Enhancing underwater soft robotic arms through modular multi-segment design, local hydraulic actuation and electronic sensing, and advanced control

In recent years, there has been a surge of interest in hydraulically-driven underwater soft robotic arms, particularly for delicately grasping sea creatures in marine biology research. This type of arm can be tuned to be neutrally buoyant, draw water from its environment to pressurize its actuators, and reach around obstacles to manipulate objects. Currently, the approach to constructing these robots separates the arm from its hydraulic infrastructure and electronic sensors. As more segments are added to increase length, this approach limits the flexibility, configurability, and sensor augmentation of the arm due to the increasing number of tubes and wires fed through the center of the robot. To address this challenge, a modular approach is proposed that distributes sensing and hydraulic actuation components throughout the arm at the base of each segment. This approach is explored through three projects. First, a 2D two-module underwater arm is developed with solenoid valves and pressure sensors embedded in the base of each module. Second, this 2D robot is controlled using an automatically-tuned model predictive control algorithm. Finally, the limited workspace and size of the 2D robot are addressed through the development of a six-segment hydraulically-actuated underwater soft robotic arm with a gripper attachment. This arm was tested in water and shown to be highly dexterous in grasping experiments, capable of extending and bending around obstacles to reach its target. It is also highly configurable, as modules can be added or removed in less than an hour.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Electrical & Computer Engr

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2024

Author dc:creator

• Null, W. David

Contributors dc:contributor

• Zhang, Yang
• Hauser, Kris
• Gruev, Viktor
• Kim, Joohyung

• Underwater Robotics
• Soft Robotics
• Soft Hydraulic Actuation
• Model Predictive Control

Statement dc:rights

• Copyright 2024 W. David Null

Language dc:language

en, eng

Handle dc:identifier

https://hdl.handle.net/2142/124702

OAI record oai:identifier

https://www.ideals.illinois.edu/oai-pmh?verb=GetRecord&metadataPrefix=etdms&identifier=oai%3Awww.ideals.illinois.edu%3A2142%2F124702