Automated Proximity Operations Using Image-Based Relative Navigation

This paper describes a system for relative navigation and automated proximity operations for a microsatellite using continuous thrust propulsion and low-cost visible and infrared imagers. Image processing algorithms provide range, range rate, and spherical angle estimates relative to a target spacecraft using knowledge of the target spacecraft’s geometry. A differential correction batch filter is used to provide relative navigation and state estimation. These state estimates are used to provide input for the automated control of the chaser spacecraft via a Linear Quadratic Regulator. Propulsive maneuvers are accomplished via low-thrust, nonthrottleable thrusters using pulse-width modulation and thrust vectoring. A waypoint logic controller is used to define intermediate goals to reach the final goal in order to limit operational risk from an error in estimation of the spacecraft’s relative state. The system is described and simulation test results are shown.