Design of Sampled-Data PID Controllers With Adaptive Updating Rules for Spacecraft Attitude Angle Tracking

To achieve precise spacecraft Eulerian attitude angle tracking control, adaptive controllers based on full-form dynamic linearization (FFDL) techniques are proposed. The open-loop system is approximated by a second-order nonlinear uncertain system, which is further transformed into an FFDL model. To ensure desirable tracking accuracy and compensate for uncertainties, corresponding cost functions are considered to establish sampled-data adaptive control algorithms. Theoretical conditions are then provided to ensure closed-loop stability and convergence of tracking errors. Finally, ground experiments on proportional spacecraft systems are conducted to validate the proposed methods. The results substantiated that the proposed method possesses a robust adaptive capacity amidst various unknown parameter variations, thereby ensuring the efficiency of the tracking control.