Mechanical Intelligence Simplifies Control in Terrestrial Limbless Locomotion
arXiv:2304.08652 · doi:10.1126/scirobotics.adi2243
Abstract
Limbless locomotors, from microscopic worms to macroscopic snakes, traverse complex, heterogeneous natural environments typically using undulatory body wave propagation. Theoretical and robophysical models typically emphasize body kinematics and active neural/electronic control. However, we contend that because such approaches often neglect the role of passive, mechanically controlled processes (those involving "mechanical intelligence"), they fail to reproduce the performance of even the simplest organisms. To uncover principles of how mechanical intelligence aids limbless locomotion in heterogeneous terradynamic regimes, here we conduct a comparative study of locomotion in a model of heterogeneous terrain (lattices of rigid posts). We used a model biological system, the highly studied nematode worm Caenorhabditis elegans, and a robophysical device whose bilateral actuator morphology models that of limbless organisms across scales. The robot's kinematics quantitatively reproduced the performance of the nematodes with purely open-loop control; mechanical intelligence simplified control of obstacle navigation and exploitation by reducing the need for active sensing and feedback. An active behavior observed in C. elegans, undulatory wave reversal upon head collisions, robustified locomotion via exploitation of the systems' mechanical intelligence. Our study provides insights into how neurally simple limbless organisms like nematodes can leverage mechanical intelligence via appropriately tuned bilateral actuation to locomote in complex environments. These principles likely apply to neurally more sophisticated organisms and also provide a design and control paradigm for limbless robots for applications like search and rescue and planetary exploration.
arXiv commentPublished in Science Robotics
References in corpus (12)
- Structural Properties of the Caenorhabditis elegans Neuronal Network
- Dimensionality and dynamics in the behavior of C. elegans
- Whole-brain calcium imaging with cellular resolution in freely behaving C. elegans
- A review on locomotion robophysics: the study of movement at the intersection of robotics, soft matter and dynamical systems
- Geometric visualization of self-propulsion in a complex medium
- Robotic modeling of snake traversing large, smooth obstacles reveals stability benefits of body compliance
- Coordinating tiny limbs and long bodies: geometric mechanics of diverse undulatory lizard locomotion
- Directional Compliance in Obstacle-Aided Navigation for Snake Robots
- The dynamics of scattering in undulatory active collisions
- Optimal Gaits for Drag-dominated Swimmers with Passive Elastic Joints
- Efficient sliding locomotion with isotropic friction
- Geometric phase predicts locomotion performance in undulating living systems across scales