Damping force control of frictionless MR damper associated with hysteresis modeling

This study presents hysteresis modelling and damping force control of the frictionless magnetorheological (MR) damper for semiconductor manufacturing stage. The vibration sources of the semiconductor stage can be classified as two. The one is environmental vibration from the floor, and the other is transient vibration occurred from the stage moving. The transient vibration has serious adverse effect to the process because the vibration scale is quite larger than other vibrations. Therefore, in this research, the semi-active MR damper which can control the transient vibration is devised. In addition, the stage needs to be isolated from tiny vibration to achieve high grade vibration level. At the high frequency range, MR damper acts like a rigid body if the dry friction exists. So the tiny vibration is transferred to the stage directly. Therefore, a dry friction of the MR damper must be removed. In order to achieve this goal, a frictionless MR damper is originally designed. After then, a designed MR damper is manufactured and it's damping force characteristics and hysteresis behaviors are evaluated by experiment. The biviscous hysteresis model of MR damper is formulated and its accuracies are evaluated. Finally, damping force control performances using the hysteresis model is experimentally evaluated.