Research On Precision Measurement Technology For The Large Radio Telescope

In the project of FAST (Five hundred meter Aperture Spherical Telescope), the feed cabin is carried by six big span suspend cables to move in large area. In the system of supporting and tracking of the feed for FAST the real-time cabin tracking and dynamic measuring are key techniques. The main purpose of the research is to apply suitable measuring programming and techniques for the control system under the condition of ensuring the precision and sampling rate, and offer the control system cabin's positions to adjust the lengths of the cables coordinately to control the movement of the cabin.According to the conditions of the special system's requirements, combining the conceptual design of control and measuring system, the programming of FAST50m model is established by using laser tracker instrument. And Tracker3 series laser tracker of the Automated Precision Incorporation is used by the feed tracking and measuring system as a measuring device. Especially, the Traker3 meet the various strict requirements of equipment. In small scale local coordinate, it has the advantages such as highly precision, more flexibility, more efficient use and untouched measurement etc.First, in this paper the calibration model of platform is derived from the inverse kinematics solution, and carried out a simulation analysis. Second, the feed cabin's point system and its movement characteristics are studied. And a tracking and dynamic measuring system of the feed cabin is established, based on laser tracker. the software of measuring system is developed, which accomplishes data collecting and disposing, also and sends data to control computer synchronous. At last, the experiments show the advanced cabin's tracking model and its relevant filtering algorithm are validated. The tracking experiments are completed using the measuring software for the motion control system.