Thesis (M.S.)--University of Michigan, 1978.

Thesis (Ph. D.)--University of Texas at Austin, 2002. / Vita. Includes bibliographical references. Available also from UMI Company.

Thesis (M.S. in environmental engineering)--Washington State University. / Includes bibliographical references.

Thesis (M.S.)--University of Michigan, 1978.

Thesis (M.S.)--University of Michigan, 1983.

Thesis (M.S.)--University of Michigan, 1983.

Two new technologies, for polishing and testing large optics, are presented in this dissertation. The first is a new approach to generating and polishing aspheric surfaces which utilizes a full size stressed lap. The lap specifications are chosen to automatically generate a specific amount of spherical aberration. The required comatic distortion of the lap is induced by a system of levers and springs which are stretched and relaxed as the lap moves. A lap was constructed to grind and polish a 20cm glass blank. The resultant polished surface, in agreement with the predicted asphericity, has 28 microns of spherical aberration at its edge, appropriate for a F/2.0 convex paraboloid. The average radial profile has a residual peak-to-valley error of 200nm and an rms error of 60nm. This experiment serves as a first successful test of the stressed lap concept and as a demonstration of a new method for generating aspheric secondary mirrors. The second new technology is concerned with testing large optics where vibrations can be a serious problem. A modification to the usual phase shifting interferometry reduction algorithm permits measurements to be taken fast enough to essentially freeze out vibrations. Only two interferograms are needed with an exact phase relationship; and these can be recorded very rapidly on either side of the interline transfer of a standard CCD video camera, prior to charge transfer readout. The third required interferogram is a null. An analysis of potential phase errors was performed for this "2 + 1" algorithm. In the developed implementation, two frequencies, dν/ν≈10⁻⁸, are generated with orthogonal polarizations. A Pockels cell rapidly switches the frequency entering the interferometer, resulting in a phase shift over the long path difference of the interferometer. The two time critical interferograms are acquired with a 1ms separation resulting in a reduction in sensitivity to vibration of one to two orders of magnitude. Laboratory tests were performed to compare this "2 + 1" system with a commercial phase shifting package. Similar phase determination accuracies were found when vibrations were low. However, the "2 + 1" system also succeeded when vibrations were large enough to wash out video rate fringes.

<p>Nowadays, the polishing process is one of the most important steps of the manufacturing of moulds and dies. Occupying up to 40% of the total production time and cost, it is decisive for the final appearance and quality of a surface. Because of its complexity, the polishing is mainly carried out manually; and the final quality depends of the expertise of the operator. That is why an automation of the polishing process is necessary.</p><p>The purpose of this project was to find out the optimized sequence of polishing for a Mirrax ESR steel (Uddeholm Tooling AB) using the Strecon RAP-200 (robot assisted polishing equipment). Using a Design of Experiment, the machine parameters were tested in order to better understand their influences and interactions. The report starts with a description of general polishing knowledge and ends up with the results from a Design of Experiment.</p><p>The information from this test are a first step in the evaluation of the Strecon RAP-200. Even if many results have been found out, only four parameters have been tested, and to be able to optimize the polishing sequence, further studies need to be carried out.</p>

Nowadays, the polishing process is one of the most important steps of the manufacturing of moulds and dies. Occupying up to 40% of the total production time and cost, it is decisive for the final appearance and quality of a surface. Because of its complexity, the polishing is mainly carried out manually; and the final quality depends of the expertise of the operator. That is why an automation of the polishing process is necessary. The purpose of this project was to find out the optimized sequence of polishing for a Mirrax ESR steel (Uddeholm Tooling AB) using the Strecon RAP-200 (robot assisted polishing equipment). Using a Design of Experiment, the machine parameters were tested in order to better understand their influences and interactions. The report starts with a description of general polishing knowledge and ends up with the results from a Design of Experiment. The information from this test are a first step in the evaluation of the Strecon RAP-200. Even if many results have been found out, only four parameters have been tested, and to be able to optimize the polishing sequence, further studies need to be carried out.

The goal of this thesis is to develop a novel polishing tool system, which can be attached to a CNC machine tool and execute a precision polishing job for an axially symmetric free surface. The precision polishing job is to remove the error surface profile, left by the previous machining process, on the work to improve its form precision. The system mainly includes a mechanism of 3 degrees of freedom, a misalignment compensator mounted on the mechanism, and an oscillation-free connector between tool and driver. The mechanism was designed to meet the required motions of tool trajectories. These motions are to assure the tool can play three specific functions. The first one is to keep the tool axis maintain a constant angle with the normal of polished surface. The second one is to control the wear rate distribution of tool to reduce the effect of tool wear on polishing rate. The final one is to achieve the goal of uniform polishing quality at every spot of polished surface. The conceptual design of this mechanism is done based on a strategy of problem decomposition. The misalignment compensator is to reduce the effect of tool misalignment on the variation of polishing rate. The compensator allows a translational motion and is constrained by a spring. When the tool is mounted on the compensator, the study will show that with a proper spring constant the effect of tool misalignment can be significantly reduced. The study will indicate that the smaller the tool mass is the higher the compensation efficiency can be. The oscillation-free connector is to separate the tool and its driver so that the mass of driver is not included in tool, while the driving function retains. It is composed of two parts. One part is connected to tool and the other one is mounted on driver. These two parts are not joined together by any mean. However, the motions of two parts will interfere with each other. Thus, the driving function between tool and drive can be maintained. It is noted that the vibration of driver can be successfully isolated from the tool if a soft material is attached to one part.