Study of North Finding System with Low-cost MEMS Gyro Sensor and 3-axis Small Turntable under Non horizontal and Magnetically Disturbed Environments for UUVs

This study developed a north-finding system using low-cost sensors and a small 3-axis turntable, even in non-horizontal and magnetically disturbed environments. First, the accuracy of the developed turntable was examined based on image-based analysis. Second, the turntable was rotated to estimate an ellipsoid from the resulting point cloud, enabling use non-horizontal environment. Finally, two experiments were conducted. The first experiment is to identify the four directions. To enhance the precision of the results, it is necessary to increase the amount of experimental data. In order to the time required, this study adopted a method of increasing the amount of data through simulation by sampling without replacement. The second experiment is to detect the due north under the condition that the due north is unknown. As a result, the proposed method achieved an accuracy of ±10° in approximately 27 min, and ±0.59° in approximately 3.29 h, demonstrating enable to use these environments.