A study on control of planar variable geometry truss used for autonomous docking system

Abstract

This paper is concerned with a control of a redundant variable geometry truss (VGT). A dynamics-based control cannot guarantee the asymptotic stability of closedloop system if the controller directly uses a pseudo inverse of Jacobian matrix. To avoid this problem, a resolved acceleration control is proposed with the redundancy considering. The control scheme can achieve the asymptotic stability in spite of the redundant system. To make the control be a real-time one, an efficient formulation of inverse dynamics for the VGT is used. Then an experimental docking system of VGT is constructed, which is a redundant system with many sensors and actuators. The experimental system is composed of a docking mechanism, a frictionless table system, a computer system, and a vision sensor system. Feasibility and effectiveness of the control method are examined by numerical simulations and experiments using the developed system.