Thesis: S.B., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2016. / Cataloged from PDF version of thesis. / Includes bibliographical references (pages 53-54). / A model was developed for measuring the drag and effects of inertia for a cyclist during a race. Professional cyclist data from the Tour de France was acquired for several athletes. The data contained elevation, distance, velocity, and power as a function of time. Rolling resistance, drag, inertial energy, and potential energy were then evaluated. An integral energy equation relating these terms to input power was developed. This is much more stable numerically than differential equations in the power and force equations. This formula gave excellent agreement with the theoretical assumption that inertial effects are negligible. Additionally, the measured drag agreed with wind tunnel results. This work is the first to extract drag data from a cyclist during actual race conditions. In the future, this evaluation of drag variation coupled with energy equations could lead to optimizing cycling strategy. / by Emma Marie Steinhardt. / S.B.

Thesis (Sc. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1963. / MICROFICHE COPY AVAILABLE IN ENGINEERING. / Appendix contains numerous pamphlets. / Includes bibliographical references (leaves 55-56). / by Mikio Suo. / Sc.D.

Thesis: S.B., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2018. / Cataloged from PDF version of thesis. / Includes bibliographical references (page 55). / Through a Pappalardo Apprenticeship program, MIT undergraduates in mechanical engineering collaborated to construct an 1897 Herreshoff steam engine for intent for demonstration at an MIT Museum exhibit scheduled to open in fall 2018. With a brief overview of the functionality and inner workings of the engine provided, this thesis focuses on the fabrication process followed in making a sand cast part for this project. Two specific parts exemplify the variations in this fabrication process: the iron column and the bronze bearing crosshead. In both cases, the same CAD and CAM practices, pattern fabrication processes, and post-machining techniques were used. / by Elizabeth Bianchini. / S.B.

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1987. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING / Bibliography: v.2, leaves 286-291. / by Richard J. Phillips. / M.S.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2004. / Includes bibliographical references (p. 197-209). / This thesis presents a method for creating continuously parametrized maneuver classes for autonomous vehicles. These classes provide useful tools for motion planners, bundling sets of related vehicle motions based on a low-dimensional parameter vector that describes the fundamental high-level variations within the trajectory set. The method follows from a relaxation of nonlinear parametric programming necessary conditions that discards the objective function, leaving a simple coordinatized feasible space including all dynamically admissible vehicle motions. A trajectory interpolation algorithm uses projection and integration methods to create the classes, starting from arbitrary user-provided maneuver examples, including those obtained from standard nonlinear optimization or motion capture of human-piloted vehicle flights. The interpolation process, which can be employed for real-time trajectory generation, efficiently creates entire maneuver sets satisfying nonlinear equations of motion and nonlinear state and control constraints without resorting to iterative optimization. Experimental application to a three degree-of-freedom rotorcraft testbed and the design of a stable feedforward control framework demonstrates the essential features of the method on actual hardware. Integration of the trajectory classes into an existing hybrid system motion planning framework illustrates the use of parametrized maneuvers for solving vehicle guidance problems. The earlier relaxation of strict optimality conditions makes possible the imposition of affine state transformation constraints, allowing maneuver sets to fit easily into a mixed integer-linear programming path planner. / (cont.) The combined scheme generalizes previous planning techniques based on fixed, invariant representations of vehicle equilibrium states and maneuver elements. The method therefore increases the richness of available guidance solutions while maintaining problem tractability associated with hierarchical system models. Application of the framework to one and two-dimensional path planning examples demonstrates its usefulness in practical autonomous vehicle guidance scenarios. / by Christopher Walden Dever. / Ph.D.

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2006. / Includes bibliographical references (p. 25). / The MIT Media Laboratory Robotic Life Group's Leonardo is a highly expressive robot used for, among other things, social learning and human-robot teamwork research. A mixed reality workspace was conceived to aid in experimentation and demonstration of human-robot interaction by providing a complex state space and several interaction possibilities. A box concept was selected for its ability to incorporate several interaction mechanisms while allowing for meaningful physical tasks. A first iteration of the system was completed, which was controllable primarily through serial communication with a computer, while providing minimal physical communication. For a second revision of the system, physical interaction devices were developed which could be actuated by either the robot or a human, so as to better explore social interaction. Further development of the project will yield a robust, flexible and expandable tool with which future robot social learning and teamwork research can be performed. / by Javier G. Matamoros. / S.B.

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2008. / Includes bibliographical references (leaf 50). / Rapid prototyping tools empower individuals to create almost anything. Unfortunately, these tools are still far too expensive for personal ownership. The do-it-yourself community has responded with a slew of home-made rapid prototyping machines, but development times are slow because of the complexity of the necessary control system and the need to design the mechanical elements from scratch. This thesis seeks to address both of these issues. A control system is developed which treats the machine as a distributed Internet Zero network controlled by a software virtual machine with the benefits of simplified configuration and greater flexibility. A low cost circuit board milling machine, built as the test bed for this distributed controller, is described in detail. Finally, a parametrically designed XY table is introduced as a prototype for a universal machine axis and a first step towards the creation of reusable machine designs. These contributions will hopefully aid in accelerating the development of new rapid prototyping machines. / by Ilan Ellison Moyer. / S.B.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2009. / This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections. / Cataloged from student-submitted PDF version of thesis. / Includes bibliographical references (p. 131-133). / The development of micro/nanofluidics is expected to be the enabling technology for sample preparation of proteomic biosamples, which has been the bottleneck in proteomics. Most microfabricated nanofluidic channels, such as planar nanochannels and square nanochannels, suffer from small open volume and, as a result, low sample throughput, compared to microchips and conventional gel-based systems. For practical and wider applications of artificial nanochannels, it is of crucial importance to enhance sample throughput of nanofluidic systems. To address this severe problem, we proposed to build high-aspect-ratio vertical nanochannels, which have the advantage of large open volume, enabling their use for high-throughput applications. Two fabrication methods for creating massively-parallel, ultra-high-aspect-ratio nanochannels have been developed by using a combination of anisotropic wet etching and thermal oxidation. Vertical nanochannels with a uniform gap size of 55 nm and aspect ratio as high as 400 have been demonstrated. In addition, we have implemented high-aspect-ratio nanochannels into a two-dimensional anisotropic nanofilter array (ANA) device and demonstrated continuous-flow separation of DNA and proteins. Compared to other nanofilter devices, the vertical ANA device achieves comparable separation speed and efficiency but allows a much higher sample throughput. Lastly, we have demonstrated the uniform layer-by-layer deposition of polyelectrolyte multilayers (PEM) within high-aspect-ratio nanochannels. / (cont.) Conformal, uniform deposition has been achieved along the entire depth of nanochannel and linear growth has been observed. Compared with the growth on flat substrate, significantly slower deposition per bilayer within nanochannels was found, which we attribute to the partioning effect. We also have performed dc conductance measurement to determine the wet-state thickness of PEM. The ability of uniform growth of PEM inside nanochannels not only allows the control of gap size, but also provides new functionalities with desired surface properties such as surface charge density, charge polarity, and hydrophobicity. / by Pan Mao. / Ph.D.

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2012. / Cataloged from PDF version of thesis. / Includes bibliographical references (p. 73-74). / A force controlled ultrasound probe is being explored as a new method of measuring blood pressure. An arterial simulator was designed and built for experiments. For this simulator, the vessels and bulk material were designed to meet the specifications of literature values of the physical dimensions and elastic modulus of carotid and brachial arteries and bulk surrounding the arteries. This was done through the use of a PVA cyrogel and Thermo rubber- mineral oil solution as the materials for the vessel and bulk material respectively. The concentration of the ingredients and the number of freeze thaw cycle of the cyrogel control the elasticity of the two materials. Custom molds were fabricated to the desired physical dimensions. Upon integration of the vessel and bulk, the vessel was connected to a network of hoses and a pump. The pump is a diaphragm pump whose volume/stroke and speed can be independently controlled to simulate the pulsing of a real human heart. Measurements were taken of the force applied to the probe for static pressures to demonstrate the force varying linearly with pressure. Further measurements were taken with fluid flowing through the vessel at various probe heights to demonstrate how force and thus pressure vary with height and to demonstrate that the probe can detect the waveforms that result from the vessels pulsing with each stroke of the diaphragm pump. / by Lauren Chai. / S.B.

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1999. / Includes bibliographical references (leaf 92). / by Ryan Edward Jones. / S.M.