Biomimetic Centering Behavior for Undulatory Robots∗

Substantial work exists in the robotics literature on the mechanical design, modeling, gait generation and implementation of undulatory robotic prototypes. However, there appears to have been relatively limited work on closing the control loop, for such robotic locomotors, using sensory information from exteroceptive sensors, thus leading to more complex reactive undulatory behaviors. This paper considers a biologically-inspired sensor-based centering behavior for undulatory robots; such behaviors have been observed and studied in bees, and robotic analogs were originally developed for nonholonomic mobile robots. Adaptation to the significantly more complex dynamics of undulatory locomotors highlights a number of issues related to the use of sensors (possibly distributed over the elongated body of the mechanism) for the generation of reactive undulatory behaviors, to biomimetic neuromuscular control and to formation control of multi-undulatory swarms. These issues are explored in simulation via computational tools specifically geared towards undulatory locomotion in robotics and biology. A series of undulatory robotic prototypes has been developed, which are able to propel themselves on hard floor, on foam elastic material, on sand, etc., both in eel-like and in polychaete-like undulatory modes. These prototypes have been equipped with infrared distance sensors, and are used to demonstrate experimentally the undulatory centering behavior in several corridor-like environments.