Shogo Inaba

Investigation method for the biomass of kichiji rockfish by hovering type AUV

We surveyed the biomass of valuable kichiji rockfish using hovering type AUV Tuna-Sand which developed for observation of the seafloor, in Kitami-Yamato bank in northern ocean of Japan at June 2013. The AUV took about 5,300 photography of the seafloor for over 24 hours. The photograph had 37 kichiji rockfishes 90 mm to 340 mm long. Kichiji rockfishes which were taken several times by the AUV stayed on the seafloor at same attitude. TS_076 dive point of 652 m depth had most number of kichiji rockfish and many brittle stars. TS_077 dive point of 305 m depth had two fishes although the AUV observed the broadest range in all dive points. In TS_079 dive, the AUV observed ten fishes although observation area was the smallest, and fish density (= number per 1 ha) was over 220 /ha. Made photomosaic shows that a kichiji rockfish stayed in oneself without troop and shortest distance between two fishes was about 4.0 m.

Fish recognition method using vector quantization histogram for investigation of fishery resources

This paper proposed a novel approach to the kichiji rockfish recognition method for investigation of the fish biomass. This method does not depend on the size, position and attitude of the fish, because SIFT feature with rotation invariant is used and is represented by vector quantization histogram. The experiment results showed that our method detected 94 % of object which is the fish from 37 photographs and recognized 57 % of the fish from detected image. And our method was able to recognize kichiji rockfish from SIFT features of the fish head. However, if more than one object is piled up, our method is a possibility of mistaken recognition because features of object other than target are used for recognition.

Tracking experiment of multiple AUVs by a semi-submersible ASV

We have developed a semi-submersible ASV (Autonomous Surface Vehicle) that tracks and controls AUVs (Autonomous Underwater Vehicles) on behalf of the mothership. In September 2016, we conducted tracking, positioning and communication tests of multiple AUVs by using the ASV. The results of the trials proved the performance as designed. And the ASV succeeded the test of each AUV tracking and multiple AUVs tracking.

Development of a regional underwater positioning and communication system for control of multiple autonomous underwater vehicles

A new complex system of underwater positioning and communication has been developed for control of multiple autonomous underwater vehicles (AUVs). It consists of a semi-submersible autonomous surface vehicle (ASV), a hovering type AUV, and three surface buoys. The operational concepts for control of multiple AUVs are discussed.