IGCSE Computer Science 0478: Programmable Robots on a Car Assembly Line

A car manufacturer replaces the human workers who used to weld car body panels together with a row of robotic arms. Each arm has a welding tool fitted to its end, sensors that detect the exact position of each panel, and a microprocessor programmed with the precise sequence and position of every weld needed for that car model.

(a) State two applications of robots, other than car manufacturing, where a mechanical structure, sensors, a microprocessor and actuators are combined in a similar way. [2]

(b) Explain how being programmable allows the same physical robot arm to be reused when the manufacturer starts building a completely different car model on the same production line. [3]

(c) Give one advantage and one disadvantage, to the workers themselves rather than to the manufacturer, of replacing the human welding team with robots. [2]

Part (a): Other applications of robots

Robots combine a mechanical structure, sensors, a microprocessor and actuators across many fields, not just car manufacturing:

Agriculture, for example a robot arm that identifies ripe fruit using sensors and picks it automatically.
Medicine, for example a surgical robot guided by a surgeon, or a robot that packs prescriptions in a pharmacy.
Warehousing/logistics. For example a robot that moves stock between storage shelves and a packing area.
The home, for example a robotic vacuum cleaner that senses obstacles and navigates a room automatically.

Any two genuinely different fields from this list (or another correct example) earn the marks. [2 marks]: [1] for each valid, distinct application.

Part (b): Why being programmable allows reuse for a new car model

When the manufacturer switches to a new car model, the robot arm’s physical parts (its mechanical structure, welding tool and actuators) stay exactly the same. What changes is the program stored in its microprocessor: a new set of instructions is written and loaded, giving the new model’s weld positions, order and movements.

Because the robot is programmable, this new set of instructions is enough to change what the arm does, without physically rebuilding or replacing any of its hardware. This is precisely what distinguishes a robot from a fixed machine built to do only one task: the same physical robot can be reprogrammed and reused for a new job. [3 marks]: [1] for recognising the hardware does not need to change, [1] for identifying that new instructions are loaded into the microprocessor, [1] for linking this specifically to the robot being programmable.

Part (c): Advantage and disadvantage to the workers

Advantage: the welders are taken out of a hazardous working environment involving sparks, fumes and intense heat from the welding process, and some may be retrained to supervise, program or maintain the robots instead, a safer role.

Disadvantage: because the robots now carry out the welding, some of the human welders lose their jobs, or must be retrained for a different role within the factory, which they may not have chosen or wanted. [2 marks]: [1] for a valid advantage to the workers, [1] for a valid disadvantage to the workers.

Final answers

(a) Any two of: agriculture, medicine, warehousing/logistics, the home (or another valid field).
(b) The arm’s hardware stays the same; a new program with the new model’s weld positions is loaded into the microprocessor, which is possible because the robot is programmable.
(c) Advantage: removed from a hazardous welding environment (and possibly retrained for a safer role). Disadvantage: job losses or the need to retrain.