.
vertical manoeuvres

.
conflict detection and conflict solving

.
sequencing and metering

The Rules are based on data emerging from the following sources:

.
LoAs

.
Route Availability Document restrictions

.
SID/STARs vertical profiles

.
speed restrictions

. operational practices
4.2.4 HOW IT WORKS
The simulator engine generates 4D trajectories (position + time) for each aircraft based upon flight plan information and rules stated in the Test Cases. The system checks each trajectory for certain predefined events. Examples of such predefined events may include conflicts (remembering that defining the parameters of what constitutes a conflict might need to be written into the rules – see para. 4.2.5), level changes, routes changes, sector entry or exit. When such an event is detected, the system increments the defined counters and trigger tasks parameters linked to the event. For example, if the system detects that an aircraft has crossed a sector border, it will increase by one the number of aircraft counted in that specific sector and will trigger as active the tasks assigned to the controllers (such as hand-over, transfer of communication, identification, etc).
In the simulator model, controller actions are described by task. These tasks are basic ATC actions, which are triggered by specific events and have a time value associated with it. This value is the time required in real life for the controller to fulfil the specific action.
The simulator adds the values of the task parameter for a given Test Case and the result value gives an indication of controller workload. Usually, a controller is considered not to be overloaded if this figure does not exceed 70% of the total time of the Test Case.
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The precision of workload indication is higher when the ATC modus operandi is better known and formalised, e.g. it could be described by basic task with clearly identified trigger events and well determined time parameters.

Figure 4 - 2: Event Triggers in FTS
4.2.5 CONFLICT DETECTION AND RESOLUTION
Based on values used in each sector for vertical and horizontal separation the simulator builds around each aircraft a protected volume (which can be assimilated usually with a cylinder). The system will detect a conflict when one aircraft’s protected volume touches or intersects another aircraft’s protected volume.
Because the FTS is based only on mathematical calculation the careful setting of the separation value is of paramount importance for the accuracy of the modelling. For example if the separation value is set for 2.999 Nm for aircraft flying on parallel routes spaced at 3 Nm the system will record no conflict, but if the separation is set at 3 Nm all the aircraft on those routes will be in conflict for the simulator.
After detecting a conflict, the simulator can handle the situation in two different ways:
.  
the conflict is recorded and the trajectories of the involved aircraft are not affected

.  
the simulator tries to "solve" the conflict by altering the trajectories of the involved aircraft at the appropriate moments. The way the simulator modifies the trajectories is dictated by the conflict solving rules, which should be set up before hand.

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本文鏈接地址：EUROCONTROL MANUAL FOR AIRSPACE PLANNING 2(100)