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Classical fabrication methods alone do not enable manufacturing of large flat mirrors that are much larger than 1 meter. This dissertation presents the development of enabling technologies for manufacturing large high performance flat mirrors and lays the foundation for manufacturing very large flat mirrors. The enabling fabrication and testing methods were developed during the manufacture of a 1.6 meter flat. The key advantage over classical methods is that our method is scalable to larger flat mirrors up to 8 m in diameter.Large tools were used during surface grinding and coarse polishing of the 1.6 m flat. During this stage, electronic levels provided efficient measurements on global surface changes in the mirror. The electronic levels measure surface inclination or slope very accurately. They measured slope changes across the mirror surface. From the slope information, we can obtain surface information. Over 2 m, the electronic levels can measure to 50 nm rms of low order aberrations that include power and astigmatism. The use of electronic levels for flatness measurements is analyzed in detail.Surface figuring was performed with smaller tools (size ranging from 15 cm to 40 cm in diameter). A radial stroker was developed and used to drive the smaller tools; the radial stroker provided variable tool stroke and rotation (up to 8 revolutions per minute). Polishing software, initially developed for stressed laps, enabled computer controlled polishing and was used to generate simulated removal profiles by optimizing tool stroke and dwell to reduce the high zones on the mirror surface. The resulting simulations from the polishing software were then applied to the real mirror. The scanning pentaprism and the 1 meter vibration insensitive Fizeau interferometer provided accurate and efficient surface testing to guide the remaining fabrication. The scanning pentaprism, another slope test, measured power to 9 nm rms over 2 meters. The Fizeau interferometer measured 1 meter subapertures and measured the 1.6 meter flat to 3 nm rms; the 1 meter reference flat was also calibrated to 3 nm rms. Both test systems are analyzed in detail. During surface figuring, the fabrication and testing were operated in a closed loop. The closed loop operation resulted in a rapid convergence of the mirror surface (11 nm rms power, and 6 nm rms surface irregularity). At present, the surface figure for the finished 1.6 m flat is state of the art for 2 meter class flat mirrors.

International Telemetering Conference Proceedings / October 26-29, 1998 / Town & Country Resort Hotel and Convention Center, San Diego, California / This paper discusses the design, configuration, and operation of a satellite station built for the Center for Space Telemetering and Telecommunications Laboratory in the Klipsch School of Electrical and Computer Engineering Engineering at New Mexico State University (NMSU). This satellite station consists of a computer-controlled antenna tracking system, 2m/70cm transceiver, satellite tracking software, and a demodulator. The satellite station receives satellite telemetry, allows for voice communications, and will be used in future classes. Currently this satellite station is receiving telemetry from an amateur radio satellite, UoSAT-OSCAR-11. Amateur radio satellites are referred to as Orbiting Satellites Carrying Amateur Radio (OSCAR) satellites.

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The Giant Magellan Telescope (GMT) primary mirror consists of seven 8.4 m light-weight honeycomb mirrors that are being manufactured at the Richard F. Caris Mirror Lab (RFCML), University of Arizona. In order to manufacture the largest and most aspheric astronomical mirrors various high precision fabrication technologies have been developed, researched and implemented at the RFCML. The unique 8.4 m (in mirror diameter) capacity fabrication facilities are fully equipped with large optical generator (LOG), large polishing machine (LPM), stressed lap, rigid conformal lap (RC lap) and their process simulation/optimization intelligence called MATRIX. While the core capability and key manufacturing technologies have been well demonstrated by completing the first GMT off-axis segment, there have been significant hardware and software level improvements in order to improve and enhance the GMT primary mirror manufacturing efficiency. The new and improved manufacturing technology plays a key role to realize GMT, the next generation extremely large telescope enabling new science and discoveries, with high fabrication efficiency and confidence.

Sliding mode control (SMC) has been successfully applied to many practical control problems due to its attractive features such as invariance to matched uncertainties. The characteristic feature of a continuous-time SMC system is that sliding mode occurs on a prescribed manifold, where switching control is employed to maintain the state on the surface. When a sliding mode is realized, the system exhibits some superior robustness properties with respect to external matched uncertainties. However, the realization of the ideal sliding mode requires switching with an infinite frequency. Control algorithms are now commonly implemented in digital electronics due to the increasingly affordable microprocessor hardware although the essential conceptual framework of the feedback design still remains to be in the continuous-time domain. Discrete sliding mode control has been extensively studied to address some basic questions associated with the sliding mode control of discrete-time systems with relatively low switching frequencies. However, the complex dynamical behaviours due to discretization in continuous-time SMC systems have not yet been fully explored. In this thesis, the discretization behaviours of SMC systems are investigated. In particular, one of the most frequently used discretization schemes for digital controller implementation, the zero-order-holder discretization, is studied. First, single-input SMC systems are discretized, stability and boundary conditions of the digitized SMC systems are derived. Furthermore, some inherent dynamical properties such as periodic phenomenon, of the discretized SMC systems are studied. We also explored the discretization behaviours of the disturbed SMC systems. Their steady-state behaviours are discussed using a symbolic dynamics approach under the constant and periodic matched uncertainties. Next, discretized high-order SMC systems and sliding mode based observers are explored using the same analysis method. At last, the thesis investigates discretization effects on the SMC systems with multiple inputs. Some conditions are first derived for ensuring the

Precision optics can be accurately fabricated by computer controlled optical surfacing (CCOS) that uses well characterized polishing tools driven by numerically controlled machines. The CCOS process is optimized to vary the dwell time of the tool on the workpiece according to the desired removal and the calibrated tool influence function (TIF), which is the shape of the wear function by the tool. This study investigates four major topics to improve current CCOS processes, and provides new solutions and approaches for the next generation CCOS processes.The first topic is to develop a tool for highly aspheric optics fabrication. Both the TIF stability and surface finish rely on the tool maintaining intimate contact with the workpiece. Rigid tools smooth the surface, but do not maintain intimate contacts for aspheric surfaces. Flexible tools conform to the surface, but lack smoothing. A rigid conformal (RC) lap using a visco-elastic non-Newtonian medium was developed. It conforms to the aspheric shape, yet maintains stability to provide natural smoothing.The second topic is a smoothing model for the RC lap. The smoothing naturally removes mid-to-high frequency errors while a large tool runs over the workpiece to remove low frequency errors efficiently. The CCOS process convergence rate can be significantly improved by predicting the smoothing effects. A parametric smoothing model was introduced and verified.The third topic is establishing a TIF model to represent measured TIFs. While the linear Preston's model works for most cases, non-linear removal behavior as the tool overhangs the workpiece edge introduces a difficulty in modeling. A parametric model for the edge TIFs was introduced and demonstrated. Various TIFs based on the model are provided as a library.The last topic is an enhanced process optimization technique. A non-sequential optimization technique using multiple TIFs was developed. Operating a CCOS with a small and well characterized TIF achieves excellent performance, but takes a long time. Sequential polishing runs using large and small tools can reduce this polishing time. The non-sequential approach performs multiple dwell time optimizations for the entire CCOS runs simultaneously. The actual runs will be sequential, but the optimization is comprehensive.

In this paper, we describe a recent trend in the introductory computer science curriculum which advocates conceptualizing computation primarily as coordinated concurrent activities [8], [9], [10]. Consistent with this philosophy is the focus on the event-driven model of computation [7]. While one can utilize these approaches with any thread and/or event supporting object-oriented language (e.g. Java) in a desktop programming environment, they become particularly worthwhile when used in conjunction with physical robots. This paper argues the case for the benefits of this approach and provides sample exercises that illustrate the use of this pedagogy using Lego Mindstorms RCX bricks programmed in Java for use in introductory programming.

Au cours de ce travail nous avons utilisé les potentialités de différentes modalités d'imagerie, que nous appliquons au domaine du végétal afin de contribuer au phénotypage haut-débit des semences et plantules. Nous nous somme principalement consacré à la recherche de réponses à deux problématiques spécifiques et importantes de ce secteur. Nous commençons par montrer l'applicabilité de l'imagerie en lumière visible inactinique et de l'imagerie thermographique passive pour imager le développement des semences et plantules, un phénomène biologique se déroulant normalement dans le sol et l’obscurité. Nous présentons nos apports à ce type d’imagerie, au travers de nos contributions à la conception et à la réalisation d’un système de vision en imagerie visible inactinique, ayant pour finalité la réalisation de mesures individualisées automatisées sur les semences, les plantules et les organes des plantules. Ce système gère les croisements de plantules, via l'utilisation originale de la diffusion anisotrope, ce qui nous a permis de multiplier, sans perte d'information, les débits par dix. De plus, ce système réalise la séparation des organes au moyen d’un critère générique basé sur le gravitropisme. La validation des algorithmes de traitement d'images du système de vision utilise des voies originales (simulation numérique et test de l'influence de l'incertitude via simulation agronomique). L’imagerie thermographique, qui capte le rayonnement thermique passif des objets, nous permet de visualiser et de mesurer les semences et plantules dans l'obscurité. Elle permet aussi de réaliser la segmentation et le suivi des organes de plantules. Cette technologie d'imagerie nous a aussi permis de montrer la faisabilité d'un dosage non destructif de teneur en sucre des organes de plantules de betterave. Ensuite nous proposons une méthodologie générique permettant la conception de capteurs bas-coût spectralement optimisés, en fonction de tâches applicatives déterminées. Cette méthodologie utilise la théorie de l’information, pour extraire de l’imagerie hyperspectrale, relativement coûteuse, l’information utile à la conception des capteurs dédiés bas-coût. L’intérêt de cette méthodologie pour le phénotypage des plantes est montré et justifie le transfert de celle-ci au monde de la recherche en biologie végétale. / Along this work, we have used the potentiality of different modalities of imagery that we apply to the plant domain so as to contribute to the high-throughput phenotyping of seeds and seedlings. We have mainly committed ourselves to the search for answers to two specific and important problematic in this domain. We begin by showing the applicability of visible imaging using an inactinic light and passive thermographic imaging to image the development of seeds and seedlings, a biological phenomenon usually occurring in soil and darkness. We present our contributions to this type of imaging through our contributions to the conception and the realization of a vision system using visible inactinic imaging, whose finality is the realization of individualized automated measurement on the seeds, the seedlings and the organs of the seedlings. This system handle seedling crossing, through the original use of anisotropic diffusion, which allowed us to multiply, without information loss, the output by ten. Furthermore, this system carries out the separation of the organs by means of a generic criterion based on gravitropism. The validation of the image processing algorithms of the vision system use original ways (numerical simulation and test of the influence of the uncertainty through agronomic simulation). Thermographic imaging, which captures the passive heat radiation of objects, allows us to visualize and to measure seeds and seedlings in the darkness. It also allows realizing the segmentation and the tracking of the organs of seedlings. This imaging technology also allowed us to demonstrate the feasibility of a non-destructive determination of sugar quantity in organs of beet seedlings. We then propose a generic methodology that allows the conception of spectrally optimized low-cost sensors, according to determined application tasks. This methodology uses information theory, to extract from, relatively expensive, hyperspectral imaging, the information needed for the conception of the dedicated low-cost sensors. The interest of this methodology for plant phenotyping has been shown and justifies its transfer to the world of research in plant biology.