← IGCSE Computer Science Paper 1

Characteristic of a robot: electrical components

Parts such as sensors, a microprocessor and actuators, powered through wiring, that let a robot sense its surroundings, decide what to do and then move.

Part of: IGCSE Computer Science 0478 — 6.2 Robotics — Module 8

Understanding Characteristic of a robot: electrical components in IGCSE Computer Science Paper 1

What it does: The IF statement shows the microprocessor reading sensor data (distance) and deciding on an action (stop the motor). The chain shows power flowing from the battery through the wires to each electrical component. Actuators, such as motors, turn the microprocessor's signals into movement. The microprocessor decides but does not move anything itself. The robot senses (sensor), decides (microprocessor), then moves (actuator). A motor causes movement, so it is an actuator. A sensor would detect something rather than move. Wires connect the parts and carry electricity and signals. Decisions are made by the microprocessor.

Common mistakes: A sensor only gives the robot information. The stop command must go to an actuator such as the motor, so line 3 should be SEND stop TO motor. The wheel motor is an actuator. It receives commands and does not give the robot information. The microprocessor should SEND stop TO wheel_motor.

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Learning
Duo
Which component gives a robot information about its surroundings?
An actuatorA sensor
Matches
A sensor makes the robot's wheels turn.
↓
This describes an actuator, not a sensor. A sensor only gathers information about the surroundings, while an actuator makes the robot move.
Applying
Meanings
Term
electrical components
Meaning
Parts such as sensors, a microprocessor and actuators, powered through wiring, that let a robot sense its surroundings, decide what to do and then move.
Practice
WHILE power = ON DO
Testing
Gaps
distance ← .read()
Check Answer
Spots
2IF distance < 10 THEN
3 SEND stop TO sensor

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Quick Questions

1. Which component gives a robot information about its surroundings?
A. A sensor ✓
B. An actuator
Sensors detect things like light, heat or distance and send that data to the microprocessor. Actuators do the moving.
2. Which part acts as the robot's brain?
A. The sensor
B. The microprocessor ✓
The microprocessor processes the sensor data and decides what the robot should do. A sensor only collects data.
3. Which component makes a robot's arm move?
A. A microprocessor
B. An actuator ✓
Actuators, such as motors, turn the microprocessor's signals into movement. The microprocessor decides but does not move anything itself.
4. What is the correct order of events in a robot's electrical system?
A. Sensor, then microprocessor, then actuator ✓
B. Actuator, then microprocessor, then sensor
The robot senses (sensor), decides (microprocessor), then moves (actuator).
5. Which statement about the electrical components of a robot is correct?
A. They need a power supply and wiring to work ✓
B. They work without any power supply
Sensors, the microprocessor and actuators are electrical, so they need power. Wiring connects them and carries the signals.

Match the Pairs

sensor → An electrical component that gives the robot information by detecting its surroundings, such as light, heat or distance.
actuator → An electrical component that makes the robot move, such as a motor turning a wheel or an arm.
The microprocessor acts as the robot's brain: it takes input from the sensor and decides what the robot should do → IF distance < 10 THEN stop_motor()
The power supply and wiring carry electricity to every electrical component so they can work together → battery -> wires -> sensor, microprocessor, actuator
A sensor makes the robot's wheels turn. → This describes an actuator, not a sensor. A sensor only gathers information about the surroundings, while an actuator makes the robot move.
The microprocessor detects the light level in the room. → Detecting is the job of a sensor. The microprocessor only processes the sensor data and decides what to do.

Key Term

electrical components
Parts such as sensors, a microprocessor and actuators, powered through wiring, that let a robot sense its surroundings, decide what to do and then move.

Fill in the Blanks

1. distance ← sensor.read() IF distance < 10 THEN motor.stop()
Hint: Type the component that gives the robot information about its surroundings.
2. data ← sensor.read() action ← microprocessor.decide(data) motor.run(action)
Hint: Type the component that acts as the robot's brain and decides what to do.
3. data ← sensor.read() action ← cpu.decide(data) actuator.move(action)
Hint: Type the component that carries out the decision by making the robot move.
4. CONNECT battery TO sensor VIA wire CONNECT battery TO cpu VIA wire CONNECT battery TO motor VIA wire
Hint: Type the part that carries electricity from the power supply to each component.
5. sensor: senses microprocessor: decides actuator: moves
Hint: Type the verb that describes the microprocessor's job in the robot.

Spot the Error

Question 1
A READ distance FROM sensor
B IF distance < 10 THEN
C SEND stop TO sensor
D ENDIF
Line C — A sensor only gives the robot information. The stop command must go to an actuator such as the motor, so line 3 should be SEND stop TO motor.
Question 2
A SWITCH ON battery
B READ dist FROM sonar_sensor
C IF dist < 5 THEN
D READ stop FROM wheel_motor
E ENDIF
Line D — The wheel motor is an actuator. It receives commands and does not give the robot information. The microprocessor should SEND stop TO wheel_motor.
Question 3
A READ heat FROM heat_sensor
B IF heat < 50 THEN
C SEND stop TO motor
D ENDIF
Line B — The microprocessor decides by comparing the sensor reading with a limit. The motor should stop when it is too hot, so the test should be heat > 50.
Question 4
A READ speed FROM wheel_motor
B IF speed > 80 THEN
C SEND slow TO wheel_motor
D ENDIF
Line A — The robot gets its speed reading from a sensor. A motor is an actuator and does not measure anything, so the line should read FROM speed_sensor.
Question 5
A SEND data FROM sensor TO cpu
B cpu PROCESSES data
C SEND signal FROM motor TO cpu
Line C — The signal travels from the microprocessor to the actuator. The motor does not make decisions. The line should be SEND signal FROM cpu TO motor.

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