Synthesis of an Extended Kalman Filter for Cable-Driven Parallel Robots

Abstract

Cable-driven parallel robots are light-weight parallel robots where cables replace rigid actuators to move an end-effector. As a consequence, they can be characterized by very large workspaces, high-dynamic handlings, ease of reconfigurability and/or low-cost architecture. Since the driving links are flexible, the state variables of the robot cannot be always directly measured, thus the development of state observers is essential. In this work a general approach to develop a nonlinear state observer based on an Extended Kalman Filter is proposed and validated numerically by referring to a cable-suspended parallel robot. The state observer is based on a system model obtained converting a set of Differential Algebraic Equations into Ordinary Differential Equations through two different methods: the penalty formulation and the Udwadia-Kalaba formulation.