Ruri Shoji

Monitor System for Remotely Small Vessel Navigating

In this research, we examine the necessary information for remotely vessel navigating and the display system for the mariner in a re-mote place. We also conduct experiments using small vessels. In remotely vessel navigating, it is important to send all information on the hull and vessel around to vessel operator at a remote location with the lowest possible delay. Since river traffic is being researched, it is targeted for remote ship navigating of small vessels in urban rivers. In this research, we examined the monitor for the ship operator for remotely vessel navigating of small vessels, and conducted the remotely vessel navigating experiments. Although it is the minimum necessary function for remotely vessel navigating, it’s possible to navigate. It is necessary to show a lot of information to the operator for safe navigation, such as distance to distant vessels, obstacles, weather, oceanic conditions etc. and consider to avoid data traffic.

The “Watch” Support System for Ship Navigation

Floating and non-floating objects such as other ships, buoys and so on must be alarmed before becoming obstacles for ship navigations. In this research, we have aimed to predict obstacles around a ship from maritime navigation images using an image recognition method and display them effectively to its operator. Faster R-CNN was used as detection method. We prepared a dataset composed of three categories for training and testing machine learning. We enumerated parameter values to obtain the best detection rate of obstacles by CNN. Then, we employed the best set of parameters for further experiments. The results are summarized as follows: (1) the detection rate of buoys is about 55 [%]; (2) large ships are sometimes mistaken for small boats. It remains to improve the detection rate and to decrease misclassifications; (3) the detection rate of small boats with distance of about 3 nautical mile(nm) from the ship is 86 [%], the detection rate of buoys with distance of about 2 [nm] from the ship is 100 [%].

Development of sea route display system by using augmented reality

A navigator draws a route on a chart to navigate a ship from an origin port to a destination port. Then, the navigator sails the ship based on the route. In other word, the navigator misidentifies the route there is a possibility of running aground. In order to prevent navigators misidentifies, this study proposed a sea route display system which displays the sea route on the surface of the sea by using augmented reality so that navigator may grasp the ships position from the sea route easily. Effectiveness of the developed system was carried out with actual ship experiment.

船舶の航跡に対するトラッキング制御に関する研究―AIS・GPS情報を利用した制御について―

Maritime traffic data are observed by many institutions. Effectually utilization of those data is inspected. Others, tracking control for straight route or curve route is effective by precedence study. In this study, target trajectories were made from three (3) observations (Coastal Station using automatic identification system (AID), Global Positioning System (GPS), and Control System in Shioji Maru). Saving data of Control System include position, heading and yaw rate and that interval is 1 second. Trajectory data by Coastal Station include position, heading and yaw rate but that interval is inconstant. Trajectory data by GPS have only position, that interval is 2 second. An order rudder angle is calculated by present ships situation and trajectorys data. This control algorithm is inspected by simulation and actual ship experiments.

ウェザールーティングシステムの構築に関する研究-II.-船載型モニタリングシステムデータの活用-

In recent years, as a measure to reduce the effect of global warming caused by the maritime transport, vessels have been strongly advised to reduce fuel consumption. Weather Routing (WR) is a relatively inexpensive and easy way to implement the solution. However, for good operation, WR requires a good estimate of the vessels propulsive performance at seas. In previous studies, it had been shown that ships performance can be estimated by analyzing abstract logbook data. In this paper, the authors proposed a method for estimating the vessels propulsive performance using thrust data obtained from an onboard monitoring system and using several possible parameterable methods. For carrying out the study, an Onboard Monitoring System was fitted onboard a 4,430TEU container ship for data collection. A minute examination of the collected data showed a clear relation between ocean wave state and thrust. A set of formulas was established to calculate the thrust increase relying on wave height and direction. The obtained equation allowed the authors to reconstruct an actual voyage within a 3% margin of error, showing the good performance of the proposed estimation method. WR simulations showed also the potential reduction of fuel consumption reduction achievable using the estimated vessel performances.

Basic Research on the Utilization of Solar Energy for Weather Routing

In maritime society, the technical development for utilizing natural energy, such as solar power or wind force, is progressing. And in order to use solar energy safely and efficiently, it is necessary to develop weather routing technology. In this study, the authors examined the possibility of weather routing for ships using solar energy. First, on several routes of the ocean, the authors investigate the seasonal variation of a total solar power and the relation between route and solar power. This paper proposes the modified route selecting method to increase the total solar power for solar power ships.