Revision as of 21:20, 27 October 2007

Robotic ants foraging for food

Overview

The goal of this assignment is to get our iRobot Creates to use teamwork to find and bring food back to our home colony. In this case, our robots will simulate ants in following a virtual pheromone trail set by ants that have already found food. The food in this instance would be the IR beam emitted from a Roomba virtual wall and detected by the IR sensor on top of the iRobot Create.

Goal

Using only the simple behaviors, drive, read pheromone, pick up food, leave pheromone, we want to find enough food to get us through the winter.

Details

Robots begin by executing a search for food. This is done by random movements until 1) food is found, or 2) a virtual pheromone is encountered.

Food

Virtual walls are what our ants will use as food. When our Create encounters a virtual wall, it will "pick up food", then return home by following it's original pheromone trail while leaving pheromones for the other robots to find. They will be positioned from above with the IR beam pointing downward to simulate the effect of a food source. There will be two virtual walls, symbolizing two food sources.

Virtual Pheromone (VirP)

Once a robot encounters a virtual wall, it will begin its journey home leaving a virtual pheromone (VirP) trail in the virtual environment. Leaving a virtual pheromone in the environment is accomplished by sending a location to a central server which will act as a virtual map.

Other robots will determine if there is a pheromone trail by querying the virtual map for VirP strength > 1 in its current location.

Behaviors

The following behaviors are required:

• "Find Food" - implement a basic behavior to find food and update it's position on the virtual map, and maintain its position and/or the path it is taking in memory (so it can find its way home).
• "Return Home" - will set virtual "pheromones" on it's return to home base
• lay down virtual pheromone - this will send a message to the virtual map
• avoid obstacles (the other robots)

Map

Since the Create is limited in its computing abilities, each robot will be controlled via a laptop computer communicating over Bluetooth. The laptops will then send their positional updates to a central "virtual" map on a central computer. We will use this virtual map as our environment from which the robots will send/receive virtual pheromones.