Doctor of Philosophy (PhD), Ohio University, 2018, Mechanical and Systems Engineering (Engineering and Technology)

Cable-Suspended Parallel Robots (CSPRs) are a class of devices that use three or more winch-activated cables to manipulate an end-effector within a workspace. A distinct advantage of CSPRs is that large payloads can be manipulated over distances that encompass a very large workspace. The application motivating this research (among other commercial applications) is harvesting algae which is commonly used in bioplastics, nutraceuticals, and biofuels. Harvesting algae from one to four acre circulating pond systems is done at significant cost, because it involves pumping the pond water to a centrifuge/filtration system to collect concentrated algae, before transporting it to a central processing location. Thus, an outcome of this research is to collect data using a prototype CSPR system with and without the assistance of GPS corrections to assess the next steps in developing this technology and support cost reductions in commercial algae harvesting. The research presented herein focuses on the requisite precision and accuracy required by the end-effector for this application. To meet these requirements, a unique control scheme incorporating Real Time Kinematics (RTK) and a Global Positioning System (GPS) was developed to significantly improve CSPR positioning. A 1/500th scale prototype CSPR system using RTK and GPS was developed for this research. The system consists of four towers equipped with a central controller and distributed motors and drivers connected via EtherCAT, a high-speed network. A series of tests were performed to demonstrate feasibility and performance of this unique control concept that uses RTK-GPS positional data to correct and improve end-effector positioning. The performance of the CSPR (without RTK-GPS) was first characterized in a well-controlled, indoor environment using a Coordinate Measuring Machine (CMM) with a single point accuracy of 0.001 inch. Subsequent tests were performed outdoors, with and without RTK-GPS activation. For all outdoor (open full item for complete abstract)

Committee: Robert Williams (Advisor); David Bayless (Committee Member); Frank Kraft (Committee Member); Natalie Kruse Daniels (Committee Member); Morgan Vis-Chiasson (Committee Member) Subjects: Alternative Energy; Engineering; Mechanical Engineering; Robotics; Robots

Doctor of Philosophy, The Ohio State University, 1986, Graduate School

Committee: Not Provided (Other) Subjects: Engineering

Doctor of Philosophy, Case Western Reserve University, 2017, EECS - Electrical Engineering

This thesis focuses on design, modeling, and analysis of a magnetically actuated robotic intravascular catheter for performing atrial fibrillation ablation under magnetic resonance imaging guidance. Specifically: A three dimensional deflection model of a steerable catheter in free space is proposed and experimentally validated using a hardware prototype. In the proposed method, the catheter is modeled as a series of finite segments. For each finite segment, a quasi-static torque-deflection equilibrium equation is calculated using the beam theory. By using the deflection displacements and torsion angles, the kinematic model of the catheter is derived. A Jacobian-based iterative inverse kinematics method for controlling the steerable catheter is presented. The repeatability and accuracy of the open-loop control of the catheter system performing complex geometric trajectories using this inverse kinematics method is experimentally evaluated. The proposed three dimensional kinematic model is extended to incorporate the catheter-surface contact by taking contact forces and torques into account. A systematic approach to the design optimization of a magnetically-actuated steerable catheter for atrial fibrillation ablation in the left atrium, is proposed. The study investigates the relationship between the catheter material and the catheter's steering performance and evaluates the design optimization of the electromagnetic coils, such as the optimal winding turns for the coils, the optimal size for the side coils and the optimal locations of the coil sets on the catheter. The selected design is validated on a simulated atrial fibrillation ablation in a realistic left atrium model. The simulation verifies that the catheter is successfully able to reach every target on the circumferential lesions.

Committee: Murat Cavusoglu Dr. (Committee Chair); Wyatt Newman Dr. (Committee Member); Mark Griswold Dr. (Committee Member); Vira Chankong Dr. (Committee Member); Francis Merat Dr. (Committee Member) Subjects: Robotics; Robots

Doctor of Philosophy (Ph.D.), University of Dayton, 2015, Electrical Engineering

Motion planning of robotic arms in a cluttered environment is a computationally challenging task especially with increased number of Degrees of Freedom (DOF). Path planning and execution are two key aspects of autonomous behavior of robots. The operating environment produces great challenges in the form of obstacles which require collision avoidance between them and robot arms. Additionally, an optimal behavior is always desired in terms of energy spent, path distance or time of travel. The optimal behavior of the robots depends on the kinematics of the arm, the task to be performed, the environment it is operating in and the obstacles that needs to be encountered. Computation efficiency is very critical while operating in dynamic environments. In this thesis, we present a novel path planning algorithm based on optimal control technique that searches for a path of manipulator in the free operational space that models the kinematics of the world. This path planner takes in the starting and target configuration from the novel real-time Inverse Kinematics (IK) algorithm developed for a general (2n+1) DOF manipulator arm. The IK algorithm uses an optimization procedure based on obstacle avoidance criterion, to produce a joint configuration for a given End Effector (EE) position and orientation defined by the task. The path planner operates on this, producing path points that not only keeps the entire arm free of collision with every obstacle in the workspace but also is optimal in terms of the additional constraints. The results are simulated and implemented on a 9-DOF hyper-redundant manipulator designed for this purpose.

Committee: Raul Ordonez (Advisor); Russel Hardie (Committee Member); Vijay Asari (Committee Member); Muhammad Usman (Committee Member) Subjects: Electrical Engineering; Engineering; Robotics; Robots

Doctor of Philosophy, Case Western Reserve University, 2010, EMC - Mechanical Engineering

Walking is a means of locomotion that is ubiquitous among terrestrial animals and the matter of considerable technical inquiry; both for biological understanding and description, and engineering construction and control. Although wheels and treads have numerous advantages over legs for low-complexity terrain, the promise of adept legged locomotion in a much broader range of rugged environments is eloquently demonstrated in the animal kingdom. Of primary interest in the understanding of such agility is the ability of animals to smoothly transition between behaviors requiring substantially different local behavior of locomotor appendages. Recent developments in our understanding of insect walking systems, encapsulated in the study of the neural mechanisms of stick insect leg coordination by (Ekeberg, Blumel, & Buschges, 2004), have made it possible to construct models of local leg control based on known properties of biological systems. Such models can provide the appropriate “ports” to investigate and predict the effects of descending commands in the transition between and generation of different local behaviors. This dissertation describes the development and use of robotic models of step generation to address questions about descending control. Robotic models were desired both for the ease of experimental interaction and the fidelity of physical modeling they can provide. The NeuRoMod software suite was developed, and provides interactive operation and experimental scripting for the robotic models. The local control methods of the stick insect described by Ekeberg et al. are standardized as Sensory Coupled Action Switching Modules (SCASM), and tools for the use of this concept in modeling are developed and demonstrated. The apparent generality of SCASM as a computationally simple control concept is also addressed. Experiments were conducted to demonstrate model usage, in the testing and generation of biologically relevant hypotheses. The basic function, neu (open full item for complete abstract)

Committee: Roger Quinn Ph.D. (Advisor); Roy Ritzmann Ph.D. (Committee Member); Kiju Lee Ph.D. (Committee Member); Mark Willis Ph.D. (Committee Member); Robert Kirsch Ph.D. (Committee Member) Subjects: Biology; Engineering; Mechanical Engineering; Neurology; Robots