Research Overview:

Performing experimental verification and validation (V&V) for robot swarms with large numbers of agents is challenging. As such, our theoretical insights far exceed our experimental results. The goal of this program was to bridge the scalability gap using new experimental tools, mainly: Mixed Reality. This method combines simulated and real robots to help achieve large numbers without needing all of the physical platforms.

Mixed reality allows for early testing and evaluation of theoretical models, which improves field deployment readiness, and serves as a step in the experimental pipeline. In this work, we were specifically interested in the emergence of different collective behaviors which arise due to communication or sensor data processing time delay.

Two experimental platforms were studied including the Pelican Unmanned Ariel Vehicle (UAV) and the Crazyflie micro Ariel Vehicle.

Left: Pelican UAV, Right: Bitcraze Crazyflie UAV

This video demonstrates mixed reality used with 8 real and 16 simulated agents executing a known Ring behavior. The controller used has been theoretically studied and we know there are multiple different forms of emergent behavior. This result shows one such behavior.

Experimental results focused on demonstrating the ring emergent behavior, as well as demonstrating switching from one behavior to another, (Ring to Rotating behavior). For more details please consult the citations below.

Associated Publications

Delay induced swarm pattern bifurcations in mixed reality experiments

Edwards, Victoria, deZonia, Philip, Hsieh, M Ani, Hindes, Jason, Triandaf, Ioana, and Schwartz, Ira B

Chaos: An Interdisciplinary Journal of Nonlinear Science 2020

Abs

Swarms of coupled mobile agents subject to inter-agent wireless communication delays are known to exhibit multiple dynamic patterns in space that depend on the strength of the interactions and the magnitude of the communication delays. We experimentally demonstrate communication delay-induced bifurcations in the spatio-temporal patterns of robot swarms using two distinct hardware platforms in a mixed reality framework. Additionally, we make steps toward experimentally validating theoretically predicted parameter regions where transitions between swarm patterns occur. We show that multiple rotation patterns persist even when collision-avoidance strategies are incorporated, and we show the existence of multi-stable, co-existing rotational patterns not predicted by usual mean field dynamics. Our experiments are the first significant steps towards validating existing theory and the existence and robustness of the delay-induced patterns in real robotic swarms.
Unstable modes and bistability in delay-coupled swarms

Hindes, Jason, Edwards, Victoria, Kamimoto, Sayomi, Triandaf, Ioana, and Schwartz, Ira B

Physical Review E 2020
Torus bifurcations of large-scale swarms having range dependent communication delay

Schwartz, Ira B, Edwards, Victoria, Kamimoto, Sayomi, Kasraie, Klimka, Ani Hsieh, M, Triandaf, Ioana, and Hindes, Jason

Chaos: An Interdisciplinary Journal of Nonlinear Science 2020

This work was done in collaboration with Dr. Jason Hindes, Dr. Ira B. Schwartz, Dr. Ioana Triandof, and Donald Sofge at the US Naval Research Laboratory.