Having established that the basic CASU functionality works as expected, the ASSISIbf team was ready to undertake the first collective-behavior experiments, lead by Rob Mills of Lisboa who had worked out and coded up a number of interesting test cases.
In the first group of experiments, two CASUs were heating opposite corners of the arena, with one of them providing the Bee’s preferred temperature of 36 degrees, and the other one heating to a two degree lower temperature. After the bees had aggregated at the optimal spot, the heating CASUs were turned off, and two new attractive spots were created, in the other two corners of the arena. Again, one spot was only locally optimal, the other one was globally optimal. The experiment was performed in two varinats: one with an abrupt optimum change, as descirbed above, and another where the optima moved along a chain of neigboring CASUs. The goal was to see whether the CASU array can be used to “guide” the bees to the global optimum. Further experiments are needed in order to draw definite conclusions, however, in the performed experiments, the bees’ time to reach the global optimum was decreased with the help of the CASUs.
The other set of experiments was the first step towards the ambitious ASSISIbf goals of interaction between spatialy-separated societies. Two groups of bees, physically separated in two smaller arenas within the CASU array, were required to coordinate their decision on an aggregation spot. The CASUs were “counting” the bees in their surroundings by means of IR proximity sensors and closing a positive feedback loop by producing more heat when counting more bees. This was the first set of fully autonomous CASU experiments!
Additional experiments featured a mixed society, but the details of this experiment will be kept secret for the time being.
One of the highlights of the workshop was the bee detection and tracking software implemented and tested by Marcelo of EPFL. Due to their high density and unpredictable motion, bee-tracking is a notoriously difficult problem and to the best of our knowledge no robust solutions, weather commercial or academic, are currently avalable. Well, at least until the end of this week, when Marcelo adapted his fish-tracking tool to tracking bees. It took a lot of coding and some adjustments to the environment
but the results are more than impressive:
All in all, the whole ASSISIbf team is satisfied with the progress achieved and confident that they can keep up the dynamic pace set out in the project DoW.