These creatures were designed by David Hogg, Fred Martin, and Mitchel Resnick of the MIT Media Laboratory. They are inspired by a set of thought experiments created by Valentino Braitenberg in his book, Vehicles: Experiments in Synthetic Psychology, MIT Press, 1984. Hogg et al used specialized electronic LEGO bricks to build these creatures. For more details, see their paper Braitenberg Creatures.
Mount the HB onto the Lego bug
Create a fairly secure way to hold the HB on your Lego vehicle. You may want to add some more Lego underneath the large green platform to facilitate this.
Running the HB without a host computer
In the Interactive C file containing your behavior functions, add a main procedure that calls the appropriate functions. Download this file to the HB. Disconnect the HB from the host computer. Now whenever you turn the HB on it will automatically begin executing the main procedure. To cancel this effect, turn the HB on while pressing the Start button. This should make it easier to test your creatures.
Timid is capable of moving forward in a straight line. It has one threshold light sensor, pointing up. When the light sensor detects light, the creature moves forward, otherwise, it stays still. The threshold of the light sensor can be adjusted using the HandyBoard knob. The threshold of the light sensor should be set to ambient light. That way, when the creature can "see" the light, it will move. When it enters a shadow (which can be cast by a hand or another object) it stops. If whatever is casting the shadow is moved, the creature will move again. Therefore, Timid could be viewed as a shadow seeker. Remember that brighter light equates to lower values on the light sensors.
Indecisive is similar to Timid, except, it never stops: its motors are always running, either in forward direction, or in reverse direction, controlled by the threshold light sensor. When the light sensor detects light, it moves forward, otherwise, it moves backwards. When you run this creature, you will notice that it tends to oscillate back and forth at shadow edges. Thus, Indecisive could be viewed as a shadow edge seeker.
Paranoid is capable of turning. Its threshold light sensor is pointed up and is attached on an arm that extends forward a few inches from the body. When the sensor detects light, it moves forward. When the sensor enters a shadow, it reverses while turning. Soon the sensor will swing around, out of the shadow. When that heppens, it resumes its forward motion. Paranoid could be viewed as a shadow fearing creature.
Creature#4: ???Design a creature of your own that employs several different types of sensors in controlling the motors. Explain its behavior and choose a descriptive name for it.
A single conroller
Write a single program which uses the knob to select which of the previous four creatures to run.
Once completed, you should invite at least three people to observe these creatures and record their reactions. Let the observers assign names to the creatures, rather than telling them the names we have given them. Write down what they say as they interact with the robot.
What to hand in
Turn the following in at the start of next week's lab.