Evolutionary Sets of Safe Ship Trajectories Within Traffic Separation Schemes

Abstract

The paper presents the continuation of the author's research on Evolutionary Sets of Safe Ship Trajectories (ESoSST) methodology. In an earlier paper (Szlapczynski, 2011) the author described the foundations of this methodology, which used Evolutionary Algorithms (EA) to search for an optimal set of safe trajectories for all the ships involved in an encounter. The methodology was originally designed for open waters or restricted waters when only the standard Convention on the International Regulations for Preventing Collisions at Sea (COLREGS, 1972) rules apply. However, within Traffic Separation Schemes (TSS), where additionally Rule 10 of COLREGS applies, the problem is much more complex and a new solution is needed. This paper introduces the extended ESoSST methodology, with a focus on changes that have to be made to obey Rule 10 and fully support TSS. These changes include detecting and penalizing TSS violations, as well as the pre-processing phase (generating the initial population, which includes predefined TSS-compliant tracks). The methodology has been designed for possible application in Vessel Traffic Service (VTS) centres. Its new mechanisms are presented with details. The examples are included of the results of the computer simulation tests carried out for the Gulf of Gdansk TSS to illustrate the methodology's effectiveness and functional scope.

Evolutionary sets of safe ship trajectories with speed reduction manoeuvres within traffic separation schemes

“…( 1) where: f i = e i s i a i c i t i (2) s i (static constraint factor), a i (collision avoidance factor), c i (COLREGS-compliance factor) have already been described in [10]. Symbol e i (trajectory economy factor) is computed in a different way for ships which have to reduce their speed than for those, which do not.…”

“…In an earlier paper [10] the author has presented the Evolutionary Sets of Safe Ship Trajectories (ESoSST) method working for Traffic Separation Schemes (TSS) and possible to be applied in Vessel Traffic Service (VTS) centres. This method combined evolutionary approach [9] with goals typical for methods based on games theory [7].…”

Effect of Different Structure Type Traffic On Railway Line Capacity

“…Variety of traffic influences the increase in speed range with which individual types of trains travel, and their movement is not evenly distributed in successive time intervals (so called windows). In fact, there are additional time reserves between successive trains to enable neutralization of possible interference (primary or secondary), thereby increasing system reliability [22,23,26,27,28,31]. Therefore, the value of the track successive time interval is individual for each train included in the timetable and consists of the time taken by the particular train and the preceding reserve of time (2).…”

The Effect of Fishing Basin Construction On the Behaviour of a Footbrdge Over the Port Channel

“…Its function is to pass the pedestrian and cycle traffic over the port channel being the mouth of the Słupia river. The rotating structure of the bridge makes it possible to close the passage temporarily to allow the watercraft to enter or leave the port [19][20][21][22].…”