Abstract
In order for a robotic system autonomously to capture an unknown rigid body rotating freely in zero gravity, it is necessary for it to detect the object's motion. This paper presents a method of estimating object motion based on position information concerning a point located on the object's surface. We assume that the object's motion is described in term of the combination of the rotations with constant angular velocities. When position sensors, etc., can obtain three dimensional position information about a point on the object, we can estimate parameters describing its motion. In other words, using this method we can calculate each frequency and direction of the axes of rotation by applying the Fourier transform to a time sequence of the point's three dimensional position. This is also useful in case temporal sequence of the observed point has interruption owing to occlusion, etc..