1. Simulation was done without any disturbance input for c = 0.1. Smooth responses were obtained (Fig. 1-4). Eventhough, the dynamics of the spacecraft are assumed to be unknown in (6), attitude vector p(t) converged to zero. The response time of the order of 12 seconds was obtained. The control torque required for maneuver is reasonable.
2. To examine the effect of disturbance input, sinusoidal disturbance torques along the three axes of the spacecraft where assumed to be acting, where go = (sin 3i, cos 4< sin 2icos 2<)T. The selected responses are shown in Fig. 5-8. Eventhough, the chosen disturbance torque does not vanish at the origin as required for stability in Theorem 1, attitude regulation close to the origin was accomplished and as indicated in the Remark 3, the trajectories are found to be ultimately bounded. The oscillations in control input are required to cancel the sinusoidal disturbance torque. Only a small steady state tracking error is observed. It is pointed out that the steady state attitude error can be further reduced by taking smaller values of f, however this requires larger control torque.