Meeting Abstract
Undulatory locomotion is ubiquitous among soft-bodied animals and it inspires novel robot designs. However, manufacturing flexible robots is not straightforward due to technological constraints. Compared to their biological counterparts with high degrees of freedom, robots need to navigate around with a limited number of actuators. To bridge the gap between biology and engineering, we present a novel approach to identify the minimum number of segments required to describe the body movements of undulatory animals accurately. We use a kinematic chain model which consists of a series of linear segments with connected joints. We use empirical data and least square methods to automatically estimate the model parameters (i.e. number and position of joints) so that the difference between predicted and measured motion is minimized. We tested our approach to describe the midline kinematics of 10 fish species with varying body length (L), morphology and flexibility during steady swimming (up to 5 L s-1). Our preliminary results indicate that the minimum number of segments that can describe the midline kinematics with 95% accuracy vary significantly between species (e.g. five segments for Northern barracuda, Sphyraena borealis, and ten segments for Clown knifefish, Chitala ornata). The position of the most anterior joint (connecting segment one and two) also varies between species (e.g. 0.5 L for barracuda and 0.2 L for knifefish). The goal of this research is to develop an analytical tool that describes animal movements with parsimonious kinematic models. These models can be used by biologists to quantify movement capability of animals, by roboticists to enhance the design of underactuated robots, and by software engineers to generate realistic animal movements for computer simulations.
