A robot arm welding cars, a vacuum cleaner finding its way round a sofa, a drone checking crops from the air: all are robots. Learn what makes something a robot, the jobs robots do in six areas, and how to argue for and against using them.
Robotics is a branch of computer science that incorporates the design, construction and operation of robots. A robot has three characteristics: a mechanical structure or framework (body, arms, wheels, joints); electrical components such as sensors, microprocessors and actuators that let it sense and move; and it is programmable, so it follows a stored program and can be reprogrammed to do a different task. Examples include factory equipment, domestic robots and drones.
Fig. 1: a robot arm shows all three characteristics of a robot
Section 01
What makes a robot?
Exam questions often ask you to describe the characteristics of a robot. There are three, and you need all of them: a machine without a program is not a robot, and nor is a program without a body.
Mechanical structure or framework: the physical body that does the work, e.g. an arm with joints, a wheeled base, legs or rotors. It often has an end effector such as a gripper, drill, welder or spray gun.
Electrical components:sensors collect data about the surroundings (e.g. cameras, proximity, pressure, infrared); a microprocessor processes the data; actuators (motors, pneumatic or hydraulic pistons) make the parts move.
Programmable: the robot carries out a stored sequence of instructions. It can be reprogrammed for a new task, e.g. a factory arm switched from welding one car model to another. Some robots are programmed by a person physically guiding the arm through the movements so it records them.
Your turn
A remote-control toy car is driven entirely by a child using a handset. Explain why it is not usually classed as a robot.
It has a mechanical structure and electrical parts, but it does not run a stored program or use sensor data to make its own decisions: every movement comes directly from the child. A robot must be programmable.
Examiner trap
"A robot is a machine that looks like a human" is wrong. Most robots look nothing like people; what matters is the structure, the electrical components and being programmable.
Section 02
Robots at work.
The syllabus lists six areas. For each, learn a role a robot performs and one specific advantage there.
Area
Roles robots perform
Why use a robot here
Industry
welding, paint spraying, assembling car parts, packing, moving goods round a warehouse
works 24/7 with the same precision; keeps workers away from fumes and heavy loads
Transport
driverless cars, buses and trains; delivery robots and drones; automated parking
fewer accidents caused by tired or distracted drivers; smoother driving saves fuel
Agriculture
harvesting fruit, weeding, milking cows, drones spraying crops or checking crop health
works long hours in the field; sprays only where needed, so uses less chemical
Medicine
surgical robots controlled by a surgeon, pharmacy robots that dispense medicines, disinfecting rooms
very steady, precise movements; smaller cuts so patients recover faster
Domestic
robot vacuum cleaners, lawn mowers, window and pool cleaners
frees people from repetitive chores; works while the owner is out
Entertainment
animatronics in theme parks and films, robot toys and pets, camera drones filming sport
repeats the same show perfectly; films from angles a person could not reach
Worked example Domestic robot
Describe how a robot vacuum cleaner uses its components to clean a room.
Sensors (e.g. infrared or bump sensors) detect walls, furniture and stairs, and send data to the microprocessor.
The microprocessor processes the data and decides which way to go, following its stored program (and may build a map of the room).
It sends signals to actuators: the wheel motors to steer and the brush and suction motors to clean.
A sensor detects when the battery is low, and the robot returns to its charging base.
Answer: sensors → microprocessor → actuators, guided by a program
Examiner trap
A drone is a robot when it is programmed to fly a route or uses its sensors to act on its own (e.g. a crop-spraying drone). Say what it does in the scenario, not just "it flies".
Stage 1 · Learn
Check what the sim just showed you
Four quick checks. Each correct answer earns XP and records this skill on your profile.
Quick check+10 XP
Which is the best description of robotics?
Quick check+10 XP
Which of these is NOT one of the three characteristics of a robot?
Quick check+10 XP
In a robot arm, which component makes the joints move?
Quick check+10 XP
Which is an example of a domestic robot?
Section 03
For and against.
As with automated systems, learn the general points, then apply them to the robot in the question.
Advantages of robots
Disadvantages of robots
Can work 24/7 without breaks, so productivity is higher
Expensive to buy, program and maintain
Consistent, accurate results: every product the same
Can only do the tasks they are programmed for; they struggle with unusual or non-standard situations
Can work in dangerous places (bomb disposal, deep sea, space, nuclear sites, toxic fumes)
Workers may lose jobs, and skills may be lost; new skilled jobs (maintenance, programming) need training
Do boring, repetitive tasks so people can do more skilled work
Breakdowns can stop a whole production line; they may be hacked
Lower running costs over time (no wages, less waste)
Lack human judgement and the personal touch, e.g. in medicine or care
Your turn
A hospital uses a robot to help surgeons carry out operations. Give one advantage and one disadvantage.
Advantage: the robot's movements are very precise and steady, so smaller cuts can be made and the patient recovers faster. Disadvantage: the robot is very expensive, and if it develops a fault during an operation the surgeon must take over (staff also need special training).
Examiner trap
"Robots are cheaper" needs care: they are expensive to buy, but can be cheaper to run over time. Say which one you mean.
Stage 2 · Exam
Exam-style questions
Unlocks once the four checks above are done. Worth more XP, written to IGCSE Paper 1 standard.
Finish the four checks above to unlock the exam questions
Exam style+20 XP
A car factory replaces paint sprayers with robots. Which is the most likely advantage?
Exam style+20 XP
Why is it important that a factory robot is programmable?
Exam style+20 XP
Which is a disadvantage of using drones to deliver parcels?
Exam style+20 XP
A robot used for bomb disposal mainly has which advantage?
Skill unlocked
Robotics, mastered.
This skill is now recorded on your profile. Keep the chain going.