Wilson Sean, Buffin Aurélie, Pratt Stephen C, Berman Spring
School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA 30308, USA.
Life Science, Mesa Community College, Mesa, AZ 85202 USA.
R Soc Open Sci. 2018 Oct 17;5(10):180409. doi: 10.1098/rsos.180409. eCollection 2018 Oct.
In this work, teams of small mobile robots are used to test hypotheses about cooperative transport by ants. This study attempts to explain a decrease in steady-state transport speed with increasing team size that was previously observed in the ant . Two models of one-dimensional collective towing are compared: one in which transporters with different maximum speeds pull the payload with continuous, variable forces and another in which transporters with identical speeds pull with intermittent, unsynchronized forces. A statistical analysis of ant data supports the hypothesis that ants behave according to the first model, in which the steady-state transport speed is the maximum speed of the slowest teammate. By contrast, the ant data are not consistent with the second model, which predicts constant speed regardless of team size. To verify these predictions, the ant behaviours in each model are translated into decentralized controllers and implemented on teams of two to four robots. The controller for the first model incorporates a real-time reinforcement learning algorithm that successfully reproduces the observed relationship between ant team size and transport speed. The controller for the second model yields the predicted invariance of transport speed with team size. These results show the value of robotic swarms for testing mechanistic hypotheses about biological collectives.
在这项工作中，小型移动机器人团队被用于检验关于蚂蚁合作运输的假设。本研究试图解释先前在蚂蚁身上观察到的随着团队规模增加稳态运输速度下降的现象。比较了两种一维集体拖曳模型：一种是不同最大速度的运输者用连续可变的力拉动负载，另一种是相同速度的运输者用间歇性、不同步的力拉动负载。对蚂蚁数据的统计分析支持了这样的假设，即蚂蚁的行为符合第一种模型，其中稳态运输速度是最慢队友的最大速度。相比之下，蚂蚁数据与第二种模型不一致，第二种模型预测无论团队规模如何速度都恒定。为了验证这些预测，将每个模型中的蚂蚁行为转化为分散控制器，并在两到四个机器人的团队上实现。第一种模型的控制器包含一种实时强化学习算法，该算法成功再现了观察到的蚂蚁团队规模与运输速度之间的关系。第二种模型的控制器产生了预测的运输速度随团队规模不变的结果。这些结果表明了机器人集群在测试关于生物群体的机械假设方面的价值。
