The digital control implementation of swing scanning system on infrared earth sensor

Swing scanning infrared earth sensor brought forward special requirements (wide swing amplitude: ±15°, narrow swing amplitude: ±5°, frequency: 5~10Hz) to the swing scanning control system. Analog scanning control system has some shortages, such as: inflexible to adjust control parameters, hard to implement complex control algorithm and low control accuracy, etc. This paper proposed a digital control method based on FPGA to improve the flexibility and control accuracy of the system. Due to the key problem of low precision of optical grating for the swing scanning control system, this paper proposed a novel method of FPGA based subdivision for optical grating to improve the control accuracy. Experiments showed that the method could meet the requirements of low speed and high precision control for the swing scanning control system.