Design and Modeling of Anchoring Segments of Burrowing Hydraulic Soft Robots

Abstract

Many of today’s utilities, such as water, sewage, and telecommunication, use underground tunneling and excavation to install these services. Current methods of installation and repair, primarily trench excavation and directional boring, are costly and disruptive. No compact system exists that addresses the need for an efficient, high-force burrowing mechanism. This research into a soft robot burrowing solution seeks to prove the hypothesis that a power-dense, hydraulic system can be utilized to generate the high forces required in confined-space burrowing. The proposed design is a multi-segment robot that utilizes biomimicry and the peristaltic motion of an earthworm. Two ballooning segments will generate anchoring forces by radially compressing the surrounding soil substrate, balancing the force from an extending segment moving the robot’s head forward to form the burrow. This particular research focused on the design, modeling, and optimization of the traction segments of the robot. Various concepts for actuator geometry and manufacturing approaches were examined. Prototypes were tested to determine hydraulic operating pressures and to validate initial traction models in a rigid tube. Iterative actuator design framework and modeling of gait kinematics will be used to validate this type of robot for future applications, including utility installation and underwater anchoring.