Minimum power optimum control of microsatellite attitude dynamics

This paper deals with the attitude dynamics and control of a multimission microsatellite for remote sensing applications. The attitude control system consists of three small reaction wheels and three magnetic torquers. The paper presents a new control technique in which the required control torque is continuously redistributed between the reaction wheels and the magnetic torquers to minimize the electric power consumption in the attitude control. The required control torque is computed using proportional derivative control laws and the optimum control theory. Numerical results show that substantial power savings ran be obtained while retaining attitude control accuracy adequate for remote sensing applications.