Artificial Intelligence and Soft Computing: Behavioral ... - Arteimi.info

set-point + error Controller Plant / Process
Measured
process
value
Sensors
Fig. 2.17: A process control loop that executes the sensing-action
cycle.
A little thinking, however, reveals that most of the closed loop control
systems sense signals from their environment and act on it to satisfy a desired
goal (criterion). There is a controller in the control loop that receives the
deviation (error) of the measured signal from the desired signal (set-point), and
generates a control command for the plant. The plant in turn generates an
output signal, which is fed back to the controller through the error detector
module (vide fig. 2.17). The controller could be analog or digital. An analog
controller is a lag/ lead network, realized with R-C circuits. A digital controller,
on the other hand, could be realized with a microcomputer that recursively
executes a difference equation. Such controllers were called intelligent two
decades back. But, they are never called artificially intelligent. So a mere
performer of the sensing-action cycle in the elementary model of cognition
(vide fig. 2.12) cannot be called artificially intelligent. But they can be made
intelligent by replacing the standard controllers by a knowledge-based system.
It should be added here that a sensing-action cycle performer too is sometimes
called artificially intelligent, in case it requires some intelligent processing of
the raw information. For instance, consider a robot that has to plan its
trajectory from a predefined initial position of the gripper to a final position.
Suppose that the robot can take images of its neighboring world by a camera
and determine the 3-D surfaces around it that block its motion. There may exist
a large number of possible trajectories of gripper movement and the robot has
to determine the shortest path without hitting an obstacle. Such schemes
obviously require much of AI tools and techniques and thus should be called
artificially intelligent. But what are the tools that can make them intelligent?
The book provides an answer to this question through its next 22 chapters.
A brief outline of the answer to the question, however, is presented here to
hold the patience of the curious readers. A cursory view to the elementary