These are some of the simpler smart robots that you are likely to encounter, but they are nonetheless smart robots because they fulfill all of the points of our definition:

• They follow a series of pre-programmed instructions: These machines come with their vacuum-cleaning program pre-installed on their control unit. The engineers who developed the product have already sorted out what the robot needs to do during its routine to keep the floors clean. The software is installed on each robot before it leaves the factory. After the customer purchases the robot, all they have to do is charge it, then turn it on, and it gets right to work, following the instructions that the engineers defined in the software.

• They make an observation about the outside world: The vacuum robot has some sensors that allow it to make observations about where it is in the room. On the front of the robot, there is a bumper equipped with an impact sensor. When the robot collides with the wall, the impact sensor is pressed, and the robot knows it has reached the end of the room:

The user can also set up an invisible fence using infrared emitters that confine the robot to one area. The robot is equipped with an infrared sensor that can detect this fence and tell the robot that it has reached the end of the area to be cleaned.

Finally, the robot's charging pad has an infrared beacon. When the job is complete, the robot uses its infrared sensor to navigate back to the charging pad to replenish its battery:

• They have a central computer/controller that interprets instructions and sensor data: The robotic vacuum has a central controller that runs the software set at the factory and receives input form the robot's impact and infrared sensors. Though this central controller is not necessarily a powerful supercomputer, it has the ability to interpret the software and sensor measurements to decide what to do next.

• They make a decision and react based on the observation, following the instructions defined in the program: The robot proceeds during its cleaning routine as the software specifies. The sensors tell the robot when it needs to change its course; if the impact sensor detects that the robot has collided with a physical wall, or the infrared sensor detects an invisible wall, the robot knows that it has come to the end of the area it is supposed to clean. It reacts by turning and moving in a different direction. The robot decides to alter its course based on the measurements from its sensors.

• They complete all of these steps automatically: The robot does everything without the help of a person; it cleans the floor while staying within the bounds of its room and returns itself to its base to recharge when it is finished. The only human assistance it needs is when the vacuum bag needs to be replaced.