Download Norm Recognition in Multi

Figure 5: an example of our plan-library
With the completion of initPlan, PlanRecognizer waits (on a semaphore).
ObservationTower has the duty to reactivate it every waitThreshold/3 or if the
actor reaches its nal destination.
When PlanRecognizer wakes up, it checks
the number of moves performed by the actor, which is provided by the ObservationTower, and records the agent's current position (its position when ObservationTower activated it). At this point if the number of moves is greater than or
equal to plan-library levels,
extendPlan
is called. This method simply extends
the library by 3 levels. Having done all of this, the thread scans the list of the
PlanLibNodes at level
l, where l
10 : if
is equal to the recorded number of moves
one or more nodes are named with the same number as the current position, it
is tagged with
t.
A value
t
is equal to 1 at the rst iteration and is incremented
by one every time ObservationTower activates its PlanRecognizer. The tag in
the system intuitively represents the temporal information as shown in [11].
If
t
is 1, then possible plans are built by nding (and reversing) all the paths
from the tagged nodes to the root.
Otherwise, the method
propagateUp
is
called, which checks temporal consistency in a similar manner to that described
10 Note
that if we couldn't use the recorded number of moves information, the number
of possible plans would have been much larger: this simplication reduces the diculty in
adapting the SPR approach to our environment.
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