Error Analysis of the Cable-Driven Parallel Robot in the Upgraded Feed Cabin of FAST

The five-hundred-meter aperture spherical radio telescope, also called FAST, is known as one of the most famous cable-driven parallel robot (CDPR) systems in the world that has pioneered the application of CDPRs to large-scale radio telescopes. The FAST feed cabin currently uses a rigid-link structure to rotate the observation platform. In consequence, problems such as high self-magnitude and low observation angle always exist. After the preliminary research in this paper, a prototype of a CDPR with 9 cables can be used to replace the original rigid-link structure in the feed cabin and then improve the observation performance of FAST. Aiming at the new CDPR in the feed cabin, the error transfer model is established to analyze the influence of factors on the position and orientation error of the observation platform. In the simulation, the error distribution of the platform under static conditions is given, and the error control level is preliminarily analyzed. As a result, we have verified that the static error performance of the new observation platform can meet the designed expectations.