Development of active six-degrees-of-freedom micro-vibration control system using hybrid actuators comprising air actuators and giant magnetostrictive actuators

In recent years, there has been an increasing demand for micro-vibration free space from industrial and scientific organizations. In response to this demand, several active micro-vibration control systems utilizing various types of actuators have been developed and applied in various environments and to a number of machines. The authors have developed an active micro-vibration control system with six degrees of freedom using giant magnetostrictive (GMS) actuators and actually have applied it to an FIB (focused ion beam). In general, a GMS actuator has a quicker response time and bigger displacement characteristics at higher frequencies than an air actuator. Therefore, we have developed a hybrid actuator that consists of a GMS actuator and an air actuator. Its main feature is that the two actuators are arranged in parallel. Ideally, such a hybrid actuator would have the merits of both component systems. Through experimental tests on the hybrid actuator and simulation analysis on the uni-axial micro-vibration control device using the hybrid actuator, we have shown that this is the case. Following this successful result, we have developed an active 6-DOF micro-vibration control system using hybrid actuators. This paper presents an outline of the active 6-DOF micro-vibration control system, the hybrid actuator used, and the design strategy of the control system. Results of control experiments under various disturbances are described. Through these results, it is verified that an active 6-DOF micro-vibration control system using hybrid actuators controls vibration more effectively than use of air actuators alone. This good performance is realized by the efficiency of the hybrid actuator, which is attributed to the collaboration of the air actuator and GMS actuators.