Serial switching method of hybrid vehicle driving mode

Abstract

This invention relates to the technical field of automobiles, specifically to a method for serially switching drive modes in hybrid vehicles. The method includes a front-wheel drive system and a rear-wheel drive system, with the rear-wheel drive system comprising a rear motor. The front-wheel drive system includes a front motor, an engine, and front wheels. A clutch is provided between the front motor and the engine, and a clutch and gears are provided between the engine and the front wheels. By disengaging or engaging clutches one and two, and adapting them to the front motor, engine, and rear motor, the system provides five drive modes: electric four-wheel drive, electric rear-wheel drive, range-extended rear-wheel drive, hybrid four-wheel drive, and hybrid front-wheel drive. Only two adjacent drive modes can be switched between each other. Therefore, this invention reduces calibration conditions by rationally arranging the drive modes and using some drive modes as transitions.

Description

Technical Field

[0001] This invention relates to the technical field of automobiles, and specifically to a method for serial switching of drive modes in hybrid vehicles. Background Technology

[0002] Pure electric vehicles drive their wheels by supplying the electrical energy stored in their power batteries to the drive motor. They boast superior power performance, zero emissions, and zero pollution, and have seen large-scale development. However, due to issues such as the aging of power batteries and their capacity degradation at low temperatures, the driving range of pure electric vehicles is significantly limited. Therefore, electric vehicles with auxiliary power units (i.e., range-extended electric vehicles) have emerged. They combine the advantages of pure electric vehicles, such as simple structure and strong power, with the ability to compensate for the insufficient driving range of pure electric vehicles to some extent. Thus, research on range-extended electric vehicles has become one of the important research directions in the field of new energy vehicles.

[0003] For example, patent application number 2023102787608, entitled "An Invention of a Hybrid Range Extender for Auxiliary Drive," is a type of range-extended electric vehicle. It combines a motor and an engine with two clutches, allowing the motor to generate electricity and thus extend the range. The engagement and disengagement of the clutches switch the vehicle's drive mode, which includes engine-driven motor power generation, motor-only drive, engine-direct drive, and engine-motor combined drive. Furthermore, as technology advances, the number of drive modes will increase. Based on current calibration methods, at least four different operating states need to be established for pairwise switching. This results in at least eight calibration conditions (or at least ten if there are five), each requiring calibration, leading to long calibration times and high costs. Summary of the Invention

[0004] The purpose of this invention is to provide a serial switching method for hybrid vehicle drive modes. By rationally arranging the drive modes and using some drive modes as transitions, the calibration conditions are reduced, thus solving the problem of long calibration time and high cost caused by the large number of existing calibration conditions.

[0005] The objective of this invention is achieved as follows: A serial switching method for hybrid vehicle drive modes includes a front-wheel drive system and a rear-wheel drive system, wherein the rear-wheel drive system includes a rear motor, the front-wheel drive system includes a front motor, an engine and front wheels, and a clutch one is provided between the front motor and the engine, and a clutch two and a gear are provided between the engine and the front wheels. By disengaging or engaging clutch one and clutch two, and adapting to the front motor, engine and rear motor, it can have electric four-wheel drive mode, electric rear-wheel drive mode, range-extended rear-wheel drive mode, hybrid four-wheel drive mode and hybrid front-wheel drive mode. Of the five drive modes—electric four-wheel drive mode, electric rear-wheel drive mode, range-extended rear-wheel drive mode, hybrid four-wheel drive mode, and hybrid front-wheel drive mode—only two adjacent modes can be switched between each other.

[0006] Preferably, the conversion process between the two modes is as follows: CE static engagement, CE static disengagement, CG dynamic engagement, CG dynamic disengagement, RM output torque, and RM zero torque. The transition from electric rear-drive mode to range-extended rear-drive mode is achieved by static engagement of the CE (Electric Rear-drive) system, and the transition from range-extended rear-drive mode to electric rear-drive mode is achieved by static disengagement of the CE system. The switching from electric four-wheel drive mode to electric rear-wheel drive mode and from hybrid four-wheel drive mode to range-extended rear-wheel drive mode is dynamically disconnected by CG, and the switching from electric rear-wheel drive mode to electric four-wheel drive mode and from range-extended rear-wheel drive mode to hybrid four-wheel drive mode is also dynamically disconnected by CG. When the hybrid four-wheel drive mode is switched to the hybrid front-wheel drive mode, RM is zero torque, and when the hybrid front-wheel drive mode is switched to the hybrid four-wheel drive mode, RM is the output torque.

[0007] Preferably, the front motor is connected to a second drive shaft, and the second drive shaft is connected to the engine via a first clutch. The second drive shaft is also connected to a fourth drive shaft via a gear set. One side of the fourth drive shaft is connected to the second clutch, and the second clutch is connected to a gear. The prerequisite for static engagement of CE is that both clutch one and clutch two are disengaged, the engine is stopped, and both drive shaft two and drive shaft four are stationary. The static engagement of the CE includes power-on and engagement. Power-on involves the clutch being powered on and engaged, while engagement involves the front motor rotating forward at a speed of 5 revolutions per minute, with the maximum torque limited to less than or equal to 1 Newton-meter.

[0008] Preferably, the CE static connection includes verification, and the verification content is that when the current motor experiences a current step, the front motor is immediately switched to a zero torque state. If a current step occurs for more than 200 milliseconds, the front motor continues to rotate, and the coil of clutch one is repeatedly energized and de-energized until the front motor experiences a current step.

[0009] Preferably, the front motor is connected to a second drive shaft, and the second drive shaft is connected to the engine via a first clutch. The second drive shaft is also connected to a fourth drive shaft via a gear set. One side of the fourth drive shaft is connected to the second clutch, and the second clutch is connected to a gear. The prerequisite for static CE disconnection is that clutch one is engaged, clutch two is disengaged, the engine is stopped, and drive shaft two and drive shaft four are stationary. The static disconnection of CE includes torque release and power-off. Torque release means that the front motor enters a zero torque state, thereby eliminating torque transmission in clutch one. Power-off means that clutch one is energized and disconnected.

[0010] Preferably, the CE static engagement includes verification, and the verification content is as follows: 100 milliseconds after the clutch is de-energized, the front motor rotates forward at a speed of 5 revolutions per minute and rotates for 100 milliseconds, and the maximum torque is limited to less than or equal to 1 positive Newton-meter. At this time, the FM rotary transformer will record the angle through which the rotor of the front motor rotates. When it rotates through a positive mechanical angle of 5 degrees, the verification is successful, and the front motor switches to a zero torque state. If the verification fails, the front motor will reverse at a speed of 5 revolutions per minute for 100 milliseconds, and the maximum torque will be limited to less than or equal to 1 Newton-meter. The absolute value of the angle rotated by the rotor of the current motor is 5 degrees. After rotating 5 mechanical angles, the verification is successful, and the front motor switches to zero torque state.

[0011] Preferably, the front motor is connected to a second drive shaft, and the second drive shaft is connected to the engine via a first clutch. The second drive shaft is also connected to a fourth drive shaft via a gear set. One side of the fourth drive shaft is connected to the second clutch, and the second clutch is connected to a gear. The prerequisite for CG dynamic engagement is that clutch 2 is in the disengaged state, and clutch 1 is in the disengaged or engaged state. When clutch 1 is in the engaged state, the engine needs to run but is in a zero torque state. The CG dynamic engagement includes following and torque release. Following involves the front motor adjusting its speed according to the rotational speed of the gear, with the goal of making the rotational speed of the transmission shaft four 5 to 15 revolutions per minute higher than that of the gear. Torque release involves the front motor entering a zero-torque state and the clutch two being energized and engaged.

[0012] Preferably, the CG dynamic engagement further includes verification, and the verification content is to compare the rotational speed of the drive shaft four calculated by the FM rotary transformer and the rotational speed of the gear calculated by the wheel speed sensor to obtain the speed difference. When the speed difference is less than or equal to 2 revolutions per minute and lasts for 100 milliseconds, it is determined that the clutch two is successfully engaged. If the test fails, and clutch two is in the disengaged state, then de-energize clutch two and re-perform the following, torque release, and test.

[0013] Preferably, the front motor is connected to a second drive shaft, and the second drive shaft is connected to the engine via a first clutch. The second drive shaft is also connected to a fourth drive shaft via a gear set. One side of the fourth drive shaft is connected to the second clutch, and the second clutch is connected to a gear. The prerequisite for CG dynamic disconnection is that clutch 2 is in the engaged state, and clutch 1 is in the disengaged or engaged state. When clutch 1 is in the engaged state, the engine needs to run but is in a zero torque state. The CG dynamic disconnection includes torque release, power-off, and jittering. Torque release involves the front motor entering a zero-torque state, power-off involves the second clutch being de-energized, and jittering involves the front motor performing a torque jitter of ±1 Nm within 100 milliseconds, maintaining a negative 1 Nm output, and returning to a zero-torque state after 200 milliseconds. By releasing torque, power-off, and jittering, the second clutch is disengaged.

[0014] Preferably, the CG dynamic disconnection also includes verification, and the verification content is to compare the rotational speed of the drive shaft four calculated by the FM rotary transformer and the rotational speed of the gear calculated by the wheel speed sensor to obtain the speed difference. When the speed difference is greater than 3 revolutions per minute and lasts for 100 milliseconds, it is determined that the clutch two is successfully disconnected. If the verification fails, allow the clutch to vibrate repeatedly and compare the speed difference again.

[0015] The outstanding and beneficial technical effects of this invention compared to the prior art are: This invention reduces the number of calibration conditions by rationally arranging the drive modes and using some drive modes as transitions. Specifically, the five drive modes are electric four-wheel drive mode, electric rear-wheel drive mode, range-extended rear-wheel drive mode, hybrid four-wheel drive mode and hybrid front-wheel drive mode in sequence, and can only be converted between adjacent two modes. Therefore, there are only eight calibration conditions, which is less than the no less than ten calibration conditions set by existing systems.

[0016] 2. In order to further reduce the calibration conditions, the preferred embodiment of the present invention also performs control clustering on the clutch, that is, further reducing the eight calibration conditions to six. Therefore, the conversion process between the two modes is CE static engagement, CE static disengagement, CG dynamic engagement, CG dynamic disengagement, RM output torque and RM zero torque. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of the present invention.

[0018] Figure 2 This is a diagram showing the mode transformation of the present invention (CE is clutch one, CG is clutch two, FM is front motor, RM is rear motor, and ICE is engine).

[0019] Figure 3 This is one of the structural diagrams related to the clutch.

[0020] Figure 4 This is the second structural diagram of the clutch-related structures.

[0021] Figure 5 This is the third schematic diagram of the clutch-related structures.

[0022] Figure 6 This is the fourth structural diagram of the clutch-related structures.

[0023] Attached reference numerals: 1-Front motor; 2-Rear motor; 3-Engine; 4-Front wheel; 5-Clutch 1; 6-Clutch II; 81-Drive shaft II; 82-Drive shaft IV; 83-Drive shaft I. Detailed Implementation

[0024] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0025] like Figures 1-6 As shown, the serial switching method for the driving mode of a hybrid vehicle is characterized by including a front-wheel drive system and a rear-wheel drive system, wherein the rear-wheel drive system includes a rear motor 2, the front-wheel drive system includes a front motor 1, an engine 3 and a front wheel 4, and a clutch 1 5 is provided between the front motor 1 and the engine 3, and a clutch 2 6 and a gear are provided between the engine 3 and the front wheel 4.

[0026] Therefore, in actual use, by disengaging or engaging clutch 15 and clutch 26, and adapting to the front motor 1, engine 3 and rear motor 2, it can have electric four-wheel drive mode, electric rear-wheel drive mode, range-extended rear-wheel drive mode, hybrid four-wheel drive mode and hybrid front-wheel drive mode.

[0027] Therefore, this invention achieves four-wheel drive and range extension without adding other motors by adding clutch 5, clutch 6, and gear shifting. In other words, within limited space, the pure range extender is designed as a range extender with auxiliary drive function, allowing the vehicle to perform both the original range extender function and real-time four-wheel drive. Furthermore, by controlling clutch 5 and clutch 6 differently, multiple modes are available: electric four-wheel drive mode, electric rear-wheel drive mode, range-extended rear-wheel drive mode, hybrid four-wheel drive mode, and hybrid front-wheel drive mode. This variety of modes allows for better adaptation to different terrains and provides a better user experience.

[0028] Moreover, both clutch 5 and clutch 6 of this invention are electromagnetic clutches. Therefore, compared with the conventionally used clutches, namely mechanical friction clutches, electromagnetic clutches are more efficient, have a more compact structure, and are less expensive.

[0029] At the same time, among the five drive modes—electric four-wheel drive mode, electric rear-wheel drive mode, range-extended rear-wheel drive mode, hybrid four-wheel drive mode, and hybrid front-wheel drive mode—only two adjacent modes can be switched between each other.

[0030] Therefore, in actual use, this invention reduces the number of calibration conditions by rationally arranging the drive modes and using some drive modes as transitions. Specifically, the five drive modes are electric four-wheel drive mode, electric rear-wheel drive mode, range-extended rear-wheel drive mode, hybrid four-wheel drive mode and hybrid front-wheel drive mode in sequence, and can only be converted between adjacent two modes. Therefore, there are only eight calibration conditions, which is less than the existing standard of no less than ten calibration conditions.

[0031] like Figure 2 As shown, the specific details of each mode are as follows: First, in the electric four-wheel drive mode, clutch 1 (5) is in the disengaged state, and clutch 2 (6) is in the engaged state. At this time, both the front motor 1 and the rear motor 2 are used to drive the car, and the engine 3 is off.

[0032] Secondly, in the electric rear-wheel drive mode, both clutch 1 (5) and clutch 2 (6) are disengaged. At this time, both the front motor 1 and the engine 3 are stopped, and the rear motor 2 is used to drive the car.

[0033] Then, in the range-extended rear-wheel drive mode, clutch 1 (5) is engaged and clutch 2 (6) is disengaged. At this time, the front motor 1 generates electricity under the drive of the engine 3, thereby extending the range, and the rear motor 2 is used to drive the car.

[0034] Meanwhile, in the hybrid four-wheel drive mode, clutch 1 (5) is engaged and clutch 2 (6) is engaged. At this time, engine 3 and rear motor 2 are used to drive the car, and front motor 1 rotates along with engine 3 and rear motor 2.

[0035] Moreover, in the hybrid front-wheel drive mode, both clutch 5 and clutch 6 are engaged. At this time, engine 3 is used to drive the car, and the front motor 1 and rear motor 2 rotate with the engine 3.

[0036] like Figure 2 As shown, in order to further reduce the calibration conditions, the clutch is controlled by clustering. The conversion process between the two modes is CE static engagement, CE static disengagement, CG dynamic engagement, CG dynamic disengagement, RM output torque and RM zero torque, so the eight calibration conditions are further reduced to six.

[0037] The transition from electric rear-wheel drive mode to range-extended rear-wheel drive mode is a static engagement of CE (Electric-Electric Rear-Wheel Drive), and the transition from range-extended rear-wheel drive mode to electric rear-wheel drive mode is a static disengagement of CE. Furthermore, the transition from electric four-wheel drive mode to electric rear-wheel drive mode, and from hybrid four-wheel drive mode to range-extended rear-wheel drive mode, is a dynamic disengagement of CG (Gas-Induced Controller), and the transition from electric rear-wheel drive mode to electric four-wheel drive mode, and from range-extended rear-wheel drive mode to hybrid four-wheel drive mode, is a dynamic disengagement of CG.

[0038] At the same time, when switching from hybrid four-wheel drive mode to hybrid front-wheel drive mode, RM is zero torque, and when switching from hybrid front-wheel drive mode to hybrid four-wheel drive mode, RM is the output torque.

[0039] like Figure 1-6 As shown, the clutch-related structure is as follows: First, the front motor 1 is connected to the second drive shaft 81, and the second drive shaft 81 is connected to the engine 3 through the first clutch 5. The second drive shaft 81 is connected to the fourth drive shaft 82 through the gear set, and one side of the fourth drive shaft 82 is connected to the second clutch 6, and the second clutch 6 is connected to the gear position gear.

[0040] Meanwhile, the structure between the front motor 1 and the clutch 5 is not limited to one type. The front motor 1 can also be connected to a drive shaft 83, and the drive shaft 83 can be connected to a fourth drive shaft 82 via a gear set, or to a second drive shaft 81, or located between the second drive shaft 81 and the fourth drive shaft 82, i.e., connected to all of them. Furthermore, the aforementioned gear set is an existing structure, i.e., at least two gears mesh, but since it is not the focus of this invention, it will not be described in detail.

[0041] Corresponding to the above clutch structure, the specific contents of each calibration condition are as follows: First, CE static engagement, and the prerequisite for CE static engagement is that clutch 1 5 and clutch 2 6 are both in the disengaged state, engine 3 is stopped, and drive shaft 2 81 and drive shaft 4 83 are both stationary.

[0042] Meanwhile, the static engagement of CE includes power-on and engagement. Power-on involves the clutch 5 being powered on and engaged, while engagement involves the front motor 1 rotating forward at a speed of 5 revolutions per minute, with the maximum torque limited to less than or equal to 1 Newton-meter.

[0043] Furthermore, the CE static connection also includes verification, and the verification content is that when the current motor 1 experiences a current step, the front motor 1 is immediately switched to a zero torque state. If a current step occurs for more than 200 milliseconds, the front motor 1 continues to rotate, and the coil of clutch 5 repeatedly goes through the power cycle until the front motor 1 experiences a current step.

[0044] A current step is a very typical fault signal in motor control, referring to a sudden change in motor current within a very short time, either a sudden spike or a drop. This is usually accompanied by speed fluctuations or system alarms. For example, a current step will occur when the motor is stalled.

[0045] Secondly, CE static disconnection is required, and the prerequisite for CE static disconnection is that clutch 15 is engaged, clutch 26 is disengaged, engine 3 is stopped, and drive shaft 281 and drive shaft 483 are both stationary.

[0046] Meanwhile, the static disconnection of CE includes torque release and power-off. Torque release means that the front motor 1 enters a zero torque state, thereby eliminating torque transmission on clutch 5. Power-off means that clutch 5 is de-energized and disconnected.

[0047] Furthermore, the CE static connection also includes verification, and the verification content is as follows: 100 milliseconds after the clutch 15 is powered off, the front motor 1 rotates forward at a speed of 5 revolutions per minute and rotates for 100 milliseconds. At this time, the FM rotary transformer will record the angle through which the rotor of the front motor 1 rotates. When it rotates through a positive mechanical angle of 5 degrees, the verification is successful, and the front motor 1 switches to the zero torque state.

[0048] If the verification fails, the front motor 1 will reverse at a speed of 5 revolutions per minute for 100 milliseconds, with the maximum torque limited to less than or equal to 1 Newton-meter. The verification is successful when the rotor of the front motor 1 has rotated an absolute angle of 5 degrees (i.e., 5 mechanical degrees). The front motor 1 will then switch to a zero-torque state. The reason for this measure is to move the clutch teeth by reversing the rotation, creating a gap and providing an opportunity for disengagement.

[0049] Then, CG dynamic engagement is required, and the prerequisite for CG dynamic engagement is that clutch 26 is in the disengaged state and clutch 15 is in the disengaged or engaged state. When clutch 15 is in the engaged state, engine 3 needs to run but is in a zero torque state.

[0050] Meanwhile, the CG dynamic combination includes following and unwinding torque. The following is that the front motor 1 adjusts its speed according to the speed of the gear, and the speed adjustment goal is to make the speed of the transmission shaft 83 5 to 15 revolutions per minute higher than the speed of the gear. The unwinding torque is that the front motor 1 enters a zero torque state, and the clutch 6 is energized and engaged.

[0051] Furthermore, the CG dynamic engagement also includes verification, which involves comparing the rotational speed of the drive shaft 483 calculated by the FM rotary transformer with the rotational speed of the gear shift calculated by the wheel speed sensor to obtain the speed difference. When the speed difference is less than or equal to 2 revolutions per minute and lasts for 100 milliseconds, it is determined that the clutch 26 is successfully engaged.

[0052] If the verification fails, clutch 26 is in the disengaged state. In this case, de-energize clutch 26 and re-perform the following, torque release and verification.

[0053] Next, CG is dynamically disconnected. The prerequisite for CG dynamic disconnection is that clutch 26 is in the engaged state and clutch 15 is in the disengaged or engaged state. When clutch 15 is in the engaged state, engine 3 needs to run but is in a zero torque state.

[0054] Simultaneously, the CG dynamic disconnection includes torque release, power-off, and jittering. The torque release is as follows: the front motor 1 enters a zero torque state. The power-off is as follows: the clutch 6 is powered off. The jittering is as follows: the front motor 1 performs a torque jitter of ±1 Nm within 100 milliseconds and maintains a negative 1 Nm output. After 200 milliseconds, it returns to a zero torque state. Through torque release, power-off, and jittering, the clutch 6 is disconnected.

[0055] Furthermore, the CG dynamic disconnection also includes verification, and the verification content is to compare the speed of the drive shaft 483 calculated by the FM rotary transformer with the speed of the gear calculated by the wheel speed sensor to obtain the speed difference. When the speed difference is greater than 3 revolutions per minute and lasts for 100 milliseconds, it is determined that the clutch 26 has successfully disconnected.

[0056] If the verification fails, make clutch 26 vibrate repeatedly and compare the speed difference again.

[0057] Finally, the output torque of RM and the zero torque of RM are the transitions between hybrid four-wheel drive mode and hybrid front-wheel drive mode. When the hybrid front-wheel drive mode is converted to hybrid four-wheel drive mode, it is achieved by the output torque of the rear motor 2. Then, the transition from hybrid four-wheel drive mode to hybrid front-wheel drive mode is achieved by the zero torque of the rear motor 2.

[0058] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. However, the present invention is not limited to the above embodiments; therefore, various changes and modifications can be made without departing from the principles and scope of the present invention, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. A method for serial switching of driving modes in a hybrid vehicle, characterized in that, It includes a front drive system and a rear drive system, and the rear drive system includes a rear motor (2). The front drive system includes a front motor (1), an engine (3) and a front wheel (4). A clutch (5) is provided between the front motor (1) and the engine (3), and a clutch (6) and a gear are provided between the engine (3) and the front wheel (4). By disengaging or engaging clutch one (5) and clutch two (6), and adapting to the front motor (1), engine (3) and rear motor (2), it has electric four-wheel drive mode, electric rear-wheel drive mode, range-extended rear-wheel drive mode, hybrid four-wheel drive mode and hybrid front-wheel drive mode. Of the five drive modes—electric four-wheel drive mode, electric rear-wheel drive mode, range-extended rear-wheel drive mode, hybrid four-wheel drive mode, and hybrid front-wheel drive mode—only two adjacent modes can be switched between each other.

2. The serial switching method for hybrid vehicle drive modes according to claim 1, characterized in that: The conversion process between the two modes is as follows: CE static engagement, CE static disengagement, CG dynamic engagement, CG dynamic disengagement, RM output torque, and RM zero torque. The transition from electric rear-drive mode to range-extended rear-drive mode is achieved by static engagement of the CE (Electric Rear-drive) system, and the transition from range-extended rear-drive mode to electric rear-drive mode is achieved by static disengagement of the CE system. The switching from electric four-wheel drive mode to electric rear-wheel drive mode and from hybrid four-wheel drive mode to range-extended rear-wheel drive mode is dynamically disconnected by CG, and the switching from electric rear-wheel drive mode to electric four-wheel drive mode and from range-extended rear-wheel drive mode to hybrid four-wheel drive mode is dynamically combined by CG. When the hybrid four-wheel drive mode is switched to the hybrid front-wheel drive mode, RM is zero torque, and when the hybrid front-wheel drive mode is switched to the hybrid four-wheel drive mode, RM is the output torque.

3. The serial switching method for hybrid vehicle drive modes according to claim 2, characterized in that: The front motor (1) is connected to a second drive shaft (81), and the second drive shaft (81) is connected to the engine (3) through a clutch (5). The second drive shaft (81) is connected to a fourth drive shaft (83) through a gear set. One side of the fourth drive shaft (83) is connected to a second clutch (6), and the second clutch (6) is connected to a gear. The prerequisite for CE static engagement is that clutch one (5) and clutch two (6) are both disengaged, engine (3) is stopped, and drive shaft two (81) and drive shaft four (83) are both stationary. The static engagement of the CE includes power-on and engagement, and the power-on content is that the clutch (5) is powered on and engaged, and the engagement content is that the front motor (1) rotates forward at a speed of 5 revolutions per minute, and the maximum torque is limited to less than or equal to 1 Newton-meter.

4. The serial switching method for hybrid vehicle drive modes according to claim 3, characterized in that: The CE static combination also includes verification, and the verification content is that when the current motor (1) has a current step, the front motor (1) is immediately switched to a zero torque state. If there is a current step of more than 200 milliseconds, the front motor (1) continues to rotate, and the coil of clutch one (5) is repeatedly energized and de-energized until the current step of the front motor (1) occurs.

5. The serial switching method for hybrid vehicle drive modes according to claim 2, characterized in that: The front motor (1) is connected to a second drive shaft (81), and the second drive shaft (81) is connected to the engine (3) through a clutch (5). The second drive shaft (81) is connected to a fourth drive shaft (83) through a gear set. One side of the fourth drive shaft (83) is connected to a second clutch (6), and the second clutch (6) is connected to a gear. The prerequisite for static disconnection of CE is that clutch one (5) is engaged, clutch two (6) is disengaged, engine (3) is stopped, and drive shaft two (81) and drive shaft four (83) are both stationary. The static disconnection of CE includes torque release and power-off. Torque release means that the front motor (1) enters a zero torque state, thereby making no torque transmission on clutch one (5). Power-off means that clutch one (5) is powered off and disconnected.

6. The serial switching method for hybrid vehicle drive modes according to claim 5, characterized in that: The CE static connection also includes verification, and the verification content is that 100 milliseconds after the clutch (5) is powered off, the front motor (1) rotates forward at a speed of 5 revolutions per minute and rotates for 100 milliseconds, and the maximum torque is limited to less than or equal to 1 Newton-meter. At this time, the FM rotary transformer will record the angle through which the rotor of the front motor (1) rotates. When it rotates through a positive mechanical angle of 5 degrees, the verification is successful, and the front motor (1) switches to the zero torque state. If the verification fails, the front motor (1) will reverse at a speed of 5 revolutions per minute and rotate for 100 milliseconds. The maximum torque is limited to less than or equal to 1 Newton-meter. The absolute value of the angle rotated by the rotor of the current motor (1) is 5 degrees. After rotating 5 degrees of mechanical angle, the verification is successful, and the front motor (1) switches to zero torque state.

7. The serial switching method for hybrid vehicle drive modes according to claim 2, characterized in that: The front motor (1) is connected to a second drive shaft (81), and the second drive shaft (81) is connected to the engine (3) through a clutch (5). The second drive shaft (81) is connected to a fourth drive shaft (83) through a gear set. One side of the fourth drive shaft (83) is connected to a second clutch (6), and the second clutch (6) is connected to a gear. The prerequisite for CG dynamic engagement is that clutch 2 (6) is in the disengaged state and clutch 1 (5) is in the disengaged or engaged state. When clutch 1 (5) is in the engaged state, the engine (3) needs to run but is in a zero torque state. The CG dynamic combination includes following and unwinding torque. The following is that the front motor (1) adjusts its speed according to the rotation speed of the gear, and the speed adjustment target is to make the rotation speed of the transmission shaft four (83) 5 to 15 revolutions per minute higher than the rotation speed of the gear. The unwinding torque is that the front motor (1) enters the zero torque state, and the clutch two (6) is energized and engaged.

8. The serial switching method for hybrid vehicle drive modes according to claim 7, characterized in that: The CG dynamic engagement also includes verification, and the verification content is to compare the rotational speed of the drive shaft four (83) calculated by the FM rotary transformer with the rotational speed of the gear calculated by the wheel speed sensor to obtain the speed difference. When the speed difference is less than or equal to 2 revolutions / minute and lasts for 100 milliseconds, it is determined that the clutch two (6) is successfully engaged. If the verification fails, clutch 2 (6) is in the disengaged state. Then, energize clutch 2 (6) and repeat the following, torque release and verification.

9. The serial switching method for hybrid vehicle drive modes according to claim 2, characterized in that: The front motor (1) is connected to a second drive shaft (81), and the second drive shaft (81) is connected to the engine (3) through a clutch (5). The second drive shaft (81) is connected to a fourth drive shaft (83) through a gear set. One side of the fourth drive shaft (83) is connected to a second clutch (6), and the second clutch (6) is connected to a gear. The prerequisite for CG dynamic disconnection is that clutch 2 (6) is in the engaged state and clutch 1 (5) is in the disengaged or engaged state. When clutch 1 (5) is in the engaged state, the engine (3) needs to run but is in a zero torque state. The dynamic disconnection of the CG includes torque release, power-off and jittering. The torque release is: the front motor (1) enters a zero torque state, and the power-off is: the clutch (6) is powered off. The jittering is: the front motor (1) jitters with a torque of ±1 Nm within 100 milliseconds and maintains a negative 1 Nm output. After 200 milliseconds, it returns to a zero torque state. The clutch (6) is disconnected by torque release, power-off and jittering.

10. The serial switching method for hybrid vehicle drive modes according to claim 9, characterized in that: The CG dynamic disconnection also includes verification, and the verification content is to compare the rotational speed of the drive shaft four (83) calculated by the FM rotary transformer with the rotational speed of the gear calculated by the wheel speed sensor to obtain the speed difference. When the speed difference is greater than 3 revolutions / minute and lasts for 100 milliseconds, it is determined that the clutch two (6) is successfully disconnected. If the verification fails, let clutch 2 (6) vibrate repeatedly and compare the speed difference again.

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