Distributed Magnetic Actuators for Fine Shape Control

New spacecraft designs feature large structures characterized by low natural frequencies and stringent pointing and vibration requirements. These large space structures pose unique and difficult control problems. These problems include system bandwidths greater than structural natural frequencies lack of accurate information about the dynamic characteristic of the structure being controlled complicated high-order dynamics, including non-linear behavior and stringent requirements for distributed shape control. An important part of the solution to these control problems is the development of actuators capable of applying force or torque to the structures. Conventionally these actuators have been reaction mass actuators or distributed piezoelectric materials. The objective of this research program was to investigate other innovative actuator designs for use in flexible spacecraft structure control. In particular, actuators based on the direct use of electromagnetic forces were developed.