Hybrid drive system, control method and readable storage medium

Abstract

A hybrid drive system and a control method. The system comprises: a ring gear (1); a sun gear (2) located in the ring gear; a plurality of planetary gears (3) meshing between the ring gear (1) and the sun gear (2); a planet carrier (4); a first input shaft (5), which is fixedly connected to the planet carrier (4) and is connected to an engine (23); a differential (9), which is in transmission connection with the ring gear (1); a third input shaft (10), which is in transmission connection with the differential (9) and is fixedly connected to a first electric motor (18); a second input shaft (6), which is fixedly connected to the sun gear (2) and is fixedly connected to a second electric motor (25); a first synchronizer (7), which is fixed to the ring gear (1), wherein a large driving gear (12) and a small driving gear (13), which are located on two sides of the first synchronizer, are rotationally provided on the ring gear, and the large driving gear (12) and the small driving gear (13) are respectively in transmission connection with the differential (9); and a second synchronizer (11), which is fixed to the second input shaft (6). A control module is configured to control, on the basis of at least one of a first rotational speed of the first electric motor (18), a second rotational speed of the second electric motor (25) and a third rotational speed of the engine (23), the first synchronizer (7) and the second synchronizer (11) to engage and disengage.

Description

Hybrid power drive system, control method, and readable storage medium CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The embodiments of this application are based on and claim the priority of Chinese patent application with application number 202410204807.0 and application date February 23, 2024. The entire contents of the Chinese patent application are hereby introduced into the embodiments of this application as a reference. Technical Field

[0002] The present invention relates to the field of automotive technology, and in particular to a hybrid power drive system, a control method, and a readable storage medium. Background Art

[0003] As people's awareness of energy conservation and environmental protection increases, new energy vehicle technology has begun to develop rapidly. Hybrid vehicle drive technology is the core stage of the development of new energy vehicles.

[0004] Hybrid electric vehicles (HEVs) primarily utilize three powertrain configurations: series, parallel, and hybrid. Parallel-connected vehicles are primarily powered by the engine, leveraging the electric motor's ability to generate powerful power during startup. During periods of high fuel consumption, such as during starting and acceleration, the electric motor assists the vehicle to reduce fuel consumption. Hybrid-connected vehicles rely solely on the electric motor at low speeds, with the engine and electric motor working together as speed increases. During startup and low-speed driving, the electric motor alone drives the vehicle, while at higher speeds, the engine and electric motor share the power efficiently. In series-connected vehicles, the engine alone drives the vehicle, with the engine serving solely as a power source to generate electricity for the generator. The vehicle is driven solely by the electric motor, with driving force coming directly from the motor. The addition of the motor places higher demands on the vehicle's powertrain or hybrid drive system, leading to numerous improvements in vehicle control methods and hybrid drive system control methods. Summary of the Invention

[0005] According to some aspects of the present invention, there is provided a hybrid drive system comprising:

[0006] A planetary gear assembly includes: a ring gear, a sun gear located within the ring gear, a plurality of planet gears meshed between the ring gear and the sun gear, and a planetary gear carrier rotatably connected to the plurality of planet gears; a first input shaft, a second input shaft, a third input shaft, and a differential; one end of the first input shaft is fixedly connected to the planetary gear carrier and the other end is connected to the engine; the differential is drivingly connected to the ring gear; one end of the third input shaft is drivingly connected to the differential and the other end of the third input shaft is fixedly connected to the first motor; one end of the second input shaft is fixedly connected to the sun gear and the other end of the second input shaft is fixedly connected to the second motor; a first synchronizer fixed to the ring gear, a large driving gear and a small driving gear rotatably disposed on the ring gear and located on either side of the first synchronizer; the large driving gear and the small driving gear are respectively drivingly connected to the differential; a second synchronizer fixed to the second input shaft; and a control module. The control module is configured to control the engagement and disengagement of the first and second synchronizers based on at least one of a first speed of the first motor, a second speed of the second motor, and a third speed of the engine.

[0007] According to some aspects of the present invention, a control method is provided, which is applied to the hybrid drive system, including: obtaining at least one of the first speed of the first motor, the second speed of the second motor, and the third speed of the engine; and controlling the engagement and disengagement of the first synchronizer and the second synchronizer according to at least one of the first speed, the second speed, and the third speed.

[0008] According to some aspects of the present invention, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed, the control method is implemented.

[0009] The present invention provides a hybrid power drive system, in which a control module is configured to control the engagement and disengagement of a first synchronizer and a second synchronizer according to at least one of a first speed of a first motor, a second speed of a second motor, and a third speed of an engine; in a clutchless configuration, the engagement and disengagement of the synchronizer can be controlled by judging the speed difference between a gear sleeve and a coupling tooth of the synchronizer and the speed difference change rate, thereby achieving power output of different gears of the vehicle, reducing power interruption during gear shifting, and accelerating gear shifting. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] FIG1 is a schematic structural diagram of a hybrid drive system according to an embodiment of the present disclosure;

[0011] FIG2 is a schematic diagram of a planetary gear assembly according to an embodiment of the present disclosure;

[0012] FIG3 is a schematic diagram of a shift control method according to an embodiment of the present disclosure;

[0013] FIG4 is a schematic diagram of another shift control method according to an embodiment of the present disclosure;

[0014] FIG5 is a flow chart of a control method of a system according to an embodiment of the present disclosure.

[0015] Description of reference numerals:

[0016] 1. Ring gear; 2. Sun gear; 3. Planet gears; 4. Planet gear carrier; 5. First input shaft; 6. Second input shaft; 7. First synchronizer; 8. Gearbox housing; 9. Differential; 10. Third input shaft; 11. Second synchronizer; 12. Large driving gear; 13. Small driving gear; 14. Differential driven gear; 15. First intermediate shaft; 16. First large driven gear; 17. First small driven gear; 18. First motor; 19. Drive gear; 20. Second intermediate shaft; 21. Second large driven gear; 22. Second small driven gear; 23. Engine; 24. Torsional vibration damper; 25. Second motor. DETAILED DESCRIPTION

[0017] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the specific embodiments described herein. Instead, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0018] In the following description, numerous specific details are provided to provide a more thorough understanding of the present disclosure. However, it will be apparent to those skilled in the art that the present disclosure can be practiced without one or more of these details. In other instances, certain technical features known in the art are not described to avoid confusion with the present disclosure; that is, all features of actual embodiments are not described herein, nor are well-known functions and structures described in detail.

[0019] It should be understood that “some embodiments” or “an embodiment” mentioned throughout the specification means that specific features, structures or characteristics related to the embodiments are included in at least one embodiment of the present disclosure. Therefore, “in some embodiments” or “in an embodiment” appearing throughout the specification does not necessarily refer to the same embodiment. In addition, these specific features, structures or characteristics can be combined in one or more embodiments in any suitable manner. It should be understood that in the various embodiments of the present disclosure, the size of the sequence numbers of the above-mentioned processes does not mean 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 the present disclosure.

[0020] During the shifting process in conventional new energy vehicles, the clutch is typically used to disconnect the power source. After the main drive motor completes speed regulation, a synchronizing torque is applied to the synchronizer to eliminate any remaining speed difference between the two ends during the slipping process, thereby achieving synchronization and coupling. The shift control process is as follows: After the clutch is disengaged and the main drive motor completes speed regulation, a shift force is applied to the synchronizer sleeve using a shift fork. This synchronizing torque eliminates any remaining speed difference between the two ends during the slipping process, thereby achieving synchronization and coupling. The inclusion of a clutch in a hybrid transmission reduces the transmission efficiency. Adding a clutch complicates the powertrain structure, increases component costs, and increases control difficulty.

[0021] The present invention provides a dual-motor hybrid drive system and a control method applied to the drive system, which can realize gear shifting without a clutch. The gear shaft system of the new energy gearbox is connected to the motor rotor and the engine. During the synchronization process, the synchronizer has an increased synchronous inertia that needs to be overcome. Without a clutch to disconnect the engine crankshaft inertia, the difficulty of gear shifting increases. The present invention monitors the speed difference change rate of the synchronizer, and the speed difference change rate and the inertia of the shaft system are equal to the residual torque. As long as the synchronizer torque is greater than the residual torque, gear shifting can be achieved. The gearbox controls the gear shifting by judging the speed difference change rate of the synchronizer's gear sleeve and the coupling tooth. It can transmit power without a clutch and adopts a dual-motor structure. The synchronizer of the engine and generator adjusts the speed and torque during the gear shifting process, and the drive motor can be responsible for torque filling during the gear shifting process. The gear shift control method can realize power interruption-free and fast gear shifting.

[0022] The hybrid power system provided by the embodiment of the present disclosure may be a hybrid power transmission assembly, or a part of a hybrid power transmission assembly; or, the hybrid power system may include a hybrid power transmission assembly and other mechanical components and other electronic components. The hybrid power system provided by the embodiment of the present disclosure may be applied to any hybrid electric vehicle with an engine. The hybrid power system provided by the embodiment of the present disclosure may include a multi-stage control unit or control module, may include a shift module, or include a transmission controller MTCU with a shift module, and may also include a vehicle controller VECU. The vehicle controller VECU may be used to communicate with the transmission controller MTCU, the engine controller ECU and the temperature sensor through wired or wireless communication, and calculate various data of the engine, motor and brake system to realize the control of various vehicle operations.

[0023] According to some aspects of the embodiments of the present disclosure, as shown in FIG1 , the embodiments of the present disclosure provide a hybrid drive system, including: a planetary gear assembly, including: a ring gear 1, a sun gear 2 located within the ring gear 1, a plurality of planetary gears 3 meshing between the ring gear 1 and the sun gear 2, and a planetary gear carrier 4 rotatably connected to the plurality of planetary gears 3; a first input shaft 5, a second input shaft 6, a third input shaft 10, and a differential 9; one end of the first input shaft 5 is fixedly connected to the planetary gear carrier 4, and the other end is connected to the engine 23; the differential 9 is drivingly connected to the ring gear 1; one end of the third input shaft 10 is drivingly connected to the differential 9, and the other end of the third input shaft 10 is fixedly connected to the first motor 18 ; One end of the second input shaft 6 is fixedly connected to the sun gear 2, and the other end of the second input shaft 6 is fixedly connected to the second motor 25; a first synchronizer 7 is fixed on the ring gear 1, and a large driving gear 12 and a small driving gear 13 are rotatably provided on the ring gear 1, which are respectively located on both sides of the first synchronizer 7; the large driving gear 12 and the small driving gear 13 are respectively connected to the differential 9 in driving connection; a second synchronizer 11 is fixed on the second input shaft 6; and also includes a control module; the control module is configured to: control the engagement and disengagement of the first synchronizer 7 and the second synchronizer 11 according to at least one of the first speed of the first motor 18, the second speed of the second motor 25 and the third speed of the engine 23.

[0024] The components shown in Figure 1 can be located in a gearbox. The control module is not shown in Figure 1. The control module can be a VECU or an MTCU. If the control module is an MTCU, it can be a part of the gearbox and installed inside the gearbox housing 8 or outside the gearbox housing 8; if the control module is a VECU, it can not be a part of the gearbox and can be installed outside the transmission housing.

[0025] In some embodiments, as shown in Figure 1, the planetary gear mechanism includes a ring gear 1, a sun gear 2 located at the center of the ring gear 1, a plurality of planetary gears 3 meshed between the ring gear 1 and the sun gear 2, and a planetary gear carrier 4 rotatably connected to the plurality of planetary gears 3. The plurality of planetary gears 3 form an integral body on the planetary gear carrier 4 and meshed with the ring gear 1 and the sun gear 2.

[0026] The first input shaft 5 and the second input shaft 6 have one end coaxially fixedly connected to the planetary gear carrier 4. The other end of the first input shaft 5 is connected to the engine 23 via the torsional vibration damper 24. The engine 23 drives the planetary gear carrier 4 of the planetary gear mechanism to rotate through the torsional vibration damper 24 and the first input shaft 5. One end of the second input shaft 6 is coaxially fixedly connected to the sun gear 2.

[0027] The second synchronizer 11 is fixed to the second input shaft 6 and rotates synchronously with the second input shaft 6. During gear shifting, the second synchronizer 11 can engage or disengage the second input shaft 6 with the ring gear 1, and also engage or disengage the second input shaft 6 with the transmission housing 8. The second synchronizer 11 is located between the ring gear 1 and the transmission housing 8. When the second synchronizer 11 moves rightward in Figure 1 to a set position, the second input shaft 6 engages with the ring gear 1. When the second synchronizer 11 moves leftward to a set position, the second input shaft 6 engages with the transmission housing 8.

[0028] The differential 9 is connected to the ring gear 1 in a transmission manner. When the ring gear 1 rotates, the ring gear 1 drives the differential 9 to operate, and the differential 9 transmits power to the wheel ends of the vehicle through the half shafts to drive the vehicle.

[0029] A third input shaft 10 has an axis parallel to the axis of the second input shaft 6 and is drivingly connected to the differential 9. One end of the third input shaft 10 is fixedly connected to the first motor 18, and the other end of the third input shaft 10 is provided with a drive gear 19 that drives the differential 9.

[0030] In some embodiments, when the second synchronizer 11 engages the second input shaft 6 with the transmission housing 8, power from the engine 23 is input through the planetary carrier 4 and output through the ring gear 1. The sun gear 2 is locked by the second synchronizer 11 and the transmission housing 8. The planetary gear mechanism forms a speed ratio, which is the product of the planetary gear mechanism's speed ratio and the shift mechanism's speed ratio for that gear. When the second synchronizer 11 engages the second input shaft 6 with the ring gear 1, the sun gear 2 and ring gear 1 are combined into a single unit and rotate forward simultaneously. The planetary gear mechanism's speed ratio is 1; at this point, the hybrid drive system's speed ratio is the shift mechanism's speed ratio for that gear.

[0031] In some embodiments, a first synchronizer 7 is fixed to the ring gear 1, and a second synchronizer 11 rotates synchronously with the ring gear 1. A large driving gear 12 and a small driving gear 13 are rotatably mounted on the ring gear 1, located on either side of the first synchronizer 7. During gear shifting, the first synchronizer 7 can engage or disengage the ring gear 1 with the large driving gear 12, and also engage or disengage the ring gear 1 with the small driving gear 13. The large driving gear 12 and the small driving gear 13 are each drivingly connected to the differential 9.

[0032] In some embodiments, when the first synchronizer 7 moves to the right to engage the ring gear 1 with the large driving gear 12, the power of the engine 23 is input from the planetary gear carrier 4 and output from the ring gear 1 to the large driving gear 12. The large driving gear 12 drives the differential 9 to operate, and the differential 9 transmits the power to the wheel ends of the vehicle through the half-shafts, driving the vehicle to travel at a high ratio.

[0033] In some embodiments, when the first synchronizer 7 moves to the left to engage the ring gear 1 with the small driving gear 13, the power of the engine 23 is input from the planetary gear carrier 4 and output from the ring gear 1 to the small driving gear 13. The small driving gear 13 drives the differential 9 to operate, and the differential 9 transmits the power to the wheel ends of the vehicle through the half shafts, driving the vehicle to travel at a low speed ratio.

[0034] In some embodiments, the differential 9 is provided with a differential driven gear 14. The differential driven gear 14 is connected to the large driving gear 12 via a first reduction gear train, and the differential driven gear 14 is connected to the small driving gear 13 via a second reduction gear train. The first reduction gear train is used to reduce the speed ratio between the differential driven gear 14 and the large driving gear 12, and the second reduction gear train is used to reduce the speed ratio between the differential driven gear 14 and the small driving gear 13.

[0035] The first reduction gear train includes a first intermediate shaft 15, the axis of which is parallel to the axis of the second input shaft 6. A first large driven gear 16, meshingly connected to the large driving gear 12, is fixedly mounted on one end of the first intermediate shaft 15. A first small driven gear 17, meshingly connected to the differential driven gear 14, is rotatably coupled to the other end of the first intermediate shaft 15. A third synchronizer, which engages or disengages the first small driven gear 17, may be fixedly mounted on the first intermediate shaft 15.

[0036] The second reduction gear train includes a second intermediate shaft 20, the axis of which is parallel to the axis of the second input shaft 6. A second large driven gear 21, meshingly connected to the small driving gear 13, is fixedly mounted on one end of the second intermediate shaft 20. A second small driven gear 22, meshingly connected to the differential driven gear 14, is fixedly mounted on the other end of the second intermediate shaft 20.

[0037] In some embodiments, when the first synchronizer 7 engages the ring gear 1 with the large driving gear 12, and the third synchronizer combines the first intermediate shaft 15 with the first small driven gear 17, the power of the engine 23 is input from the planetary gear carrier 4 and output from the ring gear 1 to the large driving gear 12. The large driving gear 12 drives the first large driven gear 16 to rotate. The first large driven gear 16 drives the first small driven gear 17 to rotate through the first intermediate shaft 15. The first small driven gear 17 drives the differential 9 to operate through the differential driven gear 14. The differential 9 transmits power to the wheel ends of the vehicle through the half-shafts, driving the vehicle to travel at a high ratio.

[0038] In some embodiments, when the first synchronizer 7 engages the ring gear 1 with the small driving gear 13, the power of the engine 23 is input from the planetary gear carrier 4 and output from the ring gear 1 to the small driving gear 13. The small driving gear 13 drives the second large driven gear 21 to rotate. The second large driven gear 21 drives the second small driven gear 22 to rotate through the second intermediate shaft 20. The second small driven gear 22 drives the differential 9 to operate through the differential driven gear 14. The differential 9 transmits power to the wheel ends of the vehicle through the half-shafts, driving the vehicle to travel at a low speed ratio.

[0039] In some embodiments, the other end of the first input shaft 5 is connected to the engine 23, and an idler gear mechanism may be connected between the second input shaft 6 and the large driving gear 12. The large driving gear 12 drives the second input shaft 6 and the sun gear 2 to rotate synchronously through the idler gear mechanism.

[0040] In some embodiments, the two powers output by the engine 23 and the first motor 18 are respectively input through the planetary gear carrier 4 and the sun gear 2, and after being combined, are output from the ring gear 1. The ring gear 1 drives the small driving gear 13 through the first synchronizer 7. The small driving gear 13 drives the second large driven gear 21. The second large driven gear 21 drives the second small driven gear 22 through the second intermediate shaft 20. The second small driven gear 22 drives the differential 9 through the differential driven gear 14. The differential 9 transmits the power to the vehicle's wheel ends through the half shafts, driving the vehicle at high speed.

[0041] In some embodiments, the other end of the first input shaft 5 is connected to the engine 23 through the torsional vibration damper 24, and the other end of the second input shaft 6 is connected to the second motor 25, which is preferably a generator. The axis of the first input shaft 5 is collinear with the axis of the second input shaft 6.

[0042] In some embodiments, the control module is configured to: calculate the speed difference and the speed difference change rate at the two ends of the first synchronizer 7 and the second synchronizer 11 to be engaged based on at least one of the first speed, the second speed and the third speed, and in response to the speed difference being less than or equal to a first threshold and the speed difference change rate being less than or equal to a second threshold; control the corresponding first synchronizer 7 to engage or the corresponding second synchronizer 11 to engage; in response to the speed difference being greater than the first threshold and / or the speed difference change rate being greater than the second threshold; control the corresponding synchronizer to disengage.

[0043] The first synchronizer 7 and the second synchronizer 11 provided in the embodiment of the present disclosure can be controlled by the control module to move to complete engagement or disengagement under different working conditions. For example, the control module can control the shift motor or shift assembly to drive the synchronizer (or the synchronizer's gear hub) to the left, right, or disengage along Figure 1 to complete the gear shift; wherein, when the synchronizer is in the middle position, the synchronizer is disengaged, and the synchronizer can be said to be in neutral. For example, the first synchronizer 7 is disengaged in the S1M position (the first synchronizer 7 is in the middle position and not engaged with the other ends); it engages to the left to the S1L position, so that the ring gear 1 engages with the small driving gear 13; the first synchronizer 7 engages to the right to the S1R position, so that the ring gear 1 engages with the large driving gear 12. The second synchronizer 11 is disengaged in the S2M position; it engages to the left to the S2L position, so that the second input shaft 6 engages with the transmission housing 8; it engages to the right to the S2R position, so that the second input shaft 6 engages with the ring gear 1.

[0044] When the synchronizer is engaged, there will be a certain speed difference between the two ends of the synchronizer to be engaged, such as a speed difference between the synchronizer speed (synchronizer hub speed) and the speed of the synchronizer teeth to be engaged. This speed difference has a speed difference change rate during the engagement process. The speed difference change rate can be recorded as the derivative of the speed difference with respect to the shift time, and can also be called the acceleration of the speed difference. It is understandable that if the speed difference between the two ends of the synchronizer to be engaged is too large, it will be difficult to eliminate the residual speed difference between the two ends, making it difficult for the two ends of the synchronizer to achieve synchronization and coupling, and even causing tooth knocking and damage to the synchronizer. During the shifting process, if the speed difference change rate is large, it means that the residual torque change exceeds a set threshold, which will also cause synchronization difficulties. The hybrid power drive system of the embodiment of the present disclosure controls the speed difference and the speed difference change rate between the two ends of the synchronizer to be engaged within a certain threshold, enters the shifting action, and exits the shifting action when either the speed difference or the speed difference change rate exceeds the corresponding threshold. The speed difference and speed difference change rate at the two ends of the synchronizer to be engaged can be calculated and represented by the first speed of the first motor 18, the second speed of the second motor 25 and the third speed of the engine 23 according to the different gear requirements set. The first speed, the second speed and the third speed are real-time collection values ​​when the vehicle is driving, and are obtained by the corresponding speed sensors. The first speed and the second speed are collected by the speed sensors of the corresponding motors, and the third speed is collected by the speed sensor of the engine 23. After being fed back to the control module, the control module calculates the real-time speed difference and the speed difference change rate according to the established control method or control program. The synchronizer is engaged when the speed difference is less than or equal to the first threshold and the speed difference change rate is less than or equal to the second threshold. The first threshold and the second threshold are calibration values ​​for factory testing and are stored in the vehicle memory for the control module to retrieve.

[0045] Combined with the planetary gear assembly shown in FIG2, ω1-(1+α)ω H +αω3=0; where ω1 is the speed of sun gear 2, ω H is the speed of the planetary gear carrier 4, ω3 is the speed of the ring gear 1, and α is the gear ratio between the ring gear 1 and the sun gear 2. This ratio is the design value of the planetary gear assembly.

[0046] One end of the second input shaft 6 is fixedly connected to the sun gear 2, and the other end of the second input shaft 6 is fixedly connected to the second motor 25. The speed of the sun gear 2 and the speed of the second input shaft 6 can be represented by the second speed GcuSpd of the second motor 25; one end of the first input shaft 5 is fixedly connected to the planetary carrier 4, and the other end is connected to the engine 23. The speed of the planetary carrier 4 can be represented by the third speed EngSpd of the engine 23; the speed of the ring gear 1 is also the speed of the gear hub of the first synchronizer 7 The first speed of the first motor 18 is denoted as McuSpd. The large driving gear 12 and the small driving gear 13 are connected to the first motor 18 via the differential 9. The reduction ratio of the first motor 18 is denoted as i1. The engine direct drive first gear speed ratio is denoted as i2; the engine direct drive second gear speed ratio is denoted as i3. The speeds of the first and second synchronizer 7 and 11 at both ends of the synchronizer to be engaged during gear shifting are shown in Table 1 for ease of explanation: the first speed is McuSpd, the second speed is GcuSpd, and the third speed is EngSpd.

[0047] Table 1:

[0048]

[0049] In some embodiments, the control module is configured to: calculate the rotational speeds of the small driving gear 13 and the large driving gear 12 according to the first rotational speed and the gear ratio, respectively; calculate the rotational speed of the ring gear 1 according to the second rotational speed, the third rotational speed, and the gear ratio of the ring gear 1 and the sun gear 2; in response to the first rotational speed difference between the ring gear 1 and the small driving gear 13 being less than or equal to the first threshold value, and the rate of change of the first rotational speed difference being less than or equal to the second threshold value; control the first synchronizer 7 to engage (move left to the S1L position) so that the ring gear 1 engages with the small driving gear 13.

[0050] Referring to Table 1, when the first synchronizer 7 moves from S1M to the left to S1L, the two ends of the first synchronizer 7 to be engaged are the synchronizer hub or the first synchronizer 7 itself (the first synchronizer 7 is fixedly connected to the ring gear 1), and the small driving gear 13. The speed of the first synchronizer 7 hub is the speed of the ring gear 1, and the speeds of the two ends to be engaged are respectively 、 The speed of the ring gear 1 can be calculated by the third speed EngSpd, the second speed GcuSpd and the gear ratio α between the ring gear 1 and the sun gear 2, and the speed of the small driving gear 13 can be calculated by the first speed McuSpd and the gear ratio. The difference between the speed of the ring gear 1 and the speed of the small driving gear 13 is calculated as the first speed difference ; The first speed difference change rate is also obtained by derivation of the shift time based on the first speed difference. The first speed, the second speed and the third speed are collected real-time values, and α, i1 and i2 are calibration values ​​stored in the vehicle memory; when the first speed difference is less than or equal to the first threshold value, and the first speed difference change rate is less than or equal to the second threshold value; the first synchronizer 7 is controlled to engage (move left to the S1L position) to engage the ring gear 1 with the small driving gear 13.

[0051] For example, referring to Figure 3, when responding to the vehicle's gear shifting demand, the first synchronizer needs to be moved left to the S1L position, the control module obtains the first speed, the second speed and the third speed to calculate the speed difference (first speed difference) between the speed of the ring gear 1 and the small driving gear 13. If the speed difference is less than or equal to the first threshold, the engagement of the first synchronizer 7 can be started at this time, and the first speed difference is monitored in real time and the first speed difference is derived from the shifting time. The shifting time is calculated from the start of the engagement of the first synchronizer 7. When the rate of change of the first speed difference is less than or equal to the second threshold, the two ends of the first synchronizer 7 are engaged to complete the gear shift. If any of the following situations occurs during this process: the first speed difference is greater than the first threshold or the rate of change of the first speed difference is greater than the second threshold, the first synchronizer 7 exits the gear shifting operation and is in the middle position S1M. The control module shown in Figure 3 can be a VECU. When the VECU receives the vehicle's gear shifting request, it needs to engage the corresponding synchronizer (such as the first synchronizer 7) to the corresponding position of the gear. The VECU obtains the first speed, the second speed and the third speed and calculates the first speed difference and the first speed difference change rate, and determines whether the first speed difference is less than or equal to the first threshold value, and whether the first speed difference change rate is less than or equal to the second threshold value. If the gear shifting conditions are met, a gear shift instruction is sent to the MTCU, and the MTCU controls the first synchronizer 7 to engage to the target position; if the gear shifting conditions are not met, the VECU sends a gear shift cancellation instruction to the MTCU, and the MTCU controls the first synchronizer 7 to return to the neutral position S1M.

[0052] In some embodiments, after the first synchronizer 7 cancels the shift, the VECU may control the speed and torque of at least one of the engine 23, the first motor 18, and the second motor 25 until the first speed difference during the shift is less than or equal to the first threshold value, and the rate of change of the first speed difference is less than or equal to the second threshold value, so that the first synchronizer 7 meets the threshold condition for engagement and the shift is successful. In some embodiments, after the VECU receives the vehicle's shift request, the VECU may control the speed and torque of at least one of the engine 23, the first motor 18, and the second motor 25 so that the speed difference and the rate of change of the speed difference between the two ends of the corresponding synchronizer to be engaged meet the shift condition, thereby achieving smoother and faster shifting and reducing the interruption of power during shifting.

[0053] In some embodiments, referring to that shown in FIG4 , the control module for acquiring the first speed, the second speed, and the third speed in the disclosed embodiment is the MTCU. After the MTCU receives the shift instruction from the VECU, the shift instruction corresponds to the synchronizer that needs to perform the shift operation, such as the first synchronizer 7, and instructs the first synchronizer 7 to engage to the S1L position; the MTCU acquires the above three speeds, and calculates the first speed and the first speed change rate. When the first speed is less than or equal to the first threshold value, and the first speed change rate is less than or equal to the second threshold value, the first synchronizer 7 is controlled to engage to S1L; if the first speed difference is greater than the first threshold value, and / or the first speed difference change rate is greater than the second threshold value, the shift operation is exited, and the first synchronizer 7 is controlled to be in S1M.

[0054] In some embodiments, as shown in Figures 3 and 4, after the corresponding synchronizer exits the gear shifting operation, the MTCU or VECU can control the speed and torque of at least one of the engine 23, the first motor 18, and the second motor 25; before the gear shifting begins, the MTCU or VECU can control the speed and torque of at least one of the engine 23, the first motor 18, and the second motor 25 to speed up the gear shifting and reduce power interruption during the gear shifting process.

[0055] In some embodiments, the control module is further configured to: in response to the second speed difference between the ring gear 1 and the large driving gear 12 being less than or equal to the first threshold, and the rate of change of the second speed difference being less than or equal to the second threshold; control the first synchronizer 7 to engage (move right to the S1R position) so that the ring gear 1 engages with the large driving gear 12.

[0056] As shown in Table 1, when the first synchronizer 7 moves rightward from S1M to S1R, the first synchronizer 7 is engaged with the gear hub of the synchronizer, which can also be called the first synchronizer 7 itself, and the large driving gear 12. The control module calculates the second speed difference (ω1-ω2). At this time, the second speed difference ω2 and the ω2 in the first speed difference represent the speeds of different components. The second speed difference The second speed difference change rate is calculated by derivatizing the second speed difference with respect to the shift time. When the second speed difference is less than or equal to the first threshold, and the second speed difference change rate is less than or equal to the second threshold, the first synchronizer 7 is controlled to move to S1R. If the second speed difference is greater than the first threshold, and / or the second speed difference change rate is greater than the second threshold, the shift operation is canceled, and the first synchronizer 7 is controlled to be in S1M.

[0057] In some embodiments, the control module is configured to: in response to the second speed being less than or equal to the first threshold and the rate of change of the second speed being less than or equal to the second threshold; control the second synchronizer 11 to engage (engage left to the S2L position) to engage the second input shaft 6 with the transmission housing 8.

[0058] As shown in Table 1, when the second synchronizer 11 moves leftward from S2M to S2L, the two ends of the second synchronizer 11 to be engaged are the synchronizer hub (the second synchronizer 11 is connected to the second input shaft 6) and the transmission housing 8. The transmission housing 8 is a fixed structure with a speed of 0. The speed of the second synchronizer 11 hub is the speed of the second input shaft 6, which is also the second speed GcuSpd of the second motor 25. The speed difference at this time is the second speed GcuSpd. When the second speed is less than or equal to the first threshold and the second speed change rate is less than or equal to the second threshold, the second synchronizer 11 is controlled to move leftward to S2L, locking the second synchronizer 11 to the transmission housing 8. When the second speed is greater than the first threshold and / or the second speed change rate is greater than the second threshold, the shift operation is exited and the second synchronizer 11 is controlled to be in S2M.

[0059] In some embodiments, the control module is configured to: calculate the speed of the ring gear 1 based on the second speed, the third speed, and the gear ratio of the ring gear 1 to the sun gear 2; in response to the third speed difference between the second speed and the speed of the ring gear 1 being less than or equal to the first threshold, and the rate of change of the third speed difference being less than or equal to the second threshold; control the second synchronizer 11 to engage (engage rightward to the S2R position) to engage the second input shaft 6 with the ring gear 1.

[0060] As shown in Table 1, when the second synchronizer 11 moves rightward from S2M to S2R, the two ends of the second synchronizer 11 to be engaged are the synchronizer hub and the ring gear 1; the speeds are the second speed GcuSpd and , the third speed difference is When the third speed difference is less than or equal to the first threshold value, and the rate of change of the third speed difference is less than or equal to the second threshold value, the second synchronizer 11 is controlled to engage to the S2R position; when the third speed difference is greater than the first threshold value, and / or the rate of change of the third speed difference is greater than the second threshold value, the shifting operation is exited and the second synchronizer 11 is controlled to be in S2M.

[0061] The hybrid drive system provided by the embodiment of the present disclosure provides multiple driving modes and driving gears. The corresponding engagement states of the driving modes and gears and the first synchronizer 7 and the second synchronizer 11 are shown in Table 2.

[0062] In some embodiments, Table 3 below illustrates the shifting sequence of the hybrid drive system of the disclosed embodiment, the engagement states of the first synchronizer 7 and the second synchronizer 11 corresponding to upshifts and downshifts. A certain driving mode in Table 2 may appear multiple times. The disclosed embodiment may not limit the shifting sequence of the gears as shown in Table 3. The shifting sequence and shifting logic are only used as an explanation. Different hybrid vehicle platforms have different shifting logic settings, and different shifting logics and synchronizer adaptations may exist. In some embodiments, the shifting logic for shifting to direct drive gear may be to first engage the ECVT gear and then engage the engine direct drive gear. In order to ensure the success rate of shifting, the target gear for shifting is simplified.

[0063] Among them, the EV gear in Table 2 is the pure electric driving mode; 1 represents engagement, and 0 represents disconnection; S1L represents the state in which the first synchronizer 7 causes the ring gear 1 to be engaged with the small driving gear 13, S1M represents the state in which the first synchronizer 7 is disconnected and is in neutral, and S1R represents the state in which the first synchronizer 7 causes the ring gear 1 to be engaged with the large driving gear 12; S2L represents the state in which the second synchronizer 11 causes the second input shaft 6 to be engaged with the transmission housing 8, S2M represents the state in which the second synchronizer 11 is disconnected and is in neutral, and S2R represents the state in which the second synchronizer 11 causes the second input shaft 6 to be engaged with the ring gear 1.

[0064] Table 2:

[0065]

[0066] Table 3 provides an example of a shifting logic. The shifting logic provided in Table 3 of the embodiment of the present disclosure is only used as an example and may have other sequence settings in different tuning embodiments.

[0067] Table 3:

[0068]

[0069] For example, combining Tables 2 and 3, if the target vehicle gear is 2nd gear (engine direct drive 1st gear) according to the shift logic in Table 3, a shift command corresponding to 2nd gear requires the first synchronizer 7 to be in S1L and the second synchronizer 11 to be in S2R. The control module obtains the relevant speeds and calculates the corresponding speed difference and speed difference change rate. When the shift conditions are met, the control module controls the first synchronizer 7 to engage in S1L and the second synchronizer 11 to engage in S2R, allowing the two synchronizers to shift sequentially. When an upshift or downshift is required, the control module generates a shift command for the corresponding target gear. For example, to shift from 2nd gear (engine direct drive 1st gear) to 3rd gear (ECVT1-1) according to Table 3, the shift command requires shifting from S1L+S2R to S1L+S2M. In this case, S1L of the first synchronizer 7 remains unchanged, and only S2R of the second synchronizer 11 is shifted to S2M. When downshifting from 2nd gear to 1st gear, only S1L of the first synchronizer 7 needs to be shifted to S1M. In this embodiment, each upshift and shift can control only one synchronizer to perform the shift operation, thereby reducing shift interference caused by simultaneous shifting of two synchronizers, which can lead to shift failures, and improving shift smoothness and shift speed. Referring to Figure 1, taking engine direct drive 1st gear as an example, the engagement state of the first synchronizer 7 and the second synchronizer 11 is S1L+S2R. The first synchronizer 7 engages the ring gear 1 with the small driving gear 13, and the second synchronizer 11 engages the second input shaft 6 with the ring gear 1. The ring gear 1 and the sun gear 2 are connected via the second input shaft 6 and rotate synchronously. The output power of the engine 23 is transmitted in sequence through the torsional vibration damper 24, the first input shaft 5, the planetary gear carrier 4, the planetary gears 3, the ring gear 1, the small driving gear 13, the second large driven gear 21, the second intermediate shaft 20, the second small driven gear 22, and the differential driven gear 14 to the differential 9. The power is then transmitted to the vehicle's wheel ends through the axle shafts through the differential 9, driving the vehicle in 2nd gear. At this time, the transmission ratio of the planetary gear mechanism is 1, and the transmission ratio of the entire drive system is the transmission ratio of the shift mechanism in this gear. Other gear modes are similar and will not be described in detail.

[0070] In some embodiments, as shown in Figure 3, the control module is configured as a vehicle controller VECU; the hybrid drive system also includes a transmission controller MTCU; the control module is configured to: generate a shift instruction in response to the speed difference being less than or equal to a first threshold, and the speed difference change rate being less than or equal to a second threshold; generate a cancel shift instruction in response to the speed difference being greater than the first threshold, and / or the speed difference change rate being greater than the second threshold; the transmission controller MTCU is configured to: receive a shift instruction, control the first synchronizer 7 to engage, or control the second synchronizer 11 to engage; receive a cancel shift instruction, control the first synchronizer 7 to disengage, or control the second synchronizer 11 to disengage.

[0071] In some embodiments, as shown in FIG3 , the vehicle controller is further configured to control the speed of at least one of the first motor 18 , the second motor 25 , and the engine 23 , in response to a shift request. The motors in FIG3 may be the first motor 18 and / or the second motor 25 ; specifically, the speed and torque of the engine 23 and the second motor 25 may be adjusted. The second motor 25 may be configured as a generator.

[0072] The shift command indicates the target gear position for the shift and the synchronizer engagement state corresponding to the target gear position. In the disclosed embodiment, the first speed, second speed, third speed, and other parameters for calculating the speed difference between the two ends of the synchronizer to be engaged are obtained by the VECU. The speed difference, the speed difference change rate, and the determination of the shift condition are all executed by the VECU. The shift command and the shift cancellation command are generated by the VECU, and the MTCU receives the corresponding commands to execute the corresponding synchronizer engagement and disengagement operations. Before the shift and when the shift condition has not been determined to be met, the VECU can control the speed and torque output of at least one of the first motor 18, the second motor 25, and the engine 23 so that the speed difference between the two ends of the synchronizer to be engaged and the speed difference change rate meet the shift condition, thereby improving the shift speed and shift smoothness.

[0073] In some embodiments, as shown in Figure 4 , the control module is configured as a transmission controller (MTCU). The MTCU is configured to control the engagement and disengagement of the first synchronizer 7 and the second synchronizer 11 in response to shift requests. In this embodiment, the MTCU receives shift commands from the VECU, obtains the corresponding speed and parameters, and calculates the corresponding speed difference and speed difference change rate. The MTCU then determines shift threshold conditions, executes and cancels shift operations. In this case, the VECU may not cancel the shift operation.

[0074] According to some aspects of the embodiments of the present disclosure, FIG5 provides a control method applied to a hybrid drive system, including:

[0075] S101: Obtain at least one of a first speed of the first motor, a second speed of the second motor, and a third speed of the engine;

[0076] S102 : Controlling engagement and disengagement of a first synchronizer and a second synchronizer according to at least one of a first speed, a second speed, and a third speed.

[0077] In some embodiments, the control method includes: calculating the speed difference and the speed difference change rate at the two ends of the first synchronizer 7 and the second synchronizer 11 to be engaged based on at least one of the first speed, the second speed and the third speed, and in response to the speed difference being less than or equal to a first threshold, and the speed difference change rate being less than or equal to a second threshold; controlling the corresponding first synchronizer 7 to engage or the corresponding second synchronizer 11 to engage; in response to the speed difference being greater than the first threshold, and / or the speed difference change rate being greater than the second threshold; controlling the corresponding synchronizer to disengage.

[0078] In some embodiments, the control method includes: calculating the rotational speed of the small driving gear 13 and the rotational speed of the large driving gear 12 according to the first rotational speed and the gear ratio; calculating the rotational speed of the ring gear 1 according to the second rotational speed, the third rotational speed, and the gear ratio of the ring gear 1 and the sun gear 2; in response to the first speed difference between the first synchronizer 7 and the small driving gear 13 being less than or equal to the first threshold value, and the rate of change of the first speed difference being less than or equal to the second threshold value; controlling the first synchronizer 7 to engage (engage to the S1L position) so that the ring gear 1 engages with the small driving gear 13.

[0079] In some embodiments, the control method further includes: in response to the second speed difference between the ring gear 1 and the large driving gear 12 being less than or equal to the first threshold, and the rate of change of the second speed difference being less than or equal to the second threshold; controlling the first synchronizer 7 to engage (engage to the S1R position) so that the ring gear 1 engages with the large driving gear 12.

[0080] In some embodiments, the control method further includes: in response to the second speed being less than or equal to the first threshold and the rate of change of the second speed being less than or equal to the second threshold; controlling the second synchronizer 11 to engage (engage to the S2L position) to engage the second input shaft 6 with the transmission housing 8.

[0081] In some embodiments, the control method further includes: calculating the speed of the ring gear 1 based on the second speed, the third speed, and the gear ratio of the ring gear 1 to the sun gear 2; in response to a third speed difference between the second speed and the speed of the ring gear 1 being less than or equal to the first threshold, and a rate of change of the third speed difference being less than or equal to the second threshold; controlling the second synchronizer 11 to engage (engage to the S2R position) so that the second input shaft 6 engages with the ring gear 1.

[0082] According to some aspects of the embodiments of the present disclosure, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed, the control method is implemented.

[0083] The storage medium may be a ferroelectric random access memory (FRAM), a magnetic random access memory (MRAM), a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), a flash memory, a magnetic surface mount storage device, an optical disc, or a compact disc read-only memory (CD-ROM).

[0084] In some embodiments, executable instructions may be in the form of a program, software, software module, script, or code, written in any form of programming language (including compiled or interpreted languages, or declarative or procedural languages), and may be deployed in any form, including as a stand-alone program or as a module, component, subroutine, or other unit suitable for use in a computing environment.

[0085] By way of example, executable instructions may, but need not, correspond to a file in a file system, may be stored as part of a file storing other programs or data, e.g., in one or more scripts within an HTML document, in a single file dedicated to the program in question, or in multiple coordinating files (e.g., files storing one or more modules, subroutines, or code portions).

[0086] As an example, executable instructions may be deployed to be executed on one electronic device, or on multiple electronic devices located at one site, or on multiple electronic devices distributed across multiple sites and interconnected by a communication network.

[0087] The above description is only a specific embodiment of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any technician familiar with the technical field can easily think of changes or replacements within the technical scope disclosed in the present disclosure, and they should all be covered by the protection scope of the present disclosure.

Claims

1. A hybrid drive system comprising: A planetary gear assembly comprising: a ring gear, a sun gear located within the ring gear, a plurality of planetary gears meshing between the ring gear and the sun gear, and a planetary gear carrier rotatably connecting the plurality of planetary gears; a first input shaft, a second input shaft, a third input shaft, and a differential; one end of the first input shaft is fixedly connected to the planetary gear carrier, and the other end is connected to the engine; the differential is drivingly connected to the ring gear; one end of the third input shaft is drivingly connected to the differential, and the other end of the third input shaft is fixedly connected to the first motor; one end of the second input shaft is fixedly connected to the sun gear, and the other end of the second input shaft is fixedly connected to the second motor; A first synchronizer is fixed to the ring gear, and a large driving gear and a small driving gear are rotatably provided on the ring gear and are respectively located on both sides of the first synchronizer; the large driving gear and the small driving gear are respectively connected to the differential; A second synchronizer is fixed on the second input shaft; and further includes a control module; the control module is configured to: The first synchronizer and the second synchronizer are controlled to be engaged and disengaged according to at least one of a first speed of the first motor, a second speed of the second motor, and a third speed of the engine.

2. The hybrid drive system according to claim 1, wherein: The control module is configured to: According to at least one of the first speed, the second speed, and the third speed, a speed difference and a speed difference change rate between the two ends of the first synchronizer and the second synchronizer to be engaged are calculated respectively. In response to the speed difference being less than or equal to a first threshold and the speed difference change rate being less than or equal to a second threshold; controlling the corresponding first synchronizer to engage or the corresponding second synchronizer to engage; In response to the speed difference being greater than a first threshold, and / or the speed difference change rate being greater than a second threshold, the corresponding synchronizer is controlled to be disengaged.

3. The hybrid drive system according to claim 2, wherein: The control module is configured to: Calculate the rotational speed of the small driving gear and the rotational speed of the large driving gear respectively according to the first rotational speed and the gear ratio; Calculating the ring gear speed according to the second speed, the third speed, and the gear ratio between the ring gear and the sun gear; In response to a first speed difference between the ring gear and the small driving gear being less than or equal to the first threshold, and a rate of change of the first speed difference being less than or equal to the second threshold, the first synchronizer is controlled to engage so that the ring gear engages with the small driving gear.

4. The hybrid drive system according to claim 3, wherein: The control module is further configured to: In response to a second speed difference between the ring gear and the large driving gear being less than or equal to the first threshold, and a rate of change of the second speed difference being less than or equal to the second threshold, the first synchronizer is controlled to engage, so that the ring gear engages with the large driving gear.

5. The hybrid drive system according to claim 2, wherein: The control module is configured to: In response to the second speed being less than or equal to the first threshold and the rate of change of the second speed being less than or equal to the second threshold, the second synchronizer is controlled to engage to engage the second input shaft with the transmission housing.

6. The hybrid drive system according to claim 2, wherein: The control module is configured to: Calculating the ring gear speed according to the second speed, the third speed, and the gear ratio between the ring gear and the sun gear; In response to a third speed difference between the second speed and the ring gear speed being less than or equal to the first threshold, and a rate of change of the third speed difference being less than or equal to the second threshold, the second synchronizer is controlled to engage, so that the second input shaft engages with the ring gear.

7. The hybrid drive system according to claim 2, wherein: The control module is configured as a vehicle controller; the hybrid drive system further includes a transmission controller; The control module is configured to: generating a shift command in response to the speed difference being less than or equal to a first threshold and the speed difference change rate being less than or equal to a second threshold; generating a cancel shift command in response to the speed difference being greater than the first threshold, and / or the speed difference change rate being greater than the second threshold; The transmission controller is configured to: receiving the shift instruction, and controlling the first synchronizer to engage, or controlling the second synchronizer to engage; The cancel shift instruction is received, and the first synchronizer is controlled to be disengaged, or the second synchronizer is controlled to be disengaged.

8. The hybrid drive system according to claim 7, wherein: The vehicle controller is further configured to: In response to a gear shift request, a speed of at least one of the first electric machine, the second electric machine, and the engine is controlled.

9. The hybrid drive system according to claim 2, wherein: The control module is configured as a transmission controller. The transmission controller is configured to control engagement and disengagement of the first synchronizer and the second synchronizer in response to a gear shift request.

10. A control method, applied to the hybrid drive system according to any one of claims 1 to 9, comprising: obtaining at least one of a first rotational speed of the first motor, a second rotational speed of the second motor, and a third rotational speed of the engine; Engagement and disengagement of the first synchronizer and the second synchronizer are controlled according to at least one of the first speed, the second speed, and the third speed.

11. The control method according to claim 10, wherein: The control method includes: According to at least one of the first speed, the second speed, and the third speed, a speed difference and a speed difference change rate between the two ends of the first synchronizer and the second synchronizer to be engaged are calculated respectively. In response to the speed difference being less than or equal to a first threshold and the speed difference change rate being less than or equal to a second threshold; controlling the corresponding first synchronizer to engage or the corresponding second synchronizer to engage; In response to the speed difference being greater than a first threshold, and / or the speed difference change rate being greater than a second threshold, the corresponding synchronizer is controlled to be disengaged.

12. The control method according to claim 11, wherein: The control method includes: Calculate the rotational speed of the small driving gear and the rotational speed of the large driving gear respectively according to the first rotational speed and the gear ratio; Calculating the ring gear speed according to the second speed, the third speed, and the gear ratio between the ring gear and the sun gear; In response to a first speed difference between the first synchronizer and the small driving gear being less than or equal to the first threshold, and a rate of change of the first speed difference being less than or equal to the second threshold, the first synchronizer is controlled to engage so that the ring gear engages with the small driving gear.

13. The control method according to claim 12, wherein: The control method further includes: In response to a second speed difference between the ring gear and the large driving gear being less than or equal to the first threshold, and a rate of change of the second speed difference being less than or equal to the second threshold, the first synchronizer is controlled to engage, so that the ring gear engages with the large driving gear.

14. The control method according to claim 12, wherein: The control method further includes: In response to the second speed being less than or equal to the first threshold and the rate of change of the second speed being less than or equal to the second threshold, the second synchronizer is controlled to engage to engage the second input shaft with the transmission housing.

15. The control method according to claim 12, wherein: The control method further includes: Calculating the ring gear speed according to the second speed, the third speed, and the gear ratio between the ring gear and the sun gear; In response to a third speed difference between the second speed and the ring gear speed being less than or equal to the first threshold, and a rate of change of the third speed difference being less than or equal to the second threshold, the second synchronizer is controlled to engage, so that the second input shaft engages with the ring gear. 16 . A computer-readable storage medium having a computer program stored thereon, wherein the computer program implements the control method according to claim 10 when executed.

Images