On incorporating reliability considerations into control system designs

Abstract

This paper considers reliability in designing control systems for large orbital structures that are expected to have appreciable flexibility. Reliability is considered for both the control configuration (i.e. selecting sensor and actuator locations over an admissible set) and the ultimate operation of the system. The approach presented is to construct a cost function that indicates the absolute goal of the system and, for a given structural design, to determine the lowest achievable costs conditioned on the failure states of the system (i.e. which actuators and sensors are operational). These costs are then weighted and summed to provide an overall system performance measure. This measure is then minimized over the set of admissible control configurations. The approach is illustrated using a beam that has four actuators with the goal of achieving a given parabolic shape.