2.3 Consideration

　

 It is found that it was shown about a ship's length 100m and 280m in the following from a result of a ship handling simulator experiment.

　

(1) Ship's length 100m

　

 Kp, Kx and Kd which it could get from the turn rate display increase from the case that none of controlled variable were indicated, and phase margins decrease by small size ship of length 100m. However, as for the average lateral deviation, it found that it became the smallest.

　

 Next, turn rate display is compared with Normalized (normalization control coefficients) as a usual ship handling system. The turn rate display of Kx, Kp and Kd is respectively larger, and the turn rate display of the phase margin as well is larger.

　

 Furthermore, as for the average lateral deviation, the one by the turn rate indication is small. Therefore, as for a result of a maneuvering, it is understood that the one by the turn rate display devised by this research is superior to a maneuvering by the usual turn rate meter more.

　

(2) Ship's length 280m

　

 As for the rudder response by the helm, changes in control coefficients are reflected, and a maximum lateral deviation exceeds 100m by the display except for the turn rate indication. And it is understood that the rudder response by steering has a undershoot form.

　

 Only the case of the turn rate display of the maximum lateral deviation as well is small with about 60m. This shows the value which is almost the same as the case of a ship's length 100m.

　

 Moreover, these are reflected, and an average lateral deviation is the smallest with 9.133m

　

 As for the effect of increase in a ship operator control coefficient by the proposed turn rate indication, it is found that it is remarkable when it considers that a rudder response by the helm is specially an under-shot form in the maneuvering by the turn rate meter which is a usual ship handling system.

　

 The above is examined. Ship operator control coefficients increased remarkably, and a result of a maneuvering turned favorable by the turn rate display proposed with this research in the large ship of a ship's length 280m.

　

3.1 The information processing of the ship operator

　

 First, a ship operator grasps the relative position relations of the surrounding ships and the ownship in the maneuvering in collision avoidance, and the target ship that an ownship must avoid is chosen.

　

 Then, the movement of the target ship is grasped by observing a relative bearing and a speed regularly using the visual observation and the RADAR/ARPA.

　

 Then, the collision avoidance plan to pass over the target ship safely is planned in consideration of the maneuverability of the ownship. Then, a ship operator avoids other ships in accordance with this collision avoidance plan.

　

 The maneuvering actions for a series of collision avoidances of such ship operators can be caught as an information processing. At this time, each phase of the information processing in collision avoidance of the ship operator shows the following.

　

3.2 A limit of the information throughput of the ship operator and support

　

 An error in the information analysis arises when the course and position of the other ship which a ship operator predicts is different from the actual. This analysis error arises concretely from the next process.

　

 A ship operator predicts the future movement of the other ship from the observation of a position of the other ship in the current constant time from the past. Then, the confirmation of the other ship movement is that an actual other ship movement almost amounts to a predicted other ship movement.

　

 And, this is to be within the range that the error of the prediction and the actual other ship movement can be permitted just small. The other ship movement becomes uncertain when a predicted other ship movement, and an actual other ship movement are conversely greatly different from this in other words when the error of the prediction and the actual other ship movement is very large.

　

 Two indications of the destination display and the way point display was devised as the display of information which made other ship actions decision in this research.

　

 First, the condition which no support display is in for the comparison is shown as a basic screen in Fig. 9.

　

　

(1) Destination display

　

 It decided to attempt for the decision of the other ship movement by indicating its destination of the other ship. A destination display screen is shown in the figure 10. The destination of the other ship is added in the neighborhood of the symbol which shows the other ship indicated on the basic screen which showed it in Fig. 10.

　

(2) Way point display

　

 It was decided that we attempted for more decision of the other ship movement by indicating the expected way point of the other ship in addition to its destination display with the expected line. A way point display screen is shown in Fig. 11.

　

　

　

 It has the function which makes it indicate time scale on the plan line which connected a plan way point selectively in consideration of the convenience of the maneuvering in this display. This time scale changes time intervals, and it can be chosen freely at the time of the maneuvering.

　

 The other ship was based on navigating on the plan line which always connected a plan way point here.

　

3.3 Support display experiment

　

 A ship operator judges conditions, and analyzes the movement of the other ship. Then, a ship operator plans a collision avoidance plan, and actually starts maneuvering behavior. The time until it actually acts after a ship operator judges condition is decided to be named with the analysis time here.