Tension vector and structure matrix associated force sensitivity of a 6-DOF cable-driven parallel robot

Abstract

This paper investigates the force sensitivity of 6-DOF cable-driven parallel robots (CDPRs) in order to propose a better force measurement device. Kinematics and dynamics for a CDPR of n-DOF are deduced and formulated, and algorithms for calculating the cable tension are developed. Then, by defining geometrical parameters related to the dimensions and configurations of the CDPRs, optimal methods for determining force sensitivity with respect to the structure matrix and twist vector of the 6-DOF CDPRs with two different moving platforms (i.e. a cubic-shaped, and a flat moving platform) are proposed. By using numerical examples integrated with external twists obtained from wind tunnel tests, simulations and analysis for the two type of 6-DOF CDPRs are carried out. The simulation results help identify the optimal dimensions that can be used to design 6-DOF-CDPR-based force measuring devices with high force sensitivity. Experiment validation is also conducted to verify the method proposed in this paper.