Robot swarm democracy: the importance of informed individuals against zealots

Abstract: In this paper we study a generalized case of best-of-n model, which considers three kind of agents: zealots, individuals who remain stubborn and do not change their opinion; informed agents, individuals that can change their opinion, are able to assess the quality of the different options; and uninformed agents, individuals that can change their opinion but are not able to assess the quality of the different opinions. We study the consensus in different regimes: we vary the quality of the options, the percentage of zealots and the percentage of informed versus uninformed agents. We also consider two decision mechanisms: the voter and majority rule. We study this problem using numerical simulations and mathematical models, and we validate our findings on physical kilobot experiments. We find that (1) if the number of zealots for the lowest quality option is not too high, the decision-making process is driven toward the highest quality option; (2) this effect can be improved increasing the number of informed agents that can counteract the effect of adverse zealots; (3) when the two options have very similar qualities, in order to keep high consensus to the best quality it is necessary to have higher proportions of informed agents

Fly with me : algorithms and methods for influencing a flock

As robots become more affordable, they will begin to exist in the world in greater quantities. Some of these robots will likely be designed to act as components in specific teams. These teams could work on tasks that are too large or complex for a single robot - or that are merely more efficiently accomplished by a team - such as surveillance in a large building or product delivery to packers in a warehouse. Multiagent systems research studies how these teams are formed and how they work together. Ad hoc teamwork, a newer area of multiagent systems research, studies how new robots can join these pre-existing teams and assist the team in accomplishing its goal. This dissertation extends and applies research in ad hoc teamwork towards the general area of flocking, which is an emergent swarm behavior. In particular, the work in this dissertation considers how ad hoc agents - called influencing agents in this dissertation - can join a flock, be recognized by the rest of the flock as part of the flock, influence the flock towards particular behaviors through their own behavior, and then separate from the flock. Specifically, the primary research question addressed in this dissertation is How can influencing agents be utilized in various types of flocks to influence the flock towards a particular behavior? In order to address this research question, this dissertation makes six main types of contributions. First, this dissertation formalizes the problem of using influencing agents to influence a flock. Second, this dissertation contributes and analyzes algorithms for influencing a flock to a desired orientation. Third, this dissertation presents methods for determining how to best add influencing agents to a flock. Fourth, this dissertation provides methods by which influencing agents can join and then leave a flock in motion. Fifth, this dissertation evaluates some of the influencing agent algorithms on a robot platform. Sixth, although the majority of this dissertation assumes the influencing agents will join a flock that behaves similarly to European starlings, this dissertation also provides insight into when and how its algorithms are generalizable to other types of flocks as well as to general teamwork and coordination research. All of the methods presented in this dissertation are empirically evaluated using a simulator that can support large flocks.Computer Science

Classical Engineering Systems Provide Behavioral Analog for Ephemeral Insect and Plant Biomechanics

In this dissertation we consider ephemeral behaviors of two small-scale living systems, mosquitoes and citrus fruit reservoirs. While these two systems share few obvious commonalities, they both express life events that are complex and conclude within approximately 50 milliseconds. We utilize high-speed videography, between 1,000-16,000 fps, to detail how complex behavior can be modeled as classical engineering systems. Beginning with the larger organism we assessed the landing and takeoff behavior of Aedes aegypti mosquitoes to ascertain the secrets of their covert interaction with humans. At takeoff, mosquitoes decrease pushing contact time with substrates of low friction through a modified takeoff behavior of striking the substrate with a hind-leg prior to a classic push phase. We propose a 2D analog where the striking leg acts as a rotating cantilever about a fixed end that generates upward momentum with a small penalty in body rotation. Landing mosquitoes are filmed in 2D and modeled as a mass-spring-damper system whose natural frequency, damping coefficient, ratio, and spring constant are determined experimentally and validated through a nonlinear least square solver fitting of the free vibration ODE\u27s general solution. Results indicate mosquitoes behave as an underdamped system to scrub their incoming momentum through extending impact duration, effectively reducing temporal impact force. Shrinking in scale we proceed to characterize citrus reservoir rupture as a passive system capable of microjetting oil through expanding orifices at accelerations greater than 5000 gravities. Citrus reservoirs are modeled as ellipsoidal pressure vessels capped by a thin membrane of contrasting stiffness to the surrounding ductile compressible albedo