Temperature control

We have seen that feedback control is used by the steersman to ensure his boat stays on course and that it can be used to ensure that our robot moves at the desired speed.

It is straightforward to realise that the concept applies everywhere. If you are driving your car, you keep on the road in the correct lane by looking where you are going (just like the steersman) and turning the steering wheel as appropriate.

Similarly, you drive at the correct speed by monitoring the speedometer. If, for instance, you are in a 30mph speed limit, and you notice that the speedometer indicates you are travelling at 40mph, you slow down (particularly if there is a speed camera!)

It should be noted that it is important that what you measure is correct – if your speedometer is faulty, and says you are travelling at 30mph when you are in fact going at 40mph, you will drive too fast.

In addition, feedback can be used to control temperature. In the video Richard discusses so-called Rein control (which the steersman uses) and how it applies to control of the temperature of a house or room, the human body – and even Earth itself – as proposed by James Lovelock in his Gaia Theory. To demonstrate his ideas, Lovelock and his colleague Andrew Watson, modelled an imaginary planet, Daisyworld, which features artificial life (in this case daisies). In the video Richard shows the web page he created to simulate Daisyworld. The video concludes by relating this to robotics.

If you’re interested in the Temperature Control demo mentioned in this video – you can try the Daisyworld Web Page yourself.