Genetic algorithm for optimal large angle maneuvers of gravity gradient stabilized micro-satellites

This paper analyzes attitude control of small satellites to determine optimal large angle attitude maneuvers for gravity gradient stabilized with three reaction wheels. The satellite attitude dynamics equations were solved by using Euler parameters to determine the gravity gradient torque and wheel motor torque. The necessary conditions for optimum solutions subject to the performance index were obtained using Pontryagin's principle. Methods for calculating the optimal solution of the minimum time attitude slewing motion and the energy optimal problems were obtained using Genetic Algorithm, which does not need initial guesses and increases the calculational efficiency. As a numerical example, the optimal control problem was analyzed for the micro satellite “Tsinghua 1”. The resulting two point boundary value problem is solved numerically with an optimal slew illustrated by example.