School of Physics, Georgia Institute of Technology, Atlanta, GA, USA.
School of Biology, Georgia Institute of Technology, Atlanta, GA, USA.
Nat Commun. 2019 Aug 13;10(1):3655. doi: 10.1038/s41467-019-11613-y.
The centralization of locomotor control from weak and local coupling to strong and global is hard to assess outside of particular modeling frameworks. We developed an empirical, model-free measure of centralization that compares information between control signals and both global and local states. A second measure, co-information, quantifies the net redundancy in global and local control. We first validate that our measures predict centralization in simulations of phase-coupled oscillators. We then test how centralization changes with speed in freely running cockroaches. Surprisingly, across all speeds centralization is constant and muscle activity is more informative of the global kinematic state (the averages of all legs) than the local state of that muscle's leg. Finally we use a legged robot to show that mechanical coupling alone can change the centralization of legged locomotion. The results of these systems span a design space of centralization and co-information for biological and robotic systems.
运动控制从弱耦合和局部集中到强耦合和全局集中，在特定的建模框架之外很难评估。我们开发了一种经验性的、无模型的集中度量方法，该方法比较了控制信号与全局状态和局部状态之间的信息。第二个度量指标，共信息量，量化了全局和局部控制的净冗余度。我们首先验证了我们的度量方法可以预测相位耦合振荡器模拟中的集中化程度。然后，我们测试了在自由跑动的蟑螂中速度变化对集中化的影响。令人惊讶的是，在所有速度下，集中化是恒定的，肌肉活动比该肌肉腿部的局部状态更能反映全局运动状态（所有腿部的平均值）。最后，我们使用一个腿式机器人来证明机械耦合本身可以改变腿式运动的集中化程度。这些系统的结果跨越了生物和机器人系统的集中化和共信息量的设计空间。
