Gear shifting method and system for P2 hybrid power system gearbox and vehicle

Abstract

The invention relates to the technical field of vehicle control, and discloses a gear shifting method and system for a P2 hybrid power system gearbox and a vehicle. The method comprises the steps that an engine receives a gear shifting request of a vehicle control unit, and the current output torque is maintained; a torque clearing state in which the resultant torque of the input shaft of the gearbox is zero is established through torque compensation of the driving motor; after the twist clearing state is established, the vehicle control unit controls the gearbox to execute gear removing operation; after gear disengagement is completed, a driving motor exerts speed regulation torque to conduct rotating speed synchronous control; after rotation speed synchronization is completed, the untwisting state is recovered, and gear-in operation is executed; and after gear shifting is completed, the power source target driving torque is recovered, and the gear shifting process is completed. The clutch does not need to participate in the process, separation and closing operation of the clutch is omitted, time is saved in the process, meanwhile, abrasion of the clutch is reduced, and the service life of the clutch is prolonged.

Description

Technical Field

[0001] The present invention relates to the field of vehicle control technology, and in particular to a shifting method, system and vehicle for a P2 hybrid power system transmission. Background Art

[0002] As global awareness of the ecological environment continues to grow and environmental regulations become increasingly refined, hybrid vehicles (HEVs) are playing an increasingly important role in modern society, leveraging their significant advantages in energy conservation and emission reduction. The parallel P2 architecture, a typical HEV configuration, has gained widespread adoption due to its high fuel efficiency and superior driving experience.

[0003] In the field of P2 hybrid system shift control, domestic and international manufacturers currently generally adopt a shifting method evolved from the traditional automatic manual transmission (AMT). The specific shifting process of this method is as follows: First, the hybrid control unit (HCU) sends a torque clearing command to the engine and electric motor. After the torque clearing operation is completed, the clutch is controlled to disengage. After the clutch is disengaged, a shift shifting command is sent to the transmission. When the gear is successfully shifted to neutral, the electric motor is controlled to adjust the speed. When the speed difference is within the acceptable range, the electric motor is subjected to torque clearing. The transmission is then controlled to shift into the target gear. After the target gear is engaged, the clutch is closed. Finally, the engine and electric motor resume torque output.

[0004] However, this traditional shift control method presents numerous problems. For one thing, the shift process involves engine torque clearance. Because engines have significantly slower response times than electric motors, torque clearance takes longer. This directly increases the overall shifting process, further prolonging the power interruption during the shift, impacting vehicle performance and ride comfort.

[0005] On the other hand, traditional control methods require the clutch to be disengaged and engaged. This not only causes vibration in the drivetrain, impacting the vehicle's NVH (noise, vibration, and harshness) performance, but also causes wear and tear during the clutch disengagement and engagement process, shortening its service life and increasing vehicle maintenance costs.

[0006] Therefore, it is of great practical significance to develop a P2 hybrid system shift control method that can effectively shorten the shift time, reduce the power interruption time, reduce the transmission system vibration and extend the service life of the clutch. Summary of the Invention

[0007] The object of the present invention is to provide a shifting method, system and vehicle for a P2 hybrid system transmission, so as to solve the technical problem in the prior art of how to shorten the shifting time while improving the shifting smoothness and the service life of the clutch.

[0008] The present invention is achieved through the following technical solutions: In a first aspect, the present invention provides a shifting method for a P2 hybrid system transmission, comprising: The engine receives the gear shift request from the vehicle controller and maintains the current output torque; The torque compensation of the driving motor is used to establish a torque-clearing state in which the total torque of the input shaft of the gearbox is zero; When the torque clearing state is established, the vehicle controller controls the transmission to execute the gear shifting operation; After the gear is disengaged, the speed is synchronously controlled by applying the speed regulating torque through the drive motor; After the speed synchronization is completed, the torque clearing state is restored and the gear shifting operation is performed; After the gear is engaged, the target driving torque of the power source is restored to complete the gear shifting process.

[0009] Preferably, maintaining the current output torque is specifically to maintain the torque value T at the time when the engine shift request is triggered. eng .

[0010] Preferably, in the clear torque state where the total torque of the input shaft of the gearbox is zero, the clear torque state is achieved by driving the motor to perform reverse torque compensation in which the torque output is opposite to the current output torque maintained by the engine, T0=-T eng , where T0 is the target torque of the drive motor, T eng is the current output torque of the engine. Furthermore, the expression for the torque-free state where the total torque of the input shaft of the gearbox is zero is as follows: T2= T0+T eng =-T eng +T eng =0 Among them, T2 is the total torque of the input shaft of the gearbox; T0 is the target torque of the drive motor; T eng is the current output torque of the engine.

[0011] Preferably, after the gear is shifted, the speed regulating torque is applied by the driving motor, and the calculation formula of the speed regulating torque is as follows: T1=T0+T spd Among them, T1 is the speed regulating torque applied by the driving motor; T spd is the speed regulation compensation torque; T0 is the target torque of the driving motor.

[0012] Preferably, the completion condition of the speed synchronization control is that the speed difference between the input shaft and the output shaft of the gearbox enters a preset threshold range, wherein the preset threshold range is dynamically adjusted according to the type of gearbox and the current gear position.

[0013] Preferably, after the speed synchronization is completed and the torque clearing state is restored, the drive motor resumes executing the target torque T0 to ensure that the total torque of the input shaft of the gearbox is 0.

[0014] In a second aspect, the present invention further provides a shifting system for a P2 hybrid power system transmission, which is used to implement the above-mentioned shifting method for a P2 hybrid power system transmission, comprising an engine, a drive motor, a transmission, and a vehicle controller; The output end of the engine is connected to the input end of the drive motor, and the output end of the drive motor is connected to the input end of the gearbox, and the gearbox is used to output power; The vehicle controller is connected to the control terminals of the engine, drive motor and gearbox respectively through the CAN communication bus.

[0015] Preferably, the vehicle controller includes a control module, the signal output end of the control module is connected to the processor and the input end of the drive module, and the output end of the drive module is respectively connected to the control end of the engine, the drive motor and the gearbox.

[0016] In a third aspect, the present invention further provides a vehicle comprising a gear shifting system for a P2 hybrid power system transmission as described above.

[0017] Compared with the prior art, the present invention has the following beneficial technical effects: The present invention provides a shifting method for a P2 hybrid system transmission. By controlling the torque of the drive motor during the shifting process, the drive motor outputs a negative torque that is equal in magnitude and opposite in direction to the engine, which is equivalent to the engine's clear torque. Since the response speed of the drive motor is much faster than that of the engine, the shifting time can be effectively shortened. The present invention utilizes drive motor torque compensation to establish a clear torque state, and after the shift is completed, the drive motor applies a speed regulation torque to synchronize the speed control, thereby achieving equivalent clear torque and equivalent speed regulation of the transmission input shaft, and ensuring the smoothness and accuracy of the shifting process. The present invention does not require the participation of a clutch, eliminating the clutch's separation and closing operations. This process saves time while reducing clutch wear and extending the clutch's service life.

[0018] Furthermore, by driving the motor to perform reverse torque compensation in the opposite direction of the current output torque of the engine to establish a clear torque state in which the total torque of the transmission input shaft is zero, the total torque of the transmission input shaft can be quickly and accurately brought to zero, avoiding problems such as gear shifting shock and prolonged power interruption time caused by inaccurate torque compensation, and ensuring smooth gear shifting.

[0019] Furthermore, the speed regulating torque applied by the drive motor ensures that the transmission input shaft speed can quickly and accurately match the target gear speed, reducing the speed difference, thereby reducing the gear shift shock and improving the smoothness and comfort of the gear shift.

[0020] Furthermore, by precisely controlling the speed difference to within a preset threshold range as a prerequisite for speed synchronization, shift shock caused by speed mismatch can be effectively avoided. Shifting gears when the speed difference between the input and output shafts is within a reasonable range ensures smoother gear engagement, reduces collision and wear between gears, and reduces shift jerk, providing a more comfortable and smooth driving experience. Dynamically adjusting the preset threshold range improves the shift system's adaptability to different operating conditions, making the shift process more stable and reliable.

[0021] This invention also provides a shifting system for a P2 hybrid powertrain transmission. The vehicle controller communicates with the engine, motor, and transmission control terminals via a CAN bus, eliminating the need for clutch control logic and facilitating system integration and optimization. This system allows for more flexible adjustment of engine and motor torque output and speed based on varying driving conditions and requirements, achieving more efficient power distribution and shifting control, and improving the performance of the entire P2 hybrid powertrain. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Flowchart of a shifting method for a P2 hybrid power system transmission according to an embodiment of the present invention; Figure 2 A structural diagram of a gear shift system for a P2 hybrid power system transmission according to an embodiment of the present invention; In the figure: 1. Engine; 2. Clutch; 3. Drive motor; 4. Transmission; 5. CAN line; 6. Vehicle controller. DETAILED DESCRIPTION

[0023] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0024] The object of the present invention is to provide a shifting method, system and vehicle for a P2 hybrid system transmission, so as to solve the technical problem in the prior art of how to shorten the shifting time while improving the shifting smoothness and the service life of the clutch.

[0025] The present invention is described in further detail below with reference to the accompanying drawings: Example 1 See also Figure 1 In one embodiment of the present invention, a shifting method for a P2 hybrid power system transmission is provided, comprising: Step 1: The engine 1 receives a shift request from the vehicle controller 6 and maintains the current output torque; Specifically, maintaining the current output torque specifically means that the engine 1 maintains the torque value T at the time when the gear shift request is triggered. eng .

[0026] In this embodiment, the vehicle controller 6 comprehensively determines whether a gear shift is necessary based on the vehicle's driving conditions (such as speed, accelerator pedal position, gear selection, etc.) and the driver's operating intention. When a gear shift is determined to be necessary, the vehicle controller 6 sends a gear shift request signal to the engine 1 via the CAN communication bus 5. After interpreting the gear shift request signal, the engine 1 control module immediately activates the torque lock mechanism. This mechanism records the engine's output torque value T at the time the gear shift request is triggered. eng and locks the engine's torque output command at this value.

[0027] Step 2: establishing a torque-clearing state in which the total torque of the input shaft of the gearbox 4 is zero by driving the motor 3 for torque compensation; Specifically, in the clear torque state where the total torque of the input shaft of the gearbox 4 is zero, the clear torque state is achieved by driving the motor to perform reverse torque compensation in the opposite direction of the current output torque maintained by the engine 1, that is, T0=-T eng , where T0 is the target torque of the drive motor, T eng is the current output torque of engine 1. The expression for the torque-free state in which the total torque of the input shaft of the gearbox 4 is zero is as follows: T2= T0+T eng =-Teng +T eng =0 Among them, T2 is the total torque of the input shaft of the gearbox; T0 is the target torque of the drive motor; T eng is the current output torque of the engine.

[0028] In this embodiment, the vehicle controller 6 continuously monitors the operating status of the engine 1 and obtains the current output torque value T of the engine through the torque sensor and other equipment on the engine. eng The real-time data is transmitted to the control module of the drive motor 3 and its own control logic for subsequent torque compensation calculation. According to the requirements of the clear torque state, that is, the input shaft torque T2 of the gearbox 4 is zero, combined with the known current output torque T of the engine eng , through the formula T0=-T eng The target torque T0 that the drive motor 3 needs to output is calculated. The vehicle controller 6 sends the calculated target torque T0 to the control module of the drive motor 3, and the drive motor control module prepares to execute the torque output operation accordingly. After receiving the instruction of the target torque T0, the control module of the drive motor 3 will quickly adjust the operating parameters of the motor, such as current, voltage, etc., so that the motor outputs the torque consistent with the instruction. Since the target torque T0 is the same as the current output torque T of the engine, eng The reverse torque in the opposite direction, the drive motor 3 will output torque in this direction. For example, if the engine currently outputs a clockwise torque T eng , the driving motor 3 will output the target torque T0 in the counterclockwise direction.

[0029] The total torque T2 of the input shaft of the gearbox 4 is composed of the torque T0 output by the drive motor and the torque T output by the engine. eng Jointly decided, the calculation formula is T2= T0+T eng . Set T0=-T eng Substituting into the formula, we can get T2=T0+T eng =-T en +T eng =0. The vehicle controller 6 continuously monitors the torque sensor data on the transmission 4's input shaft, calculates the actual net torque T2, and compares it with the theoretical value of zero. When the actual net torque T2 approaches or reaches zero, the vehicle controller 6 determines that the transmission 4's input shaft has reached a torque-clearing state, where the net torque is zero. At this point, the transmission 4's input shaft is no longer subject to additional torque and is relatively "free," creating favorable conditions for subsequent shifting operations such as shifting, speed adjustment, and shifting.

[0030] Step 3: When the torque clearing state is established, the vehicle controller 6 controls the transmission 4 to perform a shifting operation; In this embodiment, the vehicle controller 6 processes and analyzes sensor data based on pre-set decision logic to determine whether the torque clearing state is stable and meets the gear shifting conditions. Once the conditions are met, the vehicle controller 6 sends a feedback signal to the driver or other vehicle systems indicating that the torque clearing state has been established and prepares to execute the gear shifting operation.

[0031] Step 4: After the gear is shifted, the speed is synchronously controlled by applying a speed regulating torque through the drive motor 3; Specifically, after the gear is shifted, the speed regulating torque is applied by the driving motor 3. The calculation formula of the speed regulating torque is as follows: T1=T0+T spd Among them, T1 is the speed regulating torque applied by the driving motor 3; T spd is the speed regulation compensation torque; T0 is the target torque of the driving motor.

[0032] Specifically, the completion condition of the speed synchronization control is that the speed difference between the input shaft and the output shaft of the gearbox 4 enters a preset threshold range, where the preset threshold range is dynamically adjusted according to the type of the gearbox 4 and the current gear.

[0033] In this embodiment, the vehicle controller 6 continuously monitors the status of the gearbox 4 and confirms that the gearbox is successfully in neutral through the gear information and speed data fed back by the internal sensors of the gearbox, that is, the gear shifting operation is completed. The vehicle controller 6 prepares to calculate the speed compensation torque T according to the target gear and the current vehicle driving state, combined with the preset speed control strategy. spd . The calculation of the speed regulation compensation torque is usually based on the vehicle's dynamic model and the characteristics of the gearbox, aiming to enable the speed of the gearbox input shaft to quickly and smoothly match the speed of the target gear. After receiving the speed regulation torque instruction, the control module of the drive motor 3 quickly adjusts the operating parameters of the motor, such as current, voltage, etc., so that the motor outputs a torque T1 that is consistent with the instruction. In the process of applying the speed regulation torque, the drive motor 3 will continue to apply torque to the input shaft of the gearbox 4 to change the speed of the input shaft. By dynamically adjusting the preset threshold range according to the gearbox type, it can be ensured that the speed synchronization control strategy can adapt to the characteristics of different gearboxes and improve the accuracy and reliability of speed synchronization.

[0034] Step 5: After the speed synchronization is completed, the torque clearing state is restored and the gear shifting operation is performed; Specifically, after the speed synchronization is completed and the torque clearing state is restored, the drive motor 3 resumes executing the target torque T0 to ensure that the total torque of the input shaft of the gearbox 4 is 0.

[0035] In this embodiment, the vehicle controller 6 continuously receives real-time data from the speed sensors of the input shaft and output shaft of the gearbox 4, calculates and analyzes the speed difference between the two. When the speed difference stabilizes within the preset threshold range for a specified time, the vehicle controller 6 determines that the speed synchronization control is completed. During the process of the drive motor 3 restoring the output target torque T0, the torque sensor of the input shaft of the gearbox 4 will monitor the resultant torque of the input shaft in real time. Based on the data fed back by the sensor, the vehicle controller 6 verifies whether the resultant torque of the input shaft of the gearbox 4 is 0. If the resultant torque is not 0, the vehicle controller 6 will further fine-tune the output torque of the drive motor 3 to ensure that the resultant torque is stable near 0, thereby ensuring the recovery of the torque-clearing state.

[0036] The vehicle controller 6 generates a specific shift command based on the vehicle's driving requirements and target gear information. It then transmits this shift command to the transmission control module 4 via the CAN communication bus 5. Upon receiving the shift command, the transmission control module 4 first controls the synchronizer. This synchronizer further synchronizes the speed of the gear to be engaged with the input or output shaft. The control module then controls the shift fork to move, pushing the coupling sleeve into engagement with the gear in the target gear, thus enabling the shift operation.

[0037] Step 6: After the gear is engaged, the target driving torque of the power source is restored to complete the gear shifting process.

[0038] This embodiment eliminates the need for engine torque clearance and clutch actuation, shortening shift time, improving shift smoothness, and increasing clutch life. By controlling the motor torque during the shift process, the transmission input shaft achieves "equivalent torque clearance" and "equivalent speed regulation."

[0039] In this embodiment, the entire process does not require engine torque clearance. Instead, the motor outputs a negative torque equal in magnitude and opposite in direction to the engine, equivalent to engine torque clearance. Because the motor's response speed is much faster than the engine's, shifting time can be shortened. The clutch disengagement and engagement operations are also eliminated, saving time and reducing clutch wear, thereby extending the clutch's service life.

[0040] In summary, the present invention provides a shifting method for a P2 hybrid system transmission. By controlling the torque of the drive motor during the shifting process, the drive motor outputs a negative torque that is equal in magnitude and opposite in direction to the engine, which is equivalent to the engine clearing torque. Since the response speed of the drive motor is much greater than that of the engine, the shifting time can be effectively shortened. The present invention utilizes the drive motor torque compensation to establish a clearing torque state, and after the shift is completed, the drive motor applies a speed regulation torque to synchronize the speed control, thereby achieving equivalent clearing torque and equivalent speed regulation of the transmission input shaft, and ensuring the smoothness and accuracy of the shifting process. The present invention does not require the participation of a clutch in the process, eliminating the separation and closing operations of the clutch. This process saves time while reducing clutch wear and extending the service life of the clutch.

[0041] Example 2 according to Figure 2 As shown, this embodiment also provides a shifting system for a P2 hybrid power system transmission, which is used to implement the above-mentioned shifting method for a P2 hybrid power system transmission, including an engine 1, a drive motor 3, a transmission 4 and a vehicle controller 6; The output end of the engine 1 is connected to the input end of the drive motor 3, and the output end of the drive motor is connected to the input end of the gearbox 4, and the gearbox 4 is used to output power; The vehicle controller 6 is communicatively connected to the control terminals of the engine 1 , the drive motor 3 , and the gearbox 4 respectively via the CAN communication bus 5 .

[0042] This embodiment further includes a clutch 2 , the output end of the engine 1 is connected to the clutch 2 , and the input shaft of the drive motor 3 is connected to the output end of the engine 1 through the clutch 2 .

[0043] Specifically, the vehicle controller 6 includes a control module, the signal output end of the control module is connected to the processor and the input end of the drive module, and the output end of the drive module is respectively connected to the control ends of the engine 1, the clutch 2, the drive motor 3, and the gearbox 4.

[0044] In summary, this embodiment provides a shifting system for a P2 hybrid powertrain transmission. The vehicle controller communicates with the engine, motor, and transmission control terminals via a CAN bus, eliminating the need for clutch control logic. This makes system integration and optimization easier. The system can flexibly adjust the torque output and speed of the engine and motor based on different driving conditions and requirements, achieving more efficient power distribution and shifting control, and improving the performance of the entire P2 hybrid powertrain.

[0045] Example 3 This embodiment also provides a vehicle, including a shifting system for a P2 hybrid power system transmission as described above.

[0046] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered by the scope of protection of the claims of the present invention.

Claims

1. A gear shifting method for a P2 hybrid system transmission, characterized in that: include: The engine receives the gear shift request from the vehicle controller and maintains the current output torque; The torque compensation of the driving motor is used to establish a torque-clearing state in which the total torque of the input shaft of the gearbox is zero; When the torque clearing state is established, the vehicle controller controls the transmission to execute the gear shifting operation; After the gear is disengaged, the speed is synchronously controlled by applying the speed regulating torque through the drive motor; After the speed synchronization is completed, the torque clearing state is restored and the gear shifting operation is performed; After the gear is engaged, the target driving torque of the power source is restored to complete the gear shifting process.

2. The shifting method for a P2 hybrid power system transmission according to claim 1, characterized in that: The maintenance of the current output torque is specifically the torque value T of the engine (1) at the time of the gear shift request triggering. eng .

3. The shifting method for a P2 hybrid powertrain transmission according to claim 1, characterized in that: In the torque-clearing state where the total torque of the input shaft of the gearbox (4) is zero, the torque-clearing state is performed by driving the motor to perform reverse torque compensation in the opposite direction of the output torque of the current output torque maintained by the engine (1), T0=-T eng , where T0 is the target torque of the drive motor, T eng is the current output torque of the engine (1).

4. The shifting method for a P2 hybrid power system transmission according to claim 3, characterized in that: The expression for the torque-free state of the input shaft of the gearbox (4) is zero is as follows: T2= T0+T eng =-T eng +T eng =0 Among them, T2 is the total torque of the input shaft of the gearbox; T0 is the target torque of the drive motor; T eng is the current output torque of the engine.

5. The shifting method for a P2 hybrid power system transmission according to claim 1, characterized in that: After the gear shift is completed, the speed regulating torque is applied by the driving motor (3), and the calculation formula of the speed regulating torque is as follows: T1=T0+ T spd Wherein, T1 is the speed regulating torque applied by the driving motor (3); T spd is the speed regulation compensation torque; T0 is the target torque of the driving motor.

6. The shifting method for a P2 hybrid power system transmission according to claim 1, characterized in that: The completion condition of the speed synchronization control is that the speed difference between the input shaft and the output shaft of the gearbox (4) enters a preset threshold range, wherein the preset threshold range is dynamically adjusted according to the type of the gearbox (4) and the current gear position.

7. The shifting method for a P2 hybrid power system transmission according to claim 1, characterized in that: After the speed synchronization is completed and the torque clearing state is restored, the drive motor (3) resumes executing the target torque T0, so as to ensure that the input shaft torque of the gearbox (4) is 0.

8. A gear shift system for a P2 hybrid system transmission, characterized in that: A gear shifting method for a P2 hybrid power system transmission for implementing any one of claims 1 to 7, comprising an engine (1), a drive motor (3), a transmission (4) and a vehicle controller (6); The output end of the engine (1) is connected to the input end of the drive motor (3), and the output end of the drive motor is connected to the input end of the gearbox (4), and the gearbox (4) is used to output power; The vehicle controller (6) is communicatively connected to the control ends of the engine (1), the drive motor (3), and the gearbox (4) respectively via a CAN communication bus (5).

9. The shifting system for a P2 hybrid power system transmission according to claim 8, characterized in that: The vehicle controller (6) comprises a control module, wherein a signal output end of the control module is connected to an input end of a processor and a drive module, and an output end of the drive module is respectively connected to control ends of an engine (1), a drive motor (3), and a gearbox (4).

10. A vehicle, characterized in that: It includes a shifting system for a P2 hybrid system transmission as described in claim 8.

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