application;

[0034] Figure 11 This is a schematic diagram of the structure of the electronic device provided in the embodiments of this application. Detailed Implementation

[0035] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

[0036] It should be understood that, when used in this application specification and the appended claims, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or a collection thereof.

[0037] It should also be understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0038] As used in this application specification and the appended claims, the term "if" may be interpreted, depending on the context, as "when," "once," "in response to determination," or "in response to detection." Similarly, the phrase "if determined" or "if detected [the described condition or event]" may be interpreted, depending on the context, as meaning "once determined," "in response to determination," "once detected [the described condition or event]," or "in response to detection [the described condition or event]."

[0039] Furthermore, in the description of this application and the appended claims, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0040] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0041] like Figure 2 As shown, the shift control method for an electric drive assembly equipped with a two-speed dual-clutch transmission provided in this application includes the following steps S101 to S106:

[0042] Step S101: Obtain vehicle operation data.

[0043] In applications, acquire the necessary signals related to shift control.

[0044] This requires establishing communication with the vehicle to obtain vehicle speed and the driver's required torque. The electric drive system needs to collect necessary information, including information from the two clutch pressure sensors, oil temperature sensor, two clutch pump speed signals, as well as the electric drive motor's own drive speed and real-time output torque.

[0045] Step S102: Calculate the target gear based on vehicle operation data, and determine the shift strategy type based on the target gear.

[0046] In the application, gear commands are calculated based on the needs of the vehicle and the driver.

[0047] Based on vehicle information and power and fuel economy requirements, a shift curve related to vehicle speed and driver-demanded torque is set. The desired gear command is retrieved from a table based on the real-time vehicle speed and the driver's real-time torque demand. The target gear command is compared with the current gear to determine the upshift / downshift strategy.

[0048] Step S103: Calculate the clutch slippage speed based on vehicle operating data.

[0049] In application, based on the signals obtained from the transmission, the speeds at each stage within the transmission are calculated to determine the operating state of the dual-clutch transmission.

[0050] Based on the obtained drive motor speed and the reduction ratio between the drive motor and the clutch input end, calculate the clutch input end speed.

[0051] Based on the acquired vehicle speed signal and the reduction ratio between the two output ends of the clutch and the half-shaft end, the speed at the output end of the clutch can be calculated; based on the speeds at the input and output ends of the clutch, the slippage speeds of the two clutches can be calculated respectively.

[0052] Step S104: Determine the operating mode of the electric drive system based on the driver's required torque, the actual output torque of the motor, and the clutch slippage speed.

[0053] In application, the electric drive system is determined to be in drive mode or coasting mode based on the driver's required torque, the actual output torque of the motor, and the clutch slippage speed.

[0054] When the clutch slippage speed in the current gear exceeds the limit (positive value), the driver's required torque exceeds the limit, and the actual output torque of the motor exceeds the limit, the vehicle is in drive mode;

[0055] When the clutch slippage speed in the current gear is less than the limit (negative value), the torque required by the driver is less than the limit, and the actual output torque of the motor is less than the limit, the vehicle is in coasting mode;

[0056] If none of the above conditions are met, retain the previous time value for output.

[0057] Step S105: Determine the target shift mode based on vehicle speed and electric drive system operating mode.

[0058] In application, the operating state of the transmission is determined based on the information calculated in the first four steps.

[0059] Based on vehicle speed information, the non-shifting range is determined. When the vehicle speed is below the lower limit, the transmission locks in first gear; when the vehicle speed is above the upper limit, the transmission locks in second gear. When the vehicle speed is between the lower and upper limits, an upshift or downshift is determined based on the target gear calculated in step S102. Based on the vehicle driving state determined in step S104, a power shift or coasting shift is determined. During the switching process between locking first gear, locking second gear, power upshift, power downshift, coasting upshift, and coasting downshift, a transition is first performed in a coasting control state. When there is no shift command, the transmission switches to the current gear lock state.

[0060] Step S106: Based on the target shift mode, perform PI calculation on the target duty cycle of the clutch pump motor according to the target torque and target pressure of the clutch under the target shift mode, and perform clutch control based on the calculated target duty cycle of the clutch pump motor to complete the shift.

[0061] In application, this step is used to execute the corresponding target shift mode, where:

[0062] In the first-gear locking mode, the second clutch is fully open and does not transmit torque; the first clutch adds lock-up compensation torque to the actual torque of the drive motor.

[0063] In the second-level lock-up mode, the first clutch is fully open and does not transmit torque; the second clutch adds lock-up compensation torque on top of the actual torque of the drive motor.

[0064] In the power upshift mode, shifting from first to second gear begins with clutch torque interaction: the torque of the first clutch gradually decreases to zero (the timing is calibrable); the torque of the second clutch gradually increases, maintaining the sum of the torques of both clutches equal to the output torque of the drive motor throughout this process. Once the torque of the first clutch reaches zero, the torque interaction ends. Next, the drive motor speed adjustment phase begins, controlling the drive motor to enter speed mode. The target speed of the drive motor is the output shaft speed of the second clutch plus the set target slip speed for the power upshift. The duration of this speed adjustment phase is settable. During this phase, the torque of the second clutch follows the driver's torque demand, while the torque of the first clutch remains at zero. Once the drive motor speed reaches the target speed, the power upshift is complete.

[0065] In the power downshift mode, downshifting from second to first gear begins with drive motor speed adjustment. The drive motor enters a speed control mode, and the target speed is calculated as the first clutch output shaft speed plus the set target slip speed for power downshifting. The speed adjustment phase duration is settable. During this phase, the second clutch torque follows the driver's torque demand, while the first clutch torque remains at zero. Once speed adjustment is complete, clutch torque interaction begins. The second clutch torque gradually decreases to zero (the time is calibrable), while the first clutch torque gradually increases. Throughout this process, the sum of the two clutch torques remains equal to the drive motor output torque. The torque interaction ends when the second clutch torque reaches zero.

[0066] In coasting upshift mode, when shifting from first to second gear, the drive motor speed is first adjusted. The drive motor enters a speed mode, and the target speed of the drive motor is calculated as the output shaft speed of the second clutch minus the set target coasting downshift speed. The speed adjustment phase time is adjustable. During the speed adjustment phase, the torque of the first clutch follows the absolute value of the torque required by the driver, while the second clutch maintains zero torque output. After speed adjustment is complete, clutch torque interaction begins. The torque of the first clutch gradually decreases to zero, and the time can be calibrated. The torque of the second clutch gradually increases. During this process, the sum of the torques of the two clutches is always equal to the absolute value of the drive motor output torque. The torque interaction ends when the torque of the first clutch drops to zero.

[0067] In coasting downshift mode, downshifting from second to first gear begins with clutch torque interaction. The second clutch torque gradually decreases to zero (the timing is calibrable). The first clutch torque gradually increases, maintaining the sum of both clutch torques equal to the absolute value of the drive motor's output torque throughout this process. Once the second clutch torque reaches zero, the torque interaction ends. Next, the drive motor speed adjustment phase begins. The drive motor enters speed mode, and the target speed is calculated as the first clutch output shaft speed minus the set target coasting downshift speed. The speed adjustment phase duration is configurable. During this phase, the first clutch torque follows the absolute value of the torque required by the driver, while the second clutch maintains zero torque output. Once the drive motor speed reaches the target speed, the coasting downshift is complete.

[0068] Furthermore, during the switching between various modes, the slip control mode is used as a transition first. When there is no shift command, it switches to the current gear lock state. The goal of slip control mode is to control the slip speed of the clutch within the target slip speed range. Based on the vehicle drive status flag determined in step four, the calibrable target slip speed is determined. Then, based on the clutch slip speed calculated in step S103, the slip offset speed difference is calculated. Using the principle of P-phase control, the speed control target torque is calculated. Finally, combined with the output torque of the drive motor, the clutch target torque under slip control conditions is calculated.

[0069] The first aspect of this application provides a shift control method for an electric drive assembly equipped with a two-speed dual-clutch transmission, comprising: acquiring vehicle operating data; calculating a target gear based on the vehicle operating data; determining a shift strategy type based on the target gear; calculating the clutch slip speed based on the vehicle operating data; determining the electric drive system operating mode based on the driver's required torque, the actual output torque of the motor, and the clutch slip speed; determining a target shift mode based on the vehicle speed and the electric drive system operating mode; performing a PI calculation on the target duty cycle of the clutch pump motor based on the target shift mode and the target clutch torque and target clutch pressure under the target shift mode; and performing clutch control based on the calculated target duty cycle of the clutch pump motor to complete the shift. By acquiring vehicle operating data, calculating the target gear and shifting strategy, determining the slip speed and system operating mode, selecting the target shifting mode, and finally controlling the clutch pump motor duty cycle through precise PI calculation based on the clutch target parameters under the target mode, this framework clearly defines the core logic process for achieving uninterrupted and smooth shifting. It closely integrates signal acquisition, decision-making, and execution control, covering the entire process from intent recognition to power transmission control. This enables the drive motor to shift gears without power interruption when the speed ratio changes, ensuring that the electric drive system can guarantee power and economy while also taking into account shifting smoothness and comfort.

[0070] In application, based on the target clutch torque and target clutch pressure under the target shift mode, a PI calculation is performed on the target duty cycle of the clutch pump motor, including:

[0071] Based on the target torques of the two clutches calculated in step S106 and the slip friction speed difference of the two clutches calculated in step S103, the corresponding target clutch pressure signals are obtained by looking up a table. Simultaneously, based on the clutch pressure signal acquired in step S101, the slip friction speed difference of the two clutches calculated in step S103, and the cooling oil temperature signal obtained in step S101, the corresponding estimated clutch torque is obtained by looking up a table.

[0072] Based on the clutch target pressure calculated in step S106 and the cooling oil temperature signal obtained in step S101, the clutch oil pump feedforward target speed is obtained by looking up the table. Based on the clutch pressure signal obtained in step S101, the difference between the clutch target pressure calculated in step S106 is calculated, and P-phase and I-phase control is performed. The control coefficients can be calibrated. Finally, the P-phase and I-phase control parts are summed with the feedforward target speed to obtain the clutch pump target speed.

[0073] Based on the target clutch pump speed calculated in step S106, and the cooling oil temperature signal obtained in step S101, the target duty cycle of the clutch pump motor is obtained by looking up a table. The difference between the clutch pump speed signal obtained in step S101 and the target clutch pump speed calculated in step S106 is used for P-phase and I-phase control. The control coefficients can be calibrated. Finally, the P-phase and I-phase control parts are summed with the target duty cycle to obtain the target duty cycle of the clutch pump motor. The duty cycle signal is directly output to the software layer for oil pump motor control.

[0074] In one embodiment, calculating the target gear based on vehicle operating data and determining the shift strategy type based on the target gear includes:

[0075] Based on the driver's required torque, consult the shift critical speed table to obtain the critical speeds for upshifting and downshifting;

[0076] When the vehicle speed is greater than the upshift threshold speed, the shift strategy type is determined to be upshift;

[0077] When the vehicle speed is less than the downshift threshold speed, the shift strategy type is determined to be downshift;

[0078] The vehicle operation data includes driver-demanded torque data and vehicle speed data.

[0079] This application's embodiment employs a lookup method based on a preset shift threshold speed table, which is simple to implement and computationally efficient. It can quickly respond to the driver's intentions and make clear upshift or downshift decisions based on a comparison of the vehicle speed with preset thresholds (upshifting if the speed is greater than the upshift threshold speed, and downshifting if the speed is less than the downshift threshold speed). This significantly improves the real-time performance and reliability of shift decisions, avoids the computational burden caused by complex algorithms, and clarifies the key parameters (driver's required torque and vehicle speed) required for "vehicle operating data" in this step.

[0080] In one embodiment, the operating mode of the electric drive system is determined based on the driver's required torque, the actual output torque of the motor, and the clutch slippage speed, including:

[0081] When the clutch slippage speed in the current gear is greater than the first threshold, the driver's required torque is greater than the second threshold, and the motor output torque is greater than the third threshold, the electric drive system is determined to be in drive mode.

[0082] When the clutch slippage speed in the current gear is less than the fourth threshold, the driver's required torque is less than the fifth threshold, and the motor output torque is less than the sixth threshold, the electric drive system is determined to be in coasting mode.

[0083] This application introduces a triple joint criterion (direction and magnitude of the current gear clutch slip speed, the magnitude of the driver's required torque, and the magnitude of the motor's actual output torque) to accurately distinguish between driving mode and coasting mode. The core technology is to directly associate the driving or braking state with the positive or negative value of the slip speed (greater than or less than a threshold). This effectively solves the problem that electric vehicles are prone to misjudgment of driving / coasting modes near zero torque due to the characteristics of motor torque. At the same time, the calibrability of each threshold (first to sixth thresholds) allows this judgment method to be flexibly adapted to different vehicle models and operating conditions, greatly enhancing the accuracy of system operating status identification and the universality of the solution.

[0084] In one embodiment, the target shift mode includes a first gear lock mode, a second gear lock mode, a power upshift mode, a power downshift mode, a coasting upshift mode, and a coasting downshift mode;

[0085] Based on vehicle speed and the operating mode of the electric drive system, determine the target shift mode, including:

[0086] When the vehicle speed is less than the preset minimum value, the target shift mode is determined to be the first gear lock mode;

[0087] When the vehicle speed exceeds the preset high limit, the target shift mode is determined to be the second gear lock mode;

[0088] When the preset lower limit value ≤ vehicle speed ≤ preset upper limit value, is in drive mode and the shift strategy type is upshift, the target shift mode is determined to be power upshift mode.

[0089] When the preset lower limit value ≤ vehicle speed ≤ preset upper limit value, is in drive mode and the shift strategy type is downshift, the target shift mode is determined to be power downshift mode.

[0090] When the preset lower limit value ≤ vehicle speed ≤ preset upper limit value, the vehicle is in coasting mode, and the shift strategy type is upshift, the target shift mode is determined to be coasting upshift mode.

[0091] When the preset lower limit is less than or equal to the vehicle speed, and the vehicle is in coasting mode and the shift strategy type is downshift, the target shift mode is determined to be coasting downshift mode.

[0092] This application constructs a decision network for six target shift modes (first gear lock, second gear lock, power upshift, power downshift, coasting upshift, and coasting downshift) based on a dual dimension of vehicle speed range and electric drive system operating mode. This network covers all possible vehicle operating conditions: locking first gear at low speeds to ensure high torque output, locking second gear at high speeds to optimize efficiency and maximum speed, and executing the corresponding four shift modes according to the driving / coasting state and upshift / downshifting requirements in the medium speed range. This structured and comprehensive mode division logic is rigorous and hierarchical, perfectly combining shift strategy types and system operating modes, laying a solid foundation for subsequent refined control of different modes, and serving as a key decision basis for ensuring vehicle power, economy, and smoothness.

[0093] In one embodiment, it also includes:

[0094] During clutch control based on the target shift mode, if the target gear is inconsistent with the current gear, the slipping control mode is entered until the target gear is the same as the actual gear and the clutch slipping speed difference in the current gear is less than the preset difference threshold. Then the slipping control mode is exited and the current gear is locked.

[0095] The sliding wear control conditions include:

[0096] The calibrable target sliding mill speed is determined based on the operating mode of the electric drive system;

[0097] The slippage offset speed difference is calculated based on the clutch slippage speed and the calibrable target slippage speed.

[0098] The principle of P-phase control is used to calculate the torque for adjusting the sliding grinding speed;

[0099] Based on the output torque of the drive motor and the torque for adjusting the speed of the slipping mill, the target torque of the clutch under the slipping mill control condition is calculated.

[0100] Clutch control is performed based on the target torque of the clutch under slip control conditions.

[0101] In this embodiment, a slippage control stage is dynamically inserted during gear shifting (when the target gear is inconsistent with the actual gear). This stage calculates the slippage offset speed difference and uses the proportional (P) control principle to generate slippage speed regulation torque, thereby calculating the precise clutch target torque. This achieves active and precise control of the clutch slippage state, effectively absorbing shifting shocks. When the exit conditions are met (gears are consistent and slippage speed difference is less than a threshold), it smoothly transitions to the locked state. This mechanism ensures the absolute smoothness of the shifting process (especially when switching modes or gears are not aligned), significantly reduces the feeling of power interruption and the risk of clutch wear, and improves shifting quality.

[0102] In one embodiment, it also includes:

[0103] During clutch control based on the target shift mode:

[0104] When the target shift mode is the first gear lock mode, the second clutch is fully open and does not transmit torque; the first clutch adds lock-up compensation torque on the basis of the actual torque of the drive motor.

[0105] When the target shift mode is the second gear lock mode, the first clutch is fully open and does not transmit torque; the second clutch adds lock-up compensation torque on the basis of the actual torque of the drive motor.

[0106] When the target shift mode is power upshift mode, the torque interaction stage is entered, and the torque of the first clutch is gradually reduced to zero while the torque of the second clutch gradually increases. When the speed regulation stage is entered, the drive motor is controlled to enter the speed mode, so that the target speed of the drive motor is the sum of the output shaft speed of the second clutch and the set power upshift target slip speed.

[0107] When the target shift mode is power downshift mode, the speed regulation stage is entered, and the drive motor is controlled to enter the speed mode so that the target speed of the drive motor is the sum of the output shaft speed of the first clutch and the set power downshift target slip speed; when the torque interaction stage is entered, the torque of the second clutch is controlled to gradually decrease to zero, and the torque of the first clutch gradually increases.

[0108] When the target shift mode is coasting upshift mode, the speed regulation stage is entered, and the drive motor is controlled to enter the speed mode, so that the target speed of the drive motor is the output shaft speed of the second clutch minus the set coasting downshift target slip speed; when the torque interaction stage is entered, the torque of the first clutch is controlled to gradually decrease to zero, and the torque of the second clutch gradually increases.

[0109] When the target shift mode is coasting downshift mode, the torque interaction stage is entered, and the torque of the second clutch is gradually reduced to zero while the torque of the first clutch gradually increases. When the speed regulation stage is entered, the drive motor is controlled to enter the speed mode, so that the target speed of the drive motor is the output shaft speed of the first clutch minus the set coasting downshift target slip speed.

[0110] This application provides clear, executable, and differentiated operating instructions for each mode: for the locking mode, clutch slippage is completely eliminated by applying "lock-up compensation torque" to maximize transmission efficiency; for the four shifting modes, the execution sequence of the two core operations, "torque interaction" and "drive motor speed regulation," is ingeniously designed (power upshift and coast downshift interact first and then regulate speed, power downshift and coast upshift regulate speed first and then interact), and the direction of clutch torque change at each stage (reducing to zero or increasing to the target value) and the target speed calculation formula for drive motor speed regulation (adding or subtracting the output shaft speed from the target slippage speed) are clearly defined. This modular control strategy with clear operating steps is a concrete guarantee to ensure that shifting without power interruption can be achieved. In particular, the differentiated handling of the operation sequence and target speed calculation between power shifting and coasting shifting fully adapts to the dynamic differences between drive and energy recovery conditions.

[0111] In one embodiment, a PI calculation is performed on the target duty cycle of the clutch pump motor based on the target clutch torque and target clutch pressure under the target shift mode, including:

[0112] The target speed of the clutch pump is obtained through PI calculation based on the clutch pressure and the clutch target pressure.

[0113] Based on the clutch pump speed and target clutch pump speed in the vehicle operation data, the target duty cycle of the clutch pump motor is obtained through PI calculation.

[0114] This application provides a hierarchical dual-closed-loop (cascaded PI) control architecture for achieving precise hydraulic pressure control: the inner loop is a pressure loop (performing PI calculations based on the difference between the clutch target pressure and the actual pressure, outputting the clutch pump target speed), and the outer loop is a speed loop (performing PI calculations based on the difference between the pump target speed and the actual speed, outputting the pump motor target duty cycle). This strategy of decomposing a complex control problem into two relatively simple, serial PI loops greatly improves the system's control accuracy and dynamic response performance, effectively suppresses hydraulic pressure fluctuations and pump speed errors, and ensures that the hydraulic pressure ultimately applied to the clutch can accurately track the target pressure, providing a reliable guarantee for the precise control of the clutch actuator.

[0115] In one embodiment, the target speed of the clutch pump is obtained through PI calculation based on the clutch pressure and the target clutch pressure, including:

[0116] Based on the target clutch torque and clutch slip rate difference in the target shift mode, the corresponding target clutch pressure can be obtained by looking up the table.

[0117] Based on the clutch target pressure and coolant temperature, the clutch oil pump feedforward target speed can be obtained by referring to the table.

[0118] Based on the clutch pressure, clutch target pressure, and clutch oil pump feedforward target speed in the vehicle operation data, the clutch pump target speed is obtained through PI calculation.

[0119] This application's embodiments introduce a feedforward control and lookup table compensation mechanism: First, based on the clutch target torque and slippage speed difference under the target shift mode, the clutch target pressure is determined by looking up a table. Then, combined with the cooling oil temperature, the oil pump feedforward target speed is obtained by looking up a table. Finally, the output pump target speed is superimposed based on the pressure difference PI feedback control. This composite control strategy of "lookup table (target pressure, feedforward speed) + PI (pressure error)" makes full use of system model information and operating parameters (oil temperature), significantly improving the system's response speed and anti-interference ability. Especially in the initial stage of pressure establishment or when the oil temperature changes, the feedforward component can respond quickly, while the PI feedback effectively eliminates steady-state errors and disturbances, jointly ensuring the accuracy and robustness of oil pressure control.

[0120] In one embodiment, the target duty cycle of the clutch pump motor is obtained through PI calculation based on the clutch pump speed and the target clutch pump speed in the vehicle operating data, including:

[0121] Based on the target speed of the clutch pump and the temperature of the cooling oil, the target duty cycle of the clutch oil pump motor feedforward is obtained by referring to the table.

[0122] Based on the clutch pump speed, clutch pump target speed, and clutch oil pump motor feedforward target duty cycle in the vehicle operation data, the clutch pump motor target duty cycle is obtained through PI calculation.

[0123] This application's embodiment employs a feedforward combined with feedback optimization control strategy: First, the target duty cycle of the oil pump motor is obtained by looking up a table based on the target speed of the clutch pump and the cooling oil temperature. Then, the final target duty cycle is output by superimposing PI feedback control based on the pump speed difference. This scheme introduces the oil temperature parameter by looking up a table, compensating for the impact of oil viscosity changes on pump performance. The feedforward duty cycle provides the main drive signal, while the PI feedback accurately compensates for speed errors. This combined strategy greatly optimizes the drive efficiency and control accuracy of the oil pump motor, ensuring that the clutch pump can quickly and accurately reach and maintain the required speed. It is the execution guarantee for ultimately achieving precise hydraulic closed-loop control of the clutch, improving the overall performance of the entire hydraulic execution system.

[0124] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0125] This application also provides a shift control device for an electric drive assembly equipped with a two-speed dual-clutch transmission, used to execute the steps in the above-described embodiments of the shift control method for an electric drive assembly equipped with a two-speed dual-clutch transmission. The shift control device for an electric drive assembly equipped with a two-speed dual-clutch transmission can be a virtual device in an electronic device, run by the processor of the electronic device, or it can be the electronic device itself.

[0126] This application also provides a shift control method for an electric drive assembly equipped with a two-speed dual-clutch transmission, the execution flow of which is as follows: Figure 3 As shown:

[0127] Step S101: Obtain vehicle operation data.

[0128] This case study utilizes a software engineering platform for an electric drive project. It references existing platform signals including vehicle speed (veh_spd), driver-required torque (drv_tq_cmd), drive motor output torque (motor_tq_act), drive motor speed (motor_spd), and cooling oil temperature (oil_temp). New underlying signals are added: clutch pressure (vbi_clu1 / 2_prs), clutch pump motor speed (vbi_clu1 / 2_motor_spd), and clutch pump motor duty cycle control (vbo_clu1 / 2_motor_dty). SimLink is used for modeling, and the relevant input signals are integrated to build the shift control logic.

[0129] Step S102: Calculate the target gear based on vehicle operation data, and determine the shift strategy type based on the target gear.

[0130] During software initialization, the current gear (gear_act) is initially set to 1. Based on the driver's required torque signal (drv_tq_cmd), the critical shift speeds (Upshift_point_veh and Downshift_point_veh) are calculated using a lookup table. When the input vehicle speed (veh_spd) is greater than the upshift critical speed (Upshift_point_veh), the target gear (gear_des) is set to gear_act + 1; when the input vehicle speed (veh_spd) is less than the downshift critical speed (Downshift_point_veh), the target gear (gear_des) is set to gear_act - 1. Here, gear_act represents the current gear.

[0131] Step S103: Calculate the clutch slippage speed based on the vehicle operation data.

[0132] In application, intermediate variables of the transmission are calculated, including the clutch input speed, clutch output speed, and clutch slippage speed. The clutch input speed is the drive motor speed converted to a reduced speed via a gear ratio, calculated as clu_ins_spd = motor_spd / gear_ratio, where gear_ratio is the reduction gear ratio coefficient, clu_ins_spd is the clutch input speed, and motor_spd is the drive motor speed. The clutch output speed corresponds to the speed at first and second gear, which are connected to the gear ends via a speed ratio conversion. The calculation method is as follows:

[0133] clu1_ous_spd=veh_spd×kph2rpm_factor×gear1_ratio;

[0134] clu2_ous_spd = veh_spd × kph2rpm_factor × gear2_ratio, where clu1_ous_spd is the output speed of the first clutch, clu2_ous_spd is the output speed of the second clutch, kph2rpm_factor is the conversion factor from vehicle speed (km / h) to engine speed (rpm), which is related to the tire dynamic radius, and gear1_ratio and gear2_ratio are the constant speed ratio coefficients of the reduction gears of the two clutches, respectively. The clutch slippage speed is the speed difference between the driving plate and the driven plate, i.e.:

[0135] clu1_slip=clu_ins_spd-clu1_ous_spd;

[0136] clu2_slip=clu_ins_spd-clu2_ous_spd;

[0137] Where clu1_slip is the slip speed of the first clutch and clu2_slip is the slip speed of the second clutch.

[0138] Step S104: Determine the operating mode of the electric drive system based on the driver's required torque, the actual output torque of the motor, and the clutch slippage speed.

[0139] Calculate the drive state of the transmission. Based on the driver's required torque drv_tq_cmd and the actual output torque of the motor motor_tq_act, as well as the slip speeds of the two clutches clu1_slip and clu2_slip, determine the drive state flag pwd_flag of the electric drive system.

[0140] When the clutch slippage speed in the current gear exceeds the limit (positive value), the driver's required torque exceeds the limit, and the actual output torque of the motor exceeds the limit, the vehicle is in drive mode, and pwd_flag=1;

[0141] When the clutch slippage speed in the current gear is less than the limit (negative value), the driver's required torque is less than the limit, and the actual output torque of the motor is less than the limit, the vehicle is in coasting mode pwd_flag=0;

[0142] If none of the above conditions are met, retain the previous time step value for output.

[0143] Step S105: Determine the target shift mode based on vehicle speed and electric drive system operating mode.

[0144] In the application, clutch state control is performed based on the gearbox input information obtained or calculated in the first four steps. This control module uses a state machine, such as... Figure 4 As shown.

[0145] A. First, initialize the operation. In the initial state, both clutches are in the disengaged state: clu1_state=0, clu2_state=0, and the initial gearbox gear_act=1. The gearbox drive state flag pwd_flag=0, where clu1_state indicates the first clutch is engaged and clu2_state indicates the second clutch is engaged.

[0146] B. Determine the initial clutch engagement state based on vehicle speed. When the vehicle speed is less than the speed_low limit (veh_spd <= speed_low), enter the gear1_lock state (first gear locked), the first clutch is engaged (clu1_state = 1), the second clutch is disengaged (clu2_state = 0), and the gearbox gear_act = 1. When the vehicle speed is greater than the speed_high limit (veh_spd >= speed_high), enter the gear2_lock state (second gear locked), the second clutch is engaged (clu2_state = 1), the second clutch is disengaged (clu1_state = 0), and the gearbox gear_act = 2. When the vehicle speed is between the high and low speed limits, enter the gear1_lock state, the first clutch is engaged (clu1_state = 1), the second clutch is disengaged (clu2_state = 0), and the gearbox gear_act = 1.

[0147] C. Slip Control. When the target gear (gear_des) is inconsistent with the current gear (gear_act), the system enters slip control mode, meaning the clutch is in slip control mode. Slip control is executed. In slip control mode, the working clutch torque follows the drive motor output torque, while the non-working clutch torque is increased to the target torque and then to pre-zero torque. The non-working clutch lubrication status flag (clu_stroke_finish_flag) is output. When the target gear and the actual gear are the same, and the slip speed difference between the current gear clutches is less than the limit, slip control is exited, and the system enters the actual gear lock state.

[0148] D. In slip-grip control mode, when the oil filling flag is set (clu_stroke_finish_flag=1, actual gear_act=1, target gear_des=2), and pwd_flag is 1, it enters power upshift mode; when pwd_flag=0, it enters coasting upshift mode. When the actual gear_act=2, target gear_des=1, and pwd_flag is 1, it enters power downshift mode; when pwd_flag=0, it enters coasting downshift mode. When the shift completion flag is set, it returns to slip-grip control mode.

[0149] Step S106: Based on the target shift mode, perform PI calculation on the target duty cycle of the clutch pump motor according to the target torque and target pressure of the clutch under the target shift mode, and perform clutch control based on the calculated target duty cycle of the clutch pump motor to complete the shift.

[0150] In application, the clutch is controlled according to the target shift mode entered in step S105. Figure 5 This is a schematic diagram of the power shift upshift control strategy. Figure 6 This is a schematic diagram of the coasting upshift control strategy. Figure 7 This is a schematic diagram of the power downshift control strategy. Figure 8 This is a schematic diagram of the coasting downshift control strategy. The clutch control methods for each target shift mode are as follows:

[0151] First-gear lock mode. The purpose of first-gear lock is to lock the clutch, eliminate slippage, and reduce energy loss. At this time, the target torque of the first clutch is the output torque of the drive motor plus a compensation value Clu_lock_tq_ofs. The compensation value is: the output torque of the drive motor multiplied by the calibrable coefficient, and the larger of the calibrable minimum limit value, which is used to ensure the lock of the first clutch; the second clutch is fully disengaged.

[0152] Clu1_tq_des=motor_tq_act+Clu_lock_tq_ofs,

[0153] Clu_lock_tq_ofs=max(motor_tq_act×clu_lock_factor, clu_lock_tq_min);

[0154] Clu2_tq_des=clu_open_tq.

[0155] Where Clu1_tq_des is the target torque of the first clutch, motor_tq_act is the output torque of the drive motor, clu_lock_factor is the calibrable coefficient, clu_lock_tq_min is the calibrable minimum limit, and clu_open_tq is the target torque of the second clutch, which is equal to the target torque of the second clutch in the fully open state.

[0156] Second-gear lock mode. The purpose of second-gear lock is to lock the clutch, eliminate slippage, and reduce energy loss. At this time, the target torque of the second clutch is the output torque of the drive motor plus a compensation value Clu_lock_tq_ofs. The compensation value is the output torque of the drive motor multiplied by a calibrable coefficient, and the larger of the calibrable minimum limit value, used to ensure the lock of the second clutch; the first clutch is fully open.

[0157] Clu2_tq_des=motor_tq_act+Clu_lock_tq_ofs;

[0158] Clu_lock_tq_ofs=max(motor_tq_act×clu_lock_factor, clu_lock_tq_min);

[0159] Clu1_tq_des=clu_open_tq.

[0160] Power Upshift Mode. Power upshift is the control process where, with the motor in drive mode, the clutch transitions from engagement of the first clutch to engagement of the second clutch. Power upshift control consists of two processes: torque interaction and speed adjustment, performed sequentially. Torque interaction occurs first, and slip control is also performed during this process. Similar to the slip control in the transition phase, the target slip speed PUcontrol_slip_des for the power upshift process is set. Since the current speed is matched to gear 1, the slip speed difference slip_err used to calculate the clutch control torque is calculated using the speed of the first clutch, clu1_slip, as the control target.

[0161] slip_err=clu1_slip-PUcontrol_slip_des;

[0162] clu_moi_ofs=P_factor×slip_err×motor_inertia;

[0163] Where P_factor is the P-phase control coefficient, and motor_inertia is the sum of the rotational inertia of all rotating components from the drive motor to the clutch drive plate. The target torque of the clutch, clu_tq_des, is clu_tq_des = motor_tq_act + clu_moi_ofs. During this process, the torque of the first clutch gradually decreases over time, while the torque of the second clutch gradually increases over time. Throughout this process, the sum of the torques of the two clutches is always equal to the target torque, clu_tq_des. When the torque of the first clutch drops to 0, the torque interaction is complete. Next, speed matching is performed. Since the gear ratio of 1st gear is higher than that of 2nd gear, the output speed of the first clutch is higher than that of the second clutch. When the second gear bears torque, the high slippage and high torque result in significant slippage heat power, which can lead to clutch damage over time. Therefore, the speed of the clutch drive end needs to be adapted to the speed of the second gear clutch to reduce slippage and lower slippage power. During the speed matching stage, the speed of the clutch drive end needs to be matched to the speed of the second clutch. The target slippage is set, and the target clutch input speed is:

[0164] clu_ins_spd_des=clu2_ous_spd+PU_slip_des;

[0165] Converted to drive motor speed, motor_spd_req = clu_ins_spd_des × gear_ratio;

[0166] Therefore, during the speed matching phase, the drive motor needs to be controlled to enter speed control mode. The target speed of the drive motor is motor_spd_req, and the speed adjustment time can be calibrated. When the drive motor speed reaches the target speed, the speed adjustment phase is completed, and the entire power upshifting process ends.

[0167] Power downshifting mode. Power downshifting is the control process of transitioning the clutch from engagement of the second clutch to engagement of the first clutch while the motor is in drive mode. Power downshifting control consists of two processes: speed matching and torque interaction, performed sequentially. First, speed matching is performed. Since the second gear ratio is lower than the first gear, the output speed of the second clutch is lower than that of the first clutch. At this time, the clutch input speed matches the second clutch speed but is lower than the first clutch speed. If clutch switching is performed at this point, the clutch cannot transmit power. Therefore, it is necessary to first increase the clutch input speed. The target clutch input speed control is the first clutch speed, with a target slip set. The clutch input speed target clu_ins_spd_des is clu_ins_spd_des = clu1_ous_spd + PD_slip_des. Converted to the drive motor speed, motor_spd_req = clu_ins_spd_des × gear_ratio. Therefore, during the speed matching stage, the drive motor needs to be controlled to enter speed control mode. The target drive motor speed is motor_spd_req, and the speed adjustment time can be calibrated. When the drive motor speed reaches the target speed, the speed regulation phase is complete. Next, the torque interaction process begins, which involves slip control. First, the target slip speed PD_slip_des for the power downshift process is set. Since the current speed is matched to gear 1, the speed of the first clutch is used as the control target when calculating the slip speed difference used to calculate the clutch control torque.

[0168] slip_err=clu1_slip-PDcontrol_slip_des;

[0169] clu_moi_ofs=P_factor×slip_err×motor_inertia;

[0170] Where P_factor is the P-phase control coefficient, and motor_inertia is the sum of the rotational inertia of all rotating components from the drive motor to the clutch drive plate. The target torque of the clutch is clu_tq_des = motor_tq_act + clu_moi_ofs. During this process, the torque of the second clutch gradually decreases over time, while the torque of the first clutch gradually increases over time. Throughout this process, the sum of the torques of the two clutches always equals the target clutch torque clu_tq_des. When the torque of the second clutch drops to 0, the torque interaction is complete. The entire power downshifting process ends.

[0171] Coasting upshift mode. Coasting upshift is the control process that transitions the clutch from engaging the first clutch to engaging the second clutch when the motor is in generator (reverse drag) mode. Coasting upshift control consists of two processes: speed adjustment and torque interaction, performed sequentially. First, speed adjustment occurs. Since the first gear ratio is higher than the second gear, the output speed of the first clutch is higher than that of the second clutch. At this time, the input speed of the clutch matches the speed of the first clutch and is higher than that of the second clutch. Because the clutch is in reverse drag mode, torque is transmitted from the rear end of the clutch to the front end. If the clutch is switched at this time, the clutch cannot transmit power. Therefore, it is necessary to first reduce the speed at the clutch input end. The target speed control for the clutch input end is the speed of the second clutch. A target slip is set, and the target clutch input speed is clu_ins_spd_des = clu2_ous_spd - MU_slip_des. Converted to the drive motor speed, this is motor_spd_req = clu_ins_spd_des × gear_ratio. Therefore, during the speed matching phase, the drive motor needs to be controlled into speed control mode, with the target speed of the drive motor being motor_spd_req. The speed adjustment time can be calibrated. When the drive motor speed reaches the target speed, the speed adjustment phase is complete. Next, the torque interaction process begins, which involves slip control. The target slip speed MU_slip_des for the coasting upshifting process is first set. Since the current speed matching is in gear 2, the speed of the second clutch is used as the control target when calculating the slip speed difference used to calculate the clutch control torque.

[0172] slip_err=clu2_slip-PDcontrol_slip_des;

[0173] clu_moi_ofs=P_factor×slip_err×motor_inertia;

[0174] Where P_factor is the P-phase control coefficient, and motor_inertia is the sum of the rotational inertia of all rotating components from the drive motor to the clutch drive plate. The target torque of the clutch is clu_tq_des = |motor_tq_act| + clu_moi_ofs. During this process, the torque of the second clutch gradually decreases over time, while the torque of the first clutch gradually increases over time. Throughout this process, the sum of the torques of the two clutches always equals the target clutch torque clu_tq_des. When the torque of the first clutch drops to 0, the torque interaction is complete. The entire coasting upshifting process ends.

[0175] Coasting downshift mode. Coasting downshift is the control process that transitions the clutch from engagement of the second clutch to engagement of the first clutch when the motor is in generator (reverse drag) mode. Coasting downshift control consists of two processes: torque interaction and speed adjustment, performed sequentially. Torque interaction occurs first, and slip control is also performed during this process. Similar to the slip control in the transition phase, the target slip speed MDcontrol_slip_des for the coasting downshift process is set. Since the current speed is matched to gear 2, the speed difference of the second clutch is used as the control target when calculating the slip speed difference used to calculate the clutch control torque. That is:

[0176] slip_err=clu2_slip-PUcontrol_slip_des:

[0177] clu_moi_ofs=P_factor×slip_err×motor_inertia:

[0178] Where P_factor is the P-phase control coefficient, and motor_inertia is the sum of the rotational inertia of all rotating components from the drive motor to the clutch drive plate. The target torque of the clutch is clu_tq_des = |motor_tq_act| + clu_moi_ofs. During this process, the torque of the second clutch gradually decreases over time, while the torque of the first clutch gradually increases over time. Throughout this process, the sum of the torques of the two clutches is always equal to the target torque clu_tq_des. When the torque of the second clutch drops to 0, the torque interaction is complete. Next, speed matching is performed. Since the speed ratio of 2nd gear is lower than that of 1st gear, the output speed of the second clutch is lower than that of the first clutch. When 1st gear bears torque, due to the high slippage and high torque, there is a huge slippage heat power, which can lead to clutch damage after long-term operation. Therefore, the speed of the clutch drive end needs to be adapted to the speed end of the 1st gear clutch to reduce slippage and thus reduce slippage power. During the speed matching phase, the speed of the clutch's driving end needs to be matched to the speed of the first clutch. A target slip is set, with the clutch input speed target being clu_ins_spd_des = clu1_ous_spd - PU_slip_des. Converted to the drive motor speed, this is motor_spd_req = clu_ins_spd_des × gear_ratio. Therefore, during the speed matching phase, the drive motor needs to enter speed control mode, with the target speed set as motor_spd_req. The speed adjustment time can be calibrated. Once the drive motor speed reaches the target speed, the speed adjustment phase is complete, and the entire coasting downshifting process ends.

[0179] For the slip-wear control mode, the purpose is to control the clutch to operate in a micro-slip-wear state. In this mode, the indicated torque of the clutch equals the output torque, which, in conjunction with the output torque of the drive motor, allows for better control of the drive motor's speed. Under this control mode, the target torque of the clutch in the current gear is the drive motor's output torque plus the slip-wear speed control torque, i.e.: clu_tq_des = motor_tq_act + clu_moi_ofs. Here, clu_moi_ofs is the clutch slip-wear speed control torque. The slip-wear speed control torque utilizes the P-phase control principle, setting a basic target slip-wear speed and calculating the slip-wear speed difference used to calculate the clutch control torque: slip_err = clu_slip - slip_des, clu_moi_ofs = P_factor × slip_err × motor_inertia. P_factor is the P-phase control coefficient, and motor_inertia is the sum of the rotational inertia of all rotating components from the drive motor to the clutch's driving disc. In this mode, the non-working clutch torque is 0.

[0180] In application, during clutch control based on the target shift mode, the calculation process for the target duty cycle of the clutch pump motor is as follows:

[0181] Based on the target torque clu_tq_des of each clutch calculated for each working state in step S106, the target pressure clu_prs_des to be executed by the clutch is calculated by looking up the table; based on the clutch pressure signal vbi_clu_prs obtained by the sensor, the actual output torque clu_tq_est of the clutch is calculated.

[0182] First, it's necessary to determine the pressure value at which each clutch outputs zero torque, which is the half-clutch point (clu_kisspoint_prs). Then, based on the collected oil temperature signal (oil_temp) and the corresponding clutch slip speed (clu_slip), the target pressure (clu_prs_wotkissp) is obtained by looking up a table using the linear difference. The actual target pressure for clutch operation is:

[0183] clu_prs_des = clu_prs_wotkissp + clu_kisspoint_prs. Based on the collected clutch pressures vbi_clu_prs, the pressure value for lookup is calculated as clu_prs_tqcal = vbi_clu_prs - clu_kisspoint_prs. Then, based on the collected oil temperature signal oil_temp and the corresponding clutch slip speed clu_slip, the clutch output torque clu_tq_est is obtained by looking up the table using the linear difference.

[0184] Based on the clutch target pressure clu_prs_des calculated in step S106, the feedforward speed clu_spdtar_before of the clutch pump is calculated by looking up a table; based on the clutch pressure vbi_clu_prs obtained from the sensor, the pressure difference prs_err used for PI control is calculated between the target pressure and prs_perr = clu_prs_des - vbi_clu_prs. The pressure P-phase controlled speed clu_spdtar_Pcontrol = prs_err × P_factor_prsctl, where P_factor_prsctl is the P-phase control coefficient; the pressure I-phase controlled speed clu_spdtar_Icontrol = prs_err × I_factor_prsctl, and this is integrated and accumulated, where I_factor_prsctl is the I-phase control coefficient; finally, the target speed executed by the clutch is:

[0185] clu_spd_ctrl_des=clu_spdtar_before+clu_spdtar_Pcontrol+I_factor_prsctl.

[0186] Based on the target clutch pump speed clu_spd_ctrl_des calculated in step S106, the feedforward duty cycle signal clu_dtytar_before of the clutch motor is calculated by looking up a table; based on the clutch pump motor speed vbi_clu_motor_spd obtained from the sensor, the pump speed difference spd_err used for PI control is calculated between the target speed and spd_err = clu_spd_ctrl_des - vbi_clu_motor_spd. The P-phase speed control duty cycle clu_dtytar_Pcontrol = spd_err × P_factor_dtyctl, where P_factor_dtyctl is the P-phase control coefficient; the I-phase speed control duty cycle clu_dtytar_Icontrol = spd_err × I_factor_dtyctl, and is integrated and accumulated, where I_factor_dtyctl is the I-phase control coefficient; finally, the target duty cycle executed by the clutch is:

[0187] clu_dty_ctrl_des=clu_dtytar_before+clu_dtytar_Pcontrol+clu_dtytar_Icontrol.

[0188] Through the above six steps, the control objective of shifting gears and maintaining the current gear position according to the driver's intention was achieved. The drive assembly simulation test data is as follows: Figure 9 As shown.

[0189] like Figure 10 As shown in the embodiment of this application, the electric drive assembly shift control device 100 equipped with a two-speed dual-clutch transmission includes:

[0190] Data acquisition module 101 is used to acquire vehicle operation data;

[0191] The shift strategy determination module 102 is used to calculate the target gear based on vehicle operating data and determine the shift strategy type based on the target gear.

[0192] Calculation module 103 is used to calculate the clutch slippage speed based on vehicle operating data;

[0193] The operating mode determination module 104 is used to determine the operating mode of the electric drive system based on the driver's required torque, the actual output torque of the motor, and the clutch slippage speed.

[0194] The target shift mode determination module 105 is used to determine the target shift mode based on the vehicle speed and the operating mode of the electric drive system.

[0195] The shift execution module 106 is used to perform PI calculation on the target duty cycle of the clutch pump motor based on the target shift mode, the target torque of the clutch and the target pressure of the clutch in the target shift mode, and perform clutch control based on the calculated target duty cycle of the clutch pump motor to complete the shift.

[0196] In applications, the modules in the shift control device of an electric drive assembly equipped with a two-speed dual-clutch transmission can be software program modules, or they can be implemented through different logic circuits integrated in a processor, or they can be implemented through multiple distributed processors.

[0197] like Figure 11 As shown, this application embodiment also provides an electronic device 200, including: at least one processor 201 ( Figure 11 The diagram shows only one processor, memory 202, and computer program 203 stored in memory 202 and executable on at least one processor 201. When processor 201 executes computer program 203, it implements the steps in the various method embodiments described above.

[0198] In applications, electronic devices may include, but are not limited to, processors and memory. Those skilled in the art will understand that... Figure 11 This is merely an example of an electronic device and does not constitute a limitation on the electronic device. It may include more or fewer components than shown, or a combination of certain components, or different components.

[0199] In applications, the processor can be a Central Processing Unit (CPU), but it can also be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor can be a microprocessor or any conventional processor.

[0200] In applications, memory can be an internal storage unit of an electronic device in some embodiments, such as a hard drive or RAM. In other embodiments, memory can be an external storage device of the electronic device, such as a plug-in hard drive, Smart Media Card (SMC), Secure Digital (SD) card, or Flash Card. Furthermore, memory can include both internal and external storage units of the electronic device. Memory is used to store operating systems, applications, bootloaders, data, and other programs, such as program code for computer programs. Memory can also be used to temporarily store data that has been output or will be output.

[0201] It should be noted that the information interaction and execution process between the above-mentioned devices / units are based on the same concept as the method embodiments of this application. For details on their specific functions and technical effects, please refer to the method embodiments section, and they will not be repeated here.

[0202] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is merely an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit. Furthermore, the specific names of the functional units and modules are only for easy differentiation and are not intended to limit the scope of protection of this application. The specific working process of the units and modules in the above system can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0203] This application also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps described in the various method embodiments above.

[0204] This application provides a computer program product, including a computer program, which, when run on an electronic device, enables the electronic device to perform the steps described in the various method embodiments above.

[0205] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the methods of the above embodiments of this application can be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. A computer-readable medium can include at least: any entity or device capable of carrying computer program code to a device / electronic device, a recording medium, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier signal, a telecommunication signal, and a software distribution medium. Examples include USB flash drives, portable hard drives, magnetic disks, or optical disks. In some jurisdictions, according to legislation and patent practice, computer-readable media cannot be electrical carrier signals or telecommunication signals.

[0206] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0207] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0208] In the embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative. For instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0209] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0210] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A shift control method for an electric drive assembly equipped with a two-speed dual-clutch transmission, characterized in that, include: Obtain vehicle operation data; The target gear is calculated based on the vehicle operation data, and the shift strategy type is determined based on the target gear. Calculate the clutch slippage speed based on the vehicle operating data; The operating mode of the electric drive system is determined based on the driver's required torque, the actual output torque of the motor, and the clutch slippage speed. The target shift mode is determined based on the vehicle speed and the operating mode of the electric drive system; Based on the target shift mode, the target duty cycle of the clutch pump motor is calculated using PI based on the target torque and target pressure of the clutch under the target shift mode. Clutch control is then performed based on the calculated target duty cycle of the clutch pump motor to complete the shift. The determination of the electric drive system operating mode based on the driver's required torque, the actual output torque of the motor, and the clutch slippage speed includes: When the clutch slippage speed in the current gear is greater than the first threshold, the driver's required torque is greater than the second threshold, and the motor output torque is greater than the third threshold, the electric drive system is determined to be in drive mode. When the clutch slippage speed in the current gear is less than the fourth threshold, the driver's required torque is less than the fifth threshold, and the motor output torque is less than the sixth threshold, the electric drive system is determined to be in coasting mode. The target shift modes include first gear lock mode, second gear lock mode, power upshift mode, power downshift mode, coasting upshift mode, and coasting downshift mode; Determining the target shift mode based on vehicle speed and the operating mode of the electric drive system includes: When the vehicle speed is less than the preset minimum value, the target shift mode is determined to be the first gear lock mode; When the vehicle speed exceeds the preset high limit, the target shift mode is determined to be the second gear lock mode; When the preset lower limit value ≤ vehicle speed ≤ preset upper limit value, the vehicle is in drive mode, and the shift strategy type is upshift, the target shift mode is determined to be power upshift mode. When the preset lower limit value ≤ vehicle speed ≤ preset upper limit value, the vehicle is in drive mode, and the shift strategy type is downshift, the target shift mode is determined to be power downshift mode. When the preset lower limit value ≤ vehicle speed ≤ preset upper limit value, the vehicle is in coasting mode, and the shift strategy type is upshift, the target shift mode is determined to be coasting upshift mode. When the preset lower limit value ≤ vehicle speed ≤ preset upper limit value, the vehicle is in coasting mode, and the shift strategy type is downshifting, the target shift mode is determined to be coasting downshifting mode. The step of performing a PI calculation on the target duty cycle of the clutch pump motor based on the target clutch torque and target clutch pressure under the target shift mode includes: Based on the clutch pressure and the target clutch pressure, the target speed of the clutch pump is obtained through PI calculation. Based on the clutch pump speed and the target speed of the clutch pump in the vehicle operating data, the target duty cycle of the clutch pump motor is obtained through PI calculation. The step of obtaining the target speed of the clutch pump through PI calculation based on the clutch pressure and the target clutch pressure includes: Based on the clutch target torque and clutch slip rate difference in the target shift mode, the corresponding clutch target pressure is obtained by looking up the table. Based on the clutch target pressure and cooling oil temperature, the clutch oil pump feedforward target speed is obtained by referring to the table. Based on the clutch pressure, the clutch target pressure, and the clutch oil pump feedforward target speed in the vehicle operating data, the clutch pump target speed is obtained through PI calculation. The step of obtaining the target duty cycle of the clutch pump motor through PI calculation based on the clutch pump speed and the target speed of the clutch pump in the vehicle operating data includes: Based on the target speed of the clutch pump and the temperature of the cooling oil, the target duty cycle of the clutch oil pump motor feedforward is obtained by referring to the table. Based on the clutch pump speed, the clutch pump target speed, and the clutch oil pump motor feedforward target duty cycle in the vehicle operation data, the clutch pump motor target duty cycle is obtained through PI calculation.

2. The shift control method for an electric drive assembly equipped with a two-speed dual-clutch transmission as described in claim 1, characterized in that, The step of calculating the target gear based on the vehicle operating data and determining the shift strategy type based on the target gear includes: Based on the driver's required torque, consult the shift critical speed table to obtain the critical speeds for upshifting and downshifting; When the vehicle speed is greater than the upshift threshold speed, the shift strategy type is determined to be upshift; When the vehicle speed is less than the downshift threshold speed, the shift strategy type is determined to be downshift; The vehicle operating data includes driver-demanded torque data and vehicle speed data.

3. The shift control method for an electric drive assembly equipped with a two-speed dual-clutch transmission as described in claim 1, characterized in that, Also includes: During the clutch control process based on the target shift mode, if the target gear is inconsistent with the current gear, the slipping control mode is entered until the target gear is the same as the actual gear and the clutch slipping speed difference in the current gear is less than the preset difference threshold. Then the slipping control mode is exited and the current gear is locked. The sliding wear control conditions include: Based on the operating mode of the electric drive system, the calibrable target sliding grinding speed is determined; The slippage offset speed difference is calculated based on the clutch slippage speed and the calibrable target slippage speed. The principle of P-phase control is used to calculate the torque for adjusting the sliding grinding speed; Based on the output torque of the drive motor and the sliding speed regulation torque, the target torque of the clutch under the sliding control condition is calculated. Clutch control is performed based on the target clutch torque under the aforementioned slip control condition.

4. The shift control method for an electric drive assembly equipped with a two-speed dual-clutch transmission as described in claim 1, characterized in that, Also includes: During clutch control based on the target shift mode: When the target shift mode is first gear locked mode, the second clutch is fully open and no torque is transmitted; The first clutch adds a lock-up compensation torque to the actual torque of the drive motor. When the target shift mode is the second gear lock mode, the first clutch is fully open and no torque is transmitted; The second clutch adds a lock-up compensation torque to the actual torque of the drive motor. When the target shift mode is power upshift mode, the torque interaction stage is entered, and the torque of the first clutch is gradually reduced to zero while the torque of the second clutch gradually increases. When the speed regulation stage is entered, the drive motor is controlled to enter the speed mode, so that the target speed of the drive motor is the sum of the output shaft speed of the second clutch and the set power upshift target slip speed. When the target shift mode is power downshift mode, the speed regulation stage is entered, and the drive motor is controlled to enter the speed mode so that the target speed of the drive motor is the sum of the output shaft speed of the first clutch and the set power downshift target slip speed. Entering the torque interaction phase, the torque of the second clutch gradually decreases to zero, while the torque of the first clutch gradually increases. When the target shift mode is coasting upshift mode, the speed regulation stage is entered, and the drive motor is controlled to enter the speed mode, so that the target speed of the drive motor is the output shaft speed of the second clutch minus the set coasting downshift target sliding speed. Entering the torque interaction phase, the torque of the first clutch gradually decreases to zero, while the torque of the second clutch gradually increases. When the target shift mode is coasting downshift mode, the torque interaction stage is entered, and the torque of the second clutch is gradually reduced to zero while the torque of the first clutch gradually increases. When the speed regulation stage is entered, the drive motor is controlled to enter the speed mode, so that the target speed of the drive motor is the output shaft speed of the first clutch minus the set coasting downshift target slip speed.

5. An electronic device, characterized in that, The device includes a processor, a memory, and a computer program stored in the memory and executable on the processor, characterized in that, when the processor executes the computer program, the electronic device performs the method as described in any one of claims 1-4.

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