Shape, Motion, and Parameter Estimation of Flexible Space Structures using Laser Rangefinders

Abstract

Future space missions are expected to use robotic systems to assemble, inspect, and maintain large space structures in orbit. For effective planning and control, robots must know the deformations and motions of the structures with which they interact. This paper presents a method for estimating the shape, motion, and dynamic model parameters of a vibrating space structure using asynchronous raster-scanning range imagers. The method assumes that the mode shapes are approximately known a priori. A Kalman filter exploits a mechanics-based dynamic model to extract the modal frequencies and damping as well as the modal coefficients and their time rate of change. Theoretical development and experimental results using emulated space hardware are presented. Index Terms – space structure, laser rangefinder, shape estimation, motion estimation, cooperative sensing.