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Bei modernen Lokomotiven mit Drehstrom-Asynchronmotoren und mit bis zu 7 Megawatt Leistung, neigt das Antriebssystem bei nicht ausreichendem Kraftschluß zwischen Treibradsatz und Schiene zum 'Durchdrehen'. Bei diesem Vorgang wird nahezu die gesamte Energie zur Beschleunigung des Radsatzes eingesetzt, was zu mechanischen Schäden an den Rädern und Schienen führen kann. Beim Bremsen ist dies ähnlich, die Räder gleiten auf den Schienen, wenn zuviel Bremskraft gefordert wird. Die übertragbaren Zug- und Bremskräfte werden primär durch die Radsatzlast und den Kraftschlußbeiwert bestimmt, wobei der Verlauf der Kraftschlußkennlinie als Funktion des Schlupfs oder der Schlupfgeschwindigkeit im wesentlichen durch den Schienenzustand (naß oder trocken) bestimmt wird. Eine hohe Kraftschlußnutzung wird dann erreicht, wenn man laufend denjenigen Schlupfwert einstellt, der zum jeweiligen Kraftschlußmaximum führt. Hierzu werden in der Praxis verschiedene Konzepte und Methoden eingesetzt, es ist bis heute jedoch keine Methode bekannt, den Verlauf der Kraftschlußkennlinie meßtechnisch laufend zu erfassen oder rechentechnisch zu bestimmen. Bei der hier vorgestellten Vorgehensweise wurde der mechanische Antrieb zusammen mit dem Rad-Schiene-Kontakt als Zustandsraumodell beschrieben. Die Betrachtungen beruhen dann auf einer Frequenzganguntersuchung des eingeführten linearen Zustandsraummodells. Aufgrund der Linearisierung gelten die Ergebnisse der Frequenzgangsberechnung nur für den jeweiligen Betriebspunkt der Kraftschlußkennlinie, also für eine bestimmte Steigung. Variiert man nun die Steigung, so läßt sich der Einfluß der nichtlinearen Kraftschlußkennlinien ermitteln. Zur Messung von Frequenzgängen eignen sich insbesondere Verfahren der Orthogonalen Korrelation. Die technische Realisierung wird skizziert. Die Meßinformation ist dann die Basis für eine Regelung, die ein permanentes optimales Fahren im Kraftschlußmaximum zuläßt und zwar beim Beschleunigen und beim Bremsen. Das beschriebene Meß- und Regelungsverfahren ist derzeit in der Schweiz in der Betriebserprobung.
Ein neuer Ansatz wurde für mobile Roboter zur gleichzeitigen 3D (Drei-Dimensionaler) Kartierung und Lokalisierung vorgestellt. Die Grundlage bilden attributierte Flächenmodelle, die z.B. von segmentierten Laserscanner-Tiefenbildern stammen. Zur Optimierung der Gesamtähnlichkeit zwischen Flächenmodellen unter Zeitbedingungen werden mehrere Verfahren (Beschränkte Baumsuche, Iterative Verfeinerung, Evolutionäralgorithmus) kombiniert. Es wird speziell anhand der Ähnlichkeitsmaße gezeigt, wie das Wissen über die Lage stufenweise generiert und verwendet wird. Erste Messungen an realen segmentierten Tiefenbildfolgen zeigen, dass das Verfahren unbekannte übelappung, Verdeckung und Segmentierungsfehler toleriert sowie Echtzeitpotenzial besitzt.
Die Verarbeitung analoger Signale durch digitale Techniken ist durch die enorme Leistungsfähigkeit der Prozessoren zwischenzeitlich zum Standard geworden. Eine hinreichende Genauigkeit der digitalen Verarbeitung kann durch Wahl der notwendigen Wortbreite relativ einfach bewerkstelligt werden, wobei der Aufwand mit zunehmender Wortbreite linear, teilweise auch quadratisch steigt. Zum Flaschenhals in der Verarbeitung wird aber häufig die Wandlung der analog vorliegenden Signale in digitale Signale, ebenso die Rückwandlung der digitalen Signale in analoge Spannungs- oder Stromverläufe. Der Aufwand für diese teils analogen, teils digitalen Systeme steigt oft exponentiell mit der geforderten Genauigkeit bzw. Auflösung der Systeme und erfordert in konventioneller Technik bei hoher Auflösung aufwendige Maßnahmen auf dem Chip. Oversampling- und Rauschfärbungs-Methoden sind in der Verarbeitung von Audio-Signalen schon seit langem probate Mittel, um die Auflösung mit moderatem Aufwand zu erhöhen. Derartige Techniken werden zwischenzeitlich auch gerne im Bereich der Antriebstechnik, wo die Anforderungen an die erforderliche Positioniergenauigkeit zunehmen, eingesetzt. Ziel des Vortrags ist eine leicht verständliche Einführung in die Themengebiete der Überabtastung und der Rauschfärbung und ihre Anwendung im Hinblick auf Rundungsvorgänge im digitalen Bereich, in D/A-Wandlern und A/D-Wandlern vom Delta-Sigma-Typ.
The establishment of a software tool chain among requirements management tools, black box test approach tool CTE XL and RTRT is proposed in this paper. The use of Classification Tree Method ensures the reduction in the number of test cases and promises an increased efficiency when testing. The traceability of test cases and requirements is guaranteed by the established software tool chain with well defined interfaces. As the experimental results point out, a better test coverage can be achieved. Future work can be based on automatic generation of init and expected values for testing, requiring no interference from a software quality engineer. In conclusion, the tasks that need to be performed by the software quality engineers is to define the black box test cases using CTM/CTE XL, import the requirements from the requirements management tools, import the XML file to test tool RTRT. By giving the initial and expected values the testing can be performed in a comfortable way.
In the recent two years the authors have developed a light weight and low power flight control system for model helicopters consisting of an attitude and heading reference system (AHRS), a navigator (INS) augmented with GPS, barometric altitude sensor and a magnetic sensor, a flight control computer (FCC) and bidirectional ground data links. The system has been tested on a commercial stunt flight model helicopter. The AHRS consists of three MEMS-gyros, two 2-axis MEMS accelerometers and a microcontroller performing the required sensor compensation and data processing to generate attitude angles and true rate and acceleration data of the flying platform. The heading angle is augmented with a 2-axis magnetic sensor. The AHRS is stunt flight capable. The INS integrates the acceleration data to obtain velocity and position data. All data are calculated in both the helicopter and the local earth frame with 50 Hz rate. The algorithm is augmented with GPS data for the lateral movement and with a barometric altitude sensor for the vertical movement. The barometric data are compensated for air pressure changes due to the helicopter main rotor. The FCC contains a set of control loops in order to stabilize the helicopter in all axis and to perform commanded velocity and position tasks. The sampling rate for the control loops is again 50 Hz allowing flight control with high bandwidth. Various safety features are implemented in the software. The bidirectional data link is based on a 2.4 GHz Bluetooth Class I RF-link with a 115 kbaud data rate. A dipole antenna is used on the helicopter, an automatically tracking patch antenna is used on the ground. For commanded velocity flight a standard 35 MHz RF-link is used. For data sampling, monitoring and mode control a laptop is used on the ground. Several operating modes are implemented ranging from commanded velocity flight to simple automatic stunt flight according to predefined flight tracks. The model helicopter is an ALIGN TREX 600 with 3 kg flight mass and a brushless electric motor. The rotor diameter is 1.40 m. The helicopter is able to carry a payload which mass depends on the size of the installed LiPo-cells and the purpose of the flight mission. The system has been tested in quite a few flight tests and missions. The helicopter is controlled safely up to wind loads of at least 5 Beaufort - 6 Beaufort. Data and video captures will be presented. If permission is granted, a demonstration flight will be performed on the premises of the conference.
Seit den ersten Projekten der 90er Jahre arbeiten Hochschulen daran, geeignete Servicestrukturen für E-Learning zu etablieren, die die erforderliche technische, didaktische und organisatorische Unterstützung hochschulweit zur Verfügung stellen. Ging es zunächst darum, Services überhaupt dauerhaft zu sichern, steht heute die Frage des „wie“ im Vordergrund. Dabei wird am Bereich E-Learning ein eigentlich viel allgemeineres Problem deutlich: Die bisher überwiegende Organisation der Hochschule nach funktionellen Einheiten stößt an ihre Grenzen. Wir schlagen eine stärker prozessorientierte Sichtweise vor, analog zu Entwicklungen bei der Organisation von Unternehmen.
A new miniaturized capsule with 32bit processor and bidirectional communication system is being developed for multitask application. The capsule is designed to be a platform for medical assistant application inside the body. The processor core SIRIUS has been developed, simulated, synthesized to a netlist and verified. The designed telemetry unit is a synchronous bidirectional communication block using continuous phase DQPSK of 115 kHz low carrier frequency for inductive data transmission suited for human body energy transfer. The communication system can assist the electronic pill to trigger an actuator for drug delivery, to record temperature, or to measure pH of the body. The complete system is designed to fit small-size mass medical application with low power consumption, size of 7x25 mm. The system is designed, simulated, emulated on FPGA, and routed in AMIS Technology.
This paper presents an enhancement on QPSK modulation technique for near field communication (NFC). The enhanced modulation is based on continuous-phase QPSK with Gaussian filtering during switch from one phase to the other. Signal processing is done digitally with minimum external discrete components for air interface. The telemetry system can be used to assist a smart capsule (slave) that can be swallowed to establish data communication with external device (master). The system is designed, simulated, and emulated on FPGA showing 20 dB attenuation on side-lobes of the spectrum.
Das Handbuch der Electronic Design Automation ist ein unentbehrlicher Ratgeber für Praxis und Ausbildung und sollte an keinem CAE-Arbeitsplatz fehlen. Es dient all denen, die in der industriellen Praxis mit der Entwicklung moderner Elektronik betraut sind. Dazu enthält es eine Fülle von aktuellen, kompakten und praxisnahen Informationen über das Gebiet.
“Today’s network landscape consists of quite different network technologies, wide range of end-devices with large scale of capabilities and power, and immense quantity of information and data represented in different formats” [9]. A lot of efforts are being done in order to establish open, scalable and seamless integration of various technologies and content presentation for different devices including mobile considering individual situation of the end user. This is very difficult because various kinds of devices used by different users or in different times/parallel by the same user which is not predictable and have to be recognized by the system in order to know device capabilities. Not only the devices but also Content and User Interfaces are big issues because they could include different kinds of data format like text, image, audio, video, 3D Virtual Reality data and upcoming other formats. Language Learning Game (LLG) is such an example of a device independent application where different kinds of devices and data formats, as a content of a flashcard is used for a collaborative learning. The idea of this game is to create a short story in a foreign language by using mobile devices. The story is developed by a group of participants by exchanging sentences/data via a flashcard system. This way the participants can learn from each other by knowledge sharing without fear of making mistakes because the group members are anonymous. Moreover they do not need a constant support from a teacher.
The following paper presents the results of a feasibility study about Bluetooth Low Energy (BLE) based wireless sensors. The development of industrial wireless sensors leads to important demands for the wireless technologies like a low energy consumption and a resource saving simple protocol stack. Bluetooth Low Energy (BLE) is a rather new wireless standard which will completely fulfill these fundamental requirements. A self-designed BLE sensor system has been used to explore the common applicability of BLE for wireless sensor systems. The evaluation results of various analyses with the BLE sensor system are now presented in this paper.
Security in IT systems, particularly in embedded devices like Cyber Physical Systems (CPSs), has become an important matter of concern as it is the prerequisite for ensuring privacy and safety. Among a multitude of existing security measures, the Transport Layer Security (TLS) protocol family offers mature and standardized means for establishing secure communication channels over insecure transport media. In the context of classical IT infrastructure, its security with regard to protocol and implementation attacks has been subject to extensive research. As TLS protocols find their way into embedded environments, we consider the security and robustness of implementations of these protocols specifically in the light of the peculiarities of embedded systems. We present an approach for systematically checking the security and robustness of such implementations using fuzzing techniques and differential testing. In spite of its origin in testing TLS implementations we expect our approach to likewise be applicable to implementations of other cryptographic protocols with moderate efforts.
A platform of an electronic capsule is being developed for multi-task medical assistant application. It includes a near field telemetry unit for bidirectional communication system of 115 KHz low carrier frequency for inductive data transmission suited for human body energy transfer. The system triggers an actuator for drug delivery in various time and release forms via wireless external control, it has the ability to record temperature, measure pH of the body (additional sensors), and retrieve data to the outside. It consists of a 32bit processor, memory, external peripheries, and detection facility. The complete system is designed to fit small-size mass medical application with low power consumption, size of 7x25mm. The system is designed, simulated and emulated on FPGA. A final layout of the complete chip design is still under progress.
Learning to Walk With Toes
(2020)
This paper explains how a model-free (with respect to the robot model and the behavior to learn) approach can facilitate learning to walk from scratch. It is applied to a simulated Nao robot with toes. Results show an improvement of 30% in speed compared to a model without toes and also compared to our model-based approach, but with less stability.
Autonomous humanoid robots require light weight, high torque and high speed actuators to be able to walk and run. For conventional gears with a fixed gear ratio the product of torque and velocity is constant. On the other hand desired motions require maximum torque and speed. In this paper it is shown that with a variable gear ratio it is possible to vary the relation between torque and velocity. This is achieved by introducing systems of rods and levers to move the joints of our humanoid robot ”Sweaty II”. On the basis of a variable gear ratio low speed and high torque can be achieved for those joint angles, which require this motion mode, whereas high speed and low torque can be realized for those joint angles, where it is favorable for the desired motion.
Existing approaches solving multi-vehicle pickup and delivery problems with soft time windows typically use common benchmark sets to verify their performance. However, there is a gap from these benchmark sets to real world problems with respect to instance size and problem complexity. In this paper we show that a combination of existing approaches together with improved heuristics is able to deal with the instance sizes and complexity of real world problems. The cost savings potential of the heuristics is compared to human dispatching plans generated from the data of a European carrier.
Die Einhaltung der innerhalb der Designphase festgelegten Architektur eines Softwareprojektes muss w ̈ahrend der Entwicklungsphase sichergestellt werden. Dieses Papier beschreibt eine Erweiterung des Eclipse-Plugins JDepend4Eclipse, die die Verwaltung von Regels ̈atzen erlaubt und die Pr ̈ufung auf in einem Projekt vorhandene, unerlaubte Abh ̈angigkeiten auf Knopfdruck innerhalb der Entwicklungsumgebung vornimmt. Die Erweiterung des Plugins wird bereits erfolgreich in internen Projekten der Hochschule Offenburg eingesetzt und soll demn ̈achst ̈offentlich verf ̈ugbar sein.
Es sollte in dieser Schrift untersucht werden, inwieweit bei Änderungen im Bereich der Planung, Durchführung und Auswertung von klinischen Arzneimittelprüfungen die Bewertung mit wissenschaftlichen oder politischen Begründungen erfolgt und inwieweit wissenschaftliche Regeln für politische Zwecke genutzt werden.
Aktiver RFID-Sensor
(2008)
Das in Schramberg ansässige Unternehmen Schweizer Electronic, einer der großen europäischen Leiterplattenhersteller, hat sich ein neues Geschäftsfeld als Systemlieferant für mikroelektronische Geräte erschlossen. Gemeinsam mit dem Institut für Angewandte Forschung der Hochschule Offenburg und Siemens hat das Unternehmen einen Datenlogger mit einer ISO 15693 kompatiblen 13,56 MHz RFID-Luftschnittstelle zur Serienreife entwickelt. Die SEAGsens Temperaturmessgeräte aus der Vorserienproduktion haben die ersten Feldtests erfolgreich bestanden. Die Großserienproduktion wird noch in diesem Jahr anlaufen.
A new electronic capsule with bidirectional communication system is being developed for multi-task application. The capsule is designed to be a platform for medical assistant application inside the body. The designed telemetry unit is a synchronous bidirectional communication block using continuous phase DQPSK of 115 kHz low carrier frequency for inductive data transmission suited for human body energy transfer. The communication system can assist the electronic pill to trigger an actuator for drug delivery, to record temperature, or to measure pH of the body. It consists additionally to a 32bit processor, memory, external peripheries, and detection facility. The complete system is designed to fit small-size mass medical application with low power consumption, size of 7x25mm. The system is designed, simulated and emulated on FPGA. A final layout of the complete chip design is still under progress.
The Institute of Applied Research Offenburg is working in the field of autonomous data loggers since many years. In collaboration with industry, a new RFID based active sensor data logger for continuous recording of temperature has been developed and is now manufactured in mass production. Compared to existing systems, an unusual large data memory is integrated, which can be used via a simplified file system in a flexible way. The system will be used to accompany and monitor temperature sensitive goods of high value. The transponder is the first member of a new class of logging devices, the smallest will be not larger than a 2 Euro-coin with a fully integrated ASIC frontend.
Remote measurement of the physiology, so-called biotelemetry, is a key technology in the modern veterinary medicine. The usage of wireless implants has less impact on the behavior of animals than manual measurement methods and cause less disturbance than wired devices. But, common biotelemetry still uses proprietary communication and power concepts focused on small systems with one animal. Therefore, the University of Applied Sciences Offenburg is developing a low-cost RFID system called muTrans1, which is able to measure ECG, pressure, temperature, oxygen saturation and activity. The muTrans uses an own RFID sensor transponder and standardized commercial components and combines them to a scalable RFID system able to build-up RFID sensor networks with a nearly unlimited size.
In this paper, a complete passive transponder device has been discussed which is meant to monitor leakage in silicone breast implants. The passive tag operates in the HF frequency range of 13.56MHz using RFID ISO 15693 standard. The complete system consists of the transponder, reader and a PC. This paper focusses on the development of such a state of the art passive RFID transponder to monitor the wellness of the silicone breast implants periodically in order to detect leakage in the same. Keyword: RFID (Radio frequency identification device), EM (Electromagnetic) field, Passive Transponder, Silicone breast implants.
Die direkte Vermarktung von Strom aus Wind und Sonne stellt einen wichtigen Schritt der Energiewende dar. Einerseits kann durch die Marktintegration die Unabhängigkeit von EEG-Subventionen gelingen. Andererseits wird über diese Mechanismen die Stromerzeugung an der Nachfrage orientiert, wodurch zur Stabilität des Stromnetzes beigetragen wird. Ein Beispiel dafür ist die lokale Vermarktung von PV-Strom in einem Mietshaus. Für deren Umsetzung benötigen die Akteure ein Mess- und Steuerungssystem, dass vor Ort Zähler- und Anlagendaten erfasst und die Abrechnung der Mieter vereinfacht. Außerdem sollte es Kennwerte wie beispielsweise den PV-Anteil berechnen und gegebenenfalls ein Blockheizkraftwerk steuern. Weder die Zählersysteme der Messstellenbetreiber noch die Steuerungssysteme von PV- oder Blockheizkraftwerken erfüllen diese Anforderungen ausreichend. In der Forschung ist man währenddessen bereits einen Schritt weiter und arbeitet an technischen Systemen, die für wesentlich komplexere Energiesystem- und Markttopologien ausgelegt werden. In dieser Arbeit werden die neuen technischen Anforderungen der Direktvermarktung in einem Mietshaus identifiziert und mit dem Stand aktueller Marktprodukte sowie dem System »OpenMUC« aus der Forschung verglichen.
Die immer weitreichenderen Anwendungen des Smart Metering und des Smart Grid stellen immer höhere Anforderungen an Kommunikationstechnologien, die die Zielkonflikte aus Echtzeitfähige, Stabilität, Kosten und Energieeffizienz möglichst anwendungsoptimiert und auf einem immer höheren Niveau lösen. Insbesondere im Bereich der so genannten Primärkommunikation zwischen einem Sensor- oder Aktorknoten und einem Datensammler mit Gatewayfunktionalität konnten in den vergangenen Jahren wesentliche Fortschritte erzielt werden. Zu nennen sind hierbei insbesondere die Aktivitäten der ZigBee Alliance rund um den offenen Spezifikationsprozess des ZigBee Smart Energy Profiles (SEP) und der OMS-Gruppe beim ZVEI, die auf dem Wireless M-Bus nach EN13757-4 aufbauen, der sich seinerseits lebhaft und zielgerichtet weiter entwickelt. Der Beitrag diskutiert die vorhandenen Einschränkungen und die verfügbaren Lösungsansätze. Er illustriert diese anhand einiger öffentlich geförderter Projekte, an denen das Team des Autors beteiligt ist.
This paper presents the elements and the results from the European research project inCASA (Integrated Network for Completely Assisted Senior Citizen’s Autonomy), which designed and implemented a seamless integration of heterogeneous systems and network protocols for regionally distributed telecare and telehealth applications. The integration includes a multitude of physical interface, the transcoding of data models using embedded middleware, and a backend system with open interfaces. The implementation was verified in field tests in five European countries.
Immer mehr Anwendungen der Heim- und der Gebäudeautomatisierung werden vernetzt, weil damit erweiterte Funktionen ermöglicht oder Kosten gespart werden können. Dabei führt eine Reihe von Aspekten zu einem erhöhten Risiko für diese vernetzten Systeme. Gegenwärtig arbeiten verschiedene Gruppen an Sicherheitslösungen für die vernetzte Heim- und Gebäudeautomatisierung. Der Beitrag gibt einen Überblick über diese Aktivitäten und zeigt die wesentlichen Entwicklungsrichtungen auf.
Efficient, secure and reliable communication is a major precondition for powerful applications in smart metering and smart grid. This especially holds true for the so called primary communication in the Local Metrological Network (LMN) between meter and data collector, as the LMN comes with the most stringent requirements with regard to cost, range, as well as bandwidth and energy efficiency. Until today, LMN field tests are operated all over the world. In these installations, however, energy autarkic systems play a marginal role. This contribution describes the results of the framework 7 (FP 7) WiMBex project (“Remote wireless water meter reading solution based on the EN 13757 standard, providing high autonomy, interoperability and range”). In this project an energy autarkic water meter was developed and tested, which follows the specification of the Wireless M-Bus protocol (EN 13757). The complete system development covers the PCB with the RF transceiver and the microcontroller, the energy converter and storage, and the software with the protocol. This contribution especially concentrates on the design, the development and the verification of the routing protocol. The routing protocol is based on the Q mode of EN13757-5 (Wireless M-Bus) and was extended by an additional energy state related parameter. This extension is orthogonal to the existing protocol and considers both the charge level and the charge characteristics (rate of occurrences, intensity). The software was implemented in NesC under the operating system TinyOS. The system was verified in an automated test bed and in field tests in UK and Ireland.
In the last decade, IPv6 over Low power Wireless Personal Area Networks, also known as 6LoWPAN, has well evolved as a primary contender for short range wireless communication and holds the promise of an Internet of Things, which is completely based on the Internet Protocol. In the meantime, various 6LoWPAN implementations are available, be it open source or commercial. One of these implementations, which was developed by the authors' team, was tested on an Automated Physical Testbed for Wireless Systems at the Laboratory Embedded Systems and Communication Electronics of Offenburg University of Applied Sciences, which allows the flexible setup and full control of arbitrary topologies. It also supports time-varying topologies and thus helps to measure performance of the RPL implementation. The results of the measurements show a very good stability and short-term and long-term performance also under dynamic conditions. In addition, it can be proven that the performance predictions from other papers are consistent with real-life implementations.
In dem Maße, in dem sich die industrielle Automatisierung verändert, verändern sich auch die Anforderungen an die Sicherheit. Neben der funktionalen Sicherheit rückt dabei immer mehr die Datensicherheit in den Mittelpunkt. Als „best practice“ bietet es sich an, bewährte Sicherungstechniken aus der IT auch in der industriellen Kommunikation einzusetzen.
Während neue Komponenten für „Short Range Wireless Networks“ längere Zeit eher moderate technische Fortschritte gebracht haben, sind in jüngerer Zeit einige außerordentlich interessante strategische Entwicklungslinien deutlich geworden, die in diesem Beitrag an Hand von konkreten Produktbeispielen vorgestellt werden.
Monitoring of the molecular structure of lubricant oil using a FT-Raman spectrometer prototype
(2014)
The determination of the physical state of the lubricant materials in complex mechanical systems is highly critical from different points of view: operative, economical, environmental, etc. Furthermore, there are several parameters that a lubricant oil must meet for a proper performance inside a machine. The monitoring of these lubricants can represent a serious issue depending on the analytical approach applied. The molecular change of aging lubricant oils have been analyzed using an all-standard-components and self-designed FT-Raman spectrometer. This analytical tool allows the direct and clean study of the vibrational changes in the molecular structure of the oils without having direct contact with the samples and without extracting the sample from the machine in operation. The FT-Raman spectrometer prototype used in the analysis of the oil samples consist of a Michelson interferometer and a self-designed photon counter cooled down on a Peltier element arrangement. The light coupling has been accomplished by using a conventional 62.5/125μm multi-mode fiber coupler. The FT-Raman arrangement has been able to extract high resolution and frequency precise Raman spectra, comparable to those obtained with commercial FT-Raman systems, from the lubricant oil samples analyzed. The spectral information has helped to determine certain molecular changes in the initial phases of wearing of the oil samples. The proposed instrument prototype has no additional complex hardware components or costly software modules. The mechanical and thermal irregularities influencing the FT-Raman spectrometer have been removed mathematically by accurately evaluating the optical path difference of the Michelson interferometer. This has been achieved by producing an additional interference pattern signal with a λ= 632.8 nm helium-neon laser, which differs from the conventional zero-crossing sampling (also known as Connes advantage) commonly used by FT-devices. It enables the FT-Raman system to perform reliable and clean spectral measurements from the analyzed oil samples.
On the possibility to use leaky feeders for positioning in chirp spread spectrum technologies
(2014)
Real Time Localization Systems using electromagnetic waves have significantly evolved during the last years. They also might be used in industrial and in mining environments. Here, topologies might include tunnels, where it might be difficult to ensure the field coverage. Leaky feeder cables are a common solution in case of normal radio communication. In this paper, we study the possibilities to use leaky feeders also for Time-of-Flight based real time localization in such linear topologies, like tunnels, but possibly also for 2D-localization. Theoretical analysis is verified with real-life measurements, which were performed using Chirp Spread Spectrum Technologies.
Non-responder rate in cardiac resynchronization therapy (CRT) could be partly decreased by individualized parameter optimization excluding adverse hemodynamic timing. In heart failure patients with sinus rhythm, an atrial kick enables the completion of atrial contraction and may significantly enhance the ventricular filling. Compared to that, exclusion of atrial kick is a sign of suboptimal atrioventricular timing. However, the recognition of atrial kick by echocardiography will be negatively affected in patients requiring a very short or long AV delays.
Automated RF Emulator for a Highly Scalable IEEE802.11p Communication and Localization Subsystem
(2014)
The IEEE802.11p standard describes a protocol for car-to-X and mainly for car-to-car-communication. In the research project Ko-TAG, which is part of the research initiative Ko-FAS, cooperative sensor technology is developed for the support of highly autonomous driving. The Ko-TAG subsystem improves the real-time characteristics of IEEE802.11p needed for precise time of flight real-time localization while still fitting into the regulatory schemes. A secondary radar principle based on communication signals enables localization of objects with simultaneous data transmission. The Ko-TAG subsystem mainly concentrates on the support of traffic safety applications in intra-urban scenarios. This paper details on the development of a fully automated RF emulator used to test the Ko-TAG subsystem.
The RF emulator includes the physical networking nodes, but models the RF environment using RF-waveguides. The RF emulator allows the controlling of path loss and connectivity between any of the nodes with the help of RF attenuators and programmable RF switches, while it is shielded against its surrounding RF environment in the lab. Therefore it is an inexpensive alternative to an RF absorber chamber, which often is not available or exceeds the project’s budget.
Details about the system definition can be found in earlier papers. Test results are shown in the last part of the paper.
Active safety systems for advanced driver assistance systems act within a complex, dynamic traffic environment featuring various sensor systems which detect the vehicles’ surroundings and interior. This paper describes the recent progress towards a performance evaluation of car-to-car communication (C2C) for active safety systems - in particular for crash constellation prediction. The methodology introduced in this work is designed to evaluate the impact of different sensors on the accuracy of a crash constellation prediction algorithm. The benefit of C2C communication (viewed as a virtual sensor) within a sensor data fusion architecture for pre-crash collision prediction is explored. Therefore, a simulation environment for accident scenarios analysis reproducing real-world sensor behaviour, is designed and implemented. Performance evaluation results show that C2C increases confidence in the estimated position of the oncoming vehicle. With C2C enhancement the given accuracy in time-to-collision (TTC) estimation is achievable about 110 ms earlier for moderate velocities at TTC range of [0.5s..0.2s]. The uncertainty in the vehicle position prediction at the time of collision can be reduced about half by integrating C2C communication into the sensor data fusion.
Air traffic is by nature crossing borders and organizations. The supporting infrastructure represents a federative distributed system of independent Air Traffic Service Units, typically each with its own proprietary system architecture. Interaction between the centers is taking place over dedicated protocols, often organized as a mesh of 1:1 bilateral data exchanges.
This contribution gives an overview of the ongoing efforts to standardize this data exchange. At the core is a data-centric view, using a shared virtual Flight Object as the IT counterpart of a real flight. It permits a uniform way to access and update a flight’s static and dynamic attributes. A middleware is presented that implements this abstraction and maps it onto a physical level, employing DDS (Data Distribution Service) technology for the 1:N dissemination of flight data.
This book constitutes the proceedings of the 6th International Workshop on Communication Technologies for Vehicles, Nets4Cars/Nets4Trains/Nets4Aircraft 2014, held in Offenburg, Germany in May 2014. The 10 papers presented in this volume were carefully reviewed and selected from 15 submissions. The book also contains 4 invited papers. The contributions are organized in topical sections named: automotive issues, car-to-car, aviation issues, in-car, and infrastructures.
This paper presents the competence-, business- and research-orientated education approach Fit4PracSis (= Fit for Practice and Sciences). Fit4PracSis is designed for freshman students in interdisciplinary engineering degree programs. It is an education concept, which is establishing a relationship to the future profession and scientific work during the introductory study phase. The freshman students will be early trained in important skills, which are necessary for the successful achievement of the final degree and the future business and research activities.
Temperature regulation is an important component for modern high performance single -core and multi-core processors. Especially high operating frequencies and architectures with an increasing number of monolithically integrated transistors result in a high power dissipation and - since processor chips convert the consumed electrical energy into thermal energy - in high operating temperatures. High operating temperatures of processors can have drastic consequences regarding chip reliability, processor performance, and leakage currents. External components like fans or heat spreaders can help to reduce the processor temperature - with the disadvantage of additional costs and reduced reliability. Therefore, software based algorithms for dynamic temperature management are an attractive alternative and well known as Dynamic Thermal Management (DTM). However, the existing approaches for DTM are not taking into account the requirements of real-time embedded computing, which is the objective in the given project. The first steps are the profiling and the thermal modeling of the system, which is reported in this paper for a Freescale i. MX6Q quad-core microprocessor. An analytical model is developed and verified by an extensive set of measurement runs.
WirelessHART protocol was specifically designed for real-time communication in the wireless sensor networks domain for industrial process automation requirements. Whereas the major purpose of WirelessHART is the read-out of sensors with moderate real-time requirements, an increasing demand for integration of actuator applications can be observed. Therefore, it must be verified that the WirelessHART protocol gives sufficient support to real-time industry requirements. As a result, the delay of especially burst and command messages from actuator and sensor nodes to the gateway and vice versa must be analyzed. In this paper, we implemented a WirelessHART network scenario in WirelessHART simulator in NS-2 [8], simulated and analyzed its time characteristics under ideal and noisy conditions. We evaluated the performance of the implementation in order to verify whether the requirements of industrial process and control can be met. This implementation offers an early alternative to expensive test beds for WirelessHART in real-time actuator applications.
This paper describes the Sweaty II humanoid adult size robot trying to qualify for the RoboCup 2018 adult size humanoid competition. Sweaty came 2nd in RoboCup 2017 adult size league. The main characteristics of Sweaty are described in the Team Description Paper 2017. The improvements that have been made or are planned to be implemented for RoboCup 2018 are described in this paper.
This paper describes the Sweaty II humanoid adult size robot trying to qualify for the RoboCup 2017 adult size humanoid competition. Sweaty came 2nd in RoboCup 2016 adult size league. The paper describes the main characteristics of Sweaty that made this success possible, and improvements that have been made or are planned to be implemented for RoboCup 2017.