Quaternion based rate/attitude tracking system with application to gimbal attitude control

The paper deals with rate and attitude control of a rigid body. The discussed control system contains an inner velocity loop which tracks the desired rate command and an outer attitude loop which tracks the desired attitude command. The control algorithm uses quaternions as a measure of attitude errors to achieve instantaneous eigenaxis rotation. The paper discusses the stability of the new algorithm and presents its application to multi-axis gimbal attitude control.