Model Based Visual Relative Motion Estimation and Control of a Spacecraft Utilizing Computer Graphics

An algorithm is developed for estimating the motion (relative attitude and relative position) of large pieces of space debris, such as failed satellite. The algorithm is designed to be used by a debris removal space robot which would perform six degreeof-freedom motion control (control its position and attitude simultaneously). The information required as feedback signals for such a controller is relative–position, velocity, attitude and angular velocity–and these are expected to be measured or estimated from image data. The algorithm uses a combination of stereo vision, 3D model matching, applying the ICP (Iterative Closest Point) algorithm, and extended Kalman Filter to increase the reliability of estimates. To evaluate the algorithm, a simulator is prepared to simulate the on-orbit optical environment in terrestrial experiments, and the motion of a miniature satellite model is estimated using images obtained from the simulator. In addition to that, six DOF(Degrees Of Freedom) manoeuvre simulation with developed algorithm for motion estimation using image data was succefully tried for the proximity flight around a failed satellite utilizing CG(Computer Graphics).