Accuracy of Information Obtained by Smartphones for Avoidance of Collision Including Boats

Abstract

Though the number of marine accidents tends to decrease, nearly 2,000 ships have been involved in marine accidents every year for the last 10 years in Japan. More than 70% of ships involved in the accidents are boats such as pleasure boats and fishing boats. In this paper, we focused on collision avoidance support for boats by using collision alerts. There are two ways to support collision avoidance by using collision alerts; one is a guard-zone alert using position information and the other is a collision alert based on Closest Point of Approach (CPA) analysis using information of position, course and speed. Evaluation of communication time in information processing is necessary to provide timely support regardless of the aforementioned ways. Automatic Identification System (AIS) and radar Target Tracking (TT) are used for collision avoidance support. However, they are not suitable for boats because of their costs and sizes. Meanwhile, smartphones become popular in late years. When smartphones provide sufficient accuracy of information for collision avoidance support, they can be practical and useful onboard devices to support boats. In this paper, we clarified communication time, accuracy of position, course and speed obtained by smartphones that affect collision alerts.