Entwicklung eines GKS-Gerätetreibers als Java-basierte Client/Server Webanwendung

Das Institut für Festkörperforschung (IFF) im Forschungszentrum Jülich und das Jülich Centre for Neutron Science (JCNS) in Garching bei München betreiben Neutronenexperimente. Die Messungen der Instrumente werden auf der Basis eines Grafischen Kernsystems (GKS) visualisiert. Mithilfe eines GKS-Gerätetreibes, der mit einer Client/Server- Kommunikation arbeitet, soll die bisher verwendete Anzeigemethode am Standort Jülich abgelöst werden.Zur Visualisierung der Daten wurde bereits ein Kommunikationsweg zwischen den Instrumenten und einem plattformunabhängigen Java-Applet konstruiert.Die Nachbildung der Ausgabeprimitiven des GKS erfolgt, indem grafische Grundelemente auf der Zeichenfläche eines Applets erzeugt werden.Das Ziel ist die Fertigstellung eines vollwertigen GKS-Gerätetreibers, der über eine Netzanbindung zu einem Instrument die verfügbaren Daten visualisiert

Modellbasierte Ansteuerung räumlich ausgedehnter Aktuator- und Sensornetzwerke in der Strömungsregelung

The topic of this thesis deals with the model-based development of a realtime, spatially enlarged actuator and sensor network for use in flow control. Within a cascaded control loop, the external flow control is connected via the network with defined interfaces as model-in-the-loop to the electromagnetic actuator system for influencing the flow. The flow is influenced by means of transversal surface waves on a three millimeter thick aluminum plate. This approach allows both experiments in the wind tunnel as well as the analysis of differences in network configurations, which lead to the determination of a favorable topology and computation distribution. This forms the basis for the specification of network configurations for the technical implementation of a spatially enlarged actuator and sensor network. The necessary tasks are mapped to the corresponding network nodes using a model. The communication layers are defined according to the OSI reference model. A real-time protocol is integrated on the transport layer and verified by a simulation. Various network simulations are investigated with regard to different boundary conditions and configurations and the results are discussed. A method for real-time calculation and application of smooth signal transitions between differently parameterized sinusoidal signals for driving the electromagnetic actuator system is presented. Using the wave control, the system is stabilized and the accuracy of the wave motion is ensured. For this purpose, an adapted model-based iterative learning control with gain switching is developed

Integration von mobilen iOS Geräten der Firma Apple in Instrumentierungsanwendungen

Am Peter Grünberg Institut (PGI) sowie am Jülich Centre for Neutron Science (JCNS) des Forschungszentrums Jülich werden für die Softwareentwicklung im Bereich der Instrumentierung schon seit Jahren einheitliche Softwarebibliotheken für grafische Benutzeroberflächen und die Visualisierung von Daten eingesetzt. Hierbei wurden das Qt-Toolkit sowie die GR-Visualisierungsbibliothek für 2D- und OpenGL für 3D-Visualisierungen als Standard festgelegt. Zahlreiche Anwendungen und Programmierschnittstellen aus dem Bereich der Instrumentierungs- und Auswertesoftware wurden auf der Basis dieser Bibliotheken entwickelt. Mit der zunehmenden Leistungsfähigkeit und Einsatzmöglichkeit mobiler Endgeräte sind jedoch auch die Anforderungen an die Software im technisch-wissenschaftlichen Bereich gestiegen.Ziel dieser Arbeit ist es, die o.g. Bibliotheken auf mobilen Endgeräten der Firma Apple nutzbar zu machen. Hierbei ist ein geeignetes Verfahren zu entwickeln, mit dem solche Endgeräte nach dem Client-Server-Prinzip in vorhandene Anwendungen integriert werden können. Dazu sollen sich mobile Geräte über das Netzwerk an Qt- und GR-basierte Programme andocken können, um diese zu beobachten und gegebenenfalls zu steuern. Der Anpassungsaufwand für die vorhandenen Instrumentierungsanwendungen sollte dabei minimal sein. Im Rahmen dieser Arbeit ist eine flexible und effiziente Kommunikationsmethode sowohl für die Benutzerinteraktion als auch für den Austausch von Daten zu entwerfen und zu implementieren. Das resultierende Verfahren ist am Beispiel der KWS1- Livedisplay Software konkret in die Praxis umzusetzen

Deterministic Transport Protocol Verified by a Real-Time Actuator and Sensor Network Simulation for Distributed Active Turbulent Flow Control

Total drag of common transport systems such as aircrafts or railways is primarily determined by friction drag. Reducing this drag at high Reynolds numbers (<104) is currently investigated using flow control based on transversal surface waves. For application in transportation systems with large surfaces a distributed real-time actuator and sensor network is in demand. To fulfill the requirement of real-time capability a deterministic transport protocol with a master slave strategy is introduced. With our network model implemented in Simulink using TrueTime toolbox the deterministic transport protocol could be verified. In the model the Master-Token-Slave (MTS) protocol is implemented between the application layer following the IEEE 1451.1 smart transducer interface standards and the Ethernet medium access protocol. The model obeys interfaces to the flow control and the DAQ-hardware allowing additional testing in model in the loop simulations

Ethernet based time synchronization for Raspberry Pi network improving network model verification for distributed active turbulent flow control

Friction drag primarily determines the total drag of transport systems. A promising approach to reduce drag at high Reynolds numbers (> 104) are active transversal surface waves in combination with passive methods like a riblet surface. For the application in transportation systems with large surfaces such as airplanes, ships or trains, a large scale distributed real-time actuator and sensor network is required. This network is responsible for providing connections between a global flow control and distributed actuators and sensors. For the development of this network we established at first a small scale network model based on Simulink and TrueTime. To determine timescales for network events on different package sizes we set up a Raspberry Pi based testbed as a physical representation of our first model. These timescales are reduced to time differences between the deterministic network events to verify the behavior of our model. Experimental results were improved by synchronizing the testbed with sufficient precision. With this approach we assure a link between the large scale model and the later constructed microcontroller based real-time actuator and sensor network for distributed active turbulent flow control

Development of a real time actuation control in a network-simulation framework for active drag reduction in turbulent flow

Active drag reduction in high Reynolds numbers (<10^4) by span-wise transversal surface waves is a promising approach to gain less energy consumption and less pollution in air transportation. The development of robust methods for this flow control is based on numerical studies and wind tunnel experiments. In final application, flow control is expected to be performed by real time actuator and sensor networks. In a first step a SIMULINK model of the network is developed which is also used to drive wind tunnel experiments for parameter studies and testing of control algorithms. In this paper we focus on the LabView based interface to the actuating and sensing hardware enabling continuous changes of actuating parameters in real time. This implementation already allows for extensive and efficient experimental wind tunnel studies

Raspberry Pi based testbed verifying TrueTime network model parameters forapplication in distributed active turbulent flow control

The total drag of transport systems such as airplanes, ships and/or trains is primarily determined by frictiondrag. At high Reynolds numbers (< 104) transversal surface waves are a promising approach for active drag reduction.For the application in airplanes or ships a large scale distributed real-time actuator and sensor network is required in orderto provide a connection between a global flow control and the distributed actuators and sensors. For the developmentof this network we established a network model based on Simulink and TrueTime. To determine the network- andtransmission-parameters for the model we set up a Raspberry Pi based testbed as a physical representation of a first smallscale model. Using this testbed the parameters for the TrueTime network model have been retrieved. With this approachwe assure a link between the large scale model and the later microcontroller based real time actuator and sensor networkfor distributed active turbulent flow control

Control of Nonlinear Coupled Electromagnetic Actuators for Active Drag Reduction in Turbulent Flow

The research group FOR1779 “active drag reduction via wavy surface oscillations” develops robust methods for reduction of turbulent friction drag by flow control. The planned concentration on unsteady flow conditions requires a control of the electromagnetic actuator system for generation of transversal surface waves. The bars are positioned in parallel and coupled with an aluminum surface to generate a travelling wave perpendicular to the flow field. The actuator system can be approximately modelled as a system of coupled, damped, driven, one dimensional oscillators with strong nonlinear coupling. The focused parameter range guarantees only an elastic deformation of the aluminum surface. Previous model-based investigations show a successful control with an iterative learning controller (ILC). The friction, the noise (measurement- and system noise) and the delay time proved to be critical parameters. These parameters are therefore determined by measurements on the uncontrolled prototype. The determination of the parameters enables the refinement of the model and the optimization of the control. In addition to the ILC also other control strategies (e.g. PID, IMP, RC) have been investigated accordingly and compared in terms of accuracy, robustness and energy efficiency