Design of a portable observatory control system

In this thesis, we synthesize the development of a new concept of operation of small robotic telescopes operated over the Internet. Our design includes a set of improvements in control algorithmic and hardware of several critical points of the list of subsystems necessary to obtain suitable data from a telescope. We can synthesize the principal contributions of this thesis into five independent innovations: - An advanced drive closed-loop control: We designed an innovative hardware and software solution for controlling a telescope position at high precision and high robustness. - A complete Telescope Control System (TCS): We implemented a light and portable software using advanced astronomical algorithms libraries for optimally compute in real-time the telescope positioning. This software also provides a new multiple simultaneous pointing models system using state machines which allows reaching higher pointing precision and longer exposure times with external guiding telescopes. - A distributed software architecture (CoolObs): CoolObs is the implementation of a ZeroC-ICE framework allowing the control, interaction, and communication of all the peripherals present in an astronomical observatory. - A patented system for dynamic collimation of optics: SAPACAN is a mechanical parallel arrangement and its associated software used for active compensation of low-frequency aberration variations in small telescopes. - Collimation estimation algorithms: A sensor-less AO algorithm have been applied by the analysis of images obtained with the field camera. This algorithm can detect effects of lousy collimation. The measured misalignments can later feed corrections to a device like SAPACAN. Due to the constant presence of new technologies in the field of astronomy, it had been one of the first fields to introduce material which was not democratized at this time such as Coupled Charged Devices, internet, adaptive optics, remote and robotic control of devices. However, every time one of these new technologies was included in the field it was necessary to design software protocol according to the epoch’s state of the art software. Then with the democratization of the same devices, years after the definition of their protocols, the same communication rules tend to be used to keep backward compatibility with old - and progressively unused- devices. When using lots of cumulated software knowledge such as with robotic observing, we can dig in several nonsenses in the commonly used architectures due to the previously explained reasons. The described situation is the reason why we will propose as follows a new concept of considering an observatory as an entity and not a separated list of independent peripherals. We will describe the application of this concept in the field or robotic telescopes and implement it in various completely different examples to show its versatility and robustness. First of all, we will give a short introduction of the astronomical concepts which will be used all along the document, in a second part, we will expose a state of the art of the current solutions used in the different subsystems of an observing facility and explain why they fail in being used in small telescopes. The principal section will be dedicated to detail and explain each of the five innovations enumerated previously, and finally, we will present the fabrication and integration of these solutions. We will show here how the joint use of all of them allowed obtaining satisfactory outstanding results in the robotic use of a new prototype and on the adaptation on several existing refurbished telescopes. Finally, we dedicate the last chapter of this thesis to resuming the conclusions of our work.En esta tesis, presentamos el desarrollo de un nuevo concepto de operación de telescopio robótica operados a través de Internet. Nuestro diseño incluye un conjunto de mejoras de los algoritmos de control y hardware de varios puntos críticos de la lista de subsistemas necesarios para obtener datos de calidad científica con un telescopio. Podemos sintetizar las principales contribuciones de esta tesis en cinco innovaciones independientes: - Un control de motor avanzado en bucle cerrado: Diseñamos un hardware y software innovadores para controlar la posición y movimiento fino de un telescopio con alta precisión y alta robustez. - Un software de control de telescopio (TCS) integrado: Implementamos un software ligero y portátil que ocupa bibliotecas de algoritmos astronómicos avanzados para calcular de manera óptima y en tiempo real la posición teórica del telescopio. Este software también proporciona un software innovador de modelo de pointing múltiples simultáneos. Esto permite alcanzar una mayor precisión de seguimiento y así ocupar tiempos de integración más importante ocupando un telescopio de guía mecánicamente apartado al telescopio principal. - Una arquitectura de software distribuido (CoolObs): CoolObs es una implementación de software ocupando la plataforma de desarrollo ZeroC-ICE la cual permite el control, la interacción y la comunicación de todos los periféricos presentes en un observatorio astronómico. - Un sistema patentado para la colimación dinámica de la óptica: SAPACAN es un sistema mecánico de movimiento paralelo y su software asociado. Se puede ocupar para compensar activamente las aberraciones ópticas de bajo orden en pequeños telescopios. - Algoritmos de estimación de colimación: Se desarrolló un algoritmo de óptica adaptiva sin sensor en base al análisis de imágenes obtenidas con una cámara cerca del plano focal del telescopio. Este algoritmo puede detectar efectos de mala colimación de las ópticas. Los desajustes, una vez medidos, pueden posteriormente ser aplicados como correcciones a un dispositivo como SAPACAN. Astronomía es un terreno propicio al desarrollo de nuevas tecnologías y, debido a esto, los protocolos de comunicación entre periféricos pueden ser obsoletos porque se han escritos en etapas tempranas de existencia de estas nuevas tecnologías. Las mejoras se han hecho de a poco para mantener la compatibilidad de los sistemas ya existentes, ocupando un planteamiento general de la problemática de control de telescopios robóticos, proponemos un nuevo concepto de observatorio robótico visto como una entidad y no una lista de periféricos independientes. A lo largo de esta tesis, describiremos la aplicación de este concepto en el campo de telescopios robóticos e implementarlo en varios sistemas independientes y variados para mostrar la versatilidad y robustez de la propuesta.Postprint (published version

A microcontroller-based three degree-of-freedom manipulator testbed

A wheeled exploratory vehicle is under construction at the Mars Mission Research Center at North Carolina State University. In order to serve as more than an inspection tool, this vehicle requires the ability to interact with its surroundings. A crane-type manipulator, as well as the necessary control hardware and software, has been developed for use as a sample gathering tool on this vehicle. The system is controlled by a network of four Motorola M68HC11 microcontrollers. Control hardware and software were developed in a modular fashion so that the system can be used to test future control algorithms and hardware. Actuators include three stepper motors and one solenoid. Sensors include three optical encoders and one cable tensiometer. The vehicle supervisor computer provides the manipulator system with the approximate coordinates of the target object. This system maps the workspace surrounding the given location by lowering the claw, along a set of evenly spaced vertical lines, until contact occurs. Based on this measured height information and prior knowledge of the target object size, the system determines if the object exists in the searched area. The system can find and retrieve a 1.25 in. diameter by 1.25 in. tall cylinder placed within the 47.5 sq in search area in less than 12 minutes. This manipulator hardware may be used for future control algorithm verification and serves as a prototype for other manipulator hardware

"Knowing is Seeing:" The Digital Audio Workstation and the Visualization of Sound

The computers visual representation of sound has revolutionized the creation of music through the interface of the Digital Audio Workstation software (DAW). With the rise of DAW-based composition in popular music styles, many artists sole experience of musical creation is through the computer screen. I assert that the particular sonic visualizations of the DAW propagate certain assumptions about music, influencing aesthetics and adding new visually-based parameters to the creative process. I believe many of these new parameters are greatly indebted to the visual structures, interactional dictates and standardizations (such as the office metaphor depicted by operating systems such as Apples OS and Microsofts Windows) of the Graphical User Interface (GUI). Whether manipulating text, video or audio, a users interaction with the GUI is usually structured in the same mannerclicking on windows, icons and menus with a mouse-driven cursor. Focussing on the dialogs from the Reddit communities of Making hip-hop and EDM production, DAW user manuals, as well as interface design guidebooks, this dissertation will address the ways these visualizations and methods of working affect the workflow, composition style and musical conceptions of DAW-based producers

Low-power dynamic object detection and classification with freely moving event cameras

We present the first purely event-based, energy-efficient approach for dynamic object detection and categorization with a freely moving event camera. Compared to traditional cameras, event-based object recognition systems are considerably behind in terms of accuracy and algorithmic maturity. To this end, this paper presents an event-based feature extraction method devised by accumulating local activity across the image frame and then applying principal component analysis (PCA) to the normalized neighborhood region. Subsequently, we propose a backtracking-free k-d tree mechanism for efficient feature matching by taking advantage of the low-dimensionality of the feature representation. Additionally, the proposed k-d tree mechanism allows for feature selection to obtain a lower-dimensional object representation when hardware resources are limited to implement PCA. Consequently, the proposed system can be realized on a field-programmable gate array (FPGA) device leading to high performance over resource ratio. The proposed system is tested on real-world event-based datasets for object categorization, showing superior classification performance compared to state-of-the-art algorithms. Additionally, we verified the real-time FPGA performance of the proposed object detection method, trained with limited data as opposed to deep learning methods, under a closed-loop aerial vehicle flight mode. We also compare the proposed object categorization framework to pre-trained convolutional neural networks using transfer learning and highlight the drawbacks of using frame-based sensors under dynamic camera motion. Finally, we provide critical insights about the feature extraction method and the classification parameters on the system performance, which aids in understanding the framework to suit various low-power (less than a few watts) application scenarios

The drum kit and the studio : a spectral and dynamic analysis of the relevant components

The research emerged from the need to understand how engineers perceive and record drum kits in modern popular music. We performed a preliminary, exploratory analysis of behavioural aspects in drum kit samples. We searched for similarities and differences, hoping to achieve further understanding of the sonic relationship the instrument shares with others, as well as its involvement in music making. Methodologically, this study adopts a pragmatic analysis of audio contents, extraction of values and comparison of results. We used two methods to analyse the data. The first, a generalised approach, was an individual analysis of each sample in the chosen eight classes (composed of common elements in modern drum kits). The second focused on a single sample that resulted from the down-mix of the previous classes’ sample pools. For the analysis, we handpicked several subjective and objective features as well as a series of low-level audio descriptors that hold information regarding the dynamic and frequency contents of the audio samples. We then conducted a series of processes, which included visual analysis of three-dimensional graphics and software-based information computing, to retrieve the analytical data. Results showed that there are some significant similarities among the classes’ audio features. This led to the assumption that the a priori experience of engineers could, in fact, be a collective and subconscious notion, instinctively achieved in a recording session. In fact, with more research concerning this subject, one may even find new a new way to deal with drum kits in a studio context, hastening time-consuming processes and strenuous tasks that are common when doing so.A investigação científica realizada no ramo do áudio e da música tornou-se abastada e prolífica, exibindo estudos com alto teor informativo para melhor compreensão das diferentes áreas de incidência. Muita da pesquisa desenvolvida foca-se em aspectos pragmáticos: reconhecimento de voz e de padrão, recuperação de informação musical, sistemas de mistura inteligente, entre outros. No entanto, embora estes sejam aspectos formais de elevada importância, tem-se notado uma latente falta de documentação relativa a aspectos mais idílicos e artísticos. O instrumento musical de estudo que escolhemos foi a bateria. Para além de uma vontade pessoal de entender a plenitude das suas características sónicas intrínsecas para aplicações prácticas com resultados tangíveis, é de notar a ausência de discurso e pesquisa científica que por este caminho se tenha aventurado. Não obstante, a bateria tem sido objecto de estudo profundo em contextos analíticos, motivo pelo qual foi também relevante originar a nossa abordagem seminal. Por um lado, as questões físicas de construção e manutenção de baterias, bem como aspectos de índole ambiental e de espaço (salas de gravação) são dos aspectos que mais efeitos produzem na diferença timbríca em múltiplos exemplos de gravações de baterias. No entanto, questões tonais (fundamentais para uma pluralidade de instrumentos) na bateria carecem de estudo e documentação num contexto mundial generalizado. São muitos os engenheiros de som e músicos que alimentam a ideia preconcebida da dificuldade inerente em relacionar este elemento percursivo com os restantes instrumentos numa música. Aliam-se a isto questões subjectivas de gosto e preferência, bem como outros métodos que facilitam a inserção de um instrumento rítmico e semi-harmónico (porque é possível escolher uma afinação para diferentes elementos de uma bateria) numa textura sonora que remete para diferentes conceitos musicais. Portanto, a questão nuclear que este estudo se foca é: “será possível atingir um som idílico nos diferentes elementos de uma bateria?”. Em si só, a ambiguidade desta resposta pode remeter para um conceito dogmático e inflexível, bem como para a ideia de que, até ao momento, nenhuma gravação ou som de bateria alcançou um patamar de extrema qualidade, sonoridade ou ubiquidade que a responda a esta premissa. Partimos, então, desta interrogação e procedemos a uma análise pragmática de amostras sonoras que fossem o mais assimiláveis possível a um contexto comercial. Reunimos amostras de oito classes pré-definidas: bombos, tarolas, pratos de choque, timbalões graves, médios e agudos, crashs e rides. As amostras derivaram de bibliotecas que foram reunidas posteriormente à realização de uma pesquisa em busca dos fabricantes mais conceituados, com maior adesão pública e com antecedentes comerciais tangíveis. Daqui recuperamos 481 amostras. Depois de reunidas, as amostras sofreram um processo de identificação e catalogação, passando também por alguns momentos de processamento de sinal (conversão para ficheiros monofónicos, igualização da duração e normalização do pico de sinal). Em seguida, através do software de computação matemática MATLAB, desenvolvemos linhas de código que foram instrumentais para fase da análise de características e descritores de ficheiros áudio. Finalmente, procedemos a uma reunião dos resultados obtidos e a iniciação de suposições que pudessem originar os valores extraídos. De entre os resultados obtidos, surgiram ideias que, com mais investigação, podem facilitar a compreensão do comportamento sonoro dos diferentes elementos, bem como a criação de métodos de conjugação harmónica entre eles. É importante referir que, neste estudo, partimos de um conceito qualitativo do som, e como tal, omitimos aspectos físicos que, na sua essência, influenciam substancialmente o som que é emitido. No entanto, este trabalho introdutório pretende retificar de forma preliminar esta falta de conceitos subjectivos com evidências palpáveis. Evidências essas que ainda necessitam de investigação adicional para a sua confirmação

Design of Adaptive Sliding Mode Fuzzy Control for Robot Manipulator Based on Extended Kalman Filter

In this work, a new adaptive motion control scheme for robust performance control of robot manipulators is presented. The proposed scheme is designed by combining the fuzzy logic control with the sliding mode control based on extended Kalman filter. Fuzzy logic controllers have been used successfully in many applications and were shown to be superior to the classical controllers for some nonlinear systems. Sliding mode control is a powerful approach for controlling nonlinear and uncertain systems. It is a robust control method and can be applied in the presence of model uncertainties and parameter disturbances, provided that the bounds of these uncertainties and disturbances are known. We have designed a new adaptive Sliding Mode Fuzzy Control (SMFC) method that requires only position measurements. These measurements and the input torques are used in an extended Kalman filter (EKF) to estimate the inertial parameters of the full nonlinear robot model as well as the joint positions and velocities. These estimates are used by the SMFC to generate the input torques. The combination of the EKF and the SMFC is shown to result in a stable adaptive control scheme called trajectory-tracking adaptive robot with extended Kalman (TAREK) method. The theory behind TAREK method provides clear guidelines on the selection of the design parameters for the controller. The proposed controller is applied to a two-link robot manipulator. Computer simulations show the robust performance of the proposed scheme

Conceptual design of an orbital debris collector

The current Lower Earth Orbit (LEO) environment has become overly crowded with space debris. An evaluation of types of debris is presented in order to determine which debris poses the greatest threat to operation in space, and would therefore provide a feasible target for removal. A target meeting these functional requirements was found in the Cosmos C-1B Rocket Body. These launchers are spent space transporters which constitute a very grave risk of collision and fragmentation in LEO. The motion and physical characteristics of these rocket bodies have determined the most feasible method of removal. The proposed Orbital Debris Collector (ODC) device is designed to attach to the Orbital Maneuvering Vehicle (OMV), which provides all propulsion, tracking, and power systems. The OMV/ODC combination, the Rocket Body Retrieval Vehicle (RBRV), will match orbits with the rocket body, use a spin table to match the rotational motion of the debris, capture it, despin it, and remove it from orbit by allowing it to fall into the Earth's atmosphere. A disposal analysis is presented to show how the debris will be deorbited into the Earth's atmosphere. The conceptual means of operation of a sample mission is described

LookOut! Interactive Camera Gimbal Controller for Filming Long Takes

The job of a camera operator is more challenging, and potentially dangerous, when filming long moving camera shots. Broadly, the operator must keep the actors in-frame while safely navigating around obstacles, and while fulfilling an artistic vision. We propose a unified hardware and software system that distributes some of the camera operator's burden, freeing them up to focus on safety and aesthetics during a take. Our real-time system provides a solo operator with end-to-end control, so they can balance on-set responsiveness to action vs planned storyboards and framing, while looking where they're going. By default, we film without a field monitor. Our LookOut system is built around a lightweight commodity camera gimbal mechanism, with heavy modifications to the controller, which would normally just provide active stabilization. Our control algorithm reacts to speech commands, video, and a pre-made script. Specifically, our automatic monitoring of the live video feed saves the operator from distractions. In pre-production, an artist uses our GUI to design a sequence of high-level camera "behaviors." Those can be specific, based on a storyboard, or looser objectives, such as "frame both actors." Then during filming, a machine-readable script, exported from the GUI, ties together with the sensor readings to drive the gimbal. To validate our algorithm, we compared tracking strategies, interfaces, and hardware protocols, and collected impressions from a) film-makers who used all aspects of our system, and b) film-makers who watched footage filmed using LookOut.Comment: V2: - Fixed typos. - Cleaner supplemental. - New plot in control section with same data from a supplemental vide

M-CDS: Mobile Carbohydrate Delivery System

When patients with type 1 diabetes (T1D) are physically active, they encounter an issue with keeping their blood glucose (BG) stable. Generally, their blood glucose level (BGL) will drop, causing hypoglycaemia which can have fatal consequences. The simple solution is to consume carbohydrates in the form of liquids or food, but during physical activities, it can be difficult to follow their BGL at the same time as they exercise. This thesis presents the design and implementation of a mobile carbohydrate delivery system, M-CDS. Previous work has shown that it is possible to create a stationary carbohydrate delivery system that reads the user’s BG data in real-time, gives feedback to the user when their BGL is nearing hypoglycaemia, and issues a dose of juice with 15 grams of carbohydrates. The proof-of-concept system in this thesis has the same functions but is contained within a modified CamelBak backpack. A Raspberry Pi, together with various sensors and a peristaltic pump, can transfer juice from a drinking reservoir to a drinking tube, which the user can easily drink from while physically active. The results show that the backpack works as intended and was able to avoid a BGL under 3.9 mmol/L while testing the system with a user using physical activity, thus successfully avoiding a hypoglycaemic event. As the system is a proof-of-concept, many things can be improved or modified to create a more robust, user-friendly, compact, and complex system. However, creating a prototype proved to be a time-costly project, whereas future work can use this project as a base to further improve it

Recommended techniques for effective maintainability. A continuous improvement initiative of the NASA Reliability and Maintainability Steering Committee

This manual presents a series of recommended techniques that can increase overall operational effectiveness of both flight and ground based NASA systems. It provides a set of tools that minimizes risk associated with: (1) restoring failed functions (both ground and flight based); (2) conducting complex and highly visible maintenance operations; and (3) sustaining a technical capability to support the NASA mission using aging equipment or facilities. It considers (1) program management - key elements of an effective maintainability effort; (2) design and development - techniques that have benefited previous programs; (3) analysis and test - quantitative and qualitative analysis processes and testing techniques; and (4) operations and operational design techniques that address NASA field experience. This document is a valuable resource for continuous improvement ideas in executing the systems development process in accordance with the NASA 'better, faster, smaller, and cheaper' goal without compromising safety