Cable-Driven Parallel Robots (CDPRs) can execute fast motions across a large workspace. However, these performances are reached at the cost of a relatively low stiffness which often yields parasitic vibrations at the CDPR mobile platform. In this paper, vibration damping of CDPRs is addressed by means of an original active stabilizer consisting of actuated rotating arms installed on-board the CDPR mobile platform. A control strategy for the whole system, which consists of the CDPR and the stabilizer, and with one purpose for eachposition control for the platform and vibration damping for the stabilizer-is designed. The system being controlled at two different time scales, the singular perturbation theory can be used to prove the stability of the corresponding closed-loop system. The efficiency of the proposed device and control strategy is tested in simulations in the case of a planar 3-DOF CDPR equipped with a three-arm stabilizer.
The problem of verifying the absence of collision between a cable and the mobile part(s) of a device located on-board the mobile platform of a Cable-Driven Parallel Robot (CDPR) is addressed. The set of all positions taken by one cable of the CDPR for all the poses of the mobile platform in a prescribed workspace is called the cable span. A simple bounding volume approximation of the cable span is proposed in this paper. This bounding volume is a polyhedron and the characterization of the faces of this polyhedron is discussed. Using this polyhedron as a bounding volume of the cable span allows to accelerate computations related to collision avoidance checking.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.