Computer-controlled manufacturing has revolutionised the way products are made. Modern factories are full of robots; everything is automated.

In a modern factory the only people you will see are a few engineers who are responsible for keeping the robots and other machinery running smoothly.

This is very different to old factories, where everything was done manually by human workers.

What is an Industrial Robot?

When you think of the word 'robot', you might picture a human-shaped robot with arms, legs and a head - the sort you see in sci-fi films. However this is not how the sort of robots used in factories look.

Robots used in factories are called industrial robots, and they come in a wide variety of shapes and sizes.

The most common type of industrial robot looks a little bit like a human arm. The robot has joints (like our shoulder, elbow, and wrist) and some sort of manipulator / device on the end of the arm (where our hand would be).
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The robot's joints are powered by very strong electric motors. These motors are controlled by a computer.
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A scene from an old factory - no robots in sight! This type of manual labour is repetitive and boring.
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In a new factory, the same tasks are performed by robots
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The robot's manipulator / device depends upon the job that the robot has to do. It could be:
  • a gripper (like a hand, for picking things up)
  • suction pads (for lifting sheet metal or glass)
  • a paint spray gun (for painting things)
  • a welding gun (for joining metal together)

How Are Robots Used in a Factory?

Robots in factories are used to:
  • lift heavy items into from place to place
  • assemble parts together to create things
  • join parts together using glue, or by welding (melting metal)
  • paint things
Robots often work in groups, one robot holding a part, whilst another robot does something to it.

Watching robots work is fascinating - they move so quickly and confidently, that it seems almost like a choreographed dance!
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Spray painting things (a hazardous job for a human - most paint is toxic)
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Welding metals parts together (needs skill and accuracy)
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Stacking boxes for shipping (tedious and hard for a human to do all day)

How Do Computers Control Robots and Production Lines?

The basics of computer control are explained in the Controlling Real-World Things section.
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In the case of factory production lines the control system consists of:


Sensors (inputs to the computer) detect what is happening on the production line, and send data to the computer so that it can decide what to do.

Examples of sensors would be:
  • Switches / buttons - detect if something is touching them
  • Pressure sensors - detect if something is pressing down on them
  • Light sensors - detect if something is present (blocks the light)
  • Temperature sensors - detect if items are hot/cool enough
  • Liquid level sensors - detect how much liquid is in a container
  • Cameras - detect the shape / colour of objects

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The control software running on the computer is the process. It takes the data from the sensors, checks if anything needs to be done, then turns on/off various actuators to make things happen.

For example, in a soft-drink factory, the production line involves filling bottles with fluid (drink!)
  1. The computer would make sure that a bottle was in place (using data from a pressure sensor, a light sensor, or a camera) and then turn on the fluid control valve.
  2. The data from a fluid level sensor would be checked to see if the bottle was full. When it was full, the computer would turn off the fluid control valve.
  3. These steps would then be repeated for the next bottle, and so on.
In a typical production line, there will be hundreds of sensors and dozens of actuators, all connected to computers (often a large network of computers)

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Actuators (outputs form the computer) are the devices that make things happen on the production line: robots picking things up, conveyor belts moving, etc.

Examples of actuators would be:
  • Motors - used to make almost everything move, from the joints of robot arms, to the motion of conveyor belts.
  • Valves - to turn on/off the flow of paint, etc.
  • Relays (electrically operated switches) - turn on/off devices like welders

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Why Use Computer-Controlled Robots?

The robots used in factories are very expensive. Many of the larger ones can cost as much as $500,000. And some factories have dozens of robots.

So why would a factory owner spend so much money on these expensive machines?

There are a number of reasons that robots are used:
  • Robots can work 24 hours a day, every day, with no breaks
  • Robots don't need to be paid a wage (so money is saved)
  • Robots are extremely accurate compared to humans, so product quality is high
  • Robots can perform tasks more quickly than humans, so more products can be made
  • Factories with robots don't need to be heated or even have the lights on, and they don't need food (so lower day-to-day costs)
  • Robots can work in very dangerous / unhealthy conditions (e.g. with dangerous chemicals)
  • Robots don't get bored / hate their job!
There are some downsides to the use of robots in factories:
  • Robots are cannot easily adapt to unusual conditions like a human can (e.g. if an item on the line is not in the correct place, a human worker would notice and correct it)
  • People are made unemployed because robots are doing their jobs (however some new jobs are created - looking after the robots - and some employees can be retrained)
  • People are deskilled (this means that, because the robots are doing the complex, skilled tasks that the people used to do, the people are left doing simple, boring jobs)
  • The robots are very expensive, and it can take several years to pay for them (paying with the savings made by not paying any wages)
Some people get very upset when you talk about robots in factories - they see the robots 'stealing' peoples' jobs.

It is true that many jobs have been replaced by robotic production lines, but these jobs were often incredibly boring, repetitive, and often in dangerous conditions.

Some of the people who lost their jobs have been retrained to work with the robots - maintaining them so they run smoothly.

As long as alternative work can be found for people, you could argue that robots have improved the lives of people overall, since nobody has to perform those tedious and dangerous jobs anymore.
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Working alongside the robots

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