An Application of Eddy Current Effect on the Active Detumble of Uncontrolled Satellite with Tilt Air Gap

The active removal of expired satellites on orbit is essential to ensure the safety of functional spacecrafts on orbit. The high tumbling rates of the uncontrolled satellites hinder the direct removal operation. Consequently, a non-contact method based on the eddy current effect is applied to despin and detumble the uncooperative satellite. A magnetic vector-based 3-D field model under the mean radius assumption is established to calculate the eddy current forces and torques. The honeycomb structure of the target surface and tilt air gap during detumbling are considered in the theoretical model. An underactuated detumble control model is applied to stabilize the nutation angle and attitude of the target. The simulation results show that the control strategy can stabilize the target's attitude in a reasonable time. Controlling the tilt angle will generate despin and detumble torques simultaneously. The linear relationship between the despin torque and rotational velocity at several hundreds of rpm is verified by experiments. This article provides a new solution for detumbling an uncooperative satellite with a rotational magnetic field.