Thesis (M. Eng. in Manufacturing)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2012. / Cataloged from PDF version of thesis. / Includes bibliographical references (p. 150-154). / This thesis describes the development of the control system that runs the automated pin insertion machine in a surface mount technology assembly line. The control system is divided into 2 subsystems viz. pin sorting and pin insertion. The detailed design of the control system and its components is discussed, along with the programming of the Programmable Logic Controller for both subsystems. The development of the machine vision application used to sort the right pin types is described, with an emphasis on the image processing tools used. Applicability and robustness of these tools in the context of the pin insertion machine is described. The developed application can capture images and process them in 92 ms, significantly lower than the maximum allowable time of 500 ms. The vision system could totally eliminate the incidence of a wrong pin being passed on to the insertion head. Among the right pins, 98% of the right pins in the right orientation and 100% the pins in the wrong orientation were detected. / by Rejin Isaac. / M.Eng.in Manufacturing

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2001. / Includes bibliographical references (p. 205-206). / In 1991, a novel robot named Manus I was introduced as a testbed to study the potential of using robots to assist in and quantify the neuro-rehabilitation of motor skills. Using impedance control methods to drive a 2 d.o.f. planar robot, Manus I proved an excellent fit for the rehabilitation of the upper arm and shoulder. This was especially true in the case of rehabilitation after stroke. Several clinical trials showed that therapy with Manus reduced recovery time and improved long term recovery after stroke. This successful testbed naturally led to the desire for additional hardware for the rehabilitation of other degrees of freedom. This thesis outlines the mechanical design of one of four new rehabilitation robots. Its focus is the mechanical design of a robot for wrist rehabilitation. The anthropometric background data, the design's functional requirements, the strategic design selection and the detailed design are presented. / by Dustin Williams. / S.M.

Thesis: S.M., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2014. / 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 (pages 153-155). / Microfluidics has emerged as an increasingly popular field with a wide-variety of applications such as medical diagnostics, drug development, and DNA analysis. The transition of microfluidic devices from research to industry has stimulated interest in producing them at low costs and high volumes. Hot embossing has been of interest lately as a low-cost, high quality, and flexible manufacturing method that is ideal for medium-volume production. This project focuses on the continued development of a tabletop microfactory that can be used to study the control of a novel hot embossing machine. By incorporating an in-line measurement system, it would be possible to add feedback control to improve the process. This led to the design of an automated testing machine that uses an optical inspection of the microfluidic channel widths to determine embossing quality and a flow test to verify device functionality. / The total cycle time of the testing machine is 85 seconds, which is well within the time of one embossing cycle (110 seconds). In order to produce complete devices for testing, an automated taping machine was also designed to seal the embossed channels. This machine took 15 seconds to complete its cycle. These two machines were integrated with the microfactory, which is currently capable of producing an embossed, sealed, and tested device every 170 seconds. The taping and width measurement processes have an error of 0.63 μm with a standard deviation of 0.82 [mu]m. The mixing length test has an accuracy of 72.8 [mu]m. A preliminary test demonstrated the ability to generate credible run data, and the effect of embossing temperature on width was detected to a resolution of 2 [mu]m. The system is now able to characterize the embossing process and the effects of various embossing parameters on the final product. / Closed-loop cycle-to-cycle process control can then be implemented, which will create a robust production cell that is capable of adapting to a variety of conditions. / by Caitlin J. Reyda. / S.M.

Thesis: S.M., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2013. / Cataloged from PDF version of thesis. / Includes bibliographical references (pages 155-159). / In this thesis, the problem of controlling the internal and external temperatures of a robot operating within a temperature-restricted environment was addressed. One example of a temperature-restricted environment is the interior of a holding tank for Liquefied Petroleum Gas (LPG), which is the focus of the analysis in this work, but not the only possible application. This gas is stored at sub-zero temperatures to maintain its liquidity, and any significant rise in temperature can cause the gas to vaporize, posing a safety hazard. The tank in which the gas is stored must be periodically inspected for defects. Using robot inspectors while the tank is in service would reduce the cost due to lost productivity during human inspection. A thermal management system (TMS) was designed to maintain the robot's electronics and components within operating limits, while preventing the external environment from increasing in temperature above safe levels. A detailed model of the system was constructed for simulation, and the results indicate that the system performs as intended, but requires closed-loop control to maintain robot operation for extended periods of time. A control system based on system model linearization and model predictive control was implemented for the TMS. The results of the closed-loop simulations indicate that the control system enhances the operation of the TMS, maintaining robot operating temperatures for extended periods of time, while avoiding an unsafe rise in the temperature of the external environment. / by Ethan B. Heller. / S.M.

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1999. / Includes bibliographical references. / The tutorial teaches the concepts of variation risk management and the methodology of key characteristics to an audience of college-level engineers. Key problems addressed in the design of the tutorial are the need to accurately communicate the concepts and background material necessary for understanding, the need to keep the reader's interest, and the need to ensure readability of the tutorial of a wide range of audience. The use of the web's various devices (hypertext links, pictures, and interactive applets), the use of examples, and the use of a standard page format have been integrated or will be integrated into the tutorial design to address these problems. / by Daryl G. Hanna. / S.B.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1971. / Vita. / Bibliography: leaves 100-101. / Ph.D.

Includes bibliographical references (p. 131). / Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2004. / (cont.) actions can be made to decrease losses and therefore increase plant efficiencies. As production efficiencies are maximized, fuel use and thus emissions are minimized. From fiscal year 1998 to 2003, the gas turbine efficiency, based on the higher heating value, remained approximately constant at 24%. The heat recovery steam generator effectiveness has decreased 11% from 42.1% to 37.4%. It has been shown that the decrease in the heat recovery steam generator's performance can be attributed to fouling effects on the heat transfer surfaces between the hot exhaust gasses and the water stream. An accurate inventory of MIT's greenhouse gas emissions is a necessary first step in reducing these emissions. This assessment identifies areas with the greatest potential for reducing utility related emissions. This inventory will also allow MIT to continue to evaluate its greenhouse gas emission trends and thus contribute to the emission reduction target the city of Cambridge has created. / This MIT campus emission assessment has been done in response to the City of Cambridge Climate Protection Plan, which is calling for a 20% decrease in greenhouse gas emissions from 1990 levels by the year 2010. This greenhouse gas inventory includes all emissions of carbon dioxide, methane, and nitrous oxide due to utility use from fiscal year 1990 to 2003 and estimates of transportation and solid waste emissions. It accounts for utilities purchased and utilities produced from the MIT Cogeneration Power Plant. A methodology has been developed to allocate the MIT utility plant addition, the assessment includes carbon dioxide emissions due to the MIT commuting population from fiscal year 1999 to 2003, and accounts for equivalent carbon dioxide emissions from solid waste incineration from fiscal year 2000 to 2003. The 20% reduction target from 1990 emission levels sets a cap on campus emissions of 163,830 equivalent metric tons of carbon dioxide per year. At current levels, a 22% decrease in emissions would be required to achieve this target. Emissions released from utility use account for 90% of the campus emissions, with 9.5% attributed to commuters, and 0.5% emissions based on produced electricity, steam, and chilled water. This allows facilities to develop programs that will directly impact the source of highest emissions. In due to campus solid waste. Therefore, reducing the amount of emissions caused by utility production and purchasing would have the largest effect on reducing the total campus greenhouse gas emissions. A thermodynamic availability flow analysis has also been conducted on the gas turbine and heat recovery steam generator system of the MIT cogeneration power plan. Availability losses within the system were targeted and appropriate / by Tiffany Amber Groode. / S.M.

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2010. / 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. 26). / The author presents a concept for a vertical axis wind turbine that utilizes each blade's entire rotational cycle for power generation. Each blade has its own vertical axis of rotation and is constrained to rotate at the rate of one half of a revolution per full revolution of the rotor. For a rotor of radius r and blades of width b, a technical analysis predicts a theoretical maximum power coefficient of CP = b 2r+b, neglecting wind flow interference by upwind blades. This theoretical power coefficient is generally greater than the efficiency of a typical Savonius wind turbine (CP ~~ 0.15), and it reaches CP = 0.5 at the limiting blade width, b = 2r. The analysis also predicts a static torque and optimal tip-speed ratio that are both greater than those of a Savonius wind turbine with similar blade dimensions. Design considerations for implementing the kinematic constraint and for blade adjustment to account for changes in wind direction are discussed, and the author's prototype is presented. Testing of the prototype demonstrated that implementation of the kinematic constraint is feasible, and that efficiencies greater than those achievable by a Savonius turbine are plausible. In 4 m s wind conditions, the prototype yielded an estimated CP of 0.15, with much room for improvement through design changes and blade optimization in future iterations of this style of turbine. / by Samuel Bruce Weiss. / S.B.

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1999. / Includes bibliographical references (leaves 39-42). / by Cynthia R. Lee. / S.M.

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1971. / Bibliography: leaves 110-112. / M.S.