Mapping and obstacle avoidance using multi-range sonar for BSA-AUV: Methodology and lake trial

As the autonomous underwater vehicle (AUV) are considered for a wider variety of military and commercial application. Effective obstacle avoidance schemes are essential to the success missions, especially in offshore environment. Response time to a threat or incident for coastline security is an area needing improvement. Classical mapping and obstacle avoidance algorithm are too complex to be applied real-time. This paper proposes a new rapid technique based on fuzzy theory. The avoidance system is divided into some subsystem. Each of them is a fuzzy system. The AUV in a trial is equipped with three forward-looking range sonar. Comparing to multi-beam sonar, the range sonar is credible but can provide only a single range to the obstacle that is limited for decision. Thus, it is necessary to build the map in unknown environment. Min square fitting is proposed in the mapping to redeem the shortage of Haugh transform. The algorithm is validated in the lake trial.