4.22

## Begin Robotics

Skip to 0 minutes and 2 secondsOkay, it's time for an exercise. And this is about programming a robot that works a bit like Braitenberg vehicles. So here is the web page, and I'll scroll down to it so we can see all the controls. And, basically, we got a Braitenberg vehicle, as shown down at the bottom, which has got two sensors. The left sensor, the right sensor, which have a one if they detect a light, a zero if not. It's then got two sets of three neurons-- one determining the left speed, one determining the right speed.

Skip to 0 minutes and 36 secondsAnd the formulae that are used is that the left speed, as it says there, is a left sensor times the LL neuron, which is that one there, plus the right sensor times the LR neuron, plus the LM neuron. So if the robot, for instance, can't see anything, then the LM neuron will determine how fast it goes. And you type in here the different speeds, or different neuron values, to determine what the speed is. And once you've done that, you can press start. And, as ever, you have the option to have reverse left motor.

Skip to 1 minute and 14 secondsSo once you type something in you can see the robot move around, you can put back to its initial position, you can specify narrow beams like this, or wide beams. The two red dots represent the lights, and the-- that sensors can detect those. So, first, what you need to do is to find the neurons so that the robot moves forward when it sees nothing. But slows down and turns towards the light it sees, rather like a passive seeker. And try that with narrow and wide beams. Then define the neurons so that the robot moves forward when it sees nothing, but speeds up and turns towards the light. So it's more like an active seeker.

Skip to 1 minute and 56 secondsFinally, define the neurons so the robot moves forward when it sees nothing, but turns away from the light it sees, which is more like an active phobe. It's all done by typing in different values for the neurons.

# Braitenberg robots

In the final exercise on the course, you will be able to define the robot speed to specify the value of the neurons in the vehicles. In this video, Richard introduces the simulation and what you need to do to define the neurons so that the robot moves forward or moves away from a light.