A Two-Axis Tracking System with Datalogger

Abstract

A versatile two-axis tracking system with datalogger is presented. It is designed with regard to high pointing accuracy, high torque and mechanical load, high accuracy of the data acquisition, extended weather resistance, remote operability, and considerable freedom from maintenance on site. The system can be used for a variety of pointing devices and also for completely different positioning tasks, such as, for example, the operation of samplers. Depending on the version of the gear box, the maximum absolute pointing error of the tracking system is 19?71 arc min, the angular backlash of its axes is 2?35 arc min, and its peak torque is 15?20 Nm. The maximum mechanical load on the power takeoff shaft is 550 N. The mechanical, electronic, and software design is considerably modular. The modules can be used in various combinations or even stand alone, and they can be modified for future applications without modifying the whole system. The electronics is based on a programmable logic controller, which can in addition to the tracking system and datalogger also serve any pointing and further measurement devices. This facilitates an easy setup of a wide range of different measuring stations. They all have the advantage of being based on the single time process of the programmable logic controller. Four examples of the system have shown very satisfying results in up to 4-yr-long 24-h operation from alpine to seaside environments.