Robots Make Choices
Every morning you make dozens of choices. Is it cold outside? I will wear a jacket. Did I already brush my teeth? No — better do that now. Are my friends at the park? Then let's go! You make those choices based on information — what you see, hear, and feel. Robots do the exact same thing! A robot looks at what its sensors tell it about the world, then picks the right action from its program. That is a robot making a choice.
Sensing, Then Choosing
A robot cannot make a good choice without information. That information comes from sensors. Sensors are the robot's eyes, ears, nose, and touch — all rolled into small electronic parts. Some common robot sensors: A camera — like eyes, it sees things in front of the robot. A distance sensor — it measures how far away objects are. A microphone — it hears sounds. A touch sensor — it feels when something is pressing against the robot. A light sensor — it notices how bright or dark the surroundings are. A temperature sensor — it can feel if something is hot or cold. All of these sensors send data to the robot's brain. The brain looks at all that incoming data and figures out: what is the best action right now?
A robot makes choices by reading sensor data and picking the action that matches the situation. No sensor data means no good choices — a robot in the dark, with no sensors, is just guessing.
Meet Rolo, a robot that delivers snacks around an office. Rolo has a camera on the front and a distance sensor on each side. Here is how Rolo makes choices as it rolls down a hallway: Rolo's camera sees a person standing in the middle of the hallway. Distance sensor says: 80 centimeters away. Brain checks: obstacle at 80 cm — slow down. Distance sensor now says: 40 cm. Brain checks: very close — stop and wait. The person steps aside. Distance sensor says: path clear. Brain checks: path clear — continue forward. Rolo made four choices in a row based on fresh sensor data every single moment. It never just guessed. It always used real information.
Flashcards — click each card to reveal the answer
Sometimes a robot has to choose between more than two options. This is where things get interesting! Imagine a robot at a four-way intersection in a warehouse. Its sensors detect: Left path: blocked by a large box. Right path: clear, but a worker is walking there. Straight ahead: clear, no obstacles. Behind: the direction it just came from. The robot's program has a priority order: safety first, then efficiency. Because the straight path is clear and safe, it chooses that. If straight were also blocked, it would wait for the worker on the right to pass, then go right. Making the right choice depends on having the right sensor data AND having a program that tells the robot how to handle each situation.
A robot is only as smart as its sensors allow it to be. If a sensor gives wrong information — like a dusty camera that sees everything blurry — the robot will make wrong choices, even if its program is perfect. Clean sensors, good choices!
What does a robot use to gather information about the world before making a choice?
Rolo's distance sensor says 40 cm — very close to an obstacle. What does Rolo do?
Sensor Decision Maze
- Set up a simple obstacle course in a room using pillows, books, or chairs.
- Ask a friend or family member to be the 'robot.' They must close their eyes (no vision sensor!) and try to walk from one side of the room to the other while you give sensor reports.
- You are the sensor system. You can only say these exact phrases: 'clear ahead,' 'obstacle on the left,' 'obstacle on the right,' or 'obstacle directly in front.'
- The robot must use your reports to make choices and navigate to the other side.
- Switch roles!
- Afterward, talk about it: what happened when the sensor reports were slow or wrong? How does this show why good sensors are so important for robots?