Abstract
The PID H2, H∞ and mixed H2/H∞ attitude controls of spacecraft systems with external disturbances are addressed in this dissertation. These robust control techniques are very suitable for disturbance attenuation and energy cost minimization but are accompanied with high gain in control law. For this problem, the constraints on control outputs are considered. Both linear model and T-S fuzzy model of spacecraft systems are used to design the constrained PID attitude controllers. For the multiobjective problem, the PID controller design is reduced to a convex optimization problem involving linear matrix inequalities (LMI). Finally, Simulations are given to illustrate the design procedures and to confirm the performances of the proposed methods. MATLAB’s LMI Control Toolbox is used here to solve the LMI’s problems in a fast and user-friendly manner