Engine start-stop control method and system for power-split hybrid transmission

Abstract

The engine start-stop control method and system of a power-split hybrid transmission belong to the technical field of power-split hybrid vehicles. It is used to suppress the impact caused by the start-stop process of a power-split hybrid engine. The control system includes a vehicle control unit HTCU; an engine control unit ECU, which is responsible for collecting high-precision crankshaft position signals and camshaft position signals, and sending them to the generator controller MCU2 for shutdown angle control; the generator control unit MCU2 is responsible for dragging the engine to start, and dragging the engine to a specified crankshaft angle through torque control; the drive motor control unit MCU1 is responsible for responding to the vehicle control unit HTCU for torque preloading when starting the engine. The control system of the present invention integrates the functions of preloading the drive motor torque and controlling the engine shutdown angle. This special control method solves the impact caused by the engine start-stop process, thereby optimizing the vehicle NVH and improving driving comfort and smoothness.

Description

Technical Field

[0001] The present invention belongs to the technical field of power-split hybrid electric vehicles, and in particular relates to an engine start-stop control method and system based on a power-split hybrid dedicated transmission. Background Art

[0002] my country's energy and environmental situation is becoming increasingly severe, emission regulations are constantly upgraded, and people's awareness of environmental protection is gradually strengthened. At the same time, with the proposal of carbon neutrality and carbon peak, the energy strategy transformation will be further promoted. New energy vehicles represented by hybrid vehicles and pure electric vehicles will become an important direction for the development of future vehicles. For a long time in the future, due to the high cost of power batteries and the large room for improvement in technical capabilities such as energy density, cruising range, mass size, etc., hybrid technologies of various architectures will become an important transition route. Among them, the power split hybrid is composed of a hybrid-specific electric drive transmission, which is light in weight, small in size, high in transmission efficiency, and has efficient fuel-saving capabilities. The hybrid-specific transmission is the most important transmission component in the powertrain of hybrid vehicles. The hybrid transmission will directly affect the vehicle's power, fuel economy, driving comfort and smoothness.

[0003] Traditional fuel vehicles or other hybrid vehicles have a torque converter or clutch at the flywheel end of the engine to separate the engine from the wheel end, so the engine startup process will not transmit vibration to the wheel end to cause impact. However, the biggest feature of the current power-split hybrid transmission architecture is that the engine and the wheel end are rigidly connected, and the vibration during the startup process will be directly transmitted to the wheel end. It is difficult to suppress the impact of the startup process in terms of mechanical design. Among them, the engine, motor and drive wheel are always coupled together through planetary gears. The torque fluctuation of any input shaft will affect the wheel-side torque output and be transmitted to the body, resulting in a deterioration in smoothness. In particular, the impact caused by the engine start-stop process will be directly transmitted to the wheel end, affecting driving comfort. Summary of the invention

[0004] In order to solve the problems existing in the above-mentioned background technology, the present invention suppresses the impact caused by the start-stop process of a power-split hybrid engine, and further provides an engine start-stop control method and system based on a power-split hybrid dedicated transmission.

[0005] The technical solution adopted by the present invention is:

[0006] Engine start-stop control system for power-split hybrid transmission, including

[0007] The vehicle control unit HTCU is responsible for coordinating the torque management of the engine, drive motor EM1 and generator EM2, and determining the engine start and stop conditions;

[0008] The engine control unit ECU is responsible for collecting high-precision crankshaft position signals and camshaft position signals, and sends them to the generator controller MCU2 for shutdown angle control after filtering and analysis;

[0009] The generator control unit MCU2 is responsible for receiving the control command from the vehicle control unit HTCU during the engine start process, and the engine is started by the generator EM2. During the shutdown process, it is responsible for receiving and processing the crankshaft position signal and camshaft position signal fed back by the engine control unit ECU, which is used to identify the engine crankshaft angle and reverse the engine to the specified crankshaft angle through torque control;

[0010] The drive motor control unit MCU1 is responsible for receiving the drive instructions from the vehicle control unit HTCU to perform torque loading or energy recovery. When starting the engine, it is responsible for responding to the vehicle control unit HTCU to perform torque preloading and perform motor anti-shake control.

[0011] The engine start-stop control method of a power-split hybrid transmission includes a shutdown control method and a startup control method; the shutdown control method is: according to the corresponding angle of the engine reverse low-speed pulse resistance torque evaluated in the early stage, the engine is dragged to a specified crankshaft angle through the generator EM2 to prepare for the next start, so as to ensure the consistency of the calibration parameters of the startup process control software and the state of the engine body.

[0012] The shutdown control method specifically includes the following steps:

[0013] S1. In the first stage of Ph1: the engine torque is unloaded, and the drive motor EM1 performs torque compensation to meet the driver's needs. When the actual engine torque drops to a certain value (0-10Nm), it enters the second stage of Ph2;

[0014] S2. In the second stage of Ph2: the engine is self-idling controlled, the torque of the drive motor EM1 is loaded based on the exponential curve, the torque of the generator EM2 is kept at 0, and after the torque of the drive motor EM1 is loaded to a certain value, it enters the third stage of Ph3;

[0015] S3. In the third stage of Ph3: the torque of the drive motor EM1 is maintained, the engine is cut off from fuel, and the generator EM2 drags the engine with an exponential open-loop torque to quickly reduce the engine speed and pass through the resonance point. At the same time, the drive motor EM1 performs torque compensation;

[0016] S4. In the fourth stage of Ph4: the generator EM2 performs PID closed-loop control to prevent the engine speed from overshooting. After the engine speed is slowly reduced to spd=100RPM, it enters the cylinder deactivation control. During this period, the torque of the drive motor EM1 is compensated based on the torque of the generator EM2;

[0017] S5. In the fifth stage of Ph5: entering cylinder deactivation control, the generator EM2 performs cylinder deactivation control, the drive motor EM1 performs torque compensation, and the cylinder deactivation control torque and compensation torque are executed in the motor controller MCU2.

[0018] The startup control method comprises the following steps:

[0019] S1. In the first stage of Ph1, the torque of the drive motor EM1 is loaded based on an exponential curve, and the torque of the generator EM2 is kept at 0. After the torque of the drive motor EM1 is loaded to a certain value, it enters Ph2;

[0020] S2. In the second stage of Ph2, the torque of the drive motor EM1 is maintained, and the generator EM2 drags the engine with an exponential torque. At the same time, the drive motor EM1 performs torque compensation. The generator EM2 maintains after reaching a certain value. When the engine speed reaches Spd=300rpm, the torque of the generator EM2 drops to 15Nm and is maintained. When the engine speed reaches Spd=600rpm, the engine fuel injection ignition determines that the start is successful, and then enters the closed-loop idle control Ph3;

[0021] S3. In the third stage of Ph3, after the engine is ignited, the engine output torque slowly approaches the desired torque; the torque of the generator EM2 begins to decrease, and the engine speed continues to be stretched to around Spd=950rpm; after the actual engine speed reaches 950rpm, the hybrid system state switches to Running.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] The control system of the present invention integrates the functions of driving motor torque pre-loading and engine shutdown angle control, and solves the impact caused by the engine start-stop process through this special control method, thereby optimizing vehicle NVH and improving driving comfort and smoothness. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the mechanical structure of the power split hybrid transmission of the present invention;

[0025] Figure 2 This is the planetary gear lever diagram of the power split hybrid transmission of the present invention;

[0026] Figure 3 is a block diagram of the start-stop control system of the present invention;

[0027] Figure 4 is a flow chart of the startup control method of the present invention;

[0028] Figure 5 It is a flow chart of the shutdown control method of the present invention. DETAILED DESCRIPTION

[0029] In order to better understand the purpose, structure and function of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings.

[0030] like Figure 1 As shown, from the mechanical structure of the power-split hybrid transmission, it can be seen that the sun gear 1 of the planetary gear set is rigidly connected to the generator EM2, the planetary carrier 4 of the planetary gear set is rigidly connected to the engine ICE, and the outer ring gear 3 of the planetary gear set is rigidly connected to the drive motor EM1 and the drive wheel through the reducer. Therefore, the engine, the drive motor and the drive wheel are always rigidly coupled together, and the torque fluctuation of any axis will affect the final torque output. During the engine starting and shutting down process, the torque at the engine end will suddenly change, causing the whole vehicle to shake significantly under starting and shutting down conditions, seriously affecting the vehicle's smoothness and driving experience.

[0031] like Figure 2 As shown, it can be seen from the planetary gear lever diagram that when the engine is started from a standstill, the torque mode of the generator EM2 rigidly connected to the sun gear drags the engine ICE rigidly connected to the planet carrier, and after reaching the specified speed, the fuel injection ignition completes the start. In this process, the outer ring gear at the output end will be subjected to a downward reaction force. In terms of mechanical structure, the outer ring gear is rigidly connected to the drive motor EM1 and the wheel end, resulting in the wheel end being subjected to a reaction force. Therefore, during the in-situ engine starting process, a part of the force will be transmitted to the vehicle body to cause vibration. Similarly, when the load is started, the wheel end will still be subjected to a part of the reaction force. Based on this, the present invention is designed to control the drive motor EM1 torque to be loaded in advance through the vehicle control unit HTCU before the engine is started, to offset this reaction force, and at the same time eliminate the transmission system and gear clearance, thereby optimizing the impact caused by the engine starting process.

[0032] like Figure 3 As shown, the engine start-stop control system of the power split hybrid transmission of the present invention includes

[0033] The vehicle control unit HTCU is responsible for coordinating the torque management of the engine, drive motor EM1 and generator EM2, and judging the engine start and stop conditions;

[0034] The engine control unit ECU is responsible for collecting high-precision crankshaft position signals and camshaft position signals, and sends them to the generator controller MCU2 for shutdown angle control after filtering and analysis; at the same time, the engine control unit ECU interacts with the vehicle control unit HTCU for real-time torque request, resistance feedback and other signals;

[0035] The generator control unit MCU2 is responsible for receiving the control command from the vehicle control unit HTCU during the engine start process, and the engine is started by the generator EM2. During the shutdown process, it is responsible for receiving and processing the crankshaft position signal and camshaft position signal fed back by the engine control unit ECU, which is used to identify the engine crankshaft angle and reverse the engine to the specified crankshaft angle through torque control;

[0036] The drive motor control unit MCU1 is responsible for receiving the drive instructions from the vehicle control unit HTCU to perform torque loading or energy recovery. When starting the engine, it is responsible for responding to the vehicle control unit HTCU to perform torque preloading and perform motor anti-shake control.

[0037] This control system can realize the functions of preloading the drive motor torque and controlling the engine shutdown angle, and integrate the functional modules into the control unit. The vehicle control unit HTCU develops the functional modules, designs the control strategy, integrates the start-stop control conditions, and sends the torque preloading command and shutdown control command to the drive motor controller MCU1. The generator controller MCU2 develops the shutdown control functional module, and the engine control unit ECU develops the signal processing and signal output functional modules to collect high-precision crankshaft angle signals and camshaft position signals.

[0038] According to the traditional control concept, this part needs to collect the camshaft position signal and crankshaft angle signal through the CAN bus, and send them to the motor controller MCU2 to calculate the braking torque of the electric drive system. The motor controller MCU2 stops the engine to the specified position according to the given braking torque. However, due to the limitation of the CAN communication rate and the system requirements of high precision and real-time control, this part of the signal is sent to the generator controller MCU2 by hard wire for stop position control. In this way, the accuracy of sensor acquisition and transmission of signals is guaranteed, which plays a vital role in the control of the engine stop angle.

[0039] The engine start-stop control method of the power split hybrid transmission of the present invention includes a stop control method and a start control method;

[0040] The shutdown control method is:

[0041] When the engine is started, the initial crankshaft angle is necessarily related to the corresponding total engine resistance torque. The smaller the total resistance torque, the better the smoothness and rapid response of the corresponding starting process. Based on this, when the engine is stopped, according to the corresponding angle of the engine reverse low-speed pulse resistance torque evaluated in the early stage, the generator EM2 is used to drag the engine to the specified crankshaft angle for the next start, ensuring the consistency of the calibration parameters of the start process control software and the state of the engine body. Through this engine stop angle control method, the smoothness of the power split hybrid system engine start is significantly improved.

[0042] like Figure 4 As shown in the figure, the engine shutdown control process of the start-stop control system:

[0043] S1. In the first stage of Ph1: the engine torque is unloaded, and the drive motor EM1 performs torque compensation to meet the driver's needs. When the actual engine torque drops to a certain value (0-10Nm), it enters the second stage of Ph2;

[0044] S2. In the second stage of Ph2: the engine is self-idling controlled, the torque of the drive motor EM1 is preloaded based on the exponential curve, the torque of the generator EM2 is kept at 0, and after the torque of the drive motor EM1 is loaded to a certain value (P gear, -25Nm; D gear, 36Nm), it enters the third stage of Ph3;

[0045] S3. In the third stage of Ph3: the torque of the drive motor EM1 is maintained, the engine is cut off from fuel, and the generator EM2 rotates the engine with an exponential open-loop torque, quickly reducing the engine speed and passing through the resonance point (spd = about 350rpm). At the same time, the drive motor EM1 performs torque compensation (actual torque increase = TEM2*r1 / r2, and the engine angular acceleration is taken into account);

[0046] S4. In the fourth stage of Ph4: the generator EM2 performs PID closed-loop control to prevent the engine speed from overshooting. After the engine speed is slowly reduced to spd=100RPM, it enters the cylinder deactivation control. During this period, the torque of the drive motor EM1 is compensated based on the torque of the generator EM2;

[0047] S5. In the fifth stage of Ph5: entering cylinder deactivation control, the generator EM2 performs cylinder deactivation control, the drive motor EM1 performs torque compensation, and the cylinder deactivation control torque and compensation torque are executed in the motor controller MCU2.

[0048] Among them: after completing the fifth stage of Ph5, the mode is switched to Stopped, and the drive motor EM1 and the generator EM2 have no torque output;

[0049] The preload torque of the drive motor EM1 + the compensation value equivalent to the drag of the generator EM2 + the torque required by the driver (0 Nm) is used as the final torque request of the drive motor EM1;

[0050] The direction of the preload torque of the drive motor EM1 is related to the gear position, the N / D gear is positive and the P / R gear is negative;

[0051] The exponential drag curve of the generator EM2 is considered to be realized based on angular acceleration. The feedforward angular acceleration is related to the water temperature and the engine speed, and is made into an exponential curve S-shaped angular acceleration. The torque of the generator EM2 calculated based on the moment of inertia is loaded according to the exponential curve;

[0052] The vehicle control unit HTCU sends a CAN command to inform the motor controller MCU2 to enter the cylinder deactivation control mode;

[0053] During cylinder deactivation control, the motor controller MCU2 automatically completes the cylinder deactivation control torque of the generator EM2 and the torque compensation control of the drive motor EM1. The driver's required torque is completed by the vehicle control unit HTCU controlling the drive motor EM1.

[0054] When the motor controller MCU2 performs cylinder deactivation control, the motor controller MCU2 feeds back the cylinder deactivation control flag position as true. After completing the cylinder deactivation control, it feeds back the cylinder deactivation control flag position as false, indicating that the cylinder deactivation control has been completed. After receiving the completion signal, the vehicle control unit HTCU switches to the Stop state.

[0055] Startup control method:

[0056] The starting conditions are very complex, including static starting and load starting. Under different starting conditions, the control objectives and control strategies are different.

[0057] Static start: After the engine is started, the load operation is not started immediately. Since there is no torque output requirement for a short period of time after the start, the start is performed with the suppression of the start impact as the priority condition, such as static engine start.

[0058] Load start: After the engine is started, load operation is performed immediately. Since torque output is required immediately after the start, the start is based on the torque response characteristics as the priority condition, such as large throttle or constant throttle acceleration to a higher vehicle speed during pure electric driving to trigger the engine start.

[0059] When starting from a standstill, the EM1 torque of the drive motor will be loaded in advance. The pre-loading of torque can eliminate the transmission system and gear clearance on the one hand, and prepare for a quick start on the other hand. When starting from a standstill, the pre-loading of the EM1 torque of the drive motor makes the starting time significantly longer than starting while driving, with the goal of suppressing the starting shock.

[0060] When the load is started, during the starting process, the drive motor EM1 responds to the accelerator pedal and performs torque compensation. After the start is successful, the drive motor EM1 and the engine jointly respond to the accelerator pedal torque demand to drive the vehicle.

[0061] Based on this, whether it is a stationary start or a load start while driving, in order to prevent the impact of the entire vehicle during the starting process, it is necessary to use the drive motor EM1 to load the torque in advance or the motor to perform anti-shake control to reduce the output end torque fluctuation and the impact of the entire vehicle.

[0062] like Figure 5 As shown in the figure, the engine start control process of the start-stop control system:

[0063] S1. In the first stage of Ph1, the torque of the drive motor EM1 is loaded based on the exponential curve, the torque of the generator EM2 is kept at 0, and the torque of the drive motor EM1 is loaded to a certain value (46Nm) in advance before entering Ph2;

[0064] S2. In the second stage of Ph2, the torque of the drive motor EM1 is maintained, and the generator EM2 drags the engine with an exponential torque. At the same time, the drive motor EM1 performs torque compensation (actual torque increase = TEM2*r1 / r2, and the engine angular acceleration is taken into account). After the generator EM2 reaches a certain value (46Nm), it is maintained (engine speed Spd = 60RPM, calibrated based on the target angular acceleration of the actual vehicle). When the engine speed reaches Spd = 300rpm, the torque of the generator EM2 drops to 15Nm and is maintained (calibrated based on the target angular acceleration of the actual vehicle). When the engine speed reaches Spd = 600rpm, the engine fuel injection ignition determines that the start is successful, and then enters the closed-loop idle control Ph3;

[0065] S3. In the third stage of Ph3, after the engine is injected and ignited, the engine output torque slowly approaches the expected torque. In order to prevent conflicts with the engine self-idling control, the vehicle control unit HTCU always sends the engine controller ECU a 5Nm expected torque after the engine is injected and ignited; the generator EM2 torque begins to decrease, and the engine speed continues to be stretched to about Spd=950rpm; after the actual engine speed reaches 950rpm, the hybrid system state switches to Running.

[0066] Among them: after switching to Running, the pre-loaded drive motor EM1 torque approaches 0, and the drive motor EM1 performs torque compensation to ensure that the wheel side torque is 0;

[0067] The preload torque of the drive motor EM1 + the compensation value equivalent to the drag of the generator EM2 + the torque required by the driver (0 Nm) is used as the final torque request of the drive motor EM1;

[0068] The response torque of the drive motor EM1 and the generator EM2 = the torque of the cylinder deactivation control + the required torque of the vehicle control unit HTCU + the anti-shake torque.

[0069] It is to be understood that the present invention is described by some embodiments, and it is known to those skilled in the art that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. In addition, under the teachings of the present invention, these features and embodiments may be modified to adapt to specific circumstances and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the scope of protection of the present invention.

Claims

1. An engine start-stop control system for a power-split hybrid transmission, characterized in that: include The vehicle control unit HTCU is responsible for coordinating the torque management of the engine, drive motor EM1 and generator EM2, and determining the engine start and stop conditions; The engine control unit ECU is responsible for collecting high-precision crankshaft position signals and camshaft position signals, and sends them to the generator control unit MCU2 for shutdown angle control after filtering and analysis; The generator control unit MCU2 is responsible for receiving the control command from the vehicle control unit HTCU during the engine start process, and the engine is started by the generator EM2. During the shutdown process, it is responsible for receiving and processing the crankshaft position signal and camshaft position signal fed back by the engine control unit ECU, which is used to identify the engine crankshaft angle and reverse the engine to the specified crankshaft angle through torque control; The drive motor control unit MCU1 is responsible for receiving the drive instructions from the vehicle control unit HTCU to perform torque loading or energy recovery. When starting the engine, it is responsible for responding to the vehicle control unit HTCU to perform torque preloading and perform motor anti-shake control.

2. The engine start-stop control system of the power split hybrid transmission according to claim 1, characterized in that: The vehicle control unit HTCU sends a torque advance loading instruction and a shutdown control instruction to the generator control unit MCU2 according to the engine start-stop condition.

3. An engine start-stop control method for a power-split hybrid transmission, including a shutdown control method and a startup control method; characterized in that: The shutdown control method is: according to the corresponding angle of the low-speed pulse drag torque of the engine estimated in the previous stage, the engine is dragged to a specified crankshaft angle through the generator EM2 to prepare for the next start, so as to ensure the consistency of the calibration parameters of the start process control software and the state of the engine body. The shutdown control method specifically comprises the following steps: S1. In the first stage of Ph1: the engine torque is unloaded, and the drive motor EM1 performs torque compensation to meet the driver's needs. When the actual engine torque drops to a certain value, it enters the second stage of Ph2; S2. In the second stage of Ph2: the engine is self-idling controlled, the torque of the drive motor EM1 is preloaded based on the exponential curve, the torque of the generator EM2 is kept at 0, and after the torque of the drive motor EM1 is loaded to a certain value, it enters the third stage of Ph3; S3. In the third stage of Ph3: the torque of the drive motor EM1 is maintained, the engine is cut off from fuel, and the generator EM2 drags the engine with an exponential open-loop torque to quickly reduce the engine speed and pass through the resonance point. At the same time, the drive motor EM1 performs torque compensation; S4. In the fourth stage of Ph4: the generator EM2 performs PID closed-loop control to prevent the engine speed from overshooting. After the engine speed is slowly reduced to spd=100RPM, it enters the cylinder deactivation control. During this period, the torque of the drive motor EM1 is compensated based on the torque of the generator EM2; S5. In the fifth stage of Ph5: entering cylinder deactivation control, the generator EM2 performs cylinder deactivation control, the drive motor EM1 performs torque compensation, and the cylinder deactivation control torque and the compensation torque are executed in the generator control unit MCU2.

4. The engine start-stop control method of a power split hybrid transmission according to claim 3, characterized in that: In the whole control process, the preload torque of the drive motor EM1 + the compensation value equivalent to the drag of the generator EM2 + the torque required by the driver is used as the final torque request of the drive motor EM1; The direction of the preloaded torque of the drive motor EM1 is related to the gear position, with the N / D gear being positive and the P / R gear being negative.

5. The engine start-stop control method of a power split hybrid transmission according to claim 4, characterized in that: In S5, the vehicle control unit HTCU sends a CAN command to inform the generator control unit MCU2 to enter the cylinder deactivation control mode; During cylinder deactivation control, the generator control unit MCU2 automatically completes the generator EM2 cylinder deactivation control torque and the drive motor EM1 torque compensation control, and the driver's demand torque is completed by the vehicle control unit HTCU controlling the drive motor EM1; When the generator control unit MCU2 performs cylinder deactivation control, the generator control unit MCU2 feedbacks the cylinder deactivation control flag position true. After completing the cylinder deactivation control, the cylinder deactivation control flag position false is feedback, indicating that the cylinder deactivation control has been completed. After receiving the completion signal, the vehicle control unit HTCU switches to the Stop state. After switching to the Stop state, the torques of the drive motor EM1 and the generator EM2 are both 0.

6. The engine start-stop control method of a power split hybrid transmission according to claim 3, characterized in that: The startup control method comprises the following steps: S1. In the first stage of Ph1, the torque of the drive motor EM1 is loaded based on an exponential curve, the torque of the generator EM2 is kept at 0, and after the torque of the drive motor EM1 is loaded to a certain value in advance, it enters the second stage of Ph2; S2. In the second stage of Ph2, the torque of the drive motor EM1 is maintained, and the generator EM2 drags the engine with an exponential torque. At the same time, the drive motor EM1 performs torque compensation. The generator EM2 maintains after reaching a certain value. When the engine speed reaches Spd=300rpm, the torque of the generator EM2 drops to 15Nm and is maintained. When the engine speed reaches Spd=600rpm, the engine fuel injection ignition determines that the start is successful, and then enters the third stage of closed-loop idle speed control Ph3; S3. In the third stage of Ph3, after the engine is ignited, the engine output torque slowly approaches the desired torque; the torque of the generator EM2 begins to decrease, and the engine speed continues to be stretched to around Spd=950rpm; after the actual engine speed reaches 950rpm, the hybrid system state switches to Running.

7. The engine start-stop control method of a power split hybrid transmission according to claim 6, characterized in that: After switching to Running, the pre-loaded torque of the drive motor EM1 approaches 0, and at the same time, the drive motor EM1 performs torque compensation to ensure that the wheel-side torque is 0.

8. The engine start-stop control method of a power split hybrid transmission according to claim 7, characterized in that: In the whole control process, the preload torque of the drive motor EM1 + the compensation value equivalent to the drag of the generator EM2 + the torque required by the driver is used as the final torque request of the drive motor EM1; The response torque of the drive motor EM1 and the generator EM2 = the torque of the cylinder deactivation control + the required torque of the vehicle control unit HTCU + the anti-shake torque.

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