An Observer for Sensorless Variable Valve Control in Camless Internal Combustion Engines

Camless internal combustion engines offer improvements over traditional engines, in terms of increased torque performance and fuel economy, and decreased emissions and pumping losses. Theoretically, their control flexibility provides electromagnetic valve actuators with the highest potential for improving efficiency. Sensorless control is one of the most important issues with implementations of this new technology. The main contribution of this paper is the proposal of a hysteresis hybrid observer that combines an extended Kalman filter and hybrid automation, resulting in a sensorless control. The proposed hysteresis strategy allows the avoidance of not only chattering problems but to trade with possible not observable sets. Current is measured and position as well as velocity of the electromagnetic valve are estimated. Real measured data are used to show the effectiveness of the proposed method.