On a family of orthogonal wavelets on the quincunx grid

In this paper, we introduce a new family of nonseparable orthogonal wavelets on the quincunx grid arising from Butterworth wavelets with an odd number of vanishing moments. Our wavelets are closely related to bireciprocal wave digital filters

Six Step Control vs Direct Torque Control comparative evaluation for BLDC drive

This research paper deals with the two closed loop speed control algorithms namely Six-Step and Direct Torque Control for Brushless DC Motor Drive. These two control techniques are critically evaluated for the performance comparison in terms of efficiency, steady state response and transient condition. The simulation models of the two controllers are developed in MATLAB/SIMULINK environment. The simulation results show close agreements and provide good insight for the evaluation of these two control techniques

Multidimensional Wave Digital Filters and Wavelets (Mehrdimensionale Wellendigitalfilter und Wavelets)

Das Kernziel dieser Dissertation ist der Entwurf von orthogonalen, mehrdimensionalen Wellendigitalfiltern für nichtseparierbare Abtastmatritzen (z.B. Quincunx-, Hexagonal-, BCCS-Matrix). Damit der Leser einen einfacheren Einstieg in den Filterentwurf hat, sind einige Grundlagen elektrischer Netzwerke und Filter vom analogen als auch vom digitalen Typ in Kapitel 2 angegeben. Wichtiges Beiwerk, welches digitale Filter mit der Wavelettransformation verknüpft, ist zusammengefaßt. Es wird weiterführende Literatur angegeben, die diesen Stoff ausführlicher behandelt. Weiterhin werden wichtige Abtastsätze präsentiert und ein angegebener Vergleich über die minimale Abtastrate zeigt einen interessanten Aspekt. Kapitel 3 zeigt Verbindungen von Wellendigitalfiltern zu ihren analogen Referenzfiltern. Desweiteren wird gezeigt, wie man eine perfekte Rekonstruktion mit Filterbänken erreicht ohne eine spektrale Faktorisierung durchführen zu müssen. Bekannte Wavelets, wie z.B. Meyer Wavelets, Sinc-Wavelet (Littlewood-Paley Wavelet), Haar Wavelet, Daubechies Wavelets und Butterworth Wavelets, sind in Kapitel 4 präsentiert. Weiterhin werden bekannte Filter gezeigt, die (sofern einige Einschränkungen eingehalten werden) benutzt werden können um neue orthonormale Wavelets, nämlich Cosinus-Rolloff Wavelets und Chebyshev Wavelets zu generieren. Es wird auch ein Filter präsentiert mit welchem eine Verschiebung der Abtastwerte um einen beliebigen reellen Wert effizient erfolgen kann. In den Kapiteln 5, 6 und 7 werden Entwurfsmethoden für mehrdimensionale Filter angegeben mit denen nichtseparierbare, orthogonale Wavelets (zwei- und dreidimensional) erzeugt werden können

Implementation of Robots Integration in Scaled Laboratory Environment for Factory Automation

Robotic systems for research and development of factory automation are complex and unavailable for broad deployment in robotic laboratory settings. The usual robotic factory automation setup consists of series of sensors, robotic arms and mobile robots integrated and orchestrated by a central information system. Cloud-based integration has been gaining traction in recent years. In order to build such a system in a laboratory environment, there are several practical challenges that have to be resolved to come to a point when such a system can become operational. In this paper, we present the development of one such system composed of (i) a cloud-based system built on top of open platform for innovation in logistics, (ii) a prototyped mobile robot with a forklift to manipulate pallets in a “factory” floor, and (iii) industrial robot ABB IRB 140 with a customized gripper and various sensors. A mobile robot is designed as an autonomous four Mecanum wheels system with on-board LiDAR and RGB-D sensor for simultaneous localization and mapping. The paper shows a use case of the overall system and highlights the advantages of having a laboratory setting with real robots for the research of factory automation in a laboratory environment. Moreover, the proposed solution could be scaled and replicated in real factory automation applications

Implementation of Robots Integration in Scaled Laboratory Environment for Factory Automation

Robotic systems for research and development of factory automation are complex and unavailable for broad deployment in robotic laboratory settings. The usual robotic factory automation setup consists of series of sensors, robotic arms and mobile robots integrated and orchestrated by a central information system. Cloud-based integration has been gaining traction in recent years. In order to build such a system in a laboratory environment, there are several practical challenges that have to be resolved to come to a point when such a system can become operational. In this paper, we present the development of one such system composed of (i) a cloud-based system built on top of open platform for innovation in logistics, (ii) a prototyped mobile robot with a forklift to manipulate pallets in a “factory” floor, and (iii) industrial robot ABB IRB 140 with a customized gripper and various sensors. A mobile robot is designed as an autonomous four Mecanum wheels system with on-board LiDAR and RGB-D sensor for simultaneous localization and mapping. The paper shows a use case of the overall system and highlights the advantages of having a laboratory setting with real robots for the research of factory automation in a laboratory environment. Moreover, the proposed solution could be scaled and replicated in real factory automation applications