Caterpillar Locomotion

Robots inspired by caterpillar locomotion

The proper functioning of a robot is carried out by a series of tasks to be executed by the robot. The most apt way would be to design a robot who would be as efficient as humans i.e. with continuous body tissues made of a suitable material. But the accessory computation of each unit of material would be too high to handled.

So the most suitable way would be break down the movement process to segments i.e. a broader unit, primarily inspired by animals and insect we see around us.

A look into the concept of locomotion in caterpillars would be of great help owing to it’s soft-bodied, flexible nature with no rigid skeleton at all. This leads us to the concept of Softbot which is a robot which is deformable

Figure (A)

Caterpillars are some of the best evolved herbivores in the art of climbing and traversing their way in the smallest and narrowest of areas on Earth. Their coordinated crawling mechanism[ explained by the Figure (A)] is distinct and superior to that of the bouncy nature of crawling mechanism of most animals out there. Caterpillars have passive grips to hold on to complex branched structures and have the ability to shape themselves in a number of ways as they aren’t limited by a rigid body structure unlike other animals out there.

They have the ability to vary tension in various parts of their body and can traverse across narrow areas and openings that are just 10% less than their own body length.

Figure (B)

There have been many attempts at making a flexible design for an elastomeric membrane which can deform, twist and crawl based on peristalsis, conformable wheels and a continuous bending elements. T common disadvantage being that they are confined to work in a specific environment.

Our best shot? Figure (C

Caterpillars have a variation in kinematics at the posterior and the mid-body. These both areas undergo an inharmonic cyclic compression consistent with storage and viscoelastic energy. The ventral and dorsal part of the individual segments vary in length in each phase and it is further inferred that the mechanics occur due to membranes between the segments. The radii and extension length of each segment varies so as to coordinate with the other segments. At the same time segment volumes are not conserved during motion so as to allow motion of bodily fluids. These activities are largely governed by local biomechanical and proprioceptive events.

The Softbot concept under research by https://www.researchgate.net/publication/228745181_Caterpillar_locomotion_A_new_model_for_soft-bodied_climbing_and_burrowing_robots [accessed Oct 21 2017].

They implemented circular and longitudinal “muscles” used in most worm-like designs, Softbot has discrete groups of actuators modeled on those of the caterpillar. Release of pressure allows the robot to collapse and compress into a freeform volume limited only by the payload size. The design is supposed to be highly scalable and could be miniaturized very easily. Implementing a set of passive grip/active release, opposable legs capable of gripping flat surfaces, irregular