Autonomous Satellite Reconfiguration using SPHERES Micro-Satellite Testbed

摘要

Autonomous satellite reconfiguration is being implemented on the MIT Synchronized Position Hold Engage and Reorient Experimental Satellites (SPHERES) testbed. SPHERES, originally developed by the MIT Space Systems Laboratory (SSL), consists of multiple micro-satellites designed to operate inside the International Space Station to test formation flight and autonomous docking algorithms in a micro-gravity environment. Four aspects of the reconfiguration algorithm are emphasized: estimation, docking, mass property update and control of the reconfigured satellite. The estimation algorithm determines the states of the target relative to the chaser using an extended Kalman filter to process data from an ultrasound-based position and attitude sensor, as well as gyroscopes. The docking algorithm controls the chaser satellite's approach to the target and the mechanical docking interface. After the chaser docks with the target, the property update algorithm updates the mass properties of the system and the general configuration of thrusters and sensors. Finally, the controller is updated to account for the new system properties. The chaser-target system moves in a coordinated fashion, after reconfiguration. Of these four aspects, estimation and control are partially implemented, while docking and mass property updates are fully implemented. Autonomous reconfiguration is demonstrated at the MIT SSL 2-D laboratory through the implementation of the algorithms for these four aspects on SPHERES.