Stability of Large Space Structures Preserved Under Failures of Local Controllers

This note considers position and attitude control of large space structures composed of a number of subsystems (substructures) interconnected by flexible links. A decentralized control law of dynamic displacement feedback compatible with subsystems is applied under the assumption that sensors and actuators are collocated. It has been known that the overall closed-loop system is robustly stable against uncertainties in mass, damping, and stiffness, if rigid modes of each subsystem are controllable and observable. The objective of this note is to derive conditions for the overall system to be stable even when some local controllers fail. The conditions are expressed in terms of the stiffness (or damping) matrices and interconnection location matrices of the subsystems whose local controllers fail