Control of a Flexible Frame in Slewing

Many satellites require the use of slewing solar panels. A laboratory model of a slewing frame is presented here as an article for testing control laws for such solar arrays. A slewing frame presents a challenging control problem because the primary action of slewing induces torsional vibration which is relatively uncontrollable with respect to the slewing actuator. An experimental investigation of controlling this structure for combined slewing and vibration suppression is presented. The frame is modeled using finite element methods verified by experimental modal analysis. Analytical results indicate that the torsional motion can be suppressed by including an active strut in the feedback loop. Non-colocated and colocated control laws are implemented using the active strut as a sensor and an actuator. The relative effectiveness of each design in suppressing the torsional motion is discussed.