VISUAL GUIDANCE FOR FUZZY CONTROLLER...

As described in the Introduction, the autopilot system developed in this study is based on the leading line visual guidance strategy. Thus, as described in the sub-sections below, in mimicking the actions of a human pilot, the autopilot system requires image processing.
(1) the orientation of the ship relative to the front leading mark; (2) the position of the ship relative to the leading line; and (3) the distance between the ship and the berthing wall. This information is then used to instruct the necessary course adjustments required to bring the ship toward the leading line and to determine the appropriate moment at which to switch from an approach maneuvering mode to a
berthing control mode.