This function is to estimate motions of traffic vessels and to realize
a maneuver to avoid collisions. The motion estimation of traffic vessels follows the
function of conventional ARPA. In present IBS, the level of this function is low; the
functions from No.4 to No.6 shown in (Table 1) have not been realized yet. Therefore, an
operator must carry out the following tasks. As the contents of analysis and evaluation
which the system makes are limited, an operator has to evaluate, decide and execute from
various points of view.
Support for berthing maneuver
This function is to berth safely and effectively considering
complicated disturbance and maneuvering characteristics of own ship. However, the function
of present IBS is insufficient lacking the support contents from No.3 to No.5, an operator
must estimate the effect of operations and decide the degree of the operation.
2.3 Future Support System
It can hardly be said that the development of present IBS has been
proceeding based upon thorough discussions on how the support system should be. In this
paper, direction of the development of the support system is proposed. It is important to
make a discussion on the direction from the viewpoint of rationality and efficiency at
present, the period of transition in navigation technology.
In this paper, the information processing are divided into 6 items
shown in (Table 1) according to the steps of data processing. Also, it can be described as
three hierarchy based on hierarchy model of human behavior show in (Fig. 1). The
skill-based strategy corresponds to the measuring and steering. Optimizing the interface
upgrades the support for this hierarchy. The rule-based strategy corresponds to the data
processing based on specific procedure. The support for this one will be improved by using
expert-system. The knowledge-based strategy corresponds to the decision making to select
the procedure and evaluation. Present IBS has a lack in the field of the rule-based
strategy, and scarcely realizes the support for the knowledge-based strategy. The support
for knowledge-based strategy must be made satisfactorily in the next generation.
IBS must be able to keep watching the actions of the human operator as
well as the results of IBS. When human is about to make a mistake, IBS should warn and
propose the reasonable action. In order to do this, IBS must understand the object of
maneuver. And for the purpose of deciding the reasonable action, IBS has to support the
knowledge-based strategy. It is a matter of course that IBS watches over its own
condition. When a big error is made in position measuring, it is not allowable to show the
position containing the error without any evaluation. IBS must have the function to
diagnose scensor errors and
