Control method for engine shutdown vibration of clutchless hybrid electric vehicle

Abstract

The invention provides an engine shutdown jitter control method of a clutchless hybrid electric vehicle. The control method comprises the steps of controlling the actual speed and actual torque of anengine to decrease till the actual speed and the actual torque reach the corresponding preset values separately and are stable, and then monitoring the crankshaft position signals of the engine; if detecting that an engine crankshaft is rotated to the expected angle of the engine crankshaft, the engine stops ignition and oil injection, and at the moment, the actual speed of the engine starts to decrease; in the decrease process of the actual speed of the engine, continuously applying the torque to an engine output shaft through a motor; and controlling the engine crankshaft to rotate for a certain angle so that the actual speed of the corresponding engine is close to the expected engine speed corresponding to the rotation angle of the engine crankshaft, monitoring the actual speed of the engine in real time till the actual speed of the engine continuously approaches to 0 within a period. The method provided by the invention is simple, and the engine jitter generated in the shutdown process can be suppressed effectively, and the smoothness of a vehicle is improved greatly during the engine shutdown; and the comfort of the whole vehicle is improved.

Description

technical field [0001] The invention relates to a method for controlling the engine stop vibration of an automobile engine, in particular to a control method for the engine stop vibration of a clutchless hybrid electric vehicle. Background technique [0002] In order to obtain lower fuel consumption and save energy, current hybrid vehicles usually have engine start-stop function, and the smoothness of the engine flameout process directly affects the driving experience. Optimization, especially when the engine of a clutchless hybrid vehicle is shut down, since the engine of the clutchless hybrid vehicle cannot be disconnected from the transmission system, when the engine stops ignition and fuel injection, the engine speed drops from high speed to zero speed Due to the existence of engine pumping resistance, the output shaft of the engine will produce a rapidly changing torque, which is directly transmitted to the wheel output through the transmission system, resulting in seri...

AI Technical Summary

Problems solved by technology

[0002] In order to obtain lower fuel consumption and save energy, current hybrid vehicles usually have engine start-stop function, and the smoothness of the engine flameout process directly affects the driving experience. Optimization, especially when the engine of a clutchless hybrid vehicle is shut down, since the engine of the clutchless hybrid vehicle cannot be disconnected from the transmission system, when the engine stops ignition and fuel injection, the engine speed drops from high speed to zero speed Due to the existence of engine pumping resistance, the output shaft of the engine will generate a rapidly changing torque, which is directly transmitted to the wheel output through the transmission system, resulting in serious vibration of the vehicle, which seriously reduces the comfort of the vehicle

Images