Lesson 0 · What Is a Robot?

Module 1 · Learning to Drive

Lesson 0 · What Is a Robot?

30–40 minKickoff discussionNo coding

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Teacher mode is on — the gray boxes are yours only. This lesson is a guided discussion; the gray boxes hold the talking points and the "answers." Flip the switch (bottom-right) to preview the student view.

You're in a robotics class, so you should probably be able to say what a robot is. That turns out to be harder than it sounds. Before you touch the XRP, you'll look at a lineup of machines — some obviously robots, some obviously not, and a few that will split the room — and argue it out until a definition emerges.

Learning Objectives

By the end of this lesson you will be able to:

• Argue whether a given device is or isn't a robot, and say why
• Work out, from the examples, what every robot has to be able to do — and state it as a short definition
• Explain why the classic "mechanical arm" definition isn't enough anymore
• Describe how the XRP — and this course — fits that definition

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Printable knowledge checks — the 5 questions from this lesson on one page, with room to write. Teachers: answer key.

It used to be easy to tell

For most of the last century, a robot was easy to spot: a metal figure with a visor, walking stiffly out of a flying saucer in a black-and-white movie. Nobody argued about whether that was a robot.

Gort, from The Day the Earth Stood Still (1951) — the robot everyone recognizes. Today the line is a lot blurrier.

Today the machines around us are smarter and much less obvious. So: is the thing in your pocket a robot? The car in the driveway? The washing machine? Let's find out where you draw the line.

How to run this lesson (30–40 min)

This is a discussion, not a lecture. Don't reveal answers as you go — the value is in the disagreement. A format that works: show one device at a time, have students vote with their feet ("robot" on one side of the room, "not a robot" on the other, "not sure" in the middle), then call on someone from each side to defend their position. Keep a running list on the board of the reasons people give ("it moves on its own," "a person is controlling it," "it has sensors") — you'll harvest those reasons into the definition later in the lesson. The two things to listen for and amplify are sensors and acting on what was sensed: every device students call a robot senses something and decides what to do about it; every "not a robot" has a person doing the sensing and deciding. Don't name those traits for them — the student page deliberately doesn't. Use the open "Think about it" prompt under each picture (most ask what happens if the person walks away), and keep asking "what's your reason?" until sensing and deciding come out of their mouths. The Yes/No buttons and the "Why?" line under each picture are live — type the class's consensus there on the projector so nobody has to scroll back to a table. Budget roughly 15 minutes for the gallery, 10 for the definition, 5–10 for the wrap-up.

Activity · Is this a robot?

You're about to see eight devices. For each one, before your class discusses it:

1. Decide: robot or not a robot. (You have to pick — no "not sure.")
2. Say why. Write one sentence: what is it about this device that makes it a robot, or keeps it from being one?

There's a fill-in box under every picture — record your answer there (or on paper) as you go. You'll look back over all eight once you've seen them all.

A radio-controlled airplane

It flies. It has motors. Somebody's holding a controller. Robot?

Think about it: If the pilot sets the controller down, what does the plane do next?

RC airplaneRobot?

Talking points · RC plane

Most students say not a robot, and the reason they give is the key one: a person is doing all the deciding. The plane senses nothing and decides nothing — the human does the sensing (eyes) and the thinking (hands on the sticks). Push back gently: "But it has motors and it moves — isn't that enough?" You want them to articulate that moving isn't the test.

A camera drone

Also flies, also has a controller in the box. Same answer as the airplane?

Think about it: Also flies, also comes with a controller. If the pilot lets go of the sticks, what happens? If your answer is different from the airplane's, what makes the difference?

Camera droneRobot?

Talking points · Drone

This is the pair to the airplane, and it's where the room starts to split. A modern camera drone has GPS, obstacle sensors, and a computer that holds it level, stops it from hitting a wall, and flies itself home when the battery is low — even though a human is nominally controlling it. Ask: "What can the drone do that the airplane can't?" The answer — it senses and makes some decisions on its own — is the first crack in the "someone's controlling it, so it's not a robot" argument.

A vacuum cleaner

Powerful motor, does a useful job. Robot?

Think about it: Who steers it? If you walk away in the middle of cleaning, what happens?

Vacuum cleanerRobot?

Talking points · Canister vacuum

Easy no, and useful for the same reason as the airplane: a person pushes it everywhere. It has a motor and a job, but no sensing, no deciding. Keep it quick; it's here to set up the next one.

A vacuum that drives itself

Same job as the vacuum above. Different answer?

Think about it: Same job as the vacuum above. What's different about how it does the job? What happens if you walk away?

Vacuum that drives itselfRobot?

Talking points · Robot vacuum

Nearly everyone says yes — it's even called a robot vacuum. Ask them to prove it: what does it sense (bumper, cliff sensors so it doesn't fall down stairs, dirt detection), what does it decide (turn when it hits something, go back to the dock when the battery's low), what does it do (drive, vacuum). Same job as the canister vacuum, but it senses, decides, and acts on its own. Put those three words on the board — they're about to become the definition.

A car

A car. Is a car a robot?

Think about it: Answer once with a person driving. Now answer again with the car in self-driving mode. Did your answer change? If so, what changed about the car?

CarRobot?

Talking points · Self-driving-capable car

Expect a genuine split, and let it run. If a person is driving, most say no. If the car is on driver-assist or self-driving mode — cameras sense the road, a computer decides to brake or steer, and it steers — most say yes. The interesting conclusion: the same machine can be a robot or not depending on what's doing the thinking. That's a sophisticated point; if a student gets there on their own, celebrate it.

A laundry-folding machine

A research robot folding laundry.

Think about it: Most people say yes right away — so say precisely what makes it one. What would it have to know about the towel in order to fold it?

Laundry-folding machineRobot?

Talking points · Towel-folding robot

An easy yes and a chance to name why it's hard: folding a floppy towel means sensing where the cloth is (cameras), figuring out how to grab it (that's the hard part), and moving arms precisely. Note that a task trivial for a human is a research problem for a robot — a theme students will feel personally in Module 2 when line-following turns out to be harder than it looks.

A Mars rover

A rover on Mars, hundreds of millions of kilometers away.

Think about it: A radio signal to Mars takes several minutes each way. What does that mean for how the rover gets driven? Compare with the RC airplane.

Mars roverRobot?

Talking points · Mars rover

Yes — and the twist is worth stating: a radio signal to Mars takes several minutes each way, so nobody can drive it with a joystick. It has to look at the ground, decide whether a rock is safe, and drive around it by itself. Ask: "Why couldn't NASA just remote-control it like the airplane?" Distance forces autonomy — a great example of why "thinking for itself" is the heart of the definition.

A washing machine

A washing machine. Think carefully before you answer.

Think about it: Press start and walk away. What does it do on its own? Now look at what you wrote for the vacuum that drives itself — are you being consistent?

Washing machineRobot?

Talking points · Washing machine (the one that breaks the room)

Save this for last — it's the productive controversy. Students say "obviously not" … until someone points out it senses the load size and water level, follows cycle logic (it decides when to spin, how long to rinse), and acts (fills, agitates, spins) — all without a human after the button press. By the criteria on the board, it might qualify! Don't resolve it. The honest takeaway is that "robot" is a spectrum, not a switch: a washing machine does all three things in a very simple, fixed way; a rover does them in a rich, adaptable way. Both are further along the line than an RC plane. The point of a definition is to make the argument precise, not to end it.

Before reading on, scroll back through your eight Why? answers. What do your "yes" reasons have in common? What do your "no" reasons have in common? Try to write the rule in one sentence — "A device is a robot if it ______." Then see how close you got.

So what is a robot?

Here's the definition engineers wrote back in 1979 (the Robot Institute of America): a robot is "a reprogrammable, multifunctional manipulator designed to move material, parts, tools, or specialized devices through various programmed motions for the performance of a variety of tasks."

In plain English: a programmable mechanical arm that does factory work — assembly, welding, painting. The classic jobs are the three Ds: work that's dirty, dull, or dangerous for people.

That definition was fine for 1979. But check it against the eight devices: a Mars rover isn't a "manipulator," and neither is a drone or a robot vacuum. The definition is too narrow for the robots we actually have. Let's try again.

Knowledge Check

Which device from the lineup does the 1979 'reprogrammable manipulator' definition clearly leave out, even though almost everyone agrees it's a robot?

Try again: a better definition

The robotics engineering program at WPI uses three traits instead. A robot must:

1. Sense — take in information about the world with some kind of sensor.
2. Think — process what it sensed; make a decision based on it.
3. Act — do something in the world based on that decision: move, grab, change something.

1 · Sense

Take in the world

Cameras, bump sensors, distance sensors, GPS, light sensors — some way of finding out what's out there.

2 · Think

Decide

A program that turns sensor readings into a choice: turn left, stop, go home, grab here.

3 · Act

Change the world

Motors, wheels, arms, propellers — something that carries the decision out physically.

A robot must sense, think, and act. Miss one and it's something else: a machine that only acts is a tool (the vacuum); a machine where a person does the sensing and thinking is remote-controlled (the airplane).

Knowledge Check

Using sense–think–act, why isn't the RC airplane a robot?

Knowledge Check

Why can't NASA fly a Mars rover the way you'd fly the RC airplane?

Knowledge Check

A washing machine senses the load, follows cycle logic, and spins on its own. Under sense–think–act, what's the honest answer?

Harvesting the board into the definition

Before showing the three traits, have students compare their "Why?" answers. Ask what the "yes" reasons share and what the "no" reasons share. Group their words on the board into sense / think / act — you're not handing them a definition, you're naming the one they built. The punchline to draw out: every device on the list moves or acts, so acting can't be the test; what separates the robots is that they sense something and act on what they sensed. If a student says "it's not about moving, it's about sensing and deciding," you're done — write it on the board in their words. The spectrum idea (washing machine at one end, rover at the other) is the most important nuance; it inoculates against the "is it or isn't it" dead-end and sets up the idea that this course moves the XRP along that spectrum.

Why robots — and where the XRP fits

Robots are worth building because they combine so many ideas at once. A competition robot built by high-school students senses where the balls and the goal are with a camera, thinks — using trigonometry to aim — and acts, driving into position and shooting. A climbing robot needs torque, gear ratios, and speed calculations just to get off the ground. Robotics is where math, physics, and programming stop being separate subjects.

A FIRST competition robot built by high-school students: it senses where the balls and goal are with a camera, thinks (trigonometry to aim), and acts — shooting into the goal.

Now look at the robot on your desk with those three words in mind:

Sense

The XRP's senses

Reflectance sensors that see light vs. dark, an ultrasonic rangefinder that measures distance, and encoders that count how far each wheel has turned.

Think

The XRP's brain

The controller board runs your program. Every decision it makes is one you wrote — in Blockly first, then in Python.

Act

The XRP's muscles

Two motors, one per wheel. That's enough to drive straight, turn, curve, and spin.

And this is exactly the shape of the course. In Module 1 you'll mostly teach the XRP to act — driving, turning, drawing shapes. In Module 2 you'll add sensing, so it can follow a line and react to what it sees. By Modules 4 and 5 the thinking gets serious: your robot will plan its own route across a grid and re-plan around obstacles it discovers. By the end, the XRP will be doing all three — a robot by anyone's definition.

The XRP isn't a toy, either — the same robot is used in a college sophomore programming course. The tools you'll learn here are the real ones.

Knowledge Check

Which of the three traits will you spend most of Module 1 on?

Real-world connections

Robots earn their keep on the three Ds — work that's dirty, dull, or dangerous:

Dirty

Sewers & disaster sites

Inspection robots crawl pipes and rubble where people can't or shouldn't go.

Dull

Warehouses & factories

Robots move shelves, weld seams, and paint car bodies — thousands of identical times a day.

Dangerous

Bombs, reactors, deep space

Bomb-disposal robots, nuclear-plant inspectors, and rovers do the jobs where a mistake costs a life.

Wrap-up

• What three things must a robot do? (Sense, think, act.)
• Why isn't a remote-controlled plane a robot? (The person does the sensing and thinking.)
• Name a device at home and argue whether it's a robot — using all three traits.

Assessment & next lesson

Formative: can students give a reason, not just a vote, for each device, and map the reason onto sense/think/act? Exit ticket: "Pick any device in your house. Is it a robot? Defend your answer using all three traits." (Look for the spectrum idea — "it senses and acts but doesn't really decide anything.") Preview: next lesson you meet the XRP itself — the parts, the programming environment, and your first program to make it act.

Media note: the gallery images come straight from the What Is a Robot? slide deck — one per figure placeholder, in the same order.

Resources

• XRP Robot User Guide
• WPI Robotics Engineering — the source of the sense–think–act traits