Design, kinematics, and control of a soft spatial fluidic elastomer manipulator

• Published in: The International journal of robotics research Vol. 35; no. 7; pp. 840 - 869
• Main Authors: Marchese, Andrew D., Rus, Daniela
• Format: Journal Article
• Language: English
• Published: London, England SAGE Publications 01-06-2016; SAGE PUBLICATIONS, INC
• Subjects: Actuation; Automation; Circuits; Continuously variable; Control algorithms; Control theory; Curvature; Cylinders; Deformation; Elastomers; Fluidics; Kinematics; Manipulators; Manufacturing engineering; Modular design; Robot arms; Robots; Static deformation; Trajectories; design and control; Flexible arms; human-centered and life-like robotics; dexterous manipulation; mechanics; manipulation; biologically-inspired robots
• ISSN: 0278-3649; 1741-3176
• DOI: 10.1177/0278364915587925

This paper presents a robotic manipulation system capable of autonomously positioning a
multi-segment soft fluidic elastomer robot in three dimensions. Specifically, we present
an extremely soft robotic manipulator morphology that is composed entirely from low
durometer elastomer, powered by pressurized air, and designed to be both modular and
durable. To understand the deformation of a single arm segment, we develop and
experimentally validate a static deformation model. Then, to kinematically model the
multi-segment manipulator, we use a piece-wise constant curvature assumption consistent
with more traditional continuum manipulators. In addition, we define a complete
fabrication process for this new manipulator and use this process to make multiple
functional prototypes. In order to power the robot’s spatial actuation, a high capacity
fluidic drive cylinder array is implemented, providing continuously variable,
closed-circuit gas delivery. Next, using real-time data from a vision system, we develop a
processing and control algorithm that generates realizable kinematic curvature
trajectories and controls the manipulator’s configuration along these trajectories.
Lastly, we experimentally demonstrate new capabilities offered by this soft fluidic
elastomer manipulation system such as entering and advancing through confined
three-dimensional environments as well as conforming to goal shape-configurations within a
sagittal plane under closed-loop control.