Model Based Control of Soft Robots: A Survey of the State of the Art and Open Challenges

TL;DR

This survey reviews the current state and open challenges in model-based control of soft continuum robots, emphasizing the need for unified terminology and addressing intrinsic dynamic and sensing complexities.

Contribution

It provides a comprehensive overview from a control theory perspective, clarifying terminology, identifying key challenges, and outlining future research directions in soft robot control.

Findings

Highlights the variability in terminology and scientific backgrounds.

Identifies intrinsic challenges such as continuum dynamics and elastic potential fields.

Proposes a unified framework for understanding control of soft robots.

Abstract

Continuum soft robots are mechanical systems entirely made of continuously deformable elements. This design solution aims to bring robots closer to invertebrate animals and soft appendices of vertebrate animals (e.g., an elephant's trunk, a monkey's tail). This work aims to introduce the control theorist perspective to this novel development in robotics. We aim to remove the barriers to entry into this field by presenting existing results and future challenges using a unified language and within a coherent framework. Indeed, the main difficulty in entering this field is the wide variability of terminology and scientific backgrounds, making it quite hard to acquire a comprehensive view on the topic. Another limiting factor is that it is not obvious where to draw a clear line between the limitations imposed by the technology not being mature yet and the challenges intrinsic to this class of robots. In this work, we argue that the intrinsic effects are the continuum or multi-body dynamics, the presence of a non-negligible elastic potential field, and the variability in sensing and actuation strategies.