As the need for improved ride comfort and reduced noise and vibration increases in automobile industry, the problem of engine suspension is becoming even more complex and more important than ever. Passive engine mounts, which are still in wide usage, often fail in meeting such stringent requirement. Thus, vibration control with semi-active actions has been of popular interest in recent years. Among others, the controllable fluid-based device, especially magneto-rheological fluid(MRF) based device, is known to be a good candidate for such applications.
Not only to design an MRF based mount but to develop an effective control algorithm for the mount, it is necessary to construct an adequate dynamic model. In this work, an MRF based mount, developed in the laboratory, is tested for parameter identification of the mount in the frequency domain : the damping of the main rubber is first identified from the excitation test of the mount without fluid; and then the fluid resistance and the bottom chamber compliance are obtained from the test with fluid. Validity of the model is proved by comparing the time responses obtained from the simulation and experimental works. In addition, a new approach to explain the locking phenomenon is developed, which has not yet been clarified by the conventional state-space approach.
