Session: 16-01-01: Government Agency Student Poster Competition

Paper Number: 150786

150786 - Enabling Robust and Reconfigurable Modular Soft Robots With a Switchable Magnetic Connector Design 

Soft and continuum robots offer advantages over traditional multi-joint rigid manipulators in challenging environments where physical interaction between the body of the robot and its surroundings is necessary but uncertain. Modular approaches to robot design, on the other hand, can support adaptability and reconfigurability according to the environment and the task. Modular approaches to soft robot design, including the introduction of some “hard” components, may allow for the best features of each design approach.  We are exploring a novel design approach combining self-contained modular segments, some rigid and some soft, with an included magnetic connection mechanism for easy and practical reconfiguration of the modules. The strategy of combining modules, each of which possesses a different stiffness or variable stiffness capability, offers significant opportunities in terms of the ability to achieve more complex shapes in soft robot designs. By utilizing the novel design approach, the modular robots can transform from one topological shape to another for improved adaptability to environments which may vary over time and space. The modular design provides the opportunity for the segments to share sensory information and to allow the segments to implement compensation strategies for locomotion in case of a faulty module. The modules can collaborate to produce optimal locomotion and navigation strategies which may include topological reconfiguration.  In this work, we present a soft module design aimed at enabling the goal of such a highly reconfigurable, adaptable, and robust hybrid rigid-soft robot. The tendon-driven continuum robot-based module design enables a large range of mechanical stiffnesses to facilitate a variety of applications, permitting both soft interaction and stable operation under load. The requirements for the module are that it be a slender tentacle-like segment, have a self-contained power source and control system, wireless inter-module communication capability, and a means of connecting and disconnecting from other modules at its two ends which is hermetically sealed and contains no moving parts at the connector interface to prevent the ingress of contaminants that could degrade the system performance over time in harsh environments. For the connector, we present the design of a Switchable Magnetic Connector (SMAC). The design of the SMAC includes a permanent magnetic core and a closed, high-permeability magnetic circuit to ensure a high pull force and secure connection. An electric circuit integrated into the magnetic circuit allows for the temporary demagnetization of the device to enable controlled disconnection without excessive force. The magnetic connector ensures that modules become rigidly attached, with the ability to provide both reaction forces and torques.  Simplified mathematical models and magnetostatic finite element models are used to optimize the design dimensions and materials of the magnetic connector according to the design requirements. An experimental characterization demonstrates the feasibility of the SMAC. For the soft body of the modular segment, we describe a three-dimensional tendon decoupling strategy that allows for straightforward displacement-based control of tendon-driven continuum segments and variable stiffness. An experimental demonstration of this concept validates the design approach and characterizes the range of achievable stiffnesses in the variable stiffness design.

Presenting Author: Setayesh Yavari Louisiana State University

Presenting Author Biography: Setayesh Yavari completed her Bachelor's degree in Aerospace Engineering from Khajeh Nasir Toosi University of Technology, in May 2023. She is currently pursuing a Ph.D. degree in Mechanical Engineering at Louisiana State University. Her research focuses on soft robotics and modeling of continuum robots and medical devices.

Authors:

Setayesh Yavari Louisiana State University
Sunella Ramnath Louisiana State University
Parsa Molaei Louisiana State University
Hunter Gilbert Louisiana State University