Control Algorithm of Six Cable-Driven Parallel Manipulator for FAST

Abstract

The feed cabin supporting system in a Five-hundred-meter Aperture Spherical Radio Telescope (FAST) project is a large-span cable-driven parallel manipulator (CPM). In this article, the kinematics model of the six CPM was established in the global coordinate O-XYZ. A corresponding difference of cable length between the current position and next position of the feed cabin was determined by controlling the servo motor. A nonlinear adaptive interaction PID (NAIPID) controller was proposed to improve the control performance of the control system. The simulations program of traditional PID and NAIPID were implemented in MATLAB software, respectively. A 3-meter model experiment was carried out to prove the control accuracy of the feed cabin. Both simulation and experimental results showed that the proposed control method had rapid response, and can effectively improve the control performance for the six CPM systems.