4.2 Standard course alteration maneuvers

　

 The result of a questionnaire to experts on ordinary rudder angles of course alterations and used rudder angles in simulator experiments of experts are shown in Fig. 10. This distribution of used rudder angles were coincided with the ordinary rudder angles of the questionnaire. It becomes clear that the standard course alteration maneuver is composed of maneuvers using the rudder angle depending on the telegraph position.

　

 As shown in Fig. 11, the distance from the stating point of the course alteration to the way point can be found by solving the following Eqs. (5). In same way, the distance to the ending point can be found by the Eqs. (6). In these equations, TD is the delay of the steering gear, T' and K' are non-dimensional maneuverability characteristics of the vessel and others are defined in Fig. 11.

　

　

4.3 Standard stopping maneuvers

　

 By the questionnaire surveys to experts on stopping maneuvers, it became clear that the standard stopping maneuvers consists of a series of two maneuvers. First one is a deceleration maneuver with a stop order along the straight course. The other is a stopping maneuver with a slow astern order at 1.5L short of the target point. As same as Eqs. (3) and (4), the advance for the standard stopping maneuver is found as following equation (7).

　

DSTOP = 1.5L + O.865TPKPnD・・・(7)

　

 Simulations based on the above-mentioned passage planning system were executed. Planning a passage for a GT499 inland vessel from the origin/start in an open sea to the destination/goal, where is in front of a berth, were simulated. Simulation results are shown in Fig.12 - Fig.17. The origin/start is at the lower left and the destination/goal is at the upper right in the water area.

　

　

 In the target water area, there are many No-Go areas, which are defined by the water depth contour lines of the chart, based on the UKC: under keel clearance of the vessel. Paths from the origin to the destination should avoid No-Go areas. Some paths were found and the shortest path of them was selected, as shown by the line in Fig.12. But there are often some recommended passages, legal based passages and other restricted areas in and around ports in addition to a restriction of the UKC. Re-finding another shortest path through the recommended entrance passage from the origin to the destination was done, because there is a recommended passage in the target water area. Finally the modified shortest path through the recommended passages was selected, as shown by the line in Fig.13.