THE DIGITAL MOTION CONTROL SYSTEM FOR THE SUBMILLIMETER ARRAY ANTENNAS

Journal of Astronomical Instrumentation

K. KUEHN¹  R. HUPE² 

[1] Argonne National Laboratory, Lemont, IL 60439, USA;Department of Physics, The Ohio State University, Columbus, OH 43210, USA

关键词: Telescopes;    Instrumentation: Miscellaneous;    Instrumentation: Interferometers;   

DOI  :  10.1142/S2251171713500025

学科分类：天文学(综合)

来源: World Scientific Publishing Co. Pte. Ltd.

【 摘 要 】

We describe the design and performance of the digital servo and motion control system for the 6-meter parabolic antennas of the Submillimeter Array (SMA) on Mauna Kea, Hawaii. The system is divided into three nested layers operating at a different, appropriate bandwidth. (1) A rack-mounted, real-time Unix system runs the position loop which reads the high resolution azimuth and elevation encoders and sends velocity and acceleration commands at 100 Hz to a custom-designed servo control board (SCB). (2) The microcontroller-based SCB reads the motor axis tachometers and implements the velocity loop by sending torque commands to the motor amplifiers at 558 Hz. (3) The motor amplifiers implement the torque loop by monitoring and sending current to the three-phase brushless drive motors at 20 kHz. The velocity loop uses a traditional proportional-integral-derivative (PID) control algorithm, while the position loop uses only a proportional term and implements a command shaper based on the Gauss error function. C...

【 授权许可】

Unknown