FRACTIONAL REGULATORS FOR SPACECRAFT ATTITUDE STABILIZATION

In order to enhance the performances and satisfy pointing requirements of communication spacecraft or intelligence gathering purposes, Fractional Order Control (FOC) methods were applied to a three-axis reaction wheels spacecraft attitude control system. In this paper, Low Earth Orbit satellite attitude stabilisation with fractional control laws methods is presented. First, the theory relating to such a law of control have been developed, and a generalized state representation to a system feedback, using fractional derivative, have been given. Then, a comparative study between fractional control laws and an optimal control law (LQR) have been established. The aim of this paper is to highlight the damping effect of fractional regulators and then to establish an efficient fractional control law which satisfies a given specifications, and maintains sufficient stability and accuracy even under the strong effects of intrinsic parameters uncertainties, and also external perturbations.