A robust adaptive control scheme for an active mount using a dynamic engine model

Abstract

In this study, a robust adaptive control method is employed for an active engine mount in a six-degree-of-freedom model of the engine on the mounts to improve vibration behavior of the engine. The vibration isolation performance and robustness of the employed robust adaptive controller are compared with a robust and an adaptive control technique. In addition, effectiveness of the robust adaptive control is evaluated in transient conditions (accelerating and gear change conditions). In this regard, a dynamic model for the engine supported by rubber and active mounts and its governing equations are presented. Then, a robust adaptive control, namely the robust Model Reference Adaptive Control (robust MRAC) technique, based on the gradient method with σ-modification, is designed by selecting a proper reference model. Moreover, a robust control, namely the H∞ control scheme and an adaptive control, namely MRAC, are employed for the active mount. Simulation results show that the robust MRAC has a better control performance (in reducing the transmitted force to the chassis) as compared with the H∞ scheme. In addition, in the face of large uncertainties, MRAC may diverge and become unstable. However, the robust MRAC is robust in the presence of large uncertainties. Also, robust MRAC is effective not only in constant engine speeds, but also in transient conditions.