| 摘要 |
PURPOSE:To permit a turn thruster to reach a setting angle in a short time, by instructing right and left turns or a stop in the turn thruster of a tugboat through a signal of a turn direction decision device indicating a turning direction of the minimum distance and a turning signal. CONSTITUTION:A propelling turn thruster 2 is turned in accordance with a setting signal thetas of a turning angle setter 5, and its turning angle thetap is detected by a turning angle detector 6. Then an angular deviation DELTAtheta in a range of 0 deg.-360 deg. corresponding to the angular deviation thetas-thetap is converted into digital signals of i1...in in a subtractor 7, and its uppermost positioned bit i1 is output as 0 for 180 deg. or less while as 1 for 180 deg. or more, then if exceeding 180 deg. in an absolute value arithmetic circuit 30, 360 deg.-DELTAtheta is output, if larger than a signal of a blind zone setter 42, a turning signal iD is output from a comparator 41, and a left or right turn decision signal JL or JR is decided by the uppermost position bit in a turn direction decision device 50, then the both signals give instruction to the thruster 2 through a turn signal generator 60. Accordingly, the turn thruster is permitted to reach a setting angle in a short time. |
