Information Technology Reference
In-Depth Information
Fig. 3.
A sample of a task described with HAWAI-DL
1.
Mandatory
: state of the world required to perform the task
2.
Regulatory
: state of the world required by safety regulations
3.
Resources
: tools that are required to accomplish the task
4.
Safety
: Safety tasks are compromise between safety and production. They
are usually done only by expert.
5.
Favorable
: the context in which the task is relevant, for example
favorable
expertise condition
. There is two ways to remove a pipe. The expertise con-
dition can be: bolts are not rusted. If the bolts are rusted, an expert will do
the task with the good expertise conditions.
A task has conditional and dynamic states. When a precondition is true the task
state is set to active for this precondition: mandatory active, regulatory active,
favorable active, resource active. These are the conditional states. The dynamic
states are used during plan execution : active/inactive, pending/finished, con-
flicting, concurrent, failed.
Preconditions as well as postconditions have the same formalism. Both are
conditions. Conditions can be combined with some logical operators (AND, OR).
We represent conditions as a quadruple:
< operator, object, property, value >
.
Example : (=
Pipe
6
status normal
), (
>Pipe
6
diameter
50).
4.2
Reasoning with COCOM, BTCU and CREAM
According to the COCOM model, the parameter that influences the decision and
behavior of an agent is the temporal pressure. We added some supplementary pa-
rameters that influence according to us operators control mode and consequently
their behaviors. We integrate : (i) the internal state of an agent, (ii) temporal
pressure which comes from the agent itself, (iii) equipment, (iv) environmental
parameters, (v) parameters of task (Fig. 4). We distinguish three categories of
internal states: cognitive (risk perception, cognitive workload, vigilance, motiva-
tion), physical (strength, physical workload) and physiological (stress, hunger,
thirst, tiredness, agitation).
