An Estimating Orientation Using IMU Module for Autonomous Underwater Vehicle (AUV)

Abstract

In this paper, a high-rate Inertial Unit Measurement (IMU) with accelerometers, magnetometers and gyroscopes, as well as Arduino UNO is used to gather data referring to the objectives. However, there could be some errors accumulated due to the external environmental factor. Orientation accuracy heavily affects positioning accuracy. The project is to design an efficient control system for the orientation and path-following of an AUV using the MPU-9250 sensor with the AHRS algorithm in MATLAB.  This work will focus on the orientation module using IMU based on the AUV motion behavior. There are two classifications of measurements that are without the usage of the AHRS filter and with the usage of the Attitude and Heading Reference System (AHRS) filter to test the overall performance of the IMU module by observing the accuracy, precision, and stability. The result of the precision of yaw at -90° oriented without the AHRS filter in the IMU module is 0.90 and with the AHRS filter, IMU is 0.99. Other than that, the percentage of accuracy of yaw at -90° without the AHRS filter is 96.33% and with the AHRS filter is 99.99%. This means that the data obtained of yaw at -90° with the usage of the AHSR filter has a more accurate result. Pitch and roll data can be obtained in the results. Hence, the AHRS filter has improved the accuracy, precision and stability of the IMU module. Many possible improvements can be made to improve the accuracy, precision, and stability of the IMU MPU9250 module sensor. For instance, use other types of filters or test the orientation module at a place that has less magnetic disturbance to reduce the noise readings of the IMU.