Dynamic analysis and control of an active engine mount system

Dynamic characteristics of a prototype active engine mount (AEM), designed on the basis of a hydraulic engine mount, have been investigated and an adaptive controller for the AEM has been designed. An equivalent mass-spring-damper AEM model is proposed, and the transfer function that describes the dynamic characteristics of the AEM is deduced from mathematical analysis of the model. The damping coefficient of the model is derived by considering the non-linear flow effect in the inertia track. Experiments confirmed that the model precisely describes the dynamic characteristics of the AEM. An adaptive controller using the filtered-X LMS algorithm is designed to cancel the force transmitted through the AEM. The stability of the LMS algorithm is guaranteed by using the secondary path transfer function derived on the basis of the dynamic model of the AEM. The performance test in the laboratory shows that the AEM system is capable of significantly reducing the force transmitted through the AEM.