Relative Navigation Scheme of the Final Approach Phase for Space Robot

Space robotic relative navigation is one of the key technologies for on-orbital tracking and approaching. It can supplies the relative position and attitude information of target spacecraft. In this paper, a relative navigation scheme for the final approach phase was proposed, with the target spacecraft information measured by optical sensor. Firstly, we designed a linear Kalman filter which is used to relative navigation with constant gain, combining the relative motion dynamics (between two spacecrafts) with the measure principle of optimal sensor. The second, the relative navigation algorithm was improved by the coordinate transformation and the devices calibration, So the effects on the accuracy resulting from the attitude bias of spacecraft and the mounted errors of the optical sensors were largely reduced. Then, the dynamic performance of the filter was theoretically analyzed according to the positions of its poles. At last, a hardware-in-loop test-bed was introduced, on which the navigation algorithm was evaluated. The experiment results verified the developed scheme.