Test Study of the Feed-Support System for a Large Radio Telescope

2006 ◽  
pp. 261-270
Author(s):  
G. X. Ren ◽  
W. B. Zhu ◽  
H. Zhang ◽  
L. C. Zhu ◽  
Q. H. Lu
Keyword(s):  
Radio Telescope ◽  
Support System ◽  
Large Radio Telescope ◽  
Test Study ◽  
Feed Support System

scholarly journals Multi-objective pose optimal distribution method for the feed support system of Five-hundred-meter Aperture Spherical radio Telescope

2018 ◽  
Vol 15 (1) ◽  
pp. 172988141875669 ◽  
Author(s):  
Sai Deng ◽  
Fengshui Jing ◽  
Rongzhang Zheng ◽  
Zize Liang ◽  
Guodong Yang
Keyword(s):  
Radio Telescope ◽  
Support System ◽  
Parallel Robot ◽  
System Stability ◽  
Optimal Distribution ◽  
Distribution Method ◽  
Tension Distribution ◽  
Coupling System ◽  
Back Illuminated ◽  
Feed Support System

The Five-hundred-meter Aperture Spherical radio Telescope is the world’s largest single-dish radio telescope and is located in the southwest of China. The cable-driven parallel robot and A-B rotator of the feed support system in Five-hundred-meter Aperture Spherical radio Telescope are designed to realize the theoretical position and attitude of the receiver. The feed support system is a pose-redundant and rigid–flexible coupling system; thus, the method of pose distribution between the A-B rotator and the cable-driven parallel robot impacts on the cable tension distribution and stiffness of the feed support system, which are crucial to the feed support system stability. The main purpose of this study is to examine the pose optimal distribution method for the feed support system. First, a mechanical model of the feed support system, which considers the time-varying barycenter of the feed cabin and the back-illuminated strategy of the receiver, is established. Then, a pose distribution method that ensures the position and attitude accuracy of the receiver is proposed for the feed support system. Considering the performance indices of the variance of cable tensions and the stiffness of the cable-driven parallel robot, an optimization of the rotation angles of the A-B rotator with multiple objectives is implemented using a genetic algorithm. Finally, simulations are conducted to demonstrate the effectiveness of the proposed method compared with others. Results show that the proposed approach not only ensures the attitude accuracy of the receiver but also maintains the lower variance of cable tensions and higher stiffness of the feed support system.

scholarly journals Pose Planning for the Feed Support System of FAST

2014 ◽  
Vol 6 ◽  
pp. 209167 ◽  
Author(s):  
Rui Yao ◽  
Wenbai Zhu ◽  
Caihong Sun ◽  
Hui Li ◽  
Jinghai Sun
Keyword(s):  
Radio Telescope ◽  
Support System ◽  
Parallel Manipulator ◽  
Constraint Condition ◽  
Planning Function ◽  
Flexible Mechanism ◽  
Stability And Accuracy ◽  
Realization Process ◽  
Different Characteristics ◽  
Feed Support System

A six-cable driven parallel manipulator and an A-B rotator in the feed support system of the Five-hundred-meter Aperture Spherical radio Telescope (FAST) are adopted for realizing the position and pose of nine feeds. The six-cable driven parallel manipulator is a flexible mechanism, which may not be stably controlled due to a small cable tension. The A-B rotator is a rigid mechanism, and its stability and accuracy can be improved by small pose angle. Based on the different characteristics, a pose planning function is presented. The optimization target of the pose planning function is to get the smallest pose angle of the A-B rotator, and the constraint condition can reflect the controllability of the six-cable driven parallel manipulator. Then, the pose planning realization process of the feed support system is proposed. Based on the pose planning method, optimized pose angles of the feed support system for the nine feeds are obtained, which suggests that the pose angle of the six-cable driven parallel manipulator changes from 0° to 14° and the pose angle of the A-B rotator changes from 0° to 26.4°.

Non-uniform temperature distribution of the main reflector of a large radio telescope under solar radiation

2021 ◽  
Vol 21 (11) ◽  
pp. 293
Author(s):  
Shan-Xiang Wei ◽  
De-Qing Kong ◽  
Qi-Ming Wang
Keyword(s):  
Temperature Field ◽  
Temperature Distribution ◽  
Solar Radiation ◽  
Radio Telescope ◽  
Thermal Imaging ◽  
Uniform Temperature ◽  
Large Radio Telescope ◽  
Uniform Temperature Distribution ◽  
Uniform Temperature Field ◽  
Main Reflector

Abstract The non-uniform temperature distribution of the main reflector of a large radio telescope may cause serious deformation of the main reflector, which will dramatically reduce the aperture efficiency of a radio telescope. To study the non-uniform temperature field of the main reflector of a large radio telescope, numerical calculations including thermal environment factors, the coefficients on convection and radiation, and the shadow boundary of the main reflector are first discussed. In addition, the shadow coverage and the non-uniform temperature field of the main reflector of a 70-m radio telescope under solar radiation are simulated by finite element analysis. The simulation results show that the temperature distribution of the main reflector under solar radiation is very uneven, and the maximum of the root mean square temperature is 12.3°C. To verify the simulation results, an optical camera and a thermal imaging camera are used to measure the shadow coverage and the non-uniform temperature distribution of the main reflector on a clear day. At the same time, some temperature sensors are used to measure the temperature at some points close to the main reflector on the backup structure. It has been verified that the simulation and measurement results of the shadow coverage on the main reflector are in good agreement, and the cosine similarity between the simulation and the measurement is above 90%. Despite the inevitable thermal imaging errors caused by large viewing angles, the simulated temperature field is similar to the measured temperature distribution of the main reflector to a large extent. The temperature trend measured at the test points on the backup structure close to the main reflector without direct solar radiation is consistent with the simulated temperature trend of the corresponding points on the main reflector with the solar radiation. It is credible to calculate the temperature field of the main reflector through the finite element method. This work can provide valuable references for studying the thermal deformation and the surface accuracy of the main reflector of a large radio telescope.

Research on the panel adjustment method of an active main reflector for a large radio telescope

2021 ◽  
Vol 21 (2) ◽  
pp. 038
Author(s):  
Zheng-Xiong Sun ◽  
Jin-Qing Wang ◽  
Lin-Feng Yu ◽  
Wei Gou ◽  
Guang-Li Wang
Keyword(s):  
Radio Telescope ◽  
Adjustment Method ◽  
Large Radio Telescope ◽  
Main Reflector

Electronic Performance-Oriented Mold Sharing Method and Application in QTT 110 m Large Radio Telescope

2020 ◽  
Vol 68 (8) ◽  
pp. 6407-6412
Author(s):  
Shufei Feng ◽  
You Ban ◽  
Baoyan Duan ◽  
Congsi Wang ◽  
Bo Wang
Keyword(s):  
Radio Telescope ◽  
Large Radio Telescope ◽  
Electronic Performance

scholarly journals Surface adjustment strategy for a large radio telescope with adjustable dual reflectors

2019 ◽  
Vol 13 (15) ◽  
pp. 2669-2677 ◽  
Author(s):  
Peiyuan Lian ◽  
Congsi Wang ◽  
Song Xue ◽  
Qian Xu ◽  
Yu Shi ◽  
...  
Keyword(s):  
Radio Telescope ◽  
Large Radio Telescope ◽  
Adjustment Strategy

Modeling of A Feed Support System for Fast

2004 ◽  
Vol 17 (1-3) ◽  
pp. 177-184 ◽  
Author(s):  
Wenbai Zhu ◽  
Rendong Nan ◽  
Gexue Ren
Keyword(s):  
Support System ◽  
Feed Support System
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