Modeling and Control of Cable-Driven Parallel Robots with Non-affine Dynamics

Abstract

In cable-driven parallel robots (CDPRs), the cables can only apply tensile force. Therefore, the force control signal of cables must always be positive. In this paper, a novel control method is developed to ensure positive tension distribution (PTD) in CDPRs. The proposed control architecture does not require any redundancy resolution consideration. A non-affine representation for the CDPRs dynamics is first given by imposing tension positiveness within an extended dynamic model. With cable tensions as new state variables for the extended model, a robust controller is then designed using conventional methods for affine systems. Simulations are carried out on a six-degree-of-freedom cable robot to verify the effectiveness of the proposed strategy.