A Discrete Time Adaptive Disturbance Rejection and Control Algorithm Applied to a Model of a Deployable Space Telescope

Abstract

The discrete time Direct Adaptive Disturbance Rejection with Direct Model Reference Adaptive Control algorithm is applied to a model of the DOT (Deployable Optical Telescope) test bed that is being developed at the Air Force Research Laboratory (AFRL). First, a general outline of the applicable theory of Direct Adaptive Disturbance Rejection (DADR) with Direct Model Reference Model Adaptive Control (DMRAC) is presented. Then a description of how the plant model and reference model were developed is presented and discussed. Finally a summary of results obtained from a closed loop simulation of the telescope controlled by a DMRAC controller with DADR disturbance rejection control algorithm is presented. The effect of what reference model is used in the system is also considered. It is shown that when the reference model is a reducedorder Model of the plant model the disturbance is attenuated from the output signal more quickly then if a simple 2 nd order reference model is used. The good performance in simulation of the Direct Model Reference Adaptive Control method with Direct Adaptive Disturbance Rejection is found to be a feasible computationally efficient method for controlling vibrations in DOT, which is a highdimensional structural control problem.