Model based feed-forward control of electromagnetic type active control engine mount system

Abstract

As the need for reduced noise and vibration increases, the suspension systems of machines and structures are becoming even more complex and more important than ever. A lot of researches on the mounts are actively carried out to improve the vibration isolation performances. Engine mounts in automobiles conduct two main roles. One is to support the static weight of an engine-transmission structure, and the other is to isolate the vibration from the engine in order to minimize the force transmitted to the support. But in order to execute such two roles all together, stiffness of the mount must satisfy conflicting design conditions: static stiffness of the mounts should be hard to support the weight of the engine structure, but the dynamic stiffness of the mounts must be soft to minimize the transmitted force form the engine to the support. To solve these conflicting design strategies, the active noise/vibration control technology is considered as a solution for mounting system. For a decade, active control engine mounts (ACM) are considered to improve the vibration isolation performance of engine mounting system. For active vibration control, counteracting dynamic forces are created by actuators in order to suppress the transmitted disturbance forces from the engine to the chassis. A typical ACM consists of a passive hydraulic mount (HEM), an active actuator and its electric controller with force-monitoring sensors. Various types of ACMs have been developed by many researchers, but most of them were not practically used for the high cost of sensor. Recently, low-cost ACMs, eliminating sensors, were introduced to the automotive market, and good vehicle-tested results are provided in vibration isolation over the frequency range of interest. However, the analytical models in previous researches were derived without consideration of the dynamic characteristics of actuating system. Besides, the elimination of sensors caused some drawbacks in the ACM system. This paper...