Página 15 dos resultados de 10406 itens digitais encontrados em 0.040 segundos

‣ Design of a hand-held user interface for the active joint brace

Possinger, Christopher P. (Christopher Paul)
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 32 p.; 1846166 bytes; 1845186 bytes; application/pdf; application/pdf
Português
Relevância na Pesquisa
669.8232%
The continued development of the Active Joint Brace, a powered orthosis, required that a suitable user interface be designed to control the brace. Since the brace is an electronically-controlled mechanical, medical device, it was important that the user interface (UI) provide both a proper interface to the software that controls the brace, and be in conformance with human factors data. The constraints provided by the existing electronics and software of the brace, combined with suitable ergonomic data, were used to inform the design of a hand-held user interface device, pictured below. The UI features one-handed operation, utilizing an LCD character display and speaker for output devices and a navigation switch for an input device. In preparation for the new UI, the existing menu system was also reorganized for ease-of-use. In preliminary user testing within the development team, the UI has been judged as satisfactory, with only a few minor changes needed to the enclosure.; by Christopher P. Possinger.; Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, June 2005.; "May 2005." Vita.; Includes bibliographical references (p. 23).

‣ Mapping crossing myofiber populations with Diffusion Spectrum Imaging in simulated and microfabricated model tissues

Liang, Jason (Jason G.)
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 36 leavves; 1847912 bytes; 1847288 bytes; application/pdf; application/pdf
Português
Relevância na Pesquisa
669.8232%
The ability to resolve complex myofiber populations is important for relating architectural structure with mechanical unction in muscular tissues. To address this issue, we sought to validate the capacity of Diffusion Spectrum Imaging (DSI), an MRI method for assessing molecular diffusion in a confined geometry, to determine fiber alignment in tissues whose myofibers are aligned at varying orientations. By this method, molecular displacement in a tissue can be determined by Fourier transforming the echo intensity against gradient strength at fixed gradient pulse spacing. The displacement profiles are visualized by graphing 3D isocontour icons for each voxel, with the isocontour shape and size representing the magnitude and direction of the constituting fiber populations. Validation of DSI was accomplished with two sets of experiments: We simulated diffusive motion and a DSI experiment within the constraints of crossing fibers, and determined that DSI accurately depicts arbitrary angular relationships between crossing fibers. We also used DSI to accurately resolve the geometry of aligned channels in poly(dimethylsiloxane) (PDMS) microfluidic phantoms.; by Jason Liang.; Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering...

‣ Thin optic surface analysis for high resolution X-ray telescopes

Akilian, Mireille
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 122 p.; 6573039 bytes; 6580054 bytes; application/pdf; application/pdf
Português
Relevância na Pesquisa
669.8232%
The art of glass developed throughout the years has covered artifacts ranging from crude ornaments to high precision optics used in flat panel displays, hard disk drives, and x-ray telescopes. Methods for manufacturing glass sheets and further sheet shaping processes are covered. Future generation, high resolution x-ray telescopes require thin optics with large surface area to thickness ratio and a surface flatness of -500 nm. A novel method utilizing porous ceramics, which provide a thin layer of air for sheet glass to rest on during the shaping process, is investigated. The shaping process involves slumping glass on a uniform layer of air at elevated temperatures, where the viscosity of glass is low enough for it to sag under its own weight and replicate the surface it rests on. Flow in porous, rectangular air bearings is covered with both flat and grooved surfaces. The pressure distribution in the air gap between the ceramic and the glass sheet determines the surface quality of glass during slumping. The mechanical integrity of porous ceramics at elevated temperatures is investigated to predict the effect of the decrease in ceramic stiffness on the final shape of the optic.; (cont.) A metrology truss used to kinematically constrain thin optics during metrology is designed. This device mitigates the effects of external forces...

‣ Effects of lubricant viscosity and surface texturing on ring-pack performance in internal combustion engines

Takata, Rosalind (Rosalind Kazuko), 1978-
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 134 p.; 8793837 bytes; 8799454 bytes; application/pdf; application/pdf
Português
Relevância na Pesquisa
669.8232%
The piston ring-pack contributes approximately 25% of the mechanical losses in an internal combustion engine. Both lubricant viscosity and surface texturing were investigated in an effort to reduce this ring-pack friction and increase engine efficiency. While both optimizing viscosity and surface texturing are predicted to cause a reduction in ring/liner friction individually, a combined approach may cause an even greater friction reduction while mitigating unwanted side-effects such as oil consumption and wear. Existing MIT models, with some modifications and supplementary programs to allow investigation of the parameters of interest, were used to conduct this research. A ring-pack model based on average flow-factor Reynolds analysis was used for both studies, with a modified form of this program, along with a supplementary deterministic model for surface analysis, used for the study of surface texturing. Although these advanced models are applicable in a wide range of cases, the surface textures studied in this research are very different than a typical cylinder liner surface, and can be represented only approximately by the averaged Reynolds analysis upon which the ring simulation is based.; (cont.) For this reason, the analysis of surface features has focused on a parametric study...

‣ Development of a high throughput 3D perfused liver tissue bioreactor

Inman, Samuel Walker
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 178 p.; 8852695 bytes; 8860174 bytes; application/pdf; application/pdf
Português
Relevância na Pesquisa
669.8232%
This thesis describes the development of a device designed for culturing liver tissue in a 3D perfused environment. Cells form tissue inside miniature channels of a scaffold, and the tissue is perfused with culture medium to create a culture microenvironment that has previously been described by the Griffith lab. In order to support this microenvironment, the reactor needs a pumping system, reservoirs and a controller. Previously, these have all been stand-alone components. This work focuses on the development of a new, integrated culture system. This system integrates 12 reactor microenvironments, reservoirs and pumping systems onto a single plate with a configuration modeled after standard multi-well plates. Each of the 12 bioreactor units utilize pneumatic pumps driven by a single external controller. This design offers substantial advantages over previous systems as it is far more user-friendly and can be used in a higher throughput capacity. The thesis describes the design and fabrication of the reactor and controller, including several models that were used during the development process. It also offers mechanical and biological characterizations of the device.; by Samuel Walker Inman.; Thesis (S.M.)--Massachusetts Institute of Technology...

‣ Capsizing of ships : static and dynamic analysis of wind effect and cost implications

Antonopoulos, Angelos, Nav. E. Massachusetts Institute of Technology
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 173 p.
Português
Relevância na Pesquisa
669.8232%
Capsizing of small vessels, such as commercial fishing vessels, is a frequent event. This phenomenon is generally associated with the combined action of storm seas, inadequate design parameter regulations, and dangerous operational procedures. In contrast, the capsizing of large ships is rare, but does occur. For these large vessels, more strict regulations exist to ensure safe operational procedures. While the storminess of the sea cannot be controlled, the navigation procedure can. Large offshore ships tend to navigate in a path to avoid forecasted severe weather, and in cases of stormy seas they temporarily operate at safe speeds and in the direction parallel to the waves. The work presented in this thesis investigates the effect of the wind in rolling and finally capsizing a ship. For the purposes of mechanical analysis, realistic hull forms are used and fundamental issues associated with moments and forces imposed by the wind, are applied. The platforms are examined for several wind speeds that strike the ship at different angles. Both static and dynamic cases were examined. Under the assumption of general conditions, the angles of heeling in each case and the wind speeds that caused the ship to capsize are calculated.; (cont.) Furthermore...

‣ Viscoelastic characterization of collagen-GAG scaffolds

Wong, Matthew Q
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 45 p.
Português
Relevância na Pesquisa
669.8232%
An experimental study was performed to determine whether or not collagen-GAG scaffolds exhibit linear viscoelastic behavior. Tension tests were performed on dry and hydrated engineered collagen-GAG scaffolds in order to develop a stress-strain curve. Strains that fell in the linear elastic region of these curves were selected and then used in stress relaxation tests that were also performed on dry and hydrated specimens. The relaxation modulus was calculated from the resulting stress relaxation curves at different strain levels and compared to each other to determine viscoelastic linearity. In addition to the determination of viscoelastic linearity, a water bath was designed in the hopes of performing stress relaxation tests in hydrated environment with the temperature maintained at 37°C, the temperature of the human body. These tests will aid in the future studies of how cells contract and apply force to the scaffolds since no previous studies have looked at the time dependent mechanical properties of these scaffolds. Moreover, the data can be used in the future to determine whether the viscoelastic response contributes to cellular processes such as migration speeds, attachment, and contraction.; by Matthew Q. Wong.; Thesis (S.B.)--Massachusetts Institute of Technology...

‣ Design and characterization of a low cost dual differential proving ring force sensor utilizing Hall-effect sensors

Rivest, Christopher W. (Christopher Warren)
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 31 leaves
Português
Relevância na Pesquisa
669.8232%
A novel dual differential hall-effect based proving ring force sensor has been designed, manufactured, and tested. Strain gauge based force sensors are among the most common methods of measuring static and dynamic forces, yet they suffer from a wide array of negative attributes including: high cost due to signal amplification instrumentation, high temperature sensitivity, and only moderate dynamic range. The goal of the research herein described was to design and test a low cost, high dynamic range force sensor. Hall-Effect sensors have high bandwidth (>100 kHz), a wide dynamic range, are low in cost (<0.5$), and are ideally suited to dynamic and static force measurements. Proving rings - diametrally loaded hoops of metal, have long been used to measure force yet suffer many setbacks due to their historical designs utilizing mechanical and strain gauge methods of strain detection. A novel nested proving ring flexure has been combined with hall-effect sensors to fulfill the design requirements of a low cost and robust force sensor. Initial data demonstrates that the nested proving ring force sensor herein described is capable of resolving forces of in the range of 0 to 30 Newtons with an accuracy of 0.235 Newtons, all at a potential mass-manufactured cost of U.S. $10.00 per unit.; by Christopher W. Rivest.; Thesis (S.B.)--Massachusetts Institute of Technology...

‣ Design and control of a clutch for a minimally-actuated biped based on the passive-dynamic simple walker

Reynolds, Arlis (Arlis A.)
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 41 leaves
Português
Relevância na Pesquisa
669.8232%
Passive-dynamic walking robots are remarkable mechanical devices capable of maintaining dynamically stable walking gaits with no actuation or control. These systems, however, depend on ideal environmental conditions for stability. Robustness and control capabilities are increased with actuation, but so is the power consumption. Such actuated robots are designed to minimize the actuation requirement by exploiting the system natural dynamics system, but still need actuation to compensate for energy dissipated by friction and collision events, as well as for more control capabilities. A simple clutch mechanism is developed for such systems to allow intermittent control of otherwise passive joints, allowing controllers to exploit the passive or actuated control when desired. The clutch is tested on a hip actuated simple 3D walker to evaluate the performance capabilities of clutched control. Preliminary tests of several control strategies suggest the clutched actuation may provide good performance at a higher efficiency compared to fully actuated systems. This paper describes the development of the clutch device and the hip-actuated biped on with which the clutch is tested, and evaluates the performance of intermittent clutch-control for several control strategies.; by Arlis Reynolds.; Thesis (S.B.)--Massachusetts Institute of Technology...

‣ A software library for design and visualization of adaptive controllers

Rebula, John (John Robert)
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 43 p.
Português
Relevância na Pesquisa
669.8232%
An adaptive control library was written in Java that allowed a user to programatically specify the dynamics of a system and performed adaptive control. Also, visualization software was written to help monitor and modify the controller in real time. The software was tested on several simulated mechanical systems and on a DC motor.; by John Rebula.; Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2006.; Includes bibliographical references (p. 43).

‣ Automated support for experimental approaches in daylighting performances assessment

Ljubicic, Dean M
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 20 leaves
Português
Relevância na Pesquisa
669.8232%
The study of daylight and solar reflection has been a topic of increasing interest over the past two decades. A novel mechanical support has been constructed to help better understand this topic that consists of a five foot in diameter circular table driven to rotate and tilt by computer controlled motors. The first use of this machine is to conduct shadow studies on architectural models. Using the tilt and rotation axis concurrently, a model can be rotated through a path that emulates the sun throughout the course of a day. The second use of the machine is to measure the solar flux emitted from and transmitted through a sample at different angles of incidence. An elliptical shell will be cut in half and secured to the table with focal points A and B. The incoming light will shine on or through the sample placed at focal point A, bounce off of the reflective inside of the shell, then be redirected into a camera placed at focal point B. Two cameras will be used to measure the visible and infrared spectra of the reflected light.; by Dean M. Ljubicic.; Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, February 2006.; "October 2005."; Includes bibliographical references (leaf 20).

‣ A design for self-assembling robots in a system

Kim, Myunghee, Ph. D. Massachusetts Institute of Technology
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 83 p.
Português
Relevância na Pesquisa
669.8232%
This thesis presents the design, construction, control, and application for a novel concept of self-assembling robots in a system. The system is composed of multiple cooperative robots that are designed to self-assemble in a system, execute manipulative tasks, and self-repair, all without human assistance. The self-assembling feature employs four mechanical design guidelines: independent module, one touch assembly design, self-alignment, and self-guiding. The independent design feature also employs independent motor control boards and a wireless communication board. For a decoupling effect, we chose a motor with large gear ratio. For safety and modularization purpose, we implemented a newly designed Series Elastic Actuator to limit shock bandwidth by using its compliance and sense forces during manipulative tasks. This thesis introduces a control algorithm, according to design parameters. With the results of dynamic simulations, we developed a preliminary algorithm for picking up a based on subsumption architecture. Finally, we verified the design and algorithm via an application, picking up a module in unstructured environments.; by Myunghee Kim.; Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering...

‣ Analysis of walking and balancing models actuated and controlled by ankles

Ahn, Jooeun, Ph. D. Massachusetts Institute of Technology
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 182 p.
Português
Relevância na Pesquisa
669.8232%
Experimental data show that ankle torque is the most important actuator in normal human locomotion. I investigate the dynamics of simple models actuated by ankles alone. To assess the contribution of ankle actuation to locomotion, I first analyze the dynamics of some passive walkers without any joint torque. These passive walkers include a rimless wheel model and springy-legged models with and without a double stance phase. I analyze the stability of the period-one gait of each passive walker to compare it with the stability of the period-one gait of an ankle actuated model. Subsequently, I investigate whether balancing of a double inverted pendulum model whose shape and mass distribution are similar to a human can be achieved by control of ankle torque in a frontal plane. I study the dynamics of the model and design a controller that makes the model balance with biologically realistic ankle torque and a reasonable foot-floor friction coefficient. I conclude that an ankle-actuated model can make a stable period-one gait in a sagittal plane. Also, I deduce that the ankle torque control in a frontal plane can stabilize a double inverted pendulum model whose shape and mechanical properties are similar to those of humans.; by Jooeun Ahn.; Thesis (S.M.)--Massachusetts Institute of Technology...

‣ Modeling, identification, and application of multilayer polypyrrole conducting polymer actuators

Secord, Thomas W. (Thomas William)
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 112 p.
Português
Relevância na Pesquisa
669.8232%
Experiments were performed using commercially available, self-contained, multilayer polypyrrole (PPy) actuators to develop low-order lumped parameter models of actuator electrical, mechanical, and electromechanical behavior. Experimental data were processed using system identification techniques. Both grey box and black box models were identified. The grey box model consisted of a first order electrical network that was linearly and algebraically coupled to a second order viscoelastic model. The black box model incorporated a third order Box-Jenkins structure and achieved model to data residues comparable to the grey box model. When utilizing validation data, the grey box model showed very good performance for loads in the range of 0.5 to 3 N. Overall, the results of system identification experiments suggested that low order, lumped parameter models were adequate to describe the gross behavior of multilayer actuators. An online identification scheme was developed for monitoring polymer electrical impedance and thereby monitoring the degradation state of an actuator. This identification was performed successfully using recursive least squares and least squares for a discrete impedance model.; (cont.) Experimental validation data, spanning more than 5 hours of continuous operation...

‣ Lateral undulation of a snake-like robot

Gupta, Amit
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 121 p.
Português
Relevância na Pesquisa
669.8232%
Snake robots have been studied by many researchers but historically more on a theoretical basis. Recently, more and more robotic snakes have been realized in hardware. This thesis presents a design process for the electrical, sensing, and mechanical systems needed to build a functional robotic snake capable of tactile and force sensing. Implementing a simple scheme which allows this capability permits the robot to laterally undulate without the use of wheels. The design methodology and implementation is detailed with schematics and a summary of results obtained from the hardware. Through manipulation of the body shape, the robot was able to move in the horizontal plane by pushing off of obstacles to create propulsive forces. It was found that lateral undulation is highly dependent on the actuator torque output and environmental friction.; by Amit Gupta.; Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2007.; Includes bibliographical references (p. 117-121).

‣ Development of a simplified negative pressure wound device

Zurovcik, Danielle Renee
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 188 p.
Português
Relevância na Pesquisa
669.8232%
Many medical techniques are not readily available in the third world, in the military, for disaster relief, and in domestic environments. This can be due to a lack of electricity, high cost, and other economical constraints. For these reasons, a successful, chronic wound treatment, known as negative pressure wound therapy (NPWT), has not been readily used, although many patients would benefit. Aiming to expand this therapy, the viability of inexpensive, purely mechanical simplified negative pressure wound therapy (sNPWT) systems is explored in this thesis. Air leaks into the NPWT system are identified as the limiting factor for the possibility of sNPWT. An air leak detection system, along with proper dressing techniques, is defined. Once sNPWT is proven to be viable, it is developed further, based on customer needs in the targeted markets and sNPWT functional parameters. Three vacuum pump embodiments are prototyped and analyzed for possible implementation: bellows pumps, bladder pumps, and rolling diaphragm pumps. The bellows pump is chosen for the final design, and is analyzed in preparation for manufacture. Once manufactured, the bellows pump will be used in clinical trials at the Shriners Bum Hospital in Boston, Massachusetts, under the guidance of Dr. Robert Sheridan.; by Danielle R. Zurovcik.; Thesis (S.M.)--Massachusetts Institute of Technology...

‣ A large strain piezoelectric microactuator by folding assembly

Traina, Zachary J
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 75 leaves
Português
Relevância na Pesquisa
669.8232%
In-plane amplification of thin film piezoelectric strain has been previously demonstrated using mechanical flexures fabricated at the micro scale. This new work presents a method by which that amplification can be increased, along with a method to reduce parasitic out of plane bending present in prior designs. Fabricated actuator triplets demonstrated peak unblocked displacement of 15 [mu]m, 3% total contraction by length, with an estimated blocking force of [approx.] -9.2 [mu]N. Methods of arraying one such cell massively in series and in parallel are also presented, with the long term goal of creating a large strain, efficient, and low power macro scale actuator from individual micro scale components.; by Zachary J. Traina.; Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2007.; Includes bibliographical references (leaves 65-68).

‣ Tactile sensing of shape : biomechanics of contact investigated using imaging and modeling

Wu, Wan-Chen (Wan-Chen Shane), 1974-
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 131 leaves
Português
Relevância na Pesquisa
669.8232%
The overall goal of this research effort is to improve the understanding of the biomechanics of skin as it pertains to human tactile sense. During touch, mechanoreceptors beneath the skin surface are mechanically loaded due to physical contact of the skin with an object and respond with a series of neural impulses. This neural population response is decoded by the central nervous system to result in tactile perception of properties such as the shape, surface texture and softness of the object. The particular approach taken in this research is to develop a realistic model of the human fingertip based on empirical measurements of in vivo geometric and material properties of skin layers, so that the mechanical response of the fingertip skin to different shapes of objects in contact can be investigated, to help identify the relevant mechanism that triggers the mechanoreceptors in tactile encoding of object shape. To obtain geometric data on the ridged skin surface and the layers underneath together with their deformation patterns, optical coherence tomography (OCT) was used to image human fingertips in vivo, free of load as well as when loaded with rigid indenters of different shapes.; (cont.) The images of undeformed and deformed finger pads were obtained...

‣ Fracture of welded aluminum thin-walled structures

Zheng, Li, Ph. D. Massachusetts Institute of Technology
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 279 leaves
Português
Relevância na Pesquisa
669.8232%
A comprehensive methodology was developed in the thesis for damage prediction of welded aluminum thin-walled structures, which includes material modeling, calibration, numerical simulation and experimental verification. An extensive experimental program was conducted on large-scale welded panels used on Inter City Express (ICE) high-speed European passenger trains. These panels consist of geometrically complex extrusions, which are welded together to form the final structure. A wealth of data was generated to validate the proposed methodology. The current work has demonstrated the efficiency and robustness required for mainstream industrial applications. As the first step, a local fracture criterion was validated on two types of aluminum components without welds: (i) S-rails under quasi-static and dynamic axial loading; (ii) large-scale extruded aluminum panels under 4-point bending. With the fracture parameter calibrated from uniaxial tensile tests, numerical simulations gave excellent predictions of crack formation for test articles. A novel technique was developed to calibrate heterogeneous weldments for plasticity and fracture. This technique eliminates the need for machining and testing of miniature tensile specimens, cut from different zones within the weldment.; (cont.) The calibrated data was validated by comparing the numerical results with small and intermediate-scale tests. Excellent agreement was achieved. A wide range of aluminum weldments...

‣ Range-based navigation of AUVs operating near ship hulls; Range-based navigation of Autonomous Underwater Vehicles operating near ship hulls

Kokko, Michael A. (Michael Andrew)
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 109 p.
Português
Relevância na Pesquisa
669.8232%
In-water ship hull inspection is essential for both routine preventative maintenance as well as for timely detection and neutralization of limpet mines planted on military and commercial vessels. While a host of inspection methods have been proposed for this task, Autonomous Underwater Vehicles (AUVs) are particularly well-suited for such missions as they require neither constant human supervision nor a restrictive tether as do Remotely Operated Vehicles (ROVs). MIT and Bluefin Robotics have jointly developed a Hovering AUV (HAUV) for the inspection of ship hulls and other submerged marine structures which has been successfully demonstrated to achieve a coverage rate on the order of 700m2/hour with centimeter-scale resolution for a variety of hull types. AUV navigation often involves dead reckoning based on velocity measurements from an acoustic Doppler Velocity Log (DVL) sensor. As this strategy is inherently susceptible to drift, related efforts seek to generate vehicle position updates through either Simultaneous Localization and Mapping (SLAM) or the use of external sensor networks. In this work we propose a unique localization approach which relies on range measurements taken to surfaces of known curvature.; (cont.) The algorithm is developed for navigating relative to simple parabolic curvatures and is tested both in simulation and on a floating raft robot. Localization and servoing are demonstrated in real-time to achieve estimated position deviations within millimeters of their expected values. In addition to exploring other facets of hull-relative navigation...