People like to debate what makes a machine a real robot. One side says that a robot is a completely self-contained, autonomous (self-governed) machine that needs only occasional instructions from its master to set it about its various tasks. A self-contained robot has its own power system, brain, wheels (or legs or tracks), and manipulating devices such as claws or hands. This robot does not depend on any other mechanism or system to perform its tasks. It is complete in and of itself.
The other side says that a robot is anything that moves under its own power for the purpose of performing near-human tasks (this is, in fact, the definition of the word robot in many dictionaries). The mechanism that does the actual task is the robot itself; the support electronics or components may be separate. The link between the robot and its controlcomponents might be a wire, a beam of infrared light, or a radio signal. In an experimental robot from 1969 a man sat inside the mechanism and operated it, almost as if driving a car. The purpose of this four-legged lorry was not to create a selfcontained robot but to further the development of cybernetic anthropomorphous machines. These were otherwise known as cyborgs, a concept further popularized by writer Martin Caidin in his 1973 novel Cyborg (which served as the inspiration for the 1970s television series, The Six Million Dollar Man).
The semantics of robot design won’t be argued here (this book is a treasure map after all, not a textbook on theory), but it’s still necessary to establish some of the basic characteristics of robots. What makes a robot a robot and not just another machine? For the purposes of this book, let’s consider a robot as any device that—in one way or another mimics human or animal functions. How the robot does this is of no concern; the fact that it does it at all is enough.
The functions that are of interest to the robot builder run a wide gamut: from listening to sounds and acting on them, to talking and walking or moving across the floor, to picking up objects and sensing special conditions such as heat, flames, or light. Therefore, when we talk about a robot it could very well be a self-contained automaton that takes care of itself, perhaps even programming its own brain and learning from its surroundings and environment.
Or it could be a small motorized cart operated by a strict set of predetermined instructions that repeats the same task over and over again until its batteries wear out. Or it could be a radio-controlled arm operated manually from a control panel. Each is no less a robot than the others, though some are more useful and flexible. As you’ll discover in this chapter and those that follow, how complex your robot creations are is completely up to you.