Soft Arms

The goal of this work is to develop a soft-robotic manipulation system that is capable of autonomous, dynamic, and safe interactions with humans and its environment. We provide a computational approach to whole arm planning for a soft planar manipulator that advances the arm’s end effector pose in task space while simultaneously considering the arm’s entire envelope in proximity to a confined environment. Further, we develop soft planar grasping manipulators capable of grasp-and-place operations by encapsulation with uncertainty in the position and shape of the object. 

We also develop a dynamic model for a multi-body fluidic elastomer manipulator that is composed entirely from soft rubber and subject to the self-loading effects of gravity. Then, we present a strategy for independently identifying all of the unknown components of the system. Using our model and trajectory-optimization techniques we find locally-optimal open-loop policies that allow the system to perform dynamic maneuvers.

By studying extremely soft robots, we can begin to solve hard problems inhibiting the mainstream use of soft machines.

  • [PDF] [DOI] R. K. Katzschmann, A. D. Marchese, and D. Rus, “Autonomous Object Manipulation Using a Soft Planar Grasping Manipulator,” Soft robotics, vol. 2, iss. 4, pp. 155-164, 2015.
    [Bibtex]
    @article{katzschmann2015autonomous,
    abstract = {This paper presents the development of an autonomous motion planning algorithm for a soft planar grasping manipulator capable of grasp-and-place operations by encapsulation with uncertainty in the position and shape of the object. The end effector of the soft manipulator is fabricated in one piece without weakening seams using lost-wax casting instead of the commonly used multi-layer lamination process. The soft manipulation system can grasp randomly positioned objects within its reachable envelope and move them to a desired location without human intervention. The autonomous planning system leverages the compliance and continuum bending of the soft grasping manipulator to achieve repeatable grasps in the presence of uncertainty. A suite of experiments is presented that demonstrates the system's capabilities.},
    author = {Katzschmann, Robert K and Marchese, Andrew D and Rus, Daniela},
    doi = {10.1089/soro.2015.0013},
    issn = {2169-5172},
    journal = {Soft Robotics},
    mendeley-groups = {Soft Grasping},
    month = {dec},
    number = {4},
    pages = {155--164},
    publisher = {Mary Ann Liebert, Inc. 140 Huguenot Street, 3rd Floor New Rochelle, NY 10801 USA},
    title = {{Autonomous Object Manipulation Using a Soft Planar Grasping Manipulator}},
    url = {http://online.liebertpub.com/doi/10.1089/soro.2015.0013},
    volume = {2},
    year = {2015}
    }
  • [PDF] [DOI] A. D. Marchese, R. K. Katzschmann, and D. Rus, “Whole Arm Planning for a Soft and Highly Compliant 2D Robotic Manipulator,” in Intelligent robots and systems (iros), 2014 ieee/rsj international conference on, 2014, pp. 554-560.
    [Bibtex]
    @inproceedings{marchese2014whole,
    abstract = {Soft continuum manipulators have the advantage of being more compliant and having more degrees of freedom than rigid redundant manipulators. This attribute should allow soft manipulators to autonomously execute highly dexterous tasks. However, current approaches to motion planning, inverse kinematics, and even design limit the capacity of soft manipu- lators to take full advantage of their inherent compliance. We provide a computational approach to whole arm planning for a soft planar manipulator that advances the arm's end effector pose in task space while simultaneously considering the arm's entire envelope in proximity to a confined environment. The algorithm solves a series of constrained optimization problems to determine locally optimal inverse kinematics. Due to inherent limitations in modeling the kinematics of a highly compliant soft robot and the local optimality of the planner's solutions, we also rely on the increased softness of our newly designed manipulator to accomplish the whole arm task, namely the arm's ability to harmlessly collide with the environment. We detail the design and fabrication of the new modular manipulator as well as the planner's central algorithm. We experimentally validate our approach by showing that the robotic system is capable of autonomously advancing the soft arm through a pipe-like environment in order to reach distinct goal states.},
    author = {Marchese, Andrew D and Katzschmann, Robert K and Rus, Daniela},
    booktitle = {Intelligent Robots and Systems (IROS), 2014 IEEE/RSJ International Conference on},
    doi = {10.1109/IROS.2014.6942614},
    isbn = {9781479969340},
    issn = {21530866},
    pages = {554--560},
    publisher = {IEEE},
    title = {{Whole Arm Planning for a Soft and Highly Compliant 2D Robotic Manipulator}},
    year = {2014}
    }
  • [PDF] [DOI] A. D. Marchese, R. K. Katzschmann, and D. Rus, “A Recipe for Soft Fluidic Elastomer Robots,” Soft robotics, vol. 2, iss. 1, pp. 7-25, 2015.
    [Bibtex]
    @article{marchese2015recipe,
    abstract = {This work provides approaches to designing and fabricating soft fluidic elastomer robots. That is, three viable actuator morphologies composed entirely from soft silicone rubber are explored, and these morphologies are differentiated by their internal channel structure, namely, ribbed, cylindrical, and pleated. Additionally, three distinct casting-based fabrication processes are explored: lamination-based casting, retractable-pin-based casting, and lost-wax-based casting. Furthermore, two ways of fabricating a multiple DOF robot are explored: casting the complete robot as a whole and casting single degree of freedom (DOF) segments with subsequent concatenation. We experimentally validate each soft actuator morphology and fabrication process by creating multiple physical soft robot prototypes.},
    author = {Marchese, Andrew D and Katzschmann, Robert K and Rus, Daniela},
    doi = {10.1089/soro.2014.0022},
    issn = {2169-5172},
    journal = {Soft Robotics},
    number = {1},
    pages = {7--25},
    title = {{A Recipe for Soft Fluidic Elastomer Robots}},
    url = {http://online.liebertpub.com/doi/10.1089/soro.2014.0022},
    volume = {2},
    year = {2015}
    }

Link to Soft Manipulator Arms at the Distributed Robotics Laboratory, CSAIL, MIT