Theoretical and experimental investigation of space-realizable inertial actuation for passive and active structural control

Abstract

Inertial reaction devices are investigated for use as passive vibration absorbers and active control actuators for flexible space structures. Absorbers are designed for one- and two-degree-of-freedom structural representations using three parameter optimization techniques. All three yield nearly identical designs and indicate that inertial devices should be tuned to the lowest mode intended to receive increased damping. The optimal passive components of the control actuator are found to be those of the optimal passive vibration absorber. Proof-of-concept laboratory tests were performed on a quasi-free-free beam using inertial reaction devices that are space-realizable, i.e., conceptually capable of functioning in the space environment. The inertial devices were used as both passive absorbers and tuned actuators. Damping was significantly increased using both passive and passive/active techniques. Additional tests indicated the benefits and limitations of actuator tuning and the necessity of performing realistic experiments using space-realizable hardware.