ASSESSMENT OF MODELING AND ROBUST-CONTROL TECHNIQUES FOR FUTURE SPACECRAFT - MIDDECK ACTIVE CONTROL EXPERIMENT

This paper investigates several recent technical achievements on the M iddeck Active Control Experiment (MACE), which flew on STS-67 in March 1995. MACE was designed to investigate the extent to which the on-orb it behavior of a precision-controlled spacecraft can be predicted and controlled using analytic models, analysis, and ground testing prior t o launch. Several ground-based control experiments are used in this pa per to investigate the fundamental issue of the trade-offs between mod eling error, robustness, and performance. The results show that, even with severe limitations on the updates allowed to the finite element m odel, the modeling and control design procedure developed for MACE ena bles similar closed-loop performance (approximately 19 dB) to be achie ved using either analytic or measurement based control design models. These results help build confidence in the on-orbit capabilities of MA CE and other future, multi-payload spacecraft.