Multi-Sensor Fusion Based Relative Navigation for Synchronization and Capture of Free Floating Spacecraft

Abstract

This paper considers the problem of motion synchronization of free flying robotic spacecraft and serviceable floating objects in space. The synchronization maneuvers are based on a simple sample and hold Proportional-Integral-Derivative control law. The position and velocity information for implementing the control law are obtained from a GPS pseudorange measurement process fused with a vision based sensor unit. A sensor data fusion algorithm is implemented that blends the outputs of the two filters. The performance of the control law together with the navigation and sensor fusion algorithms are evaluated on a nonlinear simulation of a pursuer spacecraft attempting to rendezvous and dock with an uncontrolled free-floating target spacecraft. Orbit perturbation disturbances such as nonuniform gravity as well as atmospheric drag are imposed to study the robustness of the algorithms.