Digital Signal Processing Scheme for Open Loop and Closed Loop IFOG using MATLAB/SIMULINK

Abstract

Objective: Interferometric Fiber optic gyroscope (IFOG) is an angular rate sensor which plays a crucial role in inertial navigation system. Measuring the angular rotation rate can be done in two approaches namely open loop&closed loop. Designing and implementation of these methods using a simulation tool provides faster&accurate results. This paper presents a novel Simulink model implementation of Open loop&Closed loop Fiber optic gyroscope for the measurement of rotation rate. Method/Analysis: The gyroscope with each optical component is treated as a black box having M input and N output ports that are represented mathematically with its transfer function by connecting output to its input. This methodology is very efficient for finding the calibration&phase difference between the co-rotating&counter rotating beams. Findings: There are two major contributions in this paper. Firstly, the physical model of open loop FOG is built in Simulink model&angular rate is measured. The signal processing scheme of modulation and demodulation techniques for finding the rotation rate can also be analyzed mathematically. In second, to improve the accuracy and stability the feedback loop is very important to improve the gyro performance which can also be analyzed with different rotation rates. Experimental setup shows that an improved result is obtained in determining the direction of rotation and accuracy of the proposed model.