TALE-teller: Tendon-Actuated Linked Element Robotic Testbed for Investigating Tail Functions

TL;DR

This paper introduces TALE, a modular robotic test bed that simulates various tail morphologies to study how shape influences function, aiding in understanding biological tails and designing robotic counterparts.

Contribution

The paper presents a novel modular robotic platform, TALE, capable of replicating diverse tail morphologies to investigate their functional implications.

Findings

Different vertebral proportions affect tail bending and tip position.

Uniform joint bending results in significant differences in tail tip location.

TALE can match the morphology of real and theoretical tails for functional studies.

Abstract

Tails serve various functions in both robotics and biology, including expression, grasping, and defense. The vertebrate tails associated with these functions exhibit diverse patterns of vertebral lengths, but the precise mechanisms linking form to function have not yet been established. Vertebrate tails are complex musculoskeletal structures, making both direct experimentation and computational modeling challenging. This paper presents Tendon-Actuated Linked-Element (TALE), a modular robotic test bed to explore how tail morphology influences function. By varying 3D printed bones, silicone joints, and tendon configurations, TALE can match the morphology of extant, extinct, and even theoretical tails. We first characterized the stiffness of our joint design empirically and in simulation before testing the hypothesis that tails with different vertebral proportions curve differently. We then compared the maximum bending state of two common vertebrate proportions and one theoretical morphology. Uniform bending of joints with different vertebral proportions led to substantial differences in the location of the tail tip, suggesting a significant influence on overall tail function. Future studies can introduce more complex morphologies to establish the mechanisms of diverse tail functions. With this foundational knowledge, we will isolate the key features underlying tail function to inform the design for robotic tails. Images and videos can be found on TALE's project page: https://www.embirlab.com/tale.