Citation
Abstract
This article presents the analysis results (in terms of settling time, bandwidth, and servo error in wind disturbances) of four control systems designed for the Large Millimeter Telescope (LMT). The first system, called the PP system, consists of the proportional-and-integral (PI) controllers in the rate and position loops and is widely used in the antenna and radio telescope industry. The analysis shows that the PP control system performance is remarkably good when compared to similar control systems applied to typical antennas. This performance is achieved because the LMT structure is exceptionally rigid, but the performance does not meet the stringent pointing requirements of the LMT. The second system, called the PL system, consists of the PI controller in the rate loop and the linear-quadratic Gaussian (LQG) controller in the position loop. It is implemented at the NASA Deep Space Network antennas, and its pointing precision is twice as good as the PP control system. The third system, called the LP system, consists of the LQG controller in the rate loop and the proportional-integral-derivative (PID) controller in the position loop. It has not been implemented yet at known antennas or radio telescopes, but the analysis shows that its pointing accuracy is ten times better than the PP control system. The fourth system, called the LL system, consists of the LQG controller in the rate loop and in the position loop. It is the best of the four (its precision is 250 times better than the PP system); thus, it is worth further investigation and verification of implementation challenges for telescopes with high pointing requirements.
Keywords
Details
- Volume
- 42-154
- Published
- August 15, 2003
- Pages
- 1–17
- File Size
- 508.1 KB