.1.2 M, Altazimuth Telescope Tracking Performance

The characteristic of drive and servo control system of alt-az telescope is nonconstant motion of its azimuth and altitude axis.Their tracking performance is one of the important technical indexes of the telescope. The factors that influence the quick and smooth tracking performance of alt-az telescope are various and complex. This paper researched the tracking performance of 1.2m alt-az telescope of Yunnan Observatory. Firstly, basing on friction drive principle, I analyzed and studied the mechanism character of friction drive, and concluded that total torsion of the single point friction drive couldn't meet the requirement of quick tracking, but the multi-point friction drive greatly improved the quick tracking capability. This article analyzed the function of every measurer in servo control system too, and finded that telescope tracking performance directly connected with measurer characters, and the measure precision had an effect on telescope tracking precision. Basing on control theories, the paper also studied the effect of cascade compensation network in control system and the circuit speciality of 1.2m telescope, and drew a conclusion that PD network was good for improving telescope quick tracking capability. According to anti-disturbance technique, writer analyzed all sorts of disturbance of 1.2m telescope new servo control system, via a series of debugging experiments, and found grounding and isolating drive system were the key of restraining disturbance.With the quick developing of technique and science, astronomical telescope, with better quality and better performance, will be built. Therefore, studying the factors of affacting and limiting telescope quick and smooth tracking ability is very important for rebuilding or building telescope platforms.