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Skip to 0 minutes and 0 secondsThe final thing we're going to look at is not actually one of Valentino Braitenberg's original machines. It's a machine called Machina Speculatrix, which was a series of robots which were made by Grey Walter in the late '40s and the '50s. So although the neuron structure of the Machina Speculatrix is not the same, the body of the Machina Speculatrix is not the same as the Braitenberg vehicles, it has many of the same features. So Machina Speculatrix was also a light seeking robot, and instead of neurons, it used valves, and the valves worked in a slightly different way.

Skip to 0 minutes and 48 secondsSo one set of valves was used to drive the robot towards the light, and the other set of valves, the other set of neurons, if you like, was used just to turn a wheel if it couldn't see a light. And we'll add another light which will now turn into a Machina Speculatrix. So there's Machina Speculatrix, and here you see its very typical behaviour where it goes towards the light. If it doesn't see the light, it does a little twist until it sees the light and it almost invariably ends up orbiting around the light. So let's just move the Machina Speculatrix into a corner.

Skip to 1 minute and 28 secondsAnd at this point, Machina Speculatrix can't get enough light, isn't seeing the light in the middle of the field, so it's just staying at its position in the corner with its eye rotating endlessly around and around. So what we'll do is we'll just add a light halfway between. So when we add this light, Machina Speculatrix will pick it up and start moving towards it. It loses it, picks it up again, starts moving towards it. And in fact, now it's moving towards the second light and ends up orbiting the second light. So let's just actually pick up Machina Speculatrix move from somewhere else.

Skip to 2 minutes and 13 secondsYou can see we've got him trapped in the middle at the moment, can't see any light, so let's move him into a slightly different place. He's picked up that first light, moving towards it. Now see if it does it. It was moving. It's actually going to pick up the second light and end up orbiting at the second light. Well that, I think, about covers it. The programme is available on GitHub. If any of you are enthusiastic about playing with it, you can play with the specifications of the robot and the design of the neurons inside the brain of the robot.

Skip to 2 minutes and 55 secondsAnd you can also do things like, as I say, take the position of the robot and see its point of view as it moves around looking for light, so predators or prey animals. That's it. Thank you, and I hope you enjoyed it.

Machina Speculatrix

In this video William introduces a program that demonstrates Grey Walter’s Machina Speculatrix.

Grey Walter designed his series of ‘robot tortoises’ (so called because of their tortoise shell shaped back) in the 1940’s.-1950’s. Although the body shape differs from Braitenberg vehicles, Machina Speculatrix is also a light-seeking robot and shares many of the same features. The ‘robot tortoises’ attracted a great deal of interest at that time, because of their ability to mimic complex behaviour. They continue to play an important role within cybernetics today because they illustrate key ideas in cognitive science (the study of understanding).

These devices work by means of a set of valves instead of ‘neuron’s’ and a light sensor or ‘eye’ mounted above a wheel at the front. Instead of neurons the robots use valves. One set of valves are designed to drive the robot towards a light The other set of valves are used to turn a wheel if the robot isn’t able to see a light.

If you’d like to play with the specifications of the robot and/or the design of the neurons inside the brain, you can find this program at GitHub.

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This video is from the free online course:

Begin Robotics

University of Reading