Nobuo Mitomo

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.

Cooperation between a Human Operator and Multiple Robots for Maintenance Tasks at a Distance

A novel concept of the integrated plant system is proposed where multiple robots work together with human operators. We have principally studied how to issue operation commands effectively through a human interface to let multiple robots work in the plant. A human interface system for multi-robot operation is constructed utilizing the WWW system. It is confirmed that multiple robots can actually be operated by the system from a distant place. By applying this system to a nuclear power plant model, we have been examining the performance of the cooperative work with human operators and multiple robots.

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.

Questionnaire Survey for Adapting Common Performance Conditions to Marine Accidents

An officer of the watch (OOW) is a qualified person with the knowledge and capabilities required to safely navigate a ship. However, many collisions occur that are caused by human errors in navigation. Eighty-four percent of collision accidents are caused by inadequate lookout. It is estimated that such accidents can be prevented if the OOW performs fully to his or her knowledge and capabilities. Many factors can reduce the OOWs reliability, so it can be difficult to specify the cause of an accident. If the cause of an accident can be specified, efficient measures can be taken. This study utilizes a human reliability analysis method to analyze marine accidents. The cognitive reliability and error analysis method (CREAM) divides background factors into nine common performance conditions (CPCs). However, the manner in which CREAM is used in the nuclear industry is not applicable to the maritime domain since the working conditions are very different. To facilitate using CREAM to analyze marine accidents, we sought advice from specialists about redefining the CPCs and their descriptions. We then adapted the dependencies between the CPCs to marine accidents based on a questionnaire survey administered to OOWs. This paper reports the results of the questionnaire survey. In addition, we discuss the dependencies between the CPCs adapted for marine accident analysis. These results confirm the essence and character of the maritime industry.

A Method for Quantifying the Risks of Human Error from Experiments with the Ship Bridge Simulator

Why do vessels collide with each other even though the Navigation Officer on Watch (OOW) keeps a lookout? This study aims to discover what causes human error of the OOW. For this purpose we conducted a series of experiments and surveys. This paper reports on results of two experiments and the present state of marine accidents in Japan. The first experiment objective is to find out the correlation between the angle of an approaching target, and error in overlook (cognitive error), and to put forward a method for estimation of Human Error Probability (HEP) from experiments using a ship bridge simulator. The next experiment objective is to find out the correlation between behavior and error in judgment (decision error). The author found that the OOW tends to overlook a target that is approaching from the port side. The other result shows that the notice time is negatively correlated with the amount of time using binoculars. This study concludes that a method for quantifying the risks of human error from experiments is necessary for implementing highly reliable Human Reliability Analysis.

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.

EVALUATING THE MARINER'S WORKLOAD USING THE BRIDGE SIMULATOR

Abstract Many maritime accidents are caused by human error. Human error is mostly affected by the state of the mariners physiological and psychological aspects. For example, excessive stress creates error, lapses of attention cause the mariner to overlook or fail to notice problems. To clarify how physiological and psychological states affect human involve many problems to be solved.

Evaluation of ship navigator's mental workload for ship handling based on salivary NO 3 −

The Evaluation of mental workload/ performance has usually depended on professionals (captain, pilot) who have a lot of experience on board. We are attempting to evaluate a ship navigators mental workload based on a physiological index. The physiological indices, heart rate variability (R-R interval), nasal temperature, and salivary amylase, are good indices for reading the mental workload in ship handling. Moreover, we have found a possibility of salivary NO3- as a good index for evaluating the navigators mental workload. The salivary NO3- is expected to have a specific characteristic to represent quick response on the spot and the trend like moving average. We confirmed the response of students for simulator training, and we were carried out the experiment for professionals on a real ship. This paper proposes that salivary NO3- shows a ship navigators mental workload for ship handling in the simulator and a real ship. This research, to evaluate the mental workload of navigators using salivary NO3-, is first challenge worldwide.

Study on ship navigators' mental workload for ship handling based on salivary NO 3 −

The evaluation of mental workload/ performance has usually depended on professionals (captain, pilot) who have a lot of experience on board. We are mainly attempting to evaluate a ship navigators mental workload based on a physiological index. The physiological indices, heart rate variability (R-R interval), nasal temperature, and salivary amylase, sharply respond to events of ship handling. Moreover, we have found a possibility of salivary NO3- as a good index for evaluating the mental workload. The salivary NO3- is expected to have a specific characteristic to represent a quick response on the spot and the trend like moving average. We confirmed the response of students for simulator based training, and we were carried out the experiment for professionals on a real ship. This paper proposes that salivary NO3- shows a navigators mental workload for ship handling in a ship handling simulator (simulator), and it is compared with heart rate variability. This research, to evaluate the mental workload of navigators using salivary NO3-, is first challenge worldwide.

A study on navigator's performance in ship bridge simulator using heart rate variability

To minimize the maritime accidents, it is universal agreed that the ships officers who manoeuvring the ship must be well-trained. A ship bridge simulator is always proved to be one of the best ways to achieve the training objective, as it enables the navigator to expose to many realistic experiences. This study proposes a consideration of human performance (navigator) in such an environment by using Heart Rate Variability (HRV) or more specifically, Heart Rate R-R interval data, which can be obtained from Electrocardiogram (ECG). Upon analyzing the HRV data from navigator, a good assessment or anticipation on the performance of human factor in the interaction between human-ship can be achieved positively.