Dynamic initial coarse alignment of SINS for AUV using the velocity loci and pressure sensor

Abstract

For the high-speed and light autonomous underwater vehicle (AUV), it is moving freely, and the speed and attitude are in dynamic movement. Then, the traditional static and quasi-static ground alignment cannot be used any more. Using the optimisation-based alignment (OBA) scheme, this study presents a novel estimation method for fast initial coarse alignment of a AUV's strapdown inertial navigation system (SINS). The novel OBA method use the inertial measurement unit, the pressure sensor measurements and the navigational velocity ν v in v-frame produced by the motor thrust to solve the attitude estimation problem which is known as Wahba's problem. Unlike several current techniques, the presented estimation method is effective to any movement form. The simulation results show that the attitude determined by this novel method can meet the accuracy requirement of coarse alignment and it can be used as input for the fine alignment.