Spacecraft experiment pointing and attitude control system Patent

Development of spacecraft experiment pointing and attitude control syste

Attitude control and damping system for spacecraft Patent

Utilization of momentum devices for forming attitude control and damping system for spacecraf

NASA advanced control technology: An overview

NASA's current and projected advanced control technology programs for future transport aircraft include the design and verification of full flight envelope autopilots, the development and flight test of all-digital fly by wire systems, the evolution of low cost innovative avionics concepts such as split surface stability augmentation systems, the evaluation of integrated propulsion control and cooperative autopilot/propulsion control systems, the application of active control systems to short haul and long haul transports, and the demonstration of reconfigured active control aircraft. Key technical features and anticipated contributions of these technologies are outlined

Visual analysis for spatio-temporal event correlation in manufacturing

The analysis of events with spatio-temporal context and their interdependencies is a crucial task in the manufacturing domain. In general, understanding this context, for example investigating error messages or alerts is important to take corrective actions. In the manufacturing domain, comprehending the relations of errors is often based on the technicians\u27 experience. Validation of cause-effect relations is necessary to understand if an effect has a preceding causality, e.g., if an error is the result of multiple issues from previous working steps. We present an approach to investigate spatio-temporal relations between such events. Based on a time-sensitive correlation measure, we provide multiple coordinated views to analyze and filter the data. In collaboration with an industry partner, we developed a visual analytics approach for error logs reported by machines that covers a multitude of analysis tasks. We present a case study based on real-world event logs of an assembly line with feedback from our industry partner\u27s domain experts. The findings show that experts can effectively identify error dependencies that impair the overall assembly line productivity using our technique. Furthermore, we discuss how our approach is applicable in other domains

Fast-forward video visualization

Durch den Einsatz von Überwachungskameras kann sich eine sehr große Menge an Videomaterial ansammeln. Wenn es nötig ist, dieses Material manuell zu betrachten, so kann man durch die Verwendung des Schnellvorlaufs die Betrachtungszeit verkürzen. Bei digitalen Videos können dabei hohe Beschleunigungen durch das Überspringen von Bildern erreicht werden. Diese Sprünge können jedoch zu „Change Blindness“ führen und den Beobachter wichtige Ereignisse verpassen lassen. Im Rahmen dieser Diplomarbeit werden deshalb Methoden vorgestellt, die auf verschiedene Weise versuchen, die Informationen der übersprungenen Bilder wieder sichtbar zu machen. Biologisch motiviertes Blending erzeugt eine Bewegungsunschärfe bei den Objekten. Die Differenzen-Methode erzeugt multiple Instanzen der Objekte im Verlauf ihrer Bewegung. Beim Tracking werden die Objekte mit Pfeilen und Schweifen versehen, die Informationen über vergangene und zukünftige Bewegungen der Objekte vermitteln. Da es in Überwachungsvideos häufig Situationen gibt, in denen nichts passiert, kann man durch Adaptive Fast-Forward unterschiedliche Beschleunigungen nach Priorität der Ereignisse verwenden. Drei verschiedene Geschwindigkeitsvisualisierungen werden vorgestellt, die den Wechsel zwischen den Beschleunigungen besser vermitteln sollen. In einer Benutzerstudie werden dann die Methoden für den Schnellvorlauf genauer untersucht. Dabei wird die Objekterkennung und die Verfolgung von Bewegungen geprüft. Die Geschwindigkeitsvisualisierungen werden in einer zusätzlichen Aufgabe hinsichtlich ihrer Effektivität und Beanspruchung miteinander verglichen

The LiNiO2_2 Cathode Active Material: A Comprehensive Study of Calcination Conditions and their Correlation with Physicochemical Properties. Part I. Structural Chemistry

Following the demand for increased energy density of lithium-ion batteries, the Ni content of the Nickel-Cobalt-Manganese oxide (NCM) cathode materials has been increased into the direction of LiNiO$_2$ (LNO), which regained the attention of both industry and academia. To understand the correlations between physicochemical parameters and electrochemical performance of LNO, a calcination study was performed with variation of precursor secondary particle size, maximum calcination temperature and Li stoichiometry. The structural properties of the materials were analyzed by means of powder X-ray diffraction, magnetization measurements and half-cell voltage profiles. All three techniques yield good agreement concerning the quantification of Ni excess in the Li layer (1.6%–3.7%). This study reveals that the number of Li equivalents per Ni is the determining factor concerning the final stoichiometry rather than the calcination temperature within the used calcination parameter space. Contrary to widespread belief, the Ni excess shows no correlation to the 1$^{st}$ cycle capacity loss, which indicates that a formerly overlooked physical property of LNO, namely primary particle morphology, has to be considered

The LiNiO2_{2} Cathode Active Material: A Comprehensive Study of Calcination Conditions and their Correlation with Physicochemical Properties Part II. Morphology

A better understanding of the cathode active material (CAM) plays a crucial role in the improvement of lithium-ion batteries. We have previously reported the structural properties of the model cathode material LiNiO$_{2}$ (LNO) in dependence of its calcination conditions and found that the deviation from the ideal stoichiometry in LiNiO2 (Ni excess) shows no correlation to the 1st cycle capacity loss. Rather, the morphology of LNO appears to be decisive. As CAM secondary agglomerates fracture during battery operation, the surface area in contact with the electrolyte changes during cycle life. Thus, particle morphology and especially the primary particle size become critical and are analyzed in detail in this report for LNO, using an automated SEM image segmentation method. It is shown that the accessible surface area of the pristine CAM powder measured by physisorption is close to the secondary particle geometric surface area. The interface area between CAM and electrolyte is measured by an in situ capacitance method and approaches a value proportional to the estimated primary particle surface area determined by SEM image analysis after just a few cycles. This interface area is identified to be the governing factor determining the 1st cycle capacity loss and long-term cycling behavior