Low-Cost MEMS AHRS Design for an Autonomous Boat at Various Sea Situations

It is of particular importance to determine attitude accurately and cost-effectively for the autonomous boats. This paper presents design of an attitude and heading reference system (AHRS) based on low-cost MEMS sensor. Complementary filtering in the form of feedback control system with PI controller is used to estimate the attitude by fusion of high-frequency and low-frequency signals. Some effective calibration and filtering algorithms are developed to overcome the shortcomings of MEMS sensors such as accelerometer bias and gyro drift. In addition, for calibrating of hard iron and soft iron in magnetometer, the calibration strategy based on kalman filtering is presented. A switching approach is developed to filter the accelerated motions and distortion in the magnetic field. Finally, experimental results at various sea situations have proved acceptable performance of this AHRS design.