Approximate Static Balancing of the Supporting Posts of a Simple Cable-Driven Parallel Robot

Cable-driven parallel robots (CDPRs) are a subset of conventional parallel robots which actuate an end-effector using arrangements of unilaterally-constrained cables. They allow for large workspaces and advanced end-effector dynamics, but require substantial supporting structures to be effective. This is problematic when deploying them in space-constrained applications. This paper studies a passive counterweight system proposed for allowing the deployment of CDPRs in applications with limited space availability. The need for such easily installed structures is explained and a quasi-static suspended 2-DoF CDPR is modelled. A counterweight system is then proposed and its kinetostatic model is developed. Finally, this model is utilized within an optimisation algorithm to determine system dimensions that achieve optimal moment cancellation in the supporting structure.