Design and implementation of a tethered mobile robot system for maintenance on reflector of five-hundred-meter aperture spherical radio telescope

• A tethered mobile robot system for maintenance on reflector of FAST is developed. • Working conditions of maintenance on large-aperture radio telescope are summarized. • Tethered robot with lightweight wheel sets and three-rocker suspension is designed. • The robot system can move on the reflector surface with large angle and low load. • The robot system has been successfully verified in laboratory and the FAST site. The stable operation of large-aperture radio telescopes such as the Five hundred meter Aperture Spherical Radio Telescope is an important guarantee for continuous scientific output. How to efficiently carry out daily maintenance work under special working conditions such as low load and large slope has become an important issue and difficulty related to astronomical infrastructure. In this study, the working conditions of large aperture radio telescope reflector are analyzed and summarized through field investigation and measurement. A six-wheeled tethered mobile robot scheme based on lightweight flexible wheel sets, three-rocker adaptive suspension and recovery-release platform is developed, and the tether method is used to assist and ensure maintenance work. The theoretical model of maintenance robot system and the lightweight design scheme of main components are established. The maintenance robot system has been successfully verified on the test bench built in laboratory and FAST site,and meets the engineering requirements of actual field operations. The maintenance robot system can realize release, stable movement and recovery of the tethered mobile robot on reflector surface, and replace humans to carry out high-altitude maintenance work more safely and efficiently.