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°.

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.

Dimensional Design on the Six-Cable Driven Parallel Manipulator of FAST

2011 ◽  
Vol 133 (11) ◽  
Author(s):  
Xiaoqiang Tang ◽  
Rui Yao
Keyword(s):  
Radio Telescope ◽  
Parallel Manipulator ◽  
Optimization Design ◽  
Design Method ◽  
Guizhou Province ◽  
Large Span ◽  
Similarity Model ◽  
Dimensional Parameters ◽  
Set Up ◽  
Design Result

China is now building the world’s largest single dish radio telescope in Guizhou province, which is called Five-hundred meter Aperture Spherical radio Telescope (FAST). The main purpose of this paper is to present an effective dimensional design method on the six-cable driven parallel manipulator of FAST. Sensitivity design method is adopted for the six-cable driven parallel manipulator of FAST. Cable has the capability to bear tension but not compression, so that cable driven parallel manipulator may not be controlled as expected if tension of one cable is small or zero. Therefore, for dimensional design of the six-cable driven parallel manipulator, three functions to evaluate tension performance were proposed. The tension performance functions can reflect the uniformity of cable tension and controllability of the six-cable driven parallel manipulator. According to the sensitivity design method and tension performance evaluating functions, a set of optimized dimensional parameters is calculated for constructing the six-cable driven parallel manipulator of FAST. In order to verify the optimization design result, a similarity model of the six-cable driven parallel manipulator was set up in Beijing. A serial of experiments shows that tension performance of the six-cable driven parallel manipulator satisfies the system’s requirement. More importantly, it provides a theoretical reference for further study on dimensional design of a cable driven parallel manipulator with large span.

Evaluating the application of a decision support system in identifying adequate wastewater treatment for small communities. A case study: the Fluvia River Basin

2005 ◽  
Vol 51 (10) ◽  
pp. 179-186 ◽  
Author(s):  
J. Alemany ◽  
J. Comas ◽  
C. Turon ◽  
M.D. Balaguer ◽  
M. Poch ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Decision Support ◽  
Decision Support System ◽  
River Basin ◽  
Support System ◽  
River Basins ◽  
Complex Problem ◽  
Adequate Treatment ◽  
Small Communities ◽  
Different Characteristics

The identification of adequate wastewater treatment for small communities is a complex problem since it demands a combination of data from different sources, such as aspects of the community and landscape, the receiving environment and the available wastewater treatment technologies. The Catalan Water Agency (Agència Catalana de l'Aigua) considered using an EDSS (Environmental Decision Support System) as a tool to help water managers select the most adequate treatment for the urban wastewater of nearly 3,500 small communities in Catalonia (Spain). From that moment, EDSS was applied to all the river basins in Catalonia. In this paper the authors present the results obtained for the 76 small communities located in one of these river basins: the Fluvia River Basin. The characteristics of the community used in the reasoning process of the EDSS, the list of selected wastewater treatment alternatives, the technical environmental justification for the selected treatments and the reasons for discarding, favouring or disadvantaging them are presented. Finally, some results for the Fluvia River Basin are compared with those obtained in other Catalan river basins with different characteristics in order to evaluate which are the significant features in identifying adequate wastewater treatments.

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

Similarity model of feed support system for FAST

2011 ◽  
Vol 29 (3) ◽  
pp. 177-187 ◽  
Author(s):  
XiaoQiang Tang ◽  
WenBai Zhu ◽  
CaiHong Sun ◽  
Rui Yao
Keyword(s):  
Support System ◽  
Similarity Model ◽  
Feed Support System

Dynamic modeling and wind vibration control of the feed support system in FAST

2011 ◽  
Vol 67 (2) ◽  
pp. 965-985 ◽  
Author(s):  
Zhu-Feng Shao ◽  
Xiaoqiang Tang ◽  
Li-Ping Wang ◽  
Xu Chen
Keyword(s):  
Vibration Control ◽  
Dynamic Modeling ◽  
Support System ◽  
Wind Vibration ◽  
Feed Support System

Dimension Optimization Design of the Stewart Platform in FAST

2011 ◽  
Vol 308-310 ◽  
pp. 2110-2113 ◽  
Author(s):  
Rui Yao ◽  
Wen Bai Zhu ◽  
Qing Ge Yang
Keyword(s):  
Radio Telescope ◽  
Optimization Design ◽  
Design Method ◽  
Stewart Platform ◽  
Design Flow ◽  
Guizhou Province ◽  
Objective Functions ◽  
The World ◽  
Adjustable Mechanism ◽  
Feed Support System

China is now building the largest single dish radio telescope in the world in Guizhou province, which is called Five-hundred meter Aperture Spherical radio Telescope (FAST). A Stewart platform is introduced in FAST as an accuracy adjustable mechanism for feed receivers. The main purpose of this paper is to discuss dimension optimization design method of the Stewart platform based on three optimization objective functions. The optimization objective functions can reflect the operability and accuracy of the Stewart platform, and optimization design flow is presented according to the important degree of the three optimization objectives. Finally, a set of optimized parameters is obtained, and the study in this paper provides a basis for the coming optimization the feed support system for FAST in the next step.

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