The All-Digital Closed-Loop Processing Technology of FOG

Abstract

This paper expounded a full digital processing method of FOG using field programmable gate array FPGA as the logic circuit to accomplish digital signal processing. The ladder wave feedback of square wave modulation and digital signal through D/A converter transmit to the sum of A multifunction integrated optical chip arm on the one hand, to greatly improve the speed and reliability of FOG, on the other hand, reduces the volume of the gyro, reduction in weight. As a new type of all solid state inertial instrument without moving parts, FOG is usually used for navigation and guidance purposes. As angular rate sensor, it can also be used to control cars, robots and so on. Fiber optic gyroscope can not only measure angular rate accurately, but also provide direction data by integrating angular rate. Optical fiber gyro has been widely used in aviation, aerospace, navigation, weapons and other industrial fields. The most widely used in fiber optic gyro is interferometric fiber optic gyro, its working principle is: from the common light source of two coherent light located on the rotating carrier through a closed optical path system, travels along two opposite directions, the two direction of transmission of light waves with different optical path difference, the optical path difference to produce a phase difference, people by interference method and modem technology to detect the phase difference, which can measure the carrier's rate of rotation. This non-commutative phase difference was first proposed by the French scientist Sagnac in 1913, and is therefore called Sagnac phase shift.