Control-Oriented Modeling for Bend Propagation

Stereotypical maneuvers of octopus arms has elicited much recent interest from biologists and engineers alike. The most canonical of these maneuvers is the bend propagation where the octopus propagates (pushes) the bend from the base of the arm to the tip of the arm.

While the computational models are useful to investigate the physics of the problem, it is difficult to use these for the purposes of control design. In part due to the unavailability of suitable control-oriented models, there is no control-theoretic understanding of the traveling wave of muscle activation profile (e.g., whether it is optimal in some way). This motivates the work described in this paper which is to develop a control-oriented reduced order model.

Experimental data analysis

We recover the smooth arm and curvature profiles from images frames of recorded video using a data smoothing algorithm. The characteristics of the bend propagation movement is that the curvature has a bell shape which travels from the initial bend to the tip of the arm.

Model reduction - parameterization of curvature (Gaussian-like function)

Bend propagation motion comparison

Publication

T. Wang, U. Halder, E. Gribkova, M. Gazzola, and P.G., Mehta, "Control-oriented modeling of bend propagation in an octopus arm," in 2022 American Control Conference (ACC). IEEE, 2022, pp. 1359-1366. [DOI] (Poster)