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Wei-Hsi Chen’s Kinegami paper receives Honorable Mention for 2023 TRO Best Paper Award

Congratulations to Wei-Hsi Chen, Woohyeok Yang, and Lucien Peach for receiving honorable mention for the 2023 IEEE Transactions on Robotics King-Sun Fu Memorial Best Paper Award for their paper

Wei-Hsi Chen, Woohyeok Yang, Lucien Peach, Daniel E. Koditschek, Cynthia R. Sung: Kinegami: Algorithmic Design of Compliant Kinematic Chains From Tubular Origami. In: IEEE Transactions on Robotics, vol. 39, iss. 2, pp. 1260-1280, 2023, (Honorable mention for 2023 IEEE Transactions on Robotics King-Sun Fu Memorial Best Paper Award).

Abstract: Origami processes can generate both rigid and compliant structures from the same homogeneous sheet material. In this article, we advance the origami robotics literature by showing that it is possible to construct an arbitrary rigid kinematic chain with prescribed joint compliance from a single tubular sheet. Our “Kinegami” algorithm converts a Denavit–Hartenberg specification into a single-sheet crease pattern for an equivalent serial robot mechanism by composing origami modules from a catalogue. The algorithm arises from the key observation that tubular origami linkage design reduces to a Dubins path planning problem. The automatically generated structural connections and movable joints that realize the specified design can also be endowed with independent user-specified compliance. We apply the Kinegami algorithm to a number of common robot mechanisms and hand-fold their algorithmically generated single-sheet crease patterns into functioning kinematic chains. We believe this is the first completely automated end-to-end system for converting an abstract manipulator specification into a physically realizable origami design that requires no additional human input.

Three papers to be presented at RoboSoft

Shivangi Misra, Chris Kim, and Rongqian Chen will be sharing their work at RoboSoft this year!

Shivangi Misra, Cynthia Sung: Online Optimization of Soft Manipulator Mechanics via Hierarchical Control. 7th IEEE-RAS International Conference on Soft Robotics (RoboSoft), 2024.

Abstract: Actively tuning mechanical properties in soft robots is now feasible due to advancements in soft actuation technologies. In soft manipulators, these novel actuators can be distributed over the robot body to allow greater control over its large number of degrees of freedom and to stabilize local deformations against a range of disturbances. In this paper, we present a hierarchical policy for stiffness control for such a class of soft manipulators. The stiffness changes induce desired deformations in each segment, thereby influencing the manipulator’s end-effector position. The algorithm can be run as an online controller to influence the manipulator’s stable states – as we demonstrate in simulation – or offline as a design algorithm to optimize stiffness distributions – as we showcase in a hardware demonstration. Our proposed hierarchical control scheme is agnostic to the stiffness actuation method and can extend to other soft manipulators with nonuniform stiffness distributions.

Christopher Kim, Lele Yang, Ashwath Anbuchelvan, Raghav Garg, Niv Milbar, Flavia Vitale, Cynthia Sung: Origami-Inspired Bistable Gripper with Self-Sensing Capabilities. IEEE-RAS International Conference on Soft Robotics (Robosoft), 2024.

Abstract: An origami-inspired bistable gripper, featuring a dual-function custom PET linear solenoid actuator that acts both as an actuator and a sensor, is presented. Movements in the permanent magnet plunger, which is directly mounted to the gripper, create induced electromotive force (emf) in the solenoid, and these induced emf measurements are used to detect snap-through actions and light contacts on the gripper. The fabrication methods for the gripper, actuator, and a gel-free soft wearable EMG electrode are outlined, and the actuator’s self-sensing method utilizing the time-integral of the induced emf measurements are explored. Because a self-sensing actuator eliminates the need for extra sensors, it allows for further miniaturization of the robot while maintaining its compactness and lightweight design. The paper also introduces a full human-in-the-loop system, allowing users to open or close the gripper with their biceps via a wearable EMG electrode. This system bridges human intent with robotic action, offering a more intuitive interaction model for robotic control.

Rongqian Chen, Jun Kwon, Wei-Hsi Chen, Cynthia Sung: Design and Characterization of a Pneumatic Tunable-Stiffness Bellows Actuator. IEEE-RAS International Conference on Soft Robotics (RoboSoft), 2024.

Abstract: We introduce a self-contained pneumatic actuator capable of 1.43 times stiffness gain from 1332 N/m to 1913 N/m without needing an external air source or valve. The design incorporates an air chamber bellows and a spring bellows, connected and sealed. Stiffness modulation is achieved by altering the air chamber volume. We present an approach for computing the volume, pressurized force, and stiffness of a single bellows component, as well as methods for composing single bellows models to predict the change in stiffness of the dual bellows actuator as a function of air chamber compression. We detail the fabrication of the actuator and verify the models on the fabricated prototype. This actuator holds promise for future integration in tunable stiffness robots demanding high strength and adaptability in dynamic scenarios.