Noncolocated adaptive attitude control of a planar two-body linkage with nonminimum-phase dynamics

摘要

Adaptive control of a two-dimensional model of a flexible spacecraft with noncolocated sensors and actuators is achieved by output feedback using knowledge of only the system's impulse response. The model is composed of two planar rigid bodies linked by a torsional spring that emulates a multibody spacecraft with base body actuation and appendage pointing. Retrospective cost adaptive control is applied to a command-following problem. The controller uses a finite impulse response filter built from the Markov parameters of the nonminimum-phase (NMP) linearized model. Accordingly, this filter is constructed to contain an estimate of the location of the NMP zero; the filter's order is chosen to correspond to the number of time steps after which the plant's step response becomes positive.