Ambient Intelligence Through Agile Agents - Ambient Intelligence for Scientific Discovery - page 305

to look at the kernel functionality of AF and made an attempt at porting it.
At the heart of each agent execution lies a central process called the Agent
Deliberative Cycle, which is fundamental to the behavior of our agents and was
the starting point for the porting of Agent Factory. The Agent Deliberative Cycle
consists of 4 basic stages:
1. Perceive - All the agents preceptors sense their environment through their
perceptors and the agents mental state is updated to reflect the new state
of the agents environmental perception.
2. Deliberate - Based on the behavior of the agent and its new perception the
deliberation involves identification of those actuators that will need to be
activated in the next stage.
3. Actuate - All the actuators that need to be activated are now set in motion.
4. Pause - The thread of execution for the agent is paused for a predefined
time and the whole cycle begins again.
This cycle has been implemented on the WSN nodes. In order to demonstrate
this, we characterize the behavior through a small example illustrating what
happens at each stage within the cycle.
1. Perceive - The temperature sensor is read
2. Deliberate -If( temperature > threshold ) then commit to transmit value
to base station
3. Actuate -Transmit temperature to base station 1
4. Pause - The agent pauses for 2 seconds
In this case the AF-APL syntax for this behavior would be defined in the
following Commitment Rules (Fig. 10). A detailed discussion of Agent Factory
was provided earlier.
This small example details a program that will only transmit to the base
station if the temperature exceeds a certain threshold. Thus the base station will
not be flooded with many Motes reporting values when there is no significant
change in the sensed value. To demonstrate a more complicated version of this,
we developed an agent-based intrusion detection system on the Motes. This used
a drop in light levels as an indication that a person had entered the room. Details
of this experiment are presented elsewhere [21].
1. BELIEF(temp(?x)) ⇒
COMMIT(Self, Now, BELIEF(true), thresholdExceeded(?x));
2. BELIEF(thresholdIsExceeded(?temp)) ⇒
COMMIT(Self, Now, BELIEF(true), sendToBase(?temp));
Fig. 10. AF-APL syntax for simple agent.
1 This will only be accomplished if the previous stage deems it necessary to transmit
i.e. temperature > threshold .