Abstract: A gryowheel can output torques in three directions via changing the angular momentum’s amplitude or direction. The servo system for swing angle control is the key to achieving the function of triaxial torque output. There is a strong coupling between the highspeed rotor’s swings in two directions so that the output torques in two directions independently is unavailable under normal PID control methods. A method for decoupling control is provided via adding a series of system matrices and creating two decoupling systems. The coefficients of the series of system matrices are changing as rotor speed changing. It can be solved by calculating the coefficients in a real time digital control processor. Numerical simulation result shows the feasibility of this control method.

Key words: gyrowheel, series decoupling, swing angle control