What is a Robot?

When you think of a robot, what do you see? A machine that looks a bit like you and me? The reality is that robots can come in many different shapes and sizes. They don't need to look like humans—in fact, most don't. What a robot looks like depends on its purpose. Flying robots might look like helicopters, or have wings like insects or birds. Cleaning robots often look like little vacuums. Robots that are meant to interact with people often have a face, eyes, or a mouth—just like we do! Whether they look like us or not, most robots have three essential ingredients that make them a robot: sensors, actuators, and programs. Together, these ingredients are what make a robot different from other electronics and gadgets you might have around your house, like your computer, your washing machine, or your toaster. Sensors, Actuators, and Programs First, a robot has sensors that allow it to perceive the world. Just like we have eyes to sense light, ears to sense sound, and nerves in our skin that sense if something is touching us, robots have light sensors and cameras so they can “see,” microphones so they can “hear,” and pressure sensors so they can “feel” the things around them. The kinds of sensors that a robot needs depends on what the robot was made for. A robot vacuum cleaner might use a bumper with pressure sensors to understand where a wall is. A flying robot uses a group of sensors called an inertial measurement unit (IMU) to help it stay balanced when it flies. Some of the sensors used by robots are very different from the kinds of sensors used by people. Second, a robot has actuators that allow it to move around. We might use our legs and feet to walk and run, and we might use our hands to pick up an orange and peel it. A robot might use actuators such as motors and wheels to drive places, and finger-like grippers to grab objects and manipulate them or turn them around. Third, a robot needs a program that lets it act on its own based on what it is sensing. This ability to act on one’s own is called autonomy.