Technical Paper
An Accurate Idle Speed Control for a Gasoline Engine with a Continuously Variable Valve Actuation
2007-04-16
2007-01-1201
The gasoline engine with continuously variable valve actuation is recently focused on as a method to improve fuel consumption and performance of a vehicle. The suction air amount is controlled without using throttling, and therefore can dramatically reduce pumping losses. On the other hand, the suction air amount is significantly affected when the valve lift is slightly changed under low lift condition. In other words, the response of the suction air amount against the change of the valve lift is very sensitive. Furthermore, a conventional gasoline engine with a throttle has a self-stabilizing effect on engine speed, but an engine controlled by a valve lift is not. Therefore, accurate idle speed control is required in order to reduce engine idle speed and improve fuel consumption. The conventional control is composed of a two-degree-of-freedom sliding mode controller and an adaptive disturbance observer.