42
The functionalities of the planning phase are of the “Data recording” type and thus consist of the ele
mentary individual functions “Record input data”, “Evaluate data” and “Provide information”. These
functionalities supply the set values for the evasion track.
Functionality 2.1 (“Follow evasion track”) is of the “Influencing state variables” type. The functionalities
of the lowest level compiled here record the set/actual deviations provided by the monitored functionali
ties, assess these and execute appropriate actions to minimise the corresponding deviation.
Functionality 2.2 (“Monitor evasion track”) is of the set/actual comparison type. The set values for the
evasion track are compared with the present movement variables of the ship. The deviation between
set and actual is evaluated and made available to the system.
Functionality 2.3 (“Monitor effectiveness of the evasion manoeuvre") is likewise of the “Set/actual com
parison” type; the “set value” here represents the general objective of the executed task (“Avoidance of
collision with other vessels without endangering the own ship or third parties”) - this means that a con
tinuous comparison of the desired “target situation” with the current “actual situation” takes place.
Annex 7.5 contains the functionalities identified for this task as well as the elementary individual func
tions with their input and output data, in overview form.
52 Grounding avoidance
5.2.1 Purpose of task
In principle, voyage planning is intended to supply a track which may actually be followed by the ship.
Nevertheless, situations are conceivable in which a short-term re-planning process is necessary during
the voyage with the aim of avoiding grounding. This may be the case for example if inaccurate or out
dated information was available for voyage planning. The occurrence of temporary obstacles (eg
wrecks) may likewise necessitate re-planning.
5.2.2 Functionalities
The fundamental structure of the functionalities which are necessary for fulfilling this task is identical to
the task “Collision avoidance”. Grounding avoidance is likewise divided into a planning phase and an
executing phase. Differences in relation to collision avoidance exist with regard to the planning informa
tion used. Furthermore, fairly large degrees of scope exist in selection of the evasion manoeuvre (there
do not exist any regulations as in encounters between ships in motion); for this reason, the functionality
“Plan evasion manoeuvre” is omitted in the planning phase.
The following functionalities are obtained for the task “Grounding avoidance”:
1. Planning the evasion track;
1.1 Collect planning information: recording the hydrographic situation, particularly
water depths, land masses and traffic-diverting measures in the sea region con
sidered, determining the manoeuvring scope available.
1.2 Plan evasion track.