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- All Subjects: Automotive
- Creators: Henderson, Mark
Description
Mostly, manufacturing tolerance charts are used these days for manufacturing tolerance transfer but these have the limitation of being one dimensional only. Some research has been undertaken for the three dimensional geometric tolerances but it is too theoretical and yet to be ready for operator level usage. In this research, a new three dimensional model for tolerance transfer in manufacturing process planning is presented that is user friendly in the sense that it is built upon the Coordinate Measuring Machine (CMM) readings that are readily available in any decent manufacturing facility. This model can take care of datum reference change between non orthogonal datums (squeezed datums), non-linearly oriented datums (twisted datums) etc. Graph theoretic approach based upon ACIS, C++ and MFC is laid out to facilitate its implementation for automation of the model. A totally new approach to determining dimensions and tolerances for the manufacturing process plan is also presented. Secondly, a new statistical model for the statistical tolerance analysis based upon joint probability distribution of the trivariate normal distributed variables is presented. 4-D probability Maps have been developed in which the probability value of a point in space is represented by the size of the marker and the associated color. Points inside the part map represent the pass percentage for parts manufactured. The effect of refinement with form and orientation tolerance is highlighted by calculating the change in pass percentage with the pass percentage for size tolerance only. Delaunay triangulation and ray tracing algorithms have been used to automate the process of identifying the points inside and outside the part map. Proof of concept software has been implemented to demonstrate this model and to determine pass percentages for various cases. The model is further extended to assemblies by employing convolution algorithms on two trivariate statistical distributions to arrive at the statistical distribution of the assembly. Map generated by using Minkowski Sum techniques on the individual part maps is superimposed on the probability point cloud resulting from convolution. Delaunay triangulation and ray tracing algorithms are employed to determine the assembleability percentages for the assembly.
ContributorsKhan, M Nadeem Shafi (Author) / Phelan, Patrick E (Thesis advisor) / Montgomery, Douglas C. (Committee member) / Farin, Gerald (Committee member) / Roberts, Chell (Committee member) / Henderson, Mark (Committee member) / Arizona State University (Publisher)
Created2011
Description
Today, the United States consumer vehicle market consists of about 276 million legally registered units, a prime candidate for service skulduggery (BTS, 2019). It raised some concerns when research conducted by the author revealed that about half of United States survey participants state they feel uneasy about approaching either a mechanic they know or one that was new to them. Additionally, when only 10% of participants from the same survey fully trust mechanics, this raises the question, why are so many drivers of consumer vehicles wary about bringing their cars in for service or repair? Furthermore, the author determined that trust within the automotive repair industry is a worldwide issue, and countries with scarce resources have additional struggles of their own. The success of repair centers in countries closer to the equator weighs heavily on the mechanic's knowledge and access to repair resources. The author found that this is partially due to the rapid acceleration of the car market without a proper backbone to the automotive repair industry. Ultimately, this resulted in repair shops with untrained mechanics who perform poor quality labor for an inflated rate (Izogo, 2015). The author focuses on this global industry through the example of the Maasai Automotive Education Center (MAEC), a proposed facility and school located in Talek, Kenya. MAEC is designed to bring automotive customer and repair resources to a rural community that needs it the most to save their land, culture, and people. The author uses various recently conducted global studies, news articles and videos, and personal research to determine the crucial steps and considerations the MAEC development team needs to ensure project sustainability and success. This study's conclusion lists 11 essential attributes recommended for the MAEC repair facility for ethical and high-quality operation.
ContributorsMiller, Miles (Author) / Henderson, Mark (Thesis advisor) / Martin, Thomas (Committee member) / Rogers, Bradley (Committee member) / Arizona State University (Publisher)
Created2021
Description
Sport Utility Vehicles have grown to be one of the most popular vehicle choices in the automotive industry. This thesis explores the history of SUVs with their roots starting in the 1930s up until 2020 in order to understand the essence of what an SUV is. The definition applied to the SUV for this thesis is as follows: a vehicle that is larger and more capable than the average sedan by offering more interior space, cargo area, and possibly off-road capability. This definition must be sufficiently broad to encompass the diverse market that manufactures are calling SUVs. Then the trends of what current (2020) SUVs are experiencing are analyzed from three major aspects: sociology, economics, and technology. Sociology focuses on the roles an SUV fulfills and the type of people who own SUVs. The economics section reviews the profitability of SUVs and their dependence on a nation’s economic strength. Technology pertains to the trends in safety features and other advances such as autonomous or electric vehicles. From these current and past trends, predictions could be made on future SUVs. In regards to sociology, trends indicate that SUVs will be more comfortable as newly entering luxury brands will be able to innovate aspects of comfort. In addition, SUVs will offer more performance models so manufacturers can reach a wider variety of demographics. Economic trends revealed that SUVs are at risk of losing popularity as the economy enters a hard time due to the COVID-19 pandemic. Technological trends revealed that hybrids and electric vehicles will now move into the SUV market starting with the more compact sizes to help improve manufacturer’s fleet fuel efficiency.
ContributorsMarske, Trevor Holmes (Author) / Henderson, Mark (Thesis director) / Contes, James (Committee member) / Engineering Programs (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05