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4.7

## Begin Robotics

Skip to 0 minutes and 1 second So this is Begin Robotics and today we’re going to look at Braitenberg vehicles and a simulation of some of the Braitenberg vehicles which was inspired by the work of the Italian-Austrian cyberneticist, Valentino Braitenberg. OK. So here we have the field of play for the Braitenberg vehicles. And you can see two lights. And you can see the top light’s been selected. What we’re going to do in a second is change that top light into a shy seeker. Now shy seekers go around looking for light but not getting too close. So we’ll start this game. We’ll make that top light into a shy seeker. And initially it sees the light.

Skip to 0 minutes and 46 seconds So just to show you, we’re going to select the light and get rid of it. And a shy seeker can’t see a light but has enough neural input going through to the actuator so it keeps moving around. But as soon as it sees the light, it will start moving towards the light. So as you may recall, it’ll see the light in one eye more intensely than in the other. And that will cross over to the actuator driving the other wheel. And that tends to move it towards the light itself. So we can add another shy seeker. So first we add a light and we make it into a shy seeker.

Skip to 1 minute and 25 seconds And that one’s already in a place where it can see the light. We’ll just move it away a bit. You can see him creeping towards the light and eventually getting close enough. So it’s got enough neural input but doesn’t want to get too close to the light itself. OK. So let’s make one of these shy seekers into an aggressive light seeker. So the neural wiring is slightly different.

Skip to 1 minute and 52 seconds This time, instead of inhibiting the eyes, inhibiting the actuators, the eyes are stimulating the actuators. So the closer the aggressive seeker is to the light, the faster it will go. So let’s make this into an aggressive seeker. And it immediately goes through the light and keeps going. These robots have inertia, so they have something pushing it forward when there’s nothing there. But now aggressive seekers hit a point where there’s no light falling on its eyes. So it can’t see the light. So no stimulation is going through to the actuators. So we’ll add a light in the view of aggressive seeker so it can do some more moving. It’ll move forward. Now it might see the light in the middle now.

Skip to 2 minutes and 42 seconds Yes, it has. So it starts moving towards the light in the middle. Zooms past it. Now it’s going to get lost again. OK. And we can add another light for aggressive seeker.

Skip to 2 minutes and 58 seconds OK. So we’re going to now start looking at the light phobes. And so there are two classes of light phobe. There’s either the aggressive phobe or the shy phobe. And this time, instead of being attracted by the light, they’re going to try and move away from the light. So we’ll start here and we’ll convert this first one into a shy light phobe.

Skip to 3 minutes and 30 seconds And in fact, let’s just take that light out. So we’ll remove the light. So without any light at all, shy light phobe just goes around. It has enough in the neural system to keep the actuators going. So we’ll put a light in front of him. So let’s put a light there. And he moves away. He sees enough of the light. Now he doesn’t see the light. He carries on going. So we can put a light in and he steers away again.

Skip to 4 minutes and 3 seconds So a shy phobe is trying to stay away from the light. OK. So let’s look at the aggressive phobe. So we’ll make this into aggressive phobe. So there’s the aggressive phobe. Now aggressive phobe, no light, no movement. So aggressive phobe only moves if it can see light. So we’ll add some light in and it immediately moves away. Now it looks like it’s moving towards the light but in fact this is because of the inertia of the system. It can’t turn instantaneously. So when it sees the light, it sort of moves towards it because it is trying to turn around but isn’t turning around as fast because of the inertia of its body, the weight of its body.

Skip to 4 minutes and 47 seconds And so aggressive phobe appears to be going towards the light. Sometimes it does. But in general, it’s trying to stay away from lights. So it’s steering away from lights as far as possible. So we can add more and more lights and make it harder and harder for it to keep away from the light. And so this results in more and more complex movement for the aggressive phobe.

# The Braitenberg vehicle program

Now you’ve seen some Braitenberg vehicles in action, watch as William demonstrates his simulation program; inspired by the work of Italian-Austrian cyberneticist Valentino Braitenberg. In this video we see active and passive light seekers and light phobes.

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