A high-speed dual-motor dual-shaft input electric drive axle box system for vehicles and a gear shifting control method thereof

Abstract

This application relates to the field of vehicle drive system technology, and in particular to a high-speed dual-motor dual-axis input electric drive axle system for automobiles and its shift control method. The system includes two high-speed drive motors and an electromechanical electric drive axle structure. The electric drive axle achieves multi-gear power transmission and switching through multiple gear pairs, output shafts, and engagement sleeves. The two motors independently input power, which is output to the main reduction mechanism and then into the differential via their respective transmission paths, enabling left and right wheel drive. Selective engagement of the engagement sleeves and gears allows for low-speed, medium-speed, and high-speed multi-gear switching, and supports reverse gear and regenerative braking. The shift control method is executed collaboratively by the vehicle controller and the transmission control unit, achieving uninterrupted gear shifting through synchronized speed control, smooth torque adjustment, and coordinated actuator action. This system has a compact structure, flexible control, and can improve the vehicle's power performance, economy, and energy utilization efficiency.

Description

Technical Field

[0001] This application relates to the field of vehicle drive system technology, and in particular to a high-speed dual-motor dual-axis input electric drive axle system for vehicles and its shift control method. Background Technology

[0002] With the development of new energy vehicles, dual-motor drive systems are increasingly being applied to improve the overall vehicle power and energy efficiency. Current technologies often employ a single motor paired with a fixed reduction gear or a single-path multi-speed transmission structure to achieve vehicle drive.

[0003] However, under high-speed or high-torque conditions, existing dual-motor or single-motor drive systems generally suffer from the following problems: Existing drive systems often struggle to achieve independent and coordinated output and synchronous control of dual motors at different gears, especially during gear shifting, which can lead to problems such as uneven power delivery, large output shocks, and low energy utilization efficiency.

[0004] Therefore, how to achieve coordinated drive control of dual motors under multiple gear conditions and achieve smooth power transition during gear shifting has become a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0005] The purpose of this invention is to provide a high-speed dual-motor dual-axis input electric drive axle box system for vehicles and its shift control method, so as to solve the problems of insufficient dual-motor cooperative control capability and uneven power connection during shifting in the prior art.

[0006] This application provides a high-speed dual-motor dual-axis input electric drive axle system for vehicles, which adopts the following technical solution: including: High-speed motors with three gears (10) and high-speed motors with two and four gears (30); Electromechanical drive axle box; The electromechanical electric drive axle housing includes: The first and third high-speed gear pair consists of a first and third high-speed driving gear (8) and a first and third high-speed driven gear (6); The second and fourth gear high-speed gear pair consists of a second and fourth gear high-speed driving gear (28) and a second and fourth gear high-speed driven gear (26); A first gear pair, which consists of a first driving gear (5) and a first driven gear (11); The second gear pair consists of a second driving gear (25) and a second driven gear (17); The three-speed gear pair consists of a three-speed driving gear (4) and a three-speed driven gear (1); The four-speed gear pair consists of a four-speed driving gear (24) and a four-speed driven gear (21); The main reduction gear pair includes a first and third gear main reduction drive gear (12), a second and fourth gear main reduction drive gear (18), and a main reduction driven gear (20). The main reduction driven gear (20) meshes with both the first and third gear main reduction drive gear (12) and the second and fourth gear main reduction drive gear (18). The first and third gear coupling sleeve (2) and the second and fourth gear coupling sleeve (22); Input shafts for first and third gears (7), input shafts for second and fourth gears (27), intermediate shafts for first and third gears (3), intermediate shafts for second and fourth gears (23), output shafts for first and third gears (13) and output shafts for second and fourth gears (19); Differential (15), left half shaft (14) and right half shaft (16); in: The first and third speed high-speed motors (10) are driven and connected to the first and third speed input shafts (7), and the second and fourth speed high-speed motors (30) are driven and connected to the second and fourth speed input shafts (27). The first and third gear engagement sleeve (2) is set on the first and third gear output shaft (13) and is used to selectively connect the first gear driven gear (11) or the third gear driven gear (1). The second and fourth gear engagement sleeve (22) is set on the second and fourth gear output shaft (19) and is used to selectively connect the second gear driven gear (17) or the fourth gear driven gear (21). The system uses an electronic control module to perform independent closed-loop control of the speed and torque of the two motors, and controls the action of the coupling sleeve based on the output shaft speed synchronization condition during gear shifting, so as to realize dual-motor dual-path coordinated drive and gear shifting without power interruption.

[0007] A shift control method for a high-speed dual-motor dual-axis input electric drive axle system for automobiles includes the following steps: S1: Dual Motor Initialization Drive Steps Control the first and third speed high-speed motors (10) and the second and fourth speed high-speed motors (30) to enter the same output state, and establish independent speed and torque closed-loop control; S2: Low-speed gear control steps Control the engagement of the first and third gear engagement sleeve (2) with the first gear driven gear (11), and control the engagement of the second and fourth gear engagement sleeve (22) with the second gear driven gear (17) to achieve dual motor low-speed drive; S3: Intermediate Gear Control Steps Control the engagement of the first and third gear engagement sleeve (2) with the third gear driven gear (1), and control the engagement of the second and fourth gear engagement sleeve (22) with the second gear driven gear (17) to achieve the intermediate gear drive of the dual motors; S4: High-speed gear control steps Control the engagement of the first and third gear engagement sleeve (2) with the third gear driven gear (1), and control the engagement of the second and fourth gear engagement sleeve (22) with the fourth gear driven gear (21) to achieve high-speed drive of dual motors; S5: Speed ​​Synchronization Shifting Procedure During gear shifting, the output shaft speed difference is detected. When the speed difference between the first and third gear output shafts (13) and the second and fourth gear output shafts (19) meets the preset synchronization conditions, the coupling sleeve is controlled to complete the engagement or disengagement, thus achieving shock-free gear shifting. S6: Braking Energy Recovery Steps Under braking conditions, the two motors are reverse-driven by the differential (15) to enter the power generation state, thereby realizing the recovery of braking energy; S7: Reverse Gear Control Steps Control the first and third speed high-speed motors (10) and the second and fourth speed high-speed motors (30) to rotate in opposite directions, and combine the locking state of the first and second gear pairs to realize the vehicle reversing drive.

[0008] Optionally, the dual-motor low-speed mode includes the following steps: S1: Gear Setting Steps Control the engagement of the first and third gear engagement sleeve (2) with the first gear driven gear (11), so that the first gear driven gear (11) is fixedly connected to the first and third gear output shaft (13); S2: Gear Activation Steps Control the engagement of the second and fourth gear engagement sleeve (22) with the second gear driven gear (17), so that the second gear driven gear (17) is fixedly connected to the second and fourth gear output shaft (19); S3: Drive Output Steps Control the first and third speed high-speed motors (10) and the second and fourth speed high-speed motors (30) to output power in the same direction; S4: Power Transmission Steps The first and third gear motor paths pass sequentially through the first and third gear input shaft (7), the first and third gear high-speed gear pair, the first gear pair, the first and third gear coupling sleeve (2), the first and third gear output shaft (13), the first and third gear main reduction gear pair and the differential (15) for output; The second and fourth gear motor paths sequentially pass through the second and fourth gear input shaft (27), the second and fourth gear high-speed gear pair, the second gear pair, the second and fourth gear coupling sleeve (22), the second and fourth gear output shaft (19), the second and fourth gear main reduction gear pair and the differential (15) for output.

[0009] Optionally, the dual-motor intermediate mode includes the following steps: S1: Gear Shifting Steps Control the engagement of the first and third gear engagement sleeve (2) with the third gear driven gear (1); S2: Gear Shifting Steps Control the engagement of the second and fourth gear engagement sleeve (22) with the second gear driven gear (17); S3: Drive Control Steps The outputs of the first and third speed high-speed motors (10) and the second and fourth speed high-speed motors (30) are controlled respectively; S4: Power Output Steps The first and third gear motor paths are output to the first and third gear output shafts (13) via the third gear pair. The second and fourth gear motor paths are output to the second and fourth gear output shafts (19) via the second gear pair. The two power sources converge into the differential (15) via the main reduction gear pair for output.

[0010] Optionally, the dual-motor high-speed mode includes the following steps: S1: Gear Shifting Steps Control the engagement of the first and third gear engagement sleeve (2) with the third gear driven gear (1); S2: Gear Shifting Steps Control the engagement of the second and fourth gear engagement sleeve (22) with the fourth gear driven gear (21); S3: Drive Control Steps The outputs of the first and third speed high-speed motors (10) and the second and fourth speed high-speed motors (30) are controlled respectively; S4: Power Output Steps The first and third speed motors output power via a third-speed gear pair; The second and fourth speed motors output power via a fourth-speed gear pair; Finally, the output is fed into the differential (15) via the main reduction gear pair.

[0011] Optionally, the shift control process from the low speed gear to the intermediate and high speed gears of the dual motors includes the following steps: S1: Low gear disengagement procedure Release the engagement between the first gear pair and the first and third gear output shafts (13) to allow the first gear driven gear (11) to enter the idling state; S2: Speed ​​Synchronization Adjustment Steps Adjust the speed of the first and third speed high-speed motor (10) to synchronize the speed of the third driven gear (1) with the speed of the first and third output shaft (13); S3: Gear Combination Steps When the speed synchronization condition is met, the first and third gear engagement sleeve (2) is engaged with the third gear driven gear (1) to complete the intermediate gear switching; S4: Power Output Steps It can switch the power transmission path between the intermediate and high speeds of the dual motors and maintain the coordinated output of the dual motors.

[0012] Optionally, the shift control process from the intermediate gear to the low-speed and high-speed gears of the dual motors includes the following steps: S1: Exiting from intermediate mode Release the engagement between the second gear pair and the second and fourth gear output shafts (19), so that the second gear driven gear (17) enters the idling state; S2: Speed ​​Synchronization Adjustment Steps Adjust the speed of the second and fourth gear high-speed motor (30) so that the speed of the fourth gear driven gear (21) is synchronized with the speed of the second and fourth gear output shaft (19); S3: Gear Combination Steps When the speed synchronization condition is met, the control of the second and fourth gear engagement sleeve (22) and the fourth gear driven gear (21) are engaged to complete the high-speed gear switching; S4: Power Output Steps Complete the switching of power transmission path for high-speed mode of dual motors and maintain the coordinated output of dual motors.

[0013] Optionally, the energy recovery control method under vehicle braking conditions includes the following steps: S1: Braking Energy Input Steps During vehicle braking, the left and right half shafts (14, 16) are driven in opposite directions through the differential (15); S2: Power Reverse Driving Steps The braking force is transmitted to the first and third speed high-speed motors (10) and the second and fourth speed high-speed motors (30) through the main reduction gear pair. S3: Power Generation Control Steps Controlling the two motors to enter the power generation state converts mechanical energy into electrical energy to achieve energy recovery; S4: Braking Switching Steps When the battery level reaches a preset threshold, it switches to mechanical braking mode.

[0014] Optionally, the reverse gear control method includes the following steps: S1: Reverse Drive Steps Control the first and third speed high-speed motors (10) and the second and fourth speed high-speed motors (30) to enter the reverse rotation state; S2: Gear Locking Procedure Control the first gear pair and the second gear pair to lock with their respective output shafts; S3: Reverse Output Steps The vehicle reverses by driving the differential (15) through a dual-motor dual-path transmission system.

[0015] In summary, this application includes the following beneficial technical effects: 1. Achieve independent and coordinated drive control of dual motors By setting independent transmission paths for the first and third high-speed motors and the second and fourth high-speed motors respectively, the coordinated output of the two motors under different gear links can be achieved, thereby improving the flexibility of the vehicle's power output.

[0016] 2. Achieve efficient power distribution across multiple gears By combining first, second, third, and fourth gear pairs, efficient power matching is achieved across different speed ranges, thereby improving transmission efficiency.

[0017] 3. Improve shift smoothness By synchronously determining the engagement or disengagement of the control sleeve based on the output shaft speed, continuous power transition during gear shifting is achieved, reducing impact and improving driving smoothness.

[0018] 4. Improve system energy utilization efficiency During braking, the dual motors are reverse-drive by the differential to enter the power generation state, realizing brake energy recovery and improving the energy utilization efficiency of the whole vehicle.

[0019] 5. Possesses adaptability to multiple working conditions The system supports switching between multiple operating modes, including low speed, medium speed, high speed, and reverse gear, making it suitable for vehicle drive requirements under complex working conditions. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of the high-speed dual-motor dual-axis input electric drive bridge box provided by the present invention; The components include: 1. High-speed motor (first and third gears); 2. First and third gear coupling sleeve; 3. First and third gear intermediate shaft; 4. Third gear drive gear; 5. First gear drive gear; 6. First and third gear high-speed driven gear; 7. First and third gear input shaft; 8. First and third gear high-speed drive gear; 9. First and third gear high-speed motor output shaft; 10. First and third gear high-speed motor; 11. First gear driven gear; 12. First and third gear main reduction drive gear; 13. First and third gear output shaft; 14. Left half shaft; 15. Differential; 16. Right... Half-shaft, 17. Second gear driven gear, 18. Second and fourth gear main reduction drive gear, 19. Second and fourth gear output shaft, 20. Main reduction driven gear, 21. Fourth gear driven gear, 22. Second and fourth gear engagement sleeve, 23. Second and fourth gear intermediate shaft, 24. Fourth gear drive gear, 25. Second gear drive gear, 26. Second and fourth gear high-speed driven gear, 27. Second and fourth gear input shaft, 28. Second and fourth gear high-speed drive gear, 29. Second and fourth gear high-speed motor output shaft, 30. Second and fourth gear high-speed motor. Detailed Implementation

[0021] The present application will be further described in detail below with reference to the accompanying drawings. In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the present invention.

[0022] I. System Overall Structure The present invention provides a high-speed dual-motor dual-axis input electric drive axle system for vehicles, including a first and third-speed high-speed motor 10 and a second and fourth-speed high-speed motor 30.

[0023] The first and third speed high-speed motor 10 and the second and fourth speed high-speed motor 30 are connected to the electric drive axle box through flange connection structure to achieve coaxial power input.

[0024] The electric drive axle box is used to realize independent drive of dual motors with dual inputs, hierarchical transmission, and power confluence output.

[0025] The first and third speed high-speed motors 10 and the second and fourth speed high-speed motors 30 are respectively connected to the output shaft flange and the input shaft flange, and are rigidly connected by pre-tightening high-strength bolts, thereby ensuring no relative slippage under high-speed conditions.

[0026] II. Input Shaft Connection Structure The output shaft of the first and third speed high-speed motor 10 is connected to the first and third speed input shaft 7 by spline meshing and is fixed by axial locking nut to realize torque transmission.

[0027] The output shaft of the second and fourth speed high-speed motor 30 and the input shaft of the second and fourth speed motor 27 are rigidly coaxially connected by flange bolts.

[0028] A centering and positioning stop structure is set between the first and third gear input shaft 7 and the motor output shaft to ensure that the installation coaxiality error is no more than 0.02mm, so as to reduce high-speed vibration.

[0029] The second and fourth gear input shaft 27 is fixedly connected to the housing through a bearing support seat. Both ends of the input shaft are supported by bearings to achieve a double support arrangement and improve high-speed stability.

[0030] III. Gear and Shaft Connection Structure The first and third high-speed drive gears 8 are fixedly connected to the first and third speed input shafts 7.

[0031] The first and third high-speed driven gears 6 are rotated and sleeved on the first and third gear intermediate shafts 3, and their axial position is limited by an axial limiting structure.

[0032] The first gear drive gear 5 and the third gear drive gear 4 are fixedly connected to the first and third gear intermediate shaft 3.

[0033] The first gear driven gear 11 and the third gear driven gear 1 are rotatably mounted on the first and third gear output shafts 13.

[0034] The first and third gear output shaft 13 is fixedly connected to the first and third gear main reduction drive gear 12.

[0035] The second and fourth gear high-speed drive gear 28 is fixedly connected to the second and fourth gear input shaft 27.

[0036] The second and fourth gear high-speed driven gear 26 is rotated and mounted on the second and fourth gear intermediate shaft 23.

[0037] The second gear drive gear 25 and the fourth gear drive gear 24 are fixedly connected to the second and fourth gear intermediate shaft 23.

[0038] The second-gear driven gear 17 and the fourth-gear driven gear 21 are rotatably mounted on the second and fourth gear output shafts 19.

[0039] The second and fourth gear output shaft 19 is fixedly connected to the second and fourth gear main reduction drive gear 18.

[0040] The main reducer and driven gear 20 are fixedly connected to the differential 15.

[0041] All of the above gears are connected by keys or splines to transmit torque, and are axially limited by retaining rings or shaft shoulders to prevent axial movement.

[0042] IV. Connecting sleeve structure and actuator Both the first and third gear engagement sleeves 2 and the second and fourth gear engagement sleeves 22 are slidably mounted on the corresponding output shafts, and achieve synchronous rotation and axial sliding with the output shafts through a spline structure.

[0043] The coupling sleeve is driven to move axially by an electronically controlled actuator.

[0044] The electronically controlled actuator includes a hydraulic drive mechanism or an electric lead screw drive mechanism, used to move the engagement sleeve axially to the target gear engagement or disengagement position.

[0045] The coupling sleeve is equipped with a synchronous gear ring structure, which engages with the output shaft through an external spline and meshes with the target gear through an internal spline to achieve power locking or release.

[0046] The output end of the actuator is connected to the shift fork mechanism, and the shift fork achieves precise axial control through the guide groove.

[0047] V. Differential and Half-Shaft Structure Differential 15 is used to distribute power to the left and right drive wheels.

[0048] Differential 15 drives the left half-shaft 14 and the right half-shaft 16 to output power.

[0049] The left half-shaft 14 and the right half-shaft 16 are supported and positioned by the axle housing structure and are engaged with the output end of the differential.

[0050] The differential 15 includes a cross shaft structure, four planetary bevel gears, and left and right half shaft gears. The planetary gears are supported on the cross shaft by needle roller bearings to achieve differential distribution.

[0051] VI. Control System Structure The system includes the vehicle control unit (VCU) and the transmission control unit (TCU).

[0052] The control system performs independent closed-loop control on the first and third speed high-speed motor 10 and the second and fourth speed high-speed motor 30 respectively.

[0053] The control parameters include motor speed, output torque, and speed difference.

[0054] The speed signal is acquired by a speed sensor located at the end of the output shaft and fed back to the control unit to form a closed-loop control.

[0055] The VCU calculates the target drive torque based on the throttle opening, vehicle speed, and battery SOC, and sends the result to the TCU for gear and motor coordinated control.

[0056] The TCU dynamically adjusts the motor speed using a PI control algorithm, enabling the output shaft on the target gear side to enter the synchronization window.

[0057] VII. Gear Shifting Control Method The shift control method is executed collaboratively by the VCU and TCU to achieve multi-gear switching without power interruption.

[0058] S1: Operation Status Acquisition Steps Speed ​​signals are collected by speed sensors located at the ends of the first and third gear output shafts 13 and the second and fourth gear output shafts 19, and motor speed and torque information are also collected.

[0059] The sampling period is 1~5ms to ensure the real-time performance of high-speed shift control.

[0060] S2: Gear Recognition and Target Gear Determination Steps The current gear is determined based on the current state of engagement sleeve 2 and engagement sleeve 22.

[0061] The gear position is confirmed in real time by feedback from the engagement sleeve position sensor (magnetic encoder or Hall sensor).

[0062] S3: Speed ​​Pre-control Steps The controller performs closed-loop speed regulation on the target motor.

[0063] Output torque control is achieved by adjusting the q-axis current of the motor, so that the output shaft speed gradually approaches the synchronous speed.

[0064] S4: Synchronization Determination Steps When the speed difference between the two output shafts is less than the threshold, the gear shift preparation begins.

[0065] The synchronization threshold is ±5 to ±20 rpm.

[0066] Synchronization determination is combined with acceleration rate of change determination to avoid misjudging transient synchronization.

[0067] S5: Actuator Action Steps Drive the engagement sleeve 2 or 22 to move axially.

[0068] The shift fork generates linear motion under the action of a hydraulic cylinder or a motor-driven lead screw, and the guide groove limits the sway to achieve stable engagement.

[0069] S6: Torque Compensation Control Steps Torque is smoothly controlled during gear shifts.

[0070] A feedforward + feedback composite control method is adopted to limit the output torque of the motor by a ramp, so as to avoid impact loads.

[0071] S7: Gear Shift Completion Steps Once the engagement sleeve is fully engaged and stable, confirm that the gear shift is complete.

[0072] The system enters steady-state closed-loop control mode and locks the current gear position.

[0073] VIII. Implementation Method of Low-Speed ​​Gear Control When operating at low speed: The first gear driven gear 11 is locked to the third gear output shaft 13 by the coupling sleeve 2.

[0074] The second-gear driven gear 17 and the second and fourth-gear output shafts 19 are locked together by a coupling sleeve 22.

[0075] The power path is as follows: First and third speed high-speed motor 10 outputs power → first and third speed input shaft 7 → first and third speed high-speed drive gear 8 → first and third speed high-speed driven gear 6 → first speed drive gear 5 → first speed driven gear 11 → engagement sleeve 2 locks → first and third speed output shaft 13 → first and third speed main reduction drive gear 12 → main reduction driven gear 20 → differential 15 → left half shaft 14 / right half shaft 16 output.

[0076] The same applies to the second and fourth gears: Second and fourth gear high-speed motor 30 output power → Second and fourth gear input shaft 27 → Second and fourth gear high-speed drive gear 28 → Second and fourth gear high-speed driven gear 26 → Second gear drive gear 25 → Second gear driven gear 17 → Engaging sleeve 22 lock → Second and fourth gear output shaft 19 → Second and fourth gear main reduction drive gear 18 → Main reduction driven gear 20 → Differential 15 → Left and right half shaft output.

[0077] IX. Implementation Method of Intermediate-Level Control In the middle setting: First and third gear side: 10 High-speed motor (first and third gears) → Input shaft 7 → Drive gear 8 → Driven gear 6 → Third-speed drive gear 4 → Third-speed driven gear 1 → Engaging sleeve 2 (locked) → Output shaft 13 → Main reduction gear 12 → Differential 15.

[0078] Second and fourth gear side: Second and fourth speed high-speed motor 30 → Input shaft 27 → Drive gear 28 → Driven gear 26 → Second speed drive gear 25 → Second speed driven gear 17 → Engaging sleeve 22 (locked) → Output shaft 19 → Main reduction gear 18 → Differential 15.

[0079] At this time, the two motors bear different load proportions, and the VCU allocates the torque proportion in real time according to the load to achieve optimal power allocation.

[0080] 10. Implementation Method of High-Speed ​​Gear Control In high speed mode: First and third gear side: 10. High-speed motor with three gears → Input shaft 7 → Drive gear 8 → Driven gear 6 → Third gear drive gear 4 → Third gear driven gear 1 → Engaging sleeve 2 → Output shaft 13 → Main reduction gear 12 → Differential 15.

[0081] Second and fourth gear side: 2nd and 4th speed high-speed motor 30 → Input shaft 27 → Drive gear 28 → Driven gear 26 → 4th speed drive gear 24 → 4th speed driven gear 21 → Engaging sleeve 22 → Output shaft 19 → Main reduction gear 18 → Differential 15.

[0082] In this mode, both motors operate in the high-efficiency range, and the high-speed driving capability of the whole vehicle is improved by speed superposition.

[0083] XI. Implementation Methods of Braking Energy Recovery During braking, power is transmitted in the reverse direction: Left half-shaft 14 / Right half-shaft 16 → Differential 15 → Main reduction gear 20 → Output shaft 13 / 19 → Gear pair reverse transmission → Motor enters generator mode.

[0084] The motor controller achieves regenerative braking torque control by adjusting the d-axis current.

[0085] When the SOC reaches its limit, the system automatically switches to mechanical braking mode and cuts off the motor's generator circuit.

[0086] 12. Reverse Gear Control Implementation Method When in reverse: The first and third speed high-speed motor 10 and the second and fourth speed high-speed motor 30 rotate in opposite directions.

[0087] The first gear pair and the second gear pair are locked respectively.

[0088] Power path: Motor → Input shaft → Gear pair → Output shaft → Main reducer → Differential → Half shaft output reverse drive.

[0089] Reverse gear control sends a reverse command through the VCU and limits the vehicle speed to avoid the shock of changing direction.

[0090] Thirteen, the shift control method adopts a state machine-based control structure. The vehicle controller (VCU) establishes a multi-state operation model, and the transmission control unit (TCU) executes the shift action according to the state machine instructions.

[0091] The state machine includes low gear state, intermediate gear state, high gear state, reverse gear state, and regenerative braking state. The states are switched through preset state transition conditions.

[0092] The state transition conditions include vehicle speed, motor speed, output shaft speed difference, coupling sleeve position feedback signal, and battery state of charge (SOC).

[0093] When the target gear entry conditions are met, the VCU outputs the target gear control command to the TCU, and the TCU executes the corresponding gear shifting logic.

[0094] The safety protection state has the highest priority and is used to forcibly interrupt gear shifting and enter safe mode operation under abnormal operating conditions.

[0095] XIV. The first and third speed high-speed motor 10 and the second and fourth speed high-speed motor 30 both operate using vector control.

[0096] Vector control includes a three-level closed-loop control structure consisting of current loop control, torque loop control, and speed loop control.

[0097] The current loop is used to adjust the d-axis current and q-axis current, the torque loop is used to control the output torque, and the speed loop is used to control the motor output speed.

[0098] After the VCU outputs the target drive torque, the TCU converts the target torque into a q-axis current reference value and drives the inverter to output control signals through PWM modulation.

[0099] During gear shifting, a smooth power transition is achieved by limiting the rate of torque change, thus avoiding impact loads.

[0100] 15. During the shift synchronization control process, the system performs synchronization control based on the real-time speed difference between the first and third gear output shaft 13 and the second and fourth gear output shaft 19.

[0101] The synchronous control process includes target speed calculation, real-time speed acquisition, speed error calculation, and error feedback correction steps.

[0102] When the speed difference is greater than the preset synchronization threshold, the controller reduces the output torque of the target motor, so that the output shaft speed gradually approaches the synchronization state.

[0103] When the speed difference enters the synchronization window range, the system enters the engagement preparation state, allowing the engagement sleeve to perform the meshing action.

[0104] Synchronous control employs PID control or sliding mode control algorithms to achieve rapid convergence and disturbance rejection capabilities.

[0105] XVI. The axial movement of the coupling sleeve 2 and the coupling sleeve 22 is driven by an electrically controlled actuator.

[0106] The electronically controlled actuator includes a hydraulic drive mechanism or an electric lead screw drive mechanism, and achieves axial displacement control through a shift fork structure.

[0107] The shift fork structure is set in the guide groove, and linear motion is achieved through sliding guidance to avoid yaw error.

[0108] During the engagement process, the system performs pre-alignment control, which gradually reduces the phase difference between the engagement sleeve gear ring and the target gear tooth groove.

[0109] The pre-alignment process corrects the relative position of the tooth surfaces through short-term torque fine-tuning, thereby improving meshing efficiency.

[0110] Sixteen, the system has a comprehensive security protection mechanism to prevent system damage under abnormal operating conditions.

[0111] When the system detects motor overheating, abnormal output shaft speed, improper engagement sleeve positioning, or gear shifting failure, it immediately enters protection mode.

[0112] The protection modes include cutting off the motor output, locking the current gear, limiting the output torque, and entering a single-motor degraded drive mode.

[0113] At the same time, the system records fault information and uploads it to the vehicle diagnostic system for subsequent maintenance analysis.

[0114] 17. The regenerative braking process is dynamically controlled based on the battery's state of charge (SOC).

[0115] When the SOC is below the set threshold, the system adopts the maximum regenerative braking mode to improve energy recovery efficiency.

[0116] As the SOC gradually approaches the upper limit threshold, the system reduces the recovery current to achieve smooth transition control.

[0117] When the SOC reaches its upper limit, the system automatically shuts down the regenerative braking function and switches to mechanical braking mode.

[0118] The control process is achieved by the VCU performing closed-loop adjustment based on real-time data from the BMS.

[0119] 18. Data exchange between VCU and TCU is achieved through the CAN communication bus.

[0120] The communication cycle is 1ms to 10ms for real-time transmission, and key control signals adopt a high-priority message mechanism.

[0121] The communication data includes motor speed, output shaft speed, motor torque, coupling sleeve position status, and battery SOC parameters.

[0122] The system is equipped with a communication redundancy verification mechanism to prevent data loss or errors from causing accidental gear shifting.

[0123] 19. The gear shifting control system adopts a hierarchical real-time control architecture.

[0124] The motor control cycle is 1ms, the gear shift decision cycle is 5ms, and the vehicle control strategy update cycle is 10ms.

[0125] A balance between high-speed response and stable control is achieved through multi-cycle coordinated control.

[0126] This layered control structure can effectively improve shift smoothness and reduce system vibration and shock.

[0127] The working principle of this device has been explained through the above embodiments. These embodiments merely illustrate several implementation methods of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A high-speed dual-motor dual-axis input electric drive axle system for automobiles, characterized in that, include: High-speed motors with three gears (10) and high-speed motors with two and four gears (30); Electromechanical drive axle box; The electromechanical electric drive axle housing includes: The first and third high-speed gear pair consists of a first and third high-speed driving gear (8) and a first and third high-speed driven gear (6); The second and fourth gear high-speed gear pair consists of a second and fourth gear high-speed driving gear (28) and a second and fourth gear high-speed driven gear (26); A first gear pair, which consists of a first driving gear (5) and a first driven gear (11); The second gear pair consists of a second driving gear (25) and a second driven gear (17); The three-speed gear pair consists of a three-speed driving gear (4) and a three-speed driven gear (1); The four-speed gear pair consists of a four-speed driving gear (24) and a four-speed driven gear (21); The main reduction gear pair includes a first and third gear main reduction drive gear (12), a second and fourth gear main reduction drive gear (18), and a main reduction driven gear (20). The main reduction driven gear (20) meshes with both the first and third gear main reduction drive gear (12) and the second and fourth gear main reduction drive gear (18). The first and third gear coupling sleeve (2) and the second and fourth gear coupling sleeve (22); Input shafts for first and third gears (7), input shafts for second and fourth gears (27), intermediate shafts for first and third gears (3), intermediate shafts for second and fourth gears (23), output shafts for first and third gears (13) and output shafts for second and fourth gears (19); Differential (15), left half shaft (14) and right half shaft (16); in: The first and third speed high-speed motors (10) are driven and connected to the first and third speed input shafts (7), and the second and fourth speed high-speed motors (30) are driven and connected to the second and fourth speed input shafts (27). The first and third gear engagement sleeve (2) is set on the first and third gear output shaft (13) and is used to selectively connect the first gear driven gear (11) or the third gear driven gear (1). The second and fourth gear engagement sleeve (22) is set on the second and fourth gear output shaft (19) and is used to selectively connect the second gear driven gear (17) or the fourth gear driven gear (21). The system uses an electronic control module to perform independent closed-loop control of the speed and torque of the two motors, and controls the action of the coupling sleeve based on the output shaft speed synchronization condition during gear shifting, so as to realize dual-motor dual-path coordinated drive and gear shifting without power interruption.

2. A shift control method for a high-speed dual-motor dual-axis input electric drive axle system for automobiles, characterized in that, Includes the following steps: S1: Dual Motor Initialization Drive Steps Control the first and third speed high-speed motors (10) and the second and fourth speed high-speed motors (30) to enter the same output state, and establish independent speed and torque closed-loop control; S2: Low-speed gear control steps Control the engagement of the first and third gear engagement sleeve (2) with the first gear driven gear (11), and control the engagement of the second and fourth gear engagement sleeve (22) with the second gear driven gear (17) to achieve dual motor low-speed drive; S3: Intermediate Gear Control Steps Control the engagement of the first and third gear engagement sleeve (2) with the third gear driven gear (1), and control the engagement of the second and fourth gear engagement sleeve (22) with the second gear driven gear (17) to achieve the intermediate gear drive of the dual motors; S4: High-speed gear control steps Control the engagement of the first and third gear engagement sleeve (2) with the third gear driven gear (1), and control the engagement of the second and fourth gear engagement sleeve (22) with the fourth gear driven gear (21) to achieve high-speed drive of dual motors; S5: Speed ​​Synchronization Shifting Procedure During gear shifting, the output shaft speed difference is detected. When the speed difference between the first and third gear output shafts (13) and the second and fourth gear output shafts (19) meets the preset synchronization conditions, the coupling sleeve is controlled to complete the engagement or disengagement, thus achieving shock-free gear shifting. S6: Braking Energy Recovery Steps Under braking conditions, the two motors are reverse-driven by the differential (15) to enter the power generation state, thereby realizing the recovery of braking energy; S7: Reverse Gear Control Steps Control the first and third speed high-speed motors (10) and the second and fourth speed high-speed motors (30) to rotate in opposite directions, and combine the locking state of the first and second gear pairs to realize the vehicle reversing drive.

3. The shift control method for a high-speed dual-motor dual-axis input electric drive axle system for vehicles according to claim 2, characterized in that, The dual-motor low-speed mode includes the following steps: S1: Gear Setting Steps Control the engagement of the first and third gear engagement sleeve (2) with the first gear driven gear (11), so that the first gear driven gear (11) is fixedly connected to the first and third gear output shaft (13); S2: Gear Activation Steps Control the engagement of the second and fourth gear engagement sleeve (22) with the second gear driven gear (17), so that the second gear driven gear (17) is fixedly connected to the second and fourth gear output shaft (19); S3: Drive Output Steps Control the first and third speed high-speed motors (10) and the second and fourth speed high-speed motors (30) to output power in the same direction; S4: Power Transmission Steps The first and third gear motor paths sequentially pass through the first and third gear input shaft (7), the first and third gear high-speed gear pair, the first gear pair, the first and third gear coupling sleeve (2), the first and third gear output shaft (13), the first and third gear main reduction gear pair and the differential (15) for output; The second and fourth gear motor paths sequentially pass through the second and fourth gear input shaft (27), the second and fourth gear high-speed gear pair, the second gear pair, the second and fourth gear coupling sleeve (22), the second and fourth gear output shaft (19), the second and fourth gear main reduction gear pair and the differential (15) for output.

4. The shift control method for a high-speed dual-motor dual-axis input electric drive axle system for vehicles according to claim 2, characterized in that, The dual-motor intermediate mode includes the following steps: S1: Gear Shifting Steps Control the engagement of the first and third gear engagement sleeve (2) with the third gear driven gear (1); S2: Gear Shifting Steps Control the engagement of the second and fourth gear engagement sleeve (22) with the second gear driven gear (17); S3: Drive Control Steps The outputs of the first and third speed high-speed motors (10) and the second and fourth speed high-speed motors (30) are controlled respectively; S4: Power Output Steps The first and third gear motor paths are output to the first and third gear output shafts (13) via the third gear pair. The second and fourth gear motor paths are output to the second and fourth gear output shafts (19) via the second gear pair. The two power sources converge into the differential (15) via the main reduction gear pair for output.

5. The shift control method for a high-speed dual-motor dual-axis input electric drive axle system for vehicles according to claim 2, characterized in that, The dual-motor high-speed mode includes the following steps: S1: Gear Shifting Steps Control the engagement of the first and third gear engagement sleeve (2) with the third gear driven gear (1); S2: Gear Shifting Steps Control the engagement of the second and fourth gear engagement sleeve (22) with the fourth gear driven gear (21); S3: Drive Control Steps The outputs of the first and third speed high-speed motors (10) and the second and fourth speed high-speed motors (30) are controlled respectively; S4: Power Output Steps The first and third speed motors output power via a third-speed gear pair; The second and fourth speed motors output power via a fourth-speed gear pair; Finally, the output is fed into the differential (15) via the main reduction gear pair.

6. The shift control method for a high-speed dual-motor dual-axis input electric drive axle system for vehicles according to claim 2, characterized in that, The shift control process from the low speed gear to the intermediate and high speed gears of the dual motors includes the following steps: S1: Low gear disengagement procedure Release the engagement between the first gear pair and the first and third gear output shafts (13) to allow the first gear driven gear (11) to enter the idling state; S2: Speed ​​Synchronization Adjustment Steps Adjust the speed of the first and third speed high-speed motor (10) to synchronize the speed of the third driven gear (1) with the speed of the first and third output shaft (13); S3: Gear Combination Steps When the speed synchronization condition is met, the first and third gear engagement sleeve (2) is engaged with the third gear driven gear (1) to complete the intermediate gear switching; S4: Power Output Steps It can switch the power transmission path between the intermediate and high speeds of the dual motors and maintain the coordinated output of the dual motors.

7. The shift control method for a high-speed dual-motor dual-axis input electric drive axle system for vehicles according to claim 2, characterized in that, The shift control process from the intermediate gear to the low-speed and high-speed gears of the dual motors includes the following steps: S1: Exiting from intermediate mode Release the engagement between the second gear pair and the second and fourth gear output shafts (19), so that the second gear driven gear (17) enters the idling state; S2: Speed ​​Synchronization Adjustment Steps Adjust the speed of the second and fourth gear high-speed motor (30) so that the speed of the fourth gear driven gear (21) is synchronized with the speed of the second and fourth gear output shaft (19); S3: Gear Combination Steps When the speed synchronization condition is met, the control of the second and fourth gear engagement sleeve (22) and the fourth gear driven gear (21) are engaged to complete the high-speed gear switching; S4: Power Output Steps Complete the switching of power transmission path for high-speed mode of dual motors and maintain the coordinated output of dual motors.

8. The shift control method for a high-speed dual-motor dual-axis input electric drive axle system for vehicles according to claim 2, characterized in that, The energy recovery control method under vehicle braking conditions includes the following steps: S1: Braking Energy Input Steps During vehicle braking, the left and right half shafts (14, 16) are driven in opposite directions through the differential (15); S2: Power Reverse Driving Steps The braking force is transmitted to the first and third speed high-speed motors (10) and the second and fourth speed high-speed motors (30) through the main reduction gear pair. S3: Power Generation Control Steps Controlling the two motors to enter the power generation state converts mechanical energy into electrical energy to achieve energy recovery; S4: Braking Switching Steps When the battery level reaches a preset threshold, it switches to mechanical braking mode.

9. The shift control method for a high-speed dual-motor dual-axis input electric drive axle system for vehicles according to claim 2, characterized in that, The reverse gear control method includes the following steps: S1: Reverse Drive Steps Control the first and third speed high-speed motors (10) and the second and fourth speed high-speed motors (30) to enter the reverse rotation state; S2: Gear Locking Procedure Control the first gear pair and the second gear pair to lock with their respective output shafts; S3: Reverse Output Steps The vehicle reverses by driving the differential (15) through a dual-motor dual-path transmission system.

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