Sliding-mode control of cable-driven parallel robots with elastic cables

Abstract

Cable-driven parallel robot (CDPR) is one of robots hard to dealing with because of their nonlinear characteristics based on the elasticity of cables. This paper suggests a design of sliding-mode controller as a solution to control the over-constrained planar CDPR with consideration of cable stiffness and motor dynamics. The system model has 4 elastic cables with linear stiffness force and motor dynamics is considered to make more precise system model. Then the integrated system model has a special model structure called triangular. A backstepping approach was used to apply sliding-mode control for the integrated system model. Simulation was carried out to verify the performance of the suggested control and the result was analyzed. The suggested controller made end-effector follow various trajectories without tuning.