Forward dynamic analyses of cable-driven parallel robots with constant input with applications to their kinetostatic problems

Abstract

Forward dynamic analyses of cable-driven parallel robots (CDPRs) are performed accounting for the spatial motions of the cables while considering their mass, sag, elastic and damping properties. The winches feeding the cables are considered stationary. An efficient recursive forward dynamic algorithm is developed to perform the extremely demanding computations. As a part of this work, a solution to the kinetostatic problem of CDPRs is proposed, wherein starting with a non-equilibrium pose, the CDPR is allowed to evolve dynamically until attaining an equilibrium. This idea is demonstrated on a spatial 6-3 CDPR, the feed-support system of the Five-hundred-meter aperture spherical radio telescope (FAST), as well as the 8-8 CDPR, CoGiRo. Dynamic simulation of this nature using a full-scale model of the FAST manipulator is reported for the first time. The results are validated numerically, as well as against existing models, wherever feasible. Challenges involved in the modelling and computations at such a scale and the corresponding remedies are elaborated.