Animals move very differently from rigid robots, performing dynamic tasks efficiently, and interacting robustly, compliantly, and continuously with the external world through their body's elasticity.  With the aim of getting closer to animals’ performance, elastic elements are purposefully introduced in the mechanical structure of soft robots. When it comes to compliant control systems, however, it turns out that achieving performance is not at all easier. This fact is intuitive for such measures of performance as positional accuracy, which is the reason industrial robots have traditionally been built for maximum rigidity.

Articulated soft robots [1,6] have rigid bodies and elastic joints with either constant or variable impedance. Their source of inspiration is the vertebrate part of the animal kingdom. Model-based control of articulated soft robots is a relatively mature research field, with both theoretical and practical results showing how soft robots can outperform classical rigid robots in various applications [2,3,4,5,7,10]. However, many problems remain unsolved, for example how to properly design feedback controllers without altering the natural softness of the robot [9], or how to efficiently excite the robot’s natural dynamics [8], just to cite a few.

In contrast, soft-bodied robots [15] are primarily inspired by the invertebrate world. Their structure is continuously deformable, and typically composed by innovative materials. These characteristics make the derivation of accurate and tractable dynamic models quite challenging. While the lack of tractable models prevents the direct application of classical control theory to the control of these kind of robots, it also pushes researchers to find innovative solutions to control these soft-bodied robots [11,12,13,14,16,20,23,24,25].

Despite a common origin, which is the inspiration from nature, the two fields emerged at different times and grew separately. This workshop has the objective to bring both fields together by fostering the discussion and exchange on the similarities and differences in modeling and controlling robots that have in common their inherent compliance.

Notably, in recent years great progress has been achieved in developing dynamic models approximating the behavior of continuously deformable soft robots [17,18,19,21,22]. We believe that speakers on that topic area will help define a common ground between the two worlds, allowing for a better understanding of the challenges in representing soft robot dynamics, and providing inspiration to develop new control approaches.

To conclude, the main aim of the workshop is to inspire new approaches in modeling and controlling of soft robots. We will bring together recognized experts in both modeling and control of soft robots, trying to answer questions such as: to which extent techniques and principles developed for articulated soft robots can be extended to the control of continuously deformable soft robots? In return, what methods developed for soft-bodied robots find application in the other field? What are the remaining problems that will require a specific treatment and analysis? Which are the new challenges in these fields? Selected experts will give talks on the relevant topics. A final open discussion session will review and analyze all the insights presented during the workshop, aiming at fostering discussions between different areas of expertise. The organization of a special issue in IJRR is planned to present the outcome of these discussions.