Design Of Cable And Pulley Inspection Robot For FAST

Five-hundred-meter Aperture Spherical radio Telescope,or FAST for short,is a major scientific infrastructure in China,which has created tremendous scientific value in observing pulsars.As an important part of the FAST for high-precision posture adjustment of the feed cabin,feed support system must carry out regular safety detection and maintenance to ensure that the radio telescope can perform normal observation tasks.Therefore,a robot system capable of autonomously detecting cable defects is designed in this paper for the feed supporting cables and pulley in FAST telescope.Firstly,the overall design of the robot is carried out.According to the analysis of the working environment of the FAST feed support cable,the basic configuration and size range of the robot are determined;According to the characteristics of the obstacles such as the pulleys and cable clamps on the cable,the inspection robot is designed as bottom opening,multi wheel holding cable and multi series connection;According to the characteristics of cable length and steepness,the driving mode of winch traction driving at both ends is determined as the main driving mode and the robot wheel driving as the auxiliary driving mode.Then,subsystems of power supply,communication and detection are designed.According to the overall design scheme of the robot,the structure of the robot is designed in detail.According to the function of each robot section in the robot system,the detailed structure design is carried out,so that it can move stably and reliably along the cable and over obstacles.And through the structure design of the connecting mechanism between the robot sections,the connection and relative position adjustment between the robot sections can be realized.In addition,the structure of a robotic arm is designed to provide a structural basis for the visual inspection of electrical cable and optical cable.Then the architecture of robot motion control system is built,and on this basis,according to actual speed of the robot collected,the cooperative driving control method,the cooperative control method of driving and obstacle surmounting,and the control method of visual inspection manipulator are discussed.The cooperative driving control method of robot based on mathematical model of FAST feed support cable is proposed to control the speed of robot,and the time sequence control flow of each degree of freedom for the robot to surmount obstacles on the cable is proposed,so as to control the robot to surmount obstacles on the cable stably and reliably.The line-tracking control method of the robotic arm based on visual information is also proposed.Finally,the structure and control flow of a single robot are verified by the manufacturing and experiment of the first generation robot prototype.On this basis,the manufacturing of the second generation robot prototype and the design and construction of the experiment platform are carried out.Through the operation experiment of the second generation robot prototype on the experimental platform,the design of cable and pulley inspection robot for FAST is comprehensively verified.