Design and Realization of Temperature Control System for FOG POS Based on DSP

The measuring accuracy of FOG POS would be influenced by the environment temperature changed, and this problem can be solved by means of controlling temperature. This paper presents a digital temperature control system for FOG POS. This system utilizes method of heating up and natural cooling. Meanwhile, the control circuit and the body of inertial measurement unit (IMU) are separately installed. In addition, for the sake of avoiding interference to the performance of inertial instruments generated by varying current, hot-source is symmetrically arranged in the shell and internal platform of IMU, achieving multiple controlling. A 32-bit TMS320F2812 chip is used as the central processor, implementing the whole structure and workflow of the temperature control circuit. The expertise tuning integral separated and dead zone PID algorithm parameter is adopted in this system. The control accuracy reaches ± 0.5°C range. Finally, the experiments with and without temperature control are carried out in constant and variable temperature conditions. The result indicates that the temperature control system effectively ameliorates inertial parts´ thermal condition. Accordingly, it improves the precision of FOG POS, and satisfies the requirements.