Design and implementation of AHRS/GPS/DR Navigation algorithm applied to long-range AUVs with high underwater durability

One of the main challenges in low-cost inertial navigation systems (INSs) is inevitable errors of MEMS-grade inertial sensors which lead to time-growing navigation error. This paper aims to develop AHRS/GPS/DR integrated navigation algorithm for longrange autonomous underwater vehicle (AUV). Proper performance in deals with longterm GPS outage is the main advantage of the proposed algorithm. Online estimation of gyro biases plays noticeable role in the performance of the presented algorithm. Using Dead Reckoning (DR) method based on an axial speed sensor, an applied algorithm is developed for position estimation during the GPS outages. The algorithm is evaluated by field test executed on a long-range AUV with high underwater durability. Experimental results indicate that in spite of 500 seconds GPS outage, the estimation error in the heading angle does not exceed 5 degrees.