THREE-AXIS SATELLITE ATTITUDE CONTROL USING THREE OPTIMAL FRACTIONAL-ORDER PIλDμ CONTROLLERS AND ADVANCED SWARM INTELLIGENCE ALGORITHMS

Abstract

This work develops three optimal fractional-order PI^λD^μ controllers for a three-axis satellite tracking attitude. The nonlinear differential equation of the satellite model is linearized around its operating orbital frame, local horizontal, local vertical (LHLV), and stabilized by linear quadratic regulator (LQR), to obtain a stable linear continuous or discrete state space model with first order. Each of the three controllers to be designed consists of five parameters that should be chosen optimally: three gains K_p, K_i, and K_d; and two fractional orders λ and μ. Two advanced meta-heuristics algorithms are used to select the best parameters: the Harris hawks optimizer (HHO), and the artificial hummingbird algorithm (AHA). Based on the results shown and comparative study with conventional controllers, the proposed tuned controllers directed the satellite to follow the desired angle trajectories in the three directions efficiently.