Kinetic behavior evaluation of electromagnetic valve train subject to exhaust gas force

Abstract In recent years, great efforts have been put into fully variable electromagnetic valve train (EMVT) technologies in order to improve the power and economic performance of IC engines. However, the application of EMVT to exhaust system faces a more severe operating condition compared with intake system: the sizeable cycle-to-cycle combustion gas force makes serious disturbance to the movement of valve train, and a complicated kinetic behavior is generated because of the interplay of gas flow and valve opening motion. As a result, the exhaust efficiency and engine performance are negatively affected. Therefore, this paper analyzes the evolution mechanism of the gas force acting on exhaust valve, and explores the disturbance model in consideration of the flow stagnation effect. Based on this, a control-oriented model of EMVT is proposed, and the adaptive robust method is used for the motion control. The dynamic characteristics of EMVT are verified by the simulation and experimental results, which show that the control method has a strong anti-interference capability against the exhaust gas force. With the increase of gas force, the opening motion of EMVT would be delayed, but the opening transition time remains basically unchanged.