Adaptive Position and Attitude Tracking Controller for Satellite Proximity Operations using Dual Quaternions

Presented at Astrodynamics Specialist Conference, Hilton Head, SC, August 11-15, 2013.In this paper, we propose a nonlinear adaptive position and attitude tracking controller for satellite proximity operations. This controller requires no information about the mass and inertia matrix of the satellite, and takes into account the gravitational force, the gravity-gradient torque, the perturbing force due to Earth’s oblateness, and other constant – but otherwise unknown – disturbance forces and torques. We give sufficient conditions on the reference motion for mass and inertia matrix identification. The controller is shown to be almost globally asymptotically stable and can handle large error angles and displacements. Unit dual quaternions are used to simultaneously represent the absolute and relative attitude and position of the satellites, resulting in a compact controller representation