The Story of Robots

Machines That Act on Their Own

What do you picture when you hear the word robot? Maybe a metal person with blinking lights, a friendly helper from a film, or a tiny machine zooming across the floor. Robots come in many shapes, and most do not look like people at all. But they all share one special quality: a robot is a machine that can sense the world around it and act — often without a person guiding its every move.

Robots are some of the most exciting machines humans have ever built. They explore the deep sea and faraway planets, build cars in factories, and even help doctors. In this book we will discover what a robot really is, how robots sense, think and move, where they came from, and how they are changing our world.

Chapter 1: What Makes a Robot a Robot?

Lots of machines are clever, but not every machine is a robot. A toaster heats bread, but it cannot sense the world or make choices, so it is just a machine. A robot is different because it can do three special things:

1. Sense — it gathers information about its surroundings.
2. Think — it uses that information to decide what to do.
3. Act — it moves or changes something in the world.

A toy car you steer with a controller is not really a robot, because you are doing the thinking. But a little vacuum cleaner that drives around your home by itself, turning away from walls and stairs, is a robot — it senses, decides and acts on its own. That power to act without being told every single step is what makes a robot so special.

Chapter 2: How a Robot Senses

To do anything useful, a robot first has to know what is around it. It does this using sensors, which are like a robot's eyes, ears and skin.

Different sensors notice different things. A camera lets a robot "see" shapes and colours. A distance sensor sends out a beam and measures how long it takes to bounce back, so the robot knows how far away a wall is — a bit like how a bat finds its way in the dark. Other sensors can feel heat, detect a touch, listen for sounds or sense whether the robot is tilting over. By combining the information from many sensors, a robot builds a picture of the world around it, even though it has no real eyes or ears.

Chapter 3: How a Robot Thinks

Once a robot has gathered information, it needs to decide what to do. This is the job of the robot's computer, often called its "brain." But a robot's brain does not think by itself — it follows a set of instructions written by a person. These instructions are called a program.

A program is like a list of rules: if you see a wall, turn left; if the floor drops away, stop. Programmers write these rules carefully so the robot can handle whatever it meets. The clever part is that a single program can handle thousands of different situations, all worked out in a flash. You can learn more about how machines are given instructions in The Story of Computers.

Some modern robots use an exciting new kind of thinking called artificial intelligence, which lets them learn from experience and get better at a task over time, instead of following fixed rules alone.

Chapter 4: How a Robot Moves

Sensing and thinking are no use unless a robot can act on its decisions. To move, a robot uses parts called motors and actuators. These are like a robot's muscles. When the computer sends a signal, a motor spins a wheel, bends a joint or closes a gripper.

Robots move in all sorts of ways. Some roll on wheels. Some walk on legs, balancing carefully like a person or an animal. Some are just a single mechanical arm bolted to the floor, swinging and twisting to do its job. The robots that look like people are called humanoids, but they are actually some of the hardest of all to build, because walking on two legs without falling over is surprisingly tricky.

Chapter 5: Where Robots Came From

People have dreamed of mechanical helpers for a very long time. Hundreds of years ago, skilled inventors built automatons — wind-up machines that could write, play music or move like animals. They were not true robots, because they could not sense or think, but they showed that machines could move on their own and amazed everyone who saw them.

The word "robot" itself is only about a hundred years old. It came from a play, and was based on an old word meaning "hard work." Real robots arrived in the middle of the twentieth century, once people had built electric motors and especially computers small and powerful enough to control them. The first useful robots were big mechanical arms that worked in factories, and from there, robotics grew quickly.

Chapter 6: Robots at Work

Today, robots do an enormous range of jobs. People often say robots are best for the three Ds: jobs that are dull, dirty or dangerous.

• In factories, robot arms build cars and pack boxes, doing the same task perfectly thousands of times without getting tired.
• In hospitals, special robots help surgeons make tiny, steady movements during operations.
• On farms, robots can plant seeds, pull weeds and pick fruit.
• In homes, small robots clean floors and mow lawns.
• In dangerous places, robots defuse bombs, fight fires, and inspect places too risky for people, such as the inside of a damaged building.

By taking on these jobs, robots keep people safer and free them to do more creative and interesting work.

Chapter 7: Robots in Space and the Sea

Some of the most amazing robots go where no human could survive. Far out in space, robot rovers drive across the dusty surface of Mars, taking photos, studying rocks and searching for signs that water once flowed there. They are controlled from Earth, but because Mars is so far away that signals take many minutes to arrive, the rovers must make many decisions on their own.

Back on Earth, robot submarines dive into the crushing darkness of the deep ocean, where the pressure would flatten a person. They explore shipwrecks, study strange sea creatures and map the seafloor. Robots have visited the deepest trenches and the surfaces of other worlds — places humans have never set foot. To see more about that hidden ocean world, read Explorers of the Deep Sea.

Chapter 8: The Future of Robots

Robots are getting smarter and more capable every year. In the future, they may help care for elderly people, deliver parcels to your door, and work side by side with humans in even more places. As artificial intelligence improves, robots will be able to handle tasks that once needed a human touch.

But robots are tools, built and programmed by people. They do not have feelings, wishes or imaginations of their own, no matter how clever they seem. The exciting part is that we decide what robots are for. With careful thought, robots can help us build a safer, kinder and more wonderful world.

So the next time you see a robot — whether it is vacuuming a floor, exploring Mars, or simply a toy on your shelf — remember the three special powers behind it: to sense, to think and to act. From wind-up automatons to rovers on distant planets, the story of robots is really the story of human cleverness and imagination, and it is only just beginning.

Words to Remember

• Robot: a machine that can sense its surroundings and act, often on its own.
• Sensor: a part that lets a robot detect the world, like eyes or ears.
• Program: the set of instructions that tells a robot what to do.
• Actuator: a part, like a motor, that lets a robot move and act.
• Humanoid: a robot built to look and move like a person.