Abstract: The laser tracking system is an important device in aeronautical and astronautical engineering, for raising its tracking accuracy the synthetic design of the system is a key procedure. For the synthesis in general the continuous or discrete schemes are adopted to date, and it is difficult to eliminate the effect of unmodeled dynamics in plant and coupling action between subsystems. In this paper a new hybrid adaptive controller is proposed for the laser tracking system with high accuracy, and the controller adapts to the plant with unmodeled dynamics. When the laser tracking system is designed, the coupling action between subsystems should be firstly transfered into unmodeled dynamics in plant, then the hybrid adaptive system should be synthesized according to the procedure proposed in the paper. Both theoretical proof and simulation results demonstrate that the controller can guarantee the robust stability of the closed loop system. Since the hybrid adaptive controller possesses advantages of both continuous and discrete systems, and the tracking error in the system tends to zero, it may be extensively used in aeronautical and astronautical engineering.

Key words: laser tracking system, hybrid adaptive control, unmodeled dynamics, robust stability