Control Method of Hybrid Electric Vehicle Stationary Start Engine

Abstract

The invention provides a control method of a hybrid electric vehicle still starting engine. When a vehicle is in a stationary state, a whole vehicle controller judges whether or not a user needs to start an engine, if yes, the whole vehicle controller controls an oil pump motor to work, then the pressure of a main oil line is increased, then a second clutch is closed, then a large electric machinedrives the engine, then the torque of the large electric machine is reduced, then the second clutch is recovered to a contact point state, then oil injection and ignition are carried out on the engine, then the rotation speed of the large electric machine is increased until the absolute value of the difference value between the rotation speed of the large electric machine and the rotation speed of the engine is less than a preset threshold E, then the second clutch is closed, and at this moment, the starting of the engine is completed, and the vehicle enters into a hybrid electric working condition. The control method of the hybrid electric vehicle still starting engine has the advantages that the method is simple and feasible, the starting time is shortened, the harshness and the instantaneity of the hybrid electric vehicle still starting engine can be improved, and the riding comfort of the whole vehicle is improved.

Description

technical field [0001] The invention relates to the control field of a hybrid electric vehicle, in particular to a control method for a static starting engine of a hybrid electric vehicle. Background technique [0002] Hybrid vehicles have the function of starting and stopping the engine, and the working conditions of starting the engine are very frequent. At the same time, in order to obtain better fuel consumption, a clutch will be added to realize the function of sliding the engine to start the engine, and optimize the smoothness and real-time performance of engine starting. Therefore, the impact of starting the engine under all operating conditions on the start-stop function is very important. [0003] In the prior art, in the driving condition, the vehicle controller of the hybrid electric vehicle will determine the timing of starting the engine according to the battery power, battery power, accelerator pedal opening and vehicle speed signal. At this time, there is a sp...

AI Technical Summary

Problems solved by technology

And when the static working condition, there is no speed difference between the motor and the engine, the vehicle controller will send a torque request command to the motor controller, increase the motor speed to the preset value, and then start the engine through the clutch sliding friction; first increase the motor speed, and then The method of slipping the friction starter is only a prerequisite for creating a speed difference for the sliding friction starting engine. This method also puts forward higher requirements for control. When the motor is under no-load conditions, the time for applying torque to increase the motor speed to the preset value is very short. It is short and difficult to control, and the engine needs to be pre-filled with clutch slipping friction. The time of pre-filling oil is longer than that of increasing the motor speed, so it is necessary to pre-fill oil first, then increase the motor speed, and then carry out the clutch Slip start the engine, which will greatly increase the time to start the engine, which seriously affects the smoothness and real-time performance of the hybrid vehicle start engine

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