Date of Award

8-2023

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Electrical Engineering

Committee Chair/Advisor

Ian D. Walker

Committee Member

Richard E. Groff

Committee Member

Adam W. Hoover

Committee Member

Prasad R. Rangaraju

Abstract

This dissertation makes new contributions to the modeling and implementation of Tendon Driven Continuum Robots (TDCRs). Specifically, motivated by 3D printing of concrete using a continuum hose robot in construction applications, we focus on TDCRs featuring compliance in the robot backbone and actuating tendons, e.g. surgical robots/endoscopes/catheters with tendon actuation. We expand previous mechanics-based models to show how and why such compliance significantly restricts performance when traditional kinematics-based planning and control techniques are applied.

The main contribution of this work is a new Elasticity Compensation(EC) model that explains why the ad hoc approach of preloading/pretensioning the tendons compensates for compliance by providing an analytical expression for the minimum preload required for accurate spatial bending of compliant TDCRs. The EC model, which is used to control tendon lengths and does not require either tendon tension sensing or computationally expensive dynamics or statics (Cosserat rod) modeling, is demonstrated on a TDCR in concrete printing experiments, and is shown to be a significant improvement over the state of the art. Additionally, we augment the performance of the EC model using closed loop control with quaternion feedback from an IMU.

Available for download on Saturday, August 31, 2024

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