An air bearing table for satellite attitude control simulation

Attitude control of a spacecraft is critical for its operations, but at the same time poses a significant challenge to control engineers due to the non-linear behaviour of attitude dynamics. Hence, a physical ground testing platform for space-craft attitude dynamics and control is essential for verification of a control algorithm prior to its airborne application. In this paper, we present an air bearing based simulation platform which, unlike previous air bearing table designs, is small in size so that it can simulate the behaviour of smaller (nano) satellites such as CubeSat. Currently, the air bearing table is capable of unrestricted motion about the yaw axis and we demonstrate this by the implementation of a closed-loop yaw angle controller. However, gravitational torque prevents us from achieving a simulation about the pitch and roll axes, which should otherwise provide us with up to ±60 degrees of motion. Subsequently, an automatic counterweight system is currently being constructed to overcome this problem, and its governing algorithms are presented herein.