Novel Position Control for Ensuring Feasible Tension Distribution of Cable-Driven Parallel Manipulators

Cable-Driven Parallel Robots are considered an effective automated solution to tackle some open industrial problems such as the manipulation of large payloads into a large workspace. They are considered fully-constrained when the n degrees-of-freedom of the end-effector are commanded by means of \(n+1\) cables. The dynamics of this extended configuration is strongly non-linear and, in addition, position control strategies must face the problem of maintaining cable tensions within an acceptable range. This paper proposes a simple but effective and robust control strategy based on adding a control signal offset to the output of a linear PID type control. Simulation results show that this proposal provides an excellent tracking of the end-effector pose in a planar case maintaining all cable tensions into the allowed range. The results presented in this work can be easily applied to spatial configurations.