Microprocessor controlled force actuator

The mechanical and electrical design of a prototype force-actuator system for the vibration control of large space structures is reported. The force actuator is an electromagnetic system that produces a force by reacting against a proof mass. The actuator system is comprised of the actuator, two colocated sensors, an onboard digital microcontroller, and an onboard power amplifier. The results from an experiment are presented in which the actuator system is used to implement a rate-feedback control law to damp actively the transverse vibrations of a cantilevered beam. Finally, it is shown that the stability of the rate-feedback control law is not assured if the actuator dynamics are ignored during control-law implementation.