航行環境情報の表示方式に関する一考察-II : 実船調査によるARPA情報の解析  [in Japanese] A Study on the Navigation Decision Support Display System-II : Analysis of ARPA Data from an On-board Investigation  [in Japanese]

This report proposes one of the navigation support system to improve the safety of navigation. This is a system applied a method using synthesized voice with an aim of indicating information about other ships' movement for navigators on the bridge by processing data from ARPA. In the conventional ARPA system, several different alarms are generated. Those alarms are identified by different buzzer tones, CRT symbols and characters. We can observe the situation on the bridge in which there is not enough time for navigators to confirm the meaning of alarms especially in the congested navigable waters. This fact means that the effective use of information is difficult in the conventional ARPA system and its difficulty leads to delay in the action of avoiding collision. We could find out one of collision causes in these situation. The items investigated in this study are as follows ; 1) frequency of alarm generation in ARPA 2) error of data displayed on CRT of ARPA 3) frequency of mistaking the target in ARPA 4) mode of conversation concerned about lookout on the bridge All of these items were studied under actual ship operation. The results are as follows ; 1) The frequency of alarm generation is high, especially in mistaking targets. 2) From the fact that conversations concerned about lookout are patterned, the information concerned about other ships' movement is suitable for language processing by computer. On the basis of those results, a navigation support system applied a method using synthesized voice has been constructed experimentally. In this system, data from ARPA is processed and the aural information about the movement of other ships including targets mistaken is indicated in accordance with certain decisions. A comparison with this proposed system and the conventional system shows that the aural information could be used more effectively even in the case that it is difficult for navigators in progress of position fixing etc. to confirm the meaning of the conventional alarms.