To demonstrate the abilities of our AHHS hormone controllers in producing interesting behaviour in limited robots, we aimed to mimic taxis behavior that is found in very primitive lifeforms. For example, a unicellular algae performs phototaxis with just one photo-sensitive eye-spot and just a single actuator.
We implemented an AHHS algorithm on a robotic platform. We used an `e-puck' robot for this experiment. The robot was equipped with only one light-sensor on top, pointing upwards. Therefore, the light sensor reports local luminance without any directional information. Also, the robot is equipped with a differential drive.
For this experiment, we used two light emitters in opposing corners (top left and bottom right). At first, only one emitter (top left) was switched on. The robot was placed directly under the other light source with a heading pointing away from the light optimum. The robots objective was to navigate to the brightest spot in the arena, directly under the light emitter. After that, the light emitter was switched off, while the other emitter was switched on (bottom right). The robots task was now to locate and navigate to the new light optimum.
This figure shows the robot (running the AHHS) performing the spiral-way target approach toward the light gradient.