An Investigation of Adaptive Control Techniques for Space Stations

Of all large space structural systems, space stations present a unique challenge and requirement to advanced control technology. Their operations require control system stability over an extremely broad range of parameter changes and high level of disturbances. During shuttle docking the system mass may suddenly increase by more than 100% and during station assembly the mass may vary even more drastically. This coupled with dynamic model uncertainties require highly sophisticated controller and control architectures. An adaptive control algorithm along with the proposed inner-loop plant augmentation for controlling the space station under severe conditions of shuttle docking, mass and inertia change and modal truncation are investigated in this paper. Simulation results with a simplified Initial Operation Center model show that the controller is robust and the plant dynamics closely follows that of the reference model. Reasonable results have been observed even with the constraints of excessive control hardware saturation.