Tadatsugi Okazaki

A characteristic of a navigator’s mental workload based on nasal Temperature

A human skill is evaluated by a professional who has lots of experience and good sense. Quantitative evaluation comes from a performance and a questionnaire. Mental workload shows internal conditions and it is important for us to evaluate human skills, especially, intellectual performance. The physiological indices used to evaluate mental workload (decision-making effort). The heart rate variability (R-R interval) and the nasal temperature, are hopeful indices for the navigator based on our research. This paper proposes that the nasal temperature is an effective index to evaluate the mental workload of a navigator. The nasal temperature responds when the navigator makes a decision regarding ship-handling and collision avoidance, and shows well the whole trend of his decision-making.

Evaluation of ship navigator's mental workload using nasal temperature and heart rate variability

Mental workload is useful to evaluate performance of a ships bridge teammate: a captain, a duty officer and a helmsman, sometimes adding a pilot. The heart rate variability and the nasal temperature predict well based on pre-experiments; however, we have not evaluated them at the same time yet. In this paper, we evaluate simultaneously heart rate variability and nasal temperature of a subject as he guides a ship into port. The experiment is carried out using a ship handling simulator, not a real ship. We show they are good indices for efficient navigation skills.

A Study of Minimum Time Berthing Solutions

Abstract The conditions that ship’s masters or pilots face to in ship handling to a berth are various. The minimum time berthing solutions, which the authors have solved, might give good information to them. However, it is impossible to prepare the minimum time berthing methods for whole conditions they will face to. The paper deals with a general guideline for maneuvering of small ship gained from the minimum time solutions. Especially the geometrical points of view of the minimum time berthing solution are focused.

Development of a training support tool for marine pilot trainees

In this study, berthing simulator training data were analyzed then a method of quantitatively evaluating the training result was proposed. Effectiveness of the proposed evaluation method was described with the training results of some experiments.

A study on berth maneuvering using ship handling simulator

In this study, training data of berth maneuvering using ship handling simulator was analyzed from the viewpoint of the minimum time berth maneuvering problem. The safety margin of the minimum time berthing problem was derived from the minimum value and the maximum value of the simulator training data of the first class pilot trainee.

A study on navigator’s mental workload in ship handling simulator

Usage of a ship handling simulator extend to many topics such as crew trains, evaluation of nautical instrument and research of human factor etc. In any case, it is necessary to observe operators behavior at bridge work. The procedures of performed operators task could be recorded by a monitoring video camera. However, it is difficult to estimate operators mental workload at each performance from the monitoring video. In this paper, practical technique is introduced for presuming navigators mental workload in ship handling simulator by using data of navigators nasal temperature which is measured by thermal image video camera. And effectiveness of this technique is examined by some practical simulations.

A ship's minimum-time maneuvering system using neural networks

In this paper a ships minimum-time maneuvering system using neural networks is proposed. In the proposed method, the neural networks are used both for interpolating the pre-computed minimum-time solution for the real-time situation and for compensating the control error caused by some modeling errors, disturbances etc. In order to investigate the effectiveness of the proposed method, computer simulations and actual sea tests are carried out using a training ship Shioji Maru.

Override ship maneuvering simulator using AR toolkit

AbstractThis paper proposes an override ship maneuvering simulator using an actual training ship for young pilot trainees. In this new simulator, augmented reality toolkit was used to reproduce scenery from the bridge of a large vessel on the actual training ship. Moreover, the system reproduced the large vessel’s maneuverability under wind disturbance on the training ship. The effectiveness of the developed system was indicated with results of an actual ship experiment.

A few comments on visual system of ship handling simulator based on arriving port

We use a simulator for research of human factor in ship handling; however, in case of arriving port, it is not enough for a visual image around own ship. The ship handling simulator does not have the visual image (screen) around own ship. We tried to build up the ship handling simulator that has visual system around own ship for arriving port. In this paper, details of the visual image system of the ship handling simulator and results of some experiment performed for effectiveness of this visual system is shown.

Guidance control of vessels using minimum time control

In recent years, serious problems have arisen in coastal shipping along in Japan, because lack of expert sailors and the successors have gone on the increase year by year. Since such state of harbor operations has required immediately improving the technology of operation, authors proposed a solution to contribute to the development of the coastal shipping and the decrease of marine casualties. Taking variation of harbor circumstances into consideration, authors proposed a minimum time harbor operation system for coastal vessels in this paper. This system must make them possible of time shortening of harbor operation, load reduction for sailors and fuel consumption of vessels as well. A minimum time maneuvering method was obtained by mathematical optimal solutions with SCGRA method. The effectiveness of this new operation system was confirmed through some actual ship experiments of steering by the captains.