Development of a pilot of an Arecibo-type large spherical radio telescope for the square kilometre array

Abstract

An optomechatronics design project for the pilot of an Arecibo-type large spherical radio telescope for the square kilometre array (SKA) is proposed, concentrating on the feed-supporting system with large-span cables. The feed-supporting system consists of two parallel manipulators: the parallel cable manipulator, which provides a large workspace for the trajectory tracking and realizes the coarse tracking control, and the fine-tuning Stewart platform, which connects the parallel cable manipulator to the cabin structure and implements the high-accuracy requirement of tracking. In order to improve the real-time controllability, an approximate kinematics model of the parallel cable manipulator is developed using straight links to approximate the cables based on static equilibrium at low tracking velocity. A control strategy for the feed-supporting system is proposed using the independent control method, and the corresponding tracking accuracy of the coarse control and fine tuning is presented. The simulation results have supported the rationale of this approximate model of the parallel cable manipulator and the feasibility of this mechatronics design project for the SKA.

Keywords

mechatronics square kilometre array robotics feed-supporting system parallel manipulator kinematics accuracy analysis static equilibrium

Get full access to this article

View all access options for this article.

References

Memorandum of an Agreement to Cooperate in a Technology Study Program Leading to a Future Very Large Radio Telescope. Signed by participants from Australia, Canada, China, India, the Netherlands and the USA. Available at http://www.nfra.nl/skai/memorandum.htm.

Nan

R. D.

A proposal of international LT program. Beijing Astronomical Observatory, Beijing, China, 1996.

Nahon

Dynamics and control of a novel radio telescope antenna. AIAA paper 99–4120, 1999.

Mervis

Astronomers hang out help-wanted sign. Science, November 1995, 270 (17), 1146.

A proposal for the second Arecibo upgrading program. National Astronomy and Ionosphere Center, USA, March 1986.

Duan

B. Y.

A new design project of the line feed structure for large spherical radio telescope and its nonlinear dynamic analysis. Mechatronics, 1999, 9(1), 53–64.

Qiu

Y. H.

A novel design for a giant Arecibo-type spherical radio telescope with an active main reflector. Mor. Not. R. Astron. Soc., 1998, 301, 827–830.

Stewart

A platform with six degrees of freedom. Proc. Instn Mech. Engrs, 1965, 180, part (15), 371–386.

Y. X.

Duan

B. Y.

The application of the Stewart platform in large spherical radio telescopes, J. Robotic Syst., 2000, 17(7), 375–383.

10.

Anthony

J. W.

Robert

J. W.

Inclined cables under load-design expressions. Am. Soc. Civil Engrs J. Struct. Div., 1977, 103(ST5), 1061–1078.

11.

Lui

Fizgerald

J. M.

Lewis

F. L.

Kinematic analysis of a Stewart platform manipulator. IEEE Trans. Ind. Electr., 1993, 40(2), 282–293.

12.

Sharon

Hogan

Hardt

D. E.

The macro/micro manipulator: An improved architecture for robot control. Robotics Computer Integ. Mfg., 1993, 10(3), 209–222.

13.

Stevens

H. D.

How

The limitations of independent controller design for a multiple-link flexible macro-manipulator carrying a rigid mini-manipulator. In Proceedings of the 2nd ASCE Conference on Robotics for Challenging Environments, Albuquerque, New Mexico, June 1996, pp. 93–99.

14.

Lew

J. Y.

Trudnowski

D. J.

Vibration control of a micro/macro-manipulator system. IEEE Control Syst., February 1996, 16(1), 26–31.

15.

Furusho

J. J.

Zhang

G. G.

Sakaguchi

Vibration suppression control of robot arms using a homogeneous-type electrorheological fluid. In IEEE International Conference on Robotics and Automation, Albuquerque, New Mexico, April 1997, pp. 3441–3448.

16.

Ropponen

Arai

Accuracy analysis of a modified Stewart platform manipulator. In IEEE International Conference on Robotics and Automation, 1995, pp. 521–525.

17.

Y. X.

Duan

B. Y.

The mechanical design and kinematics accuracy analysis of a fine tuning stable platform for the large spherical radio telescope. Mechatronics, 2000, 10(7), 819–834.

18.

Y. X.

Duan

B. Y.

Adaptive tracking control of feed for the square kilometre array (in Chinese). Control Theory Application, 2001, 18 (in press).