Modelling the Decision Process in Computer Simulation of Ship Navigation

219

107

Efficient marine navigation through obstructions is still one of the many problems faced by the mariner. Many accidents can be traced to human error, recently increased traffic densities and the average cruise speed of ships impedes the collision avoidance decision making process further in the sense that decisions have to be made in reduced time. It seems logical that the decision making process be computerised and automated as a step forward to reduce the risk of collision. This article reviews the development of collision avoidance techniques and path planning for ships, particularly when engaged in close range encounters. In addition, previously published works have been categorised and their shortcomings highlighted in order to identify the ' state of the art ' and issues in close range marine navigation. K E Y

Section: S T U D I E S I N C O L L I S I O N a V O I D A N C Ementioning

confidence: 99%

Review of Collision Avoidance and Path Planning Methods for Ships in Close Range Encounters

Tam

Bucknall

Greig³

2009

219

107

“…Using the max-min rule for the resolution of the two fuzzy goals (James, 1986), the resulting ACD ( Figure 6) is given by solution of the equation:…”

Section: : (15) I+e[a]f G (X)mentioning

confidence: 99%

The Timing of Collision Avoidance Manoeuvres: Descriptive Mathematical Models

James

1994

Self Cite

This paper examines the frequency distributions of the ranges at which vessels take action to avoid collision. Published data from simulator exercises are employed. Both give-way and stand-on vessels are considered. Lognormal distributions fitted to the data are shown to be superior to those previously published. Underlying ‘causal’ models are developed which are capable of generating the observed distributions.

“…N O. 3 S H I P ' S F U Z Z Y D O M A I N One of the first applications of fuzzy logic in a decision model for ship encounter situations was included in the work of James (James, 1986). That study did not directly refer to the problem of ship domain determination.…”

Section: Introductionmentioning

confidence: 99%

Ship's Fuzzy Domain – a Criterion for Navigational Safety in Narrow Fairways

Pietrzykowski

2008

122

The concept of ship's domain plays an important role in navigating a ship. It is a criterion of safety in the process of making decisions by the navigator – in analyzing and assessing a navigational situation and in performing the right manoeuvre. This concept is particularly useful in restricted areas, including narrow fairways, which results from the fact that in such waters a manoeuvring area is restricted so that the criterion of the closest point of approach (CPA) cannot be used. This author has analyzed definitions of ship's domain and methods of its determination found in the literature on the subject. Then a method of navigational safety assessment using the fuzzy domain concept is proposed in reference to a ship in a restricted area. The concept and method of determination have been, respectively, defined and described. The method is based on relevant navigators' knowledge. The methods and tools for knowledge acquisition and representation make use of artificial intelligence. Ships and navigational areas of various size have been considered.