Topology Optimized Design, Fabrication, and Characterization of a Soft Cable-Driven Gripper

Soft-bodied robots, due to their intrinsic compliance, have shown great potential for operating within unstructured environment and interacting with unknown objects. This letter deals with automatic design and fabrication of soft robots. From a structure point of view, we synthesize a soft cable-driven gripper by recasting its mechanical design as a topology optimization problem. Building on previous work on compliant mechanism optimization, we model the interactions between the gripper and objects more practically, in form of pressure loadings and friction tractions, and furthermore, we investigate how the interaction uncertainties affect the optimization solution by varying the contact location and area. The optimized soft fingers were three-dimensionally printed and then assembled to build a gripper. The experiments show that the gripper can handle a large range of unknown objects of different shapes and weights (up to 1 kg), with different grasping modes. This letter represents an important step toward leveraging the full potential of the freeform design space to generate novel soft-bodied robots.

[1]  Ole Sigmund,et al.  On the Design of Compliant Mechanisms Using Topology Optimization , 1997 .

[2]  Xiaoming Wang,et al.  A level set method for structural topology optimization , 2003 .

[3]  YapHong Kai,et al.  High-Force Soft Printable Pneumatics for Soft Robotic Applications , 2016 .

[4]  Matthew A. Robertson,et al.  New soft robots really suck: Vacuum-powered systems empower diverse capabilities , 2017, Science Robotics.

[5]  Lin Cao,et al.  Integrated Design of Compliant Mechanisms and Embedded Rotary Actuators and Bending Actuators for Motion Generation , 2016 .

[6]  CianchettiMatteo,et al.  A Bioinspired Soft Robotic Gripper for Adaptable and Effective Grasping , 2015 .

[7]  D. Rus,et al.  Design, fabrication and control of soft robots , 2015, Nature.

[8]  Hao Jiang,et al.  A two-level approach for solving the inverse kinematics of an extensible soft arm considering viscoelastic behavior , 2017, 2017 IEEE International Conference on Robotics and Automation (ICRA).

[9]  Michael Yu Wang,et al.  Shape and topology optimization of compliant mechanisms using a parameterization level set method , 2007, J. Comput. Phys..

[10]  Metin Sitti,et al.  GeckoGripper: A soft, inflatable robotic gripper using gecko-inspired elastomer micro-fiber adhesives , 2014, 2014 IEEE/RSJ International Conference on Intelligent Robots and Systems.

[11]  C. Walsh,et al.  Biomechanical and Physiological Evaluation of Multi-Joint Assistance With Soft Exosuits , 2017, IEEE Transactions on Neural Systems and Rehabilitation Engineering.

[12]  Zhan Kang,et al.  Topological design of compliant smart structures with embedded movable actuators , 2014 .

[13]  G. Allaire,et al.  Structural optimization using sensitivity analysis and a level-set method , 2004 .

[14]  J. Sethian,et al.  Fronts propagating with curvature-dependent speed: algorithms based on Hamilton-Jacobi formulations , 1988 .

[15]  Hod Lipson,et al.  Automatic Design and Manufacture of Soft Robots , 2012, IEEE Transactions on Robotics.

[16]  M. Bendsøe,et al.  Generating optimal topologies in structural design using a homogenization method , 1988 .

[17]  Jian Zhu,et al.  A Soft Jellyfish Robot Driven by a Dielectric Elastomer Actuator , 2016, IEEE Robotics and Automation Letters.

[18]  WangMichael Yu,et al.  Multi-Axis Soft Sensors Based on Dielectric Elastomer , 2016 .

[19]  Zhan Kang,et al.  Robust shape and topology optimization considering geometric uncertainties with stochastic level set perturbation , 2017 .

[20]  Y. Xie,et al.  A simple evolutionary procedure for structural optimization , 1993 .

[21]  Oliver Brock,et al.  A novel type of compliant and underactuated robotic hand for dexterous grasping , 2016, Int. J. Robotics Res..

[22]  Yang Zheng,et al.  Topology optimization of a fully compliant prosthetic finger: Design and testing , 2016, 2016 6th IEEE International Conference on Biomedical Robotics and Biomechatronics (BioRob).

[23]  Arend L. Schwab,et al.  Toward a Unified Design Approach for Both Compliant Mechanisms and Rigid-Body Mechanisms: Module Optimization , 2015 .

[24]  Daniel M. Bodily,et al.  Multi-objective design optimization of a soft, pneumatic robot , 2017, 2017 IEEE International Conference on Robotics and Automation (ICRA).

[25]  G. Whitesides,et al.  Buckling of Elastomeric Beams Enables Actuation of Soft Machines , 2015, Advanced materials.

[26]  Allison M. Okamura,et al.  A soft robot that navigates its environment through growth , 2017, Science Robotics.

[27]  Chih-Hsing Liu,et al.  Optimal design of a soft robotic gripper with high mechanical advantage for grasping irregular objects , 2017, 2017 IEEE International Conference on Robotics and Automation (ICRA).

[28]  Ivonne Sgura,et al.  Fitting hyperelastic models to experimental data , 2004 .

[29]  Michael Yu Wang,et al.  Topology optimization of hyperelastic structures using a level set method , 2017, J. Comput. Phys..

[30]  Lorenzo Natale,et al.  A grasping approach based on superquadric models , 2017, 2017 IEEE International Conference on Robotics and Automation (ICRA).

[31]  Kyung K. Choi,et al.  Structural Sensitivity Analysis and Optimization 1: Linear Systems , 2005 .

[32]  Shinichi Hirai,et al.  Soft Gripper Dynamics Using a Line-Segment Model With an Optimization-Based Parameter Identification Method , 2017, IEEE Robotics and Automation Letters.

[33]  Wenjun Xu,et al.  Automate surgical tasks for a flexible Serpentine Manipulator via learning actuation space trajectory from demonstration , 2016, 2016 IEEE International Conference on Robotics and Automation (ICRA).

[34]  N. Chaillet,et al.  Mechanical and Control-Oriented Design of a Monolithic Piezoelectric Microgripper Using a New Topological Optimization Method , 2009, IEEE/ASME Transactions on Mechatronics.

[35]  Yang Liu,et al.  Topology design of a conforming gripper with distributed compliance via a level set method , 2014, 2014 IEEE International Conference on Robotics and Biomimetics (ROBIO 2014).

[36]  Lei Zhang,et al.  Networked soft actuators with large deformations , 2017, 2017 IEEE International Conference on Robotics and Automation (ICRA).

[37]  Michael Yu Wang,et al.  Design of multimaterial compliant mechanisms using level-set methods , 2005 .

[38]  Robert J. Wood,et al.  An integrated design and fabrication strategy for entirely soft, autonomous robots , 2016, Nature.