Project Details

  • Start: March, 2009
  • End: November, 2010


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Patterns, Transitions and the Role of Leaders in the Collective Dynamics of a Simple Robotic Flock

source:trunk/public/boats/img/boats-setup.png We have developed an experimental setup of very simple self-propelled robots to observe collective motion emerging as a result of inelastic collisions only. A circular pool and commercial RC boats were the basis of our first setup, where we demonstrated that jamming, clustering, disordered and ordered motion are all present in such a simple experiment and showed that the noise level has a fundamental role in the generation of collective dynamics. Critical noise ranges and the transition characteristics between the different collective patterns were also examined.

source:trunk/public/boats/img/boats-setup2.png In our second experiment we used a real-time tracking system and a few steerable model boats to introduce intelligent leaders into the flock. We demonstrated that even a very small portion of guiding members can determine group direction and enhance ordering through inelastic collisions. We also showed that noise can facilitate and speed up ordering with leaders.

Our work was extended with a simulation model, too, and high similarity between real and simulation results were observed. The simulation results show clear statistical evidence of three states and negative correlation between density and ordered motion due to the onset of jamming. Our experiments confirm the different theoretical studies and simulation results in the literature about collision-based, noise-dependent and leader-driven self-propelled particle systems.

Supplementary Material

Typical ordered states

The images below show some of the tipical ordered states observed during one experiment.

source:trunk/public/boats/img/27boats-2-1-1.4-1_1460-jamming.png jamming state - the boats get stuck at the side of the pool, typically at low noise level
source:trunk/public/boats/img/27boats-2-1-1.4-1_2708-clustering.png clustering state - temporary state between more stable ordered and disordered states
source:trunk/public/boats/img/27boats-2-1-1.4-1_3340-CCW.png ordered state - ordered circular motion in CCW direction, typically at mid noise level


Without Leaders

Jamming + CW Ordered motion,
No leaders, Low noise

Disordered motion,
No leaders, Middle noise

Disordered motion,
No leaders, High noise

With Leaders

Jamming + Ordered motion,
CCW leaders, Low noise

Disordered + Ordered motion,
CCW leaders, Middle noise

Disordered motion,
CW leaders, High noise


PubList(project:phase_transitions_and_the_role_of_leaders, order=-year)?