An automation of dredging operation has been highlighted in the dredging field for a longtime from the viewpoint of labor saving, improvement of efficiency and accuracy. After the various kinds of attempts have been conducted, the automation for operation of drag-arm and drag-head has been achieved, and it has been performed very good so far. The control parameter, however, which is based upon the dredging environment such as the condition of sea bed, is being relied on the operator's decision at present.
　Under these circumstances, the study on the more advanced automatic dredging system using fuzzy control has been carried out for 1700m3 trailing suction hopper
dredger named SEIRYU MARU which belongs to the 5th District Port Construction Bureau.
　This paper introduces the newly developed concept of an advanced automatic dredging system and presents the details of the application of fuzzy control to the dredger and the results of dredging trial. This automation system based on fuzzy control is more advanced and quite different from the existing automation system which gives only sequential control conducted by ON-OFF control within the given range and cannot totally and automatically perform the optimum control on whole
dredging works according to various working conditions. Through this experimental dredging trial, the production improvement by about 7%～10% in comparison with existing automatic control system was confirmed.