Large Telescope Wind Load Estimation with Gradient Segments Superposition and its Servo Control

Obtaining the wind load distribution on the telescope aperture is very important to estimate its influence and reduce the wind disturbance on the telescope system. The aperture of the radio telescope structure can be as large as 100 m and therefore, the uniform wind load on the aperture assumption is not suitable for the radio telescope with large aperture. In this paper, a gradient segments superposition method for calculating the wind load has been proposed. The proposed method has been constructed by combining two regional divisions. First, reflecting surface has been evenly divided in the altitudinal direction. Second, the reflecting surface has been divided into several uniform rings assuming that the wind load coefficient on different rings are different. For the 110 m aperture radio telescope, the wind load estimation results differ by 28%. After that, a structural dynamics model of telescope has been established and a fuzzy PID controller has been designed to reduce wind disturbance. The Root Mean Square Error of telescope pointing under wind disturbance has been reduced by 67.8%. It is suggested that the proposed wind load estimation method has lay a solid foundation for the design of the large telescope system under wind disturbance.