Precision pointing control of a flexible structure for space applications

The results of a simulation study of pointing the pinhole occulter facility (POF) by the instrument pointing system (IPS) mounted on the Space Station. The POF is an experimental payload that includes a self-deployable 30-m flexible boom. The long flexible boom causes low-frequency structural vibrations. The POF pointing performance at the tip and base are achieved by torque commands applied by the IPS at the base of the boom only. The IPS control torques are computed from attitude measurements of the boom base, and state feedbacks of the boom tip. Accelerations of the base are used for disturbance reduction. A three-axis simulation is developed with IPS/POF for pointing performance analysis. The larger Space Station disturbances, such as crew movement and treadmill operation, are modeled. The study results show that the IPS/POF configuration on the Space Station will satisfy the POF precision pointing requirements