Development of a Programmable Rotational Motion Laboratory Demonstrator

This paper presents a novel testbed capable of rotating a target to follow an arbitrary prescribed rotational trajectory, such as the tumbling motion of a satellite undergoing torque-free dynamics. This work is part of a larger research endeavor investigating technology applicable to autonomous rendezvous and docking with a tumbling satellite. This testbed provides unoccluded visibility of the target object for a large class of motions. An experimental platform with these capabilities is necessary for observing a realistically rotating target to test different sensors and motion estimation algorithms. Previous testbeds involve hardware that occludes the rotating payload or does not provide the desired flexibility of programmable motion. The platform described here uses holonomic wheels to drive a spherical target along three independent axes. The verification experiments were based on physics simulation of torque-free motion, incorporating arbitrary target mass properties and angular momenta. The hardware design and software implementation are described and verification of the resulting motion is discussed.