Sensor and Actuator Selection for Fault-Tolerant Control of Flexible Structures

Control system design for structural dynamics requires instrumenting the structure with sensors and actuators, the effectiveness of which depends strongly on spatial position. For the long duration missions typical of spacecraft, the possibility of failures must be considered and coverage provided for with redundancy and a reconfiguration strategy. To support these, it is mandatory that sensors and actuators be located such that sufficient controllability and observability of the flexible dynamics is assured in the presence of failures. This thesis develops a systematic procedure for finding such configurations of sensors and actuators for large-scale systems. Norms on the controllability and observability open loop Gramian are taken as an index for optimization. The control objectives are reflected by truncating the time interval over which the Gramian is defined, and by scaling the state basis with respect to a normalizing, or reference, signal path.