Robust control design and implementation on the Middeck Active Control Experiment

This paper presents a coherent methodology for robust controller synthesis for the Middeck Active Control Experiment (MACE): a Shuttle program scheduled for flight on STS-67 in February 1995. The experiment has been designed to investigate the extent to which the on-orbit behavior of a precision-controlled spacecraft can be predicted and controlled using analysis and ground testing prior to launch. A goal of the flight experiment is to demonstrate good payload pointing performance using active controllers designed based on the predicted structural dynamics. For systems with complicated control topologies and large model uncertainties, this requires a systematic control design methodology. The results from preliminary ground-based control experiments are used in this paper to present such a design technique and to illustrate how it can be applied to future flight experiments. This control design methodology is then used to develop controllers that obtain a 22 dB improvement in the performance metric on the current MACE hardware.