ASU Electronic Theses and Dissertations
This collection includes most of the ASU Theses and Dissertations from 2011 to present. ASU Theses and Dissertations are available in downloadable PDF format; however, a small percentage of items are under embargo. Information about the dissertations/theses includes degree information, committee members, an abstract, supporting data or media.
In addition to the electronic theses found in the ASU Digital Repository, ASU Theses and Dissertations can be found in the ASU Library Catalog.
Dissertations and Theses granted by Arizona State University are archived and made available through a joint effort of the ASU Graduate College and the ASU Libraries. For more information or questions about this collection contact or visit the Digital Repository ETD Library Guide or contact the ASU Graduate College at gradformat@asu.edu.
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- Creators: Marvi, Hamidreza
Description
Tubes and pipelines serve as a major component of several units in power plants and oil, gas, and water transmission. These structures undergo extreme conditions, where temperature and pressure vary, leading to corroding of the pipe over time, creating defects in them. A small crack in these tubes can cause major safety problems, so a regular inspection of these tubes is required. Most power plants prefer to use non-destructive testing procedures, such as long-range ultrasonic testing and phased array ultrasonic testing, to name a few. These procedures can be carried out with the help of crawlers that go inside the pipes. One of the main drawbacks of the current robotic tube inspection robots is the lack of maneuverability over complex tubular structures and the inability to traverse non-ferromagnetic pipelines. The main motivation of this project is to create a robotic system that can grab onto ferromagnetic and non-ferromagnetic tubes and move along those, move onto adjacent tubes, and maneuver around flanges and bends in the tube. Furthermore, most of the robots used for inspection rely on roller balls and suction-based components that can allow the robot to hold on to the curved surface of the tube. These techniques fail when the surface is rough or uneven, which has served as an inspiration to look at friction-based solutions. Lizards are known for their agile locomotion, as well as their ability to grab on any surface irrespective of the surface texture. The work presented here is focused on the design and control of a lizard-inspired tube inspection robot that can be used to inspect complex tubular structures made of any material.
ContributorsMasurkar, Nihar Dattaram (Author) / Marvi, Hamidreza (Thesis advisor) / Dehghan-Niri, Ehsan (Committee member) / Lee, Hyunglae (Committee member) / Arizona State University (Publisher)
Created2022
Description
This thesis presents a study on the optimization of friction pads, centered around a custom friction setup designed to enhance the operational efficiency of tube inspection robots. By surface texturing of Polydimethylsiloxane (PDMS) pads, inspired by the remarkable design of lizards' toes, this research pioneers the development of friction pads aimed at significantly elevating the adaptability and effectiveness of robotic systems in the challenging domain of industrial tube inspection. A cornerstone of this study is the novel friction setup, which has been carefully engineered to simulate real-world operational conditions with high precision. This custom-built apparatus, capable of exerting variable normal loads and accommodating diverse surface textures on curved pipe surfaces, has been instrumental in uncovering the intricate behavior of friction pads. Notably, the setup's capacity to measure forces on curved surfaces with a 6-axis load cell, providing critical insights into frictional forces in multiple directions, stands out as a pivotal contribution to the field. Through exhaustive experimentation facilitated by this advanced friction setup, the research has demonstrated that the design and texture of PDMS pads, particularly those featuring triangular grooves at a depth of 1 mm, markedly influence their frictional performance. These pads exhibit superior traction, especially under higher loads and on corroded surfaces, underscoring the importance of angular groove geometries in enhancing mechanical interlocking with surface irregularities. The inverse relationship observed between the coefficient of friction and applied normal force across various textures further highlights the nuanced mechanical behavior of PDMS friction pads under stress, accentuating the critical role of the custom friction setup in enabling these discoveries. This insight necessitates a refined approach to load application, ensuring optimal frictional engagement. This thesis not only advances the understanding of PDMS pad frictional behavior but also introduces a new frictional device testing method through its innovative friction setup. Future explorations will build on this foundation, probing the effects of different PDMS compositions, surface treatments, and environmental conditions on frictional performance, propelled by the capabilities of the custom friction setup.
ContributorsJain, Siddharth Rohit (Author) / Marvi, Hamidreza (Thesis advisor) / Dehghan-Niri, Ehsan (Committee member) / Rykaczewski, Konrad (Committee member) / Arizona State University (Publisher)
Created2024