Collision Avoidance Maneuvers for Ships

Abstract

The state-of-the-art in collision avoidance technology for ships consists of systems employing digital signal processors to compute ship tracks, target closest point of approach (CPA), and time-to-CPA. This information is presented to the ship's officers through CRT displays. Some systems provide a means for selecting and displaying trial-and-error maneuvers. Like the available shipboard radar systems, existing collision avoidance equipment relies heavily upon the ability of the ship's officer to process information and make decisions under conditions of severe stress. This paper will discuss the potential use of a shipboard digital computer to compute additional information from the radar video data and generate maneuver cues as an aid in collision avoidance. Techniques for generating collision avoidance maneuvers will be related to ship maneuvering capability, as determined by its speed and turning characteristics. One example will be given to illustrate the relationship between CPA and miss distance for cooperative and uncooperative maneuvers, and another will show how dynamic maneuver charts can be used by a privileged vessel to decide when to take action to avoid a burdened vessel.