On the synthesis of suboptimal, inertia-wheel attitude control systems

Two techniques are presented for the synthesis of suboptimal systems using motor-driven inertia wheels as the source of torque for three-dimensional attitude control. These techniques approximately minimize the integral of a quadratic function of system error and control effort, and both procedures compensate for non-linear inter-axis coupling. The techniques developed in this paper are applied to the design of attitude control systems for two typical artificial satellites. The resulting control laws are in feedback form. In a computer simulation, systems designed on the basis of the procedures developed are shown to respond faster and more accurately than those designed by optimization procedures based on linearized approximations of the equations of motion or by conventional transform methods.