Adaptive Output Feedback Control for Spacecraft Rendezvous and Docking Under Measurement Uncertainty

Abstract

An output feedback structured model reference adaptive control law has been developed for spacecraft ren-dezvous and docking problems. The effect of bounded output errors on controller performance is studied in detail. Output errors can represent an aggregation of sensor calibration errors, systematic bias, or some stochastic distur-bances present in any real sensor measurements or state estimates. The performance of the control laws for stable, bounded tracking of the relative position and attitude trajectories is evaluated, considering unmodeled external as well as parametric disturbances and realistic position and attitude measurement errors. Essential ideas and results from computer simulations are presented to illustrate the performance of the algorithm developed in the paper.