ERROR ANALYSIS IN SINGLE-AXIS INTERFEROMETRIC FIBER OPTIC GYROSCOPE PROTOTYPE DESIGN

• Main Author: Kartikaningtyas (NIM : 13313068), Ardinda
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/21203
• Institution: Institut Teknologi Bandung

Gyroscope has important roles in an INS or Inertial Navigation System, to provide orientation information which is required to transform the coordinate of the outputs of accelerometers to a relatively fixed inertial frame of the navigation system. Due to the importance of reliability and correctness of gyroscope output, the purpose of this research is to analyze potential errors in the design of Interferometric Fiber Optic Gyroscope (IFOG). IFOG works based on Sagnac effect. Sagnac effect states that the phase difference between two laser beam propagating in opposite directions along a closed path in the IFOG system will be proportional to the IFOG's rotational angular velocity. Thus the measurement objective is the phase difference which is proportional to the angular velocity change. However, in designing IFOG, numbers of different errors or disturbances that are not caused by the Sagnac effect, are found, which is called the phase angle bias. <br /> <br /> In addition to the phase angle bias, there are also deteministic noise and stochastic noise in the IFOG system. The deterministic noise is removed by least square method, while stochastic noise needs a special treatment. Stochastic noise is necessary to be identified first to obtain the dominant noise type on the system using Allan variance method. Three dominant noise type has been identified in the designed IFOG system, the ARW (angle random walk), BI (bias instability) and RRW (rate random walk). The identified noises are then used to obtain the output signal model of the IFOG system, which later is used for the implementation of Kalman filter algorithm. In this research, Kalman filter estimates the power output of gyroscope.The orientation angle given by the gyroscope can then be calculated from the estimated power output given by the Kalman filter. From this research, it is known that Kalman filter is able to produce a good estimation of gyroscope power output. In the designed prototype system, there was also identified a very low frequency disturbance caused by the optical system, which cannot be eliminated by a low-pass filter.