Continuous body 3-D reconstruction of limbless animals [METHODS [amp ] TECHNIQUES]

Qiyuan Fu, Thomas W. Mitchel, Jin Seob Kim, Gregory S. Chirikjian, and Chen Li Limbless animals such as snakes, limbless lizards, worms, eels, and lampreys move their slender, long body in three dimensions to traverse diverse environments. Accurately quantifying their continuous body's 3-D shape and motion is important for understanding body-environment interaction in complex terrain, but this is difficult to achieve (especially for local orientation and rotation). Here, we describe an interpolation method to quantify continuous body 3-D position and orientation. We simplify the body as an elastic rod and apply a backbone optimization method to interpolate continuous body shape between end constraints imposed by tracked markers. Despite over-simplifying the biomechanics, our method achieves a higher interpolation accuracy (~50% error) in both 3-D position and orientation compared with the widely-used cubic B-spline interpolation method. Beyond snakes traversing large obstacles demonstrated, our method applies to other long, slender, limbless animals and continuum robots. We provide codes and demo files for easy application of our method.

Source: Journal of Experimental Biology - February 3, 2021 Category: Biology Authors: Fu, Q., Mitchel, T. W., Kim, J. S., Chirikjian, G. S., Li, C. Tags: METHODS [amp ] TECHNIQUES Source Type: research