Robots are machines that sense, think, and act, so a small problem in any one part can make the whole robot fail. In a classroom robot, common trouble spots include the battery, power switch, motors, wheels, sensors, wires, and code. Learning how to debug helps you find the real cause instead of guessing.
A good repair plan starts with simple checks before changing parts or rewriting the program.
Most robot failures follow a chain: power must reach the controller, the controller must run the program, sensors must send useful data, and motors must turn motion parts correctly. If a motor whines but the robot does not move, the motor may be powered but the wheel or coupling may be stuck or loose. If a sensor gives strange values, the problem may be dirt, light interference, or a loose wire.
Careful testing, one change at a time, makes robot repair faster and safer.
Key Facts
- Power check: a robot that will not turn on usually needs the battery, switch, and power wires checked first.
- Ohm's law helps explain circuits: V = IR, where V is voltage, I is current, and R is resistance.
- Motor speed and wheel size affect robot speed: v = rω, where v is speed, r is wheel radius, and ω is angular speed.
- If a robot drives backward or turns the wrong way, the motor wires or motor direction settings may be reversed.
- Sensor readings can change because of loose plugs, dust, bright light, or poor calibration.
- Debugging rule: change one thing, test it, and record what happened before trying the next fix.
Vocabulary
- Debugging
- Debugging is the process of finding, testing, and fixing problems in a robot or program.
- Sensor
- A sensor is a device that detects information from the environment, such as light, distance, touch, or color.
- Actuator
- An actuator is a part that makes motion, such as a motor, servo, or gripper.
- Controller
- A controller is the robot's small computer that reads sensors and sends commands to motors.
- Calibration
- Calibration is adjusting a sensor or system so its readings match real conditions.
Common Mistakes to Avoid
- Replacing parts before checking the battery is a mistake because many robot problems are caused by low power or a switch left off.
- Uploading code without checking the cable or port is a mistake because the program may never reach the robot even if the code looks correct.
- Ignoring loose wires is a mistake because a connector can touch sometimes and fail other times, causing confusing behavior.
- Changing many things at once is a mistake because you will not know which change fixed the robot or caused a new problem.
Practice Questions
- 1 A robot battery should supply 6 V, but a meter shows 4.2 V. The robot will not turn on. How many volts lower than expected is the battery, and what should you check or do first?
- 2 A robot has wheels with radius 3 cm. If each wheel turns at 10 radians per second, estimate the forward speed using v = rω. Give your answer in cm/s.
- 3 A line-following robot keeps drifting to the right even though the program is unchanged. Explain two possible mechanical or electrical causes and one test you could do to find the cause.