The concept of future support system is provided as follows.
(1) The support system which can realize safe navigation with one-man
operator.
The system executes information processing which human is not good at
without giving overloads on one-man operator.
(2) The level of support should be up to knowledge-based strategy.
The final decision on action judgement is to be made by an operator,
and the system provides leading advice to assist making prompt and accurate decisions and
has a function to evaluate the contents of the decisions made by the operator.
Safety of navigation consists of three factors, human, ship and
environment. It is wrong to depend only on one or two of the factors in order to maintain
safety. The three factors should respectively execute their safety-securing function in
accordance with each characteristic.
In many cases, safety is assured by upgrading human functions. However,
as there is a limit to human ability, a demand for improvement of the human functions
needs to be kept within a reasonable extent.
At present, the navigation system is on a phase of innovation. The
fundamental concept is to substitute human loads by instruments on board so as to reduce
human loads. However, if the substitution is taken only by the instruments on board, it
would result in undesirable expansion of the system functions, which could cause an
economical problem and a problem with rationality of a navigation system as a whole.
In such a phase of navigation system innovation, adjustability among
human, ship and environment need to be examined. Rearrangement of the environment should
be considered from the viewpoint of establishment of a new navigation system. And
cooperation among human, ship and the function which environment should carry out must
also be considered.
The ship operation system of conventional ships has been proceeding to
be self-perfect without getting any assistance from outside of ships. Present IBS is also
developed on a independent system basis.
Although the self-perfectness is caused by the navigation-related
condition of the past, recent condition has been changed. The use of GPS for positioning
is a typical example. If we regard such independence as important, we could make a big
mistake in developing the system function. For instance, in the case of support for
collision avoiding maneuver, as it was mentioned above, estimation of the future motion of
a target ship is very important. By using present RADAR, we can only estimate the future
motion to be the extended motion from the present motion. Therefore, we might estimate the
target ship would go straight nevertheless it is following a bending fairway. We have to
know the target ship's intention in advance and decide own ship's motion corresponding to
it. For this purpose, the transponder is a very useful equipment for communication of each
other.
Furthermore, in the congested water, if IBS can decide the motion
according to the information from the vessel traffic management center, the safety
navigation and the support system will be more satisfactory. If we persist in a
self-perfecting system, development of the technology would be difficult and unreasonable
investment would be required. It is important to develop the support system being in
harmony with the technology of infrastructure.
