Artificial Intelligence

2

Stimulus–Response Agents

2.1 Perception and Action

In this chapter, I consider machines that have no internal state and that simply react to immediate stimuli in their environments. We’ll call these machines stimulus-response (S-R) agents. A variety of robots can be built that exhibit surprisingly interesting behavior based on motor responses to rather simple functions of immediate sensory inputs. One of the earliest examples of this kind of robot was Grey Walter’s Machina speculatrix–a wheeled device with motors, photocells, and two vacuum tubes [Walter 1953] that moved toward light of moderate intensity and avoided bright light. Similar machines are described by Braitenberg [Braitenberg 1984].

I begin my discussion with an illustrative example. ...