Gerd Scholl

Gerd Scholl
Helmut Schmidt University / University of the Federal Armed Forces Hamburg | HSU · Faculty of Electrical Engineering

Prof. Dr.-Ing.

About

124
Publications
24,257
Reads
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1,780
Citations
Citations since 2016
32 Research Items
516 Citations
2016201720182019202020212022020406080100
2016201720182019202020212022020406080100
2016201720182019202020212022020406080100
2016201720182019202020212022020406080100
Additional affiliations
November 2003 - present
Helmut-Schmidt-University, University of the Federal Armed Forces Hamburg
Position
  • Chair of Electrical Measurement Engineering
November 2001 - October 2003
EPOCS/TDK
Position
  • Head of Department "Basics and System Concepts"
January 2001 - September 2001
Siemens
Position
  • Team Leader "SAW Basics and Sensor Systems"
Education
November 1989 - January 1997
Munich Technical University & Siemens AG
Field of study
  • Research Assistant
November 1983 - November 1989
Munich Technical University
Field of study
  • Electrical Engineering, High-Frequency Engineering

Publications

Publications (124)
Chapter
The 5th generation technology standard for broadband cellular networks (5G) is currently being deployed at a large scale. In addition to the expansion of public 5G networks, (private) 5G campus networks are also set up in many areas. However, in parallel with the development of 5G, numerous other wireless solutions have also evolved, primarily usin...
Article
Full-text available
Communication reliability is a challenging requirement, which implies the need for over-the-air (OTA) testing. Reverberation chambers (RCs) are widely used for OTA tests in various fields. Due to their properties, such as inherent radio channel emulation or the arbitrary orientation of the equipment under test (EUT) in the test volume, they can be...
Preprint
Security is an essential requirement of Industrial Control System (ICS) environments and its underlying communication infrastructure. Especially the lowest communication level within Supervisory Control and Data Acquisition (SCADA) systems - the field level - commonly lacks security measures. Since emerging wireless technologies within field level...
Article
Full-text available
Modern production concepts generate a demand for reliable, energy-efficient, fast, and secure wireless communication solutions. Therefore, the current consumption should not increase substantially due to additional cryptographic operations. This paper shows a principle current measurement method that is exemplary of a transceiver for the IO-Link Wi...
Conference Paper
Reverberation chambers (RCs) are proposed as repeatable test environments. Often, the mode stirrers inside a RC are operated stepwise, whereby the essential measurements are performed under quasi-static conditions. However, mechanical mode stirrers usually vibrate when arriving on a new position. The influence of this mechanical vibration on the re...
Article
Full-text available
In the field of production automation, IO-Link Wireless (IOLW) offers energy-efficient and cost-effective solutions for networking wireless sensors and actuators close to the machines on the industrial shop-floor. In this paper, a concept is presented to enhance IOLW with security-for-safety and safety features in order to make safety critical syst...
Conference Paper
Wireless networks support highly flexible manufacturing processes and are recognized as a crucial pillar towards the digitization of industrial production (automation). While 5G is currently being marketed as universal solution for future wireless communication, high density of sensor and actuator nodes in industrial manufacturing environments with...
Conference Paper
Reverberation chambers (RCs) can be used as repeatable and shielded test environments for electromagnetic compatibility testing and performance evaluation of wireless communication devices, as they inherently emulate a Rician/Rayleigh fading environment. Loading a RC with radio frequency (RF) absorbing material leads to an increasing coherence band...
Research
Bislang war die kabelgestützte Kommunikation – auch bei IO-Link – das Maß aller Dinge bei der Anbindung von Sensoren und Aktoren an die übergeordnete Steuerungsebene, da eine hohe Systemverfügbarkeit bei geringer Störempfindlichkeit und geringer Latenzzeit realisierbar ist. Insbesondere bei neuen Anwendungen in der Produktion und Fertigung stößt di...
Conference Paper
Wireless communication systems are enabler technologies for modern and flexible production concepts, essentially within the Industry 4.0 directive. For reliable low-latency wireless communication, the availability of frequency spectrum is a general prerequisite.IO-Link Wireless (IOLW) is a vendor-independent wireless communication standard, which o...
Conference Paper
Full-text available
Modern production concepts generate a demand for reliable, fast and secure wireless communication solutions. Therefore, the current consumption should not increase highly due to additional security operations. This paper shows a principle current measurement method exemplarily of a transceiver for IO-Link Wireless protocol. The results show that th...
Conference Paper
In the context of the Industry 4.0 initiative, Cyber-Physical Production Systems (CPPS) or Cyber Manufacturing Systems (CMS) can be characterized as advanced networked mechatronic production systems gaining their added value by interaction with different systems using advanced communication technologies. Appropriate wired and wireless communication...
Article
Full-text available
Abstract Reverberation chambers (RCs) are a feasible option as test environment for evaluation of wireless devices with integrated antenna as they inherently emulate a Rayleigh fading channel. In this paper the dependency of deep fading on the frequency and position/orientation of an equipment under test (EUT) antenna is evaluated for different nu...
Conference Paper
Wireless technologies are intensively used in industrial environments and wireless sensor/actuator networks play a key role for highly flexible automation plants, especially within the Industry 4.0 initiative. In order to achieve a highly robust system behavior also an attentive antenna selection and placement within a manufacturing cell is of inte...
Conference Paper
Reverberation chambers (RCs) are a feasible option as test environment for evaluation of wireless devices with integrated antenna, as they inherently emulate a Rayleigh fading channel. In this paper, the dependency of fading on the frequency and position/orientation of an equipment under test (EUT) antenna is evaluated in a RC and for different num...
Conference Paper
Full-text available
Modenverwirbelungskammern (MVKn) stellen vielfältig verwendbare, reproduzierbare Messumgebungen dar. Grundsätzlich handelt es sich dabei um elektromagnetisch geschirmte Volumina, in denen sog. Modenrührer eingebracht sind, die ein elektromagnetisches Feld „verwirbeln“, sodass ein Prüfling einer definierten aber statistisch variierenden Umgebung aus...
Article
Full-text available
Reverberation chambers are well-proven test environments for radio frequency (RF) measurements. Typically, mean values are taken from the measurements to characterize the equipment under test. In the novel approach presented in this paper, the correlation of measured sample sequences is utilized to detect deviations, in particular of the radiation...
Conference Paper
Full-text available
Applications in process and factory automation increasingly use wireless technologies. In the past, the existing wireless solutions often could not offer sufficient performance with respect to real-time and reliability requirements for fast closed-loop control applications. As a result, low latency and highly synchronous wireless communication tech...
Article
Zusammenfassung WirelessHART und speziell an industrielle Bedingungen adaptierte WLAN- und Bluetooth- Systeme sind Beispiele für drahtlose Kommunikationssysteme, die sich für die Vernetzung von Sensoren und Aktoren im industriellen Umfeld etabliert haben. Im April diesen Jahres wurde ein zusätzlicher drahtloser Standard IO-Link Wireless [6] für die...
Conference Paper
Reverberation chambers are well-proven test environments for RF measurements. Typically, mean values are taken from the measurements to characterize the equipment under test. In the novel approach presented in this paper the correlation of measured sample sequences it utilized to detect deviations from a reference equipment. Links: https://www.vd...
Article
Zusammenfassung Dieser Beitrag beschreibt Messungen zur Charakterisierung einer Modenverwirbelungskammer vor dem Hintergrund der Qualifizierung von drahtlosen Sensor/Aktor-Modulen. Aufbauend auf Normen bzw. Testempfehlungen, die für andere drahtlose Anwendungen entwickelt wurden, wird in diesem Beitrag das Verhalten einer Modenverwirbelungskammer u...
Article
Full-text available
A test method for narrowband wireless sensor/actuator networks is presented, facilitating affordable and efficient performance and compliance tests prior to the deployment of the wireless communication systems. Commonly used channel models are examined to derive a worst-case test scenario. Employing frequency/time division multiple access (F/TDMA)...
Article
Full-text available
In the context of the Industry 4.0 initiative, Cyber-Physical Production Systems (CPPS) or Cyber Manufacturing Systems (CMS) can be characterized as advanced networked mechatronic production systems gaining their added value by interaction with the ambient Industrial Internet of Things (IIoT). In this context appropriate communication technologies...
Conference Paper
Full-text available
A test method for narrowband wireless sensor/actuator networks is presented, facilitating affordable and efficient performance and compliance tests prior to the deployment of the wireless communication systems. Employing frequency/time division multiple access (F/TDMA) techniques and protocol synchronization, a new and efficient test method is sugg...
Article
Zusammenfassung Dieser Beitrag beschreibt Messungen zur Evaluierung einer Modenverwirbelungskammer zur Qualifizierung von drahtlosen Sensor/Aktor-Modulen. Aufbauend auf Normen bzw. Testempfehlungen, die für andere Anwendungen entwickelt wurden, wird in diesem Beitrag das Verhalten einer Modenverwirbelungskammer unter verschiedenen Beladungen spezie...
Article
Full-text available
Custom-fit communication systems are key elements in modern cyber-physical sensor systems. Therefore a wireless communication system (WCS) for sensor/actuator communication has been developed to facilitate energy and environmental monitoring on the shop floor of industrial production sites. Initially, the distinct demands and requirements are descr...
Conference Paper
The increase of wireless devices due to the implementation of wireless sensor networks, cyber-physical systems with wireless communication interfaces and mobile monitoring as well as the installation of diagnosis applications into the shop floor improves real-time transparency of machine conditions and production processes. For a minimal invasive i...
Article
Wireless Technologies (Wireless communication) have been well-established, even in industrial applications, in the past few years. Compared to common office applications, the requirements in terms of robustness, coexistence, reliability and latency are considerably higher. Different automation solutions can be assigned to the industry sectors logis...
Data
Full-text available
Requirements of reliability and robustness for wireless systems in the industrial environment result in radio network planning due to the limited availability of dedicated frequency bands and the increased number of coexisting wireless systems. Focus of this article are two aspects: the high complexity of the (mostly) metallic structures often foun...
Conference Paper
Full-text available
Gemäß [1] gehen heute schon 80% aller Innovationen in der Produktionstechnologie auf die Integration von Maschi-nenbau und Informations- und Kommunikationstechnologien zurück. D.h. es wird zukünftig noch mehr als heute drauf ankommen, neue Kommunikationstechnologien schnell und effizient in die Produktion zu integrieren und diese auch schon nach Mö...
Conference Paper
Full-text available
In this article an experimental setup is presented to evaluate Time Difference of Arrival (TDOA) range estimations based on WiFi test signals conform to the IEEE 802.11 n standard with a conventional cross-correlation (CC) technique and the super-resolution technique Minimum Norm (MinNorm). It can be shown that MinNorm improves TDOA estimation sign...
Conference Paper
Full-text available
Requirements of reliability and robustness for wireless systems in the industrial environment result in radio network planning due to the limited availability of dedicated frequency bands and the increased number of coexisting wireless systems. Focus of this article are two aspects: the high complexity of the (mostly) metallic structures often foun...
Conference Paper
Full-text available
WiFi signals delivered by a radio frequency (RF) transceiver unit and a strapdown inertial measurement unit (IMU) are combined to realize a highly accurate navigation/localization system. The performance of this approach is evaluated by a system simulation. Mobile station (MS) motion data and WiFi range estimates are superimposed by real-world nois...
Article
Full-text available
This paper presents a novel non-resonant electromagnetic energy harvester for application in a remote car-key, to extend the lifetime of the battery or even to realize a fully energy autonomous, maintenance-free car-key product. Characteristic for a car-key are low frequency and large amplitude motions during normal daily operation. The basic idea...
Article
Full-text available
This paper demonstrates the autonomous operation of a wireless sensor node exclusively powered by thermoelectric energy harvesting. Active operation of a wireless sensor system is demonstrated successfully by means of an on-line programmable emulation kit that enables various thermoelectric energy harvesting scenarios. Moreover, this emulation kit...
Conference Paper
Full-text available
In indoor environments Received Signal Strength Indicator (RSSI) values are strongly affected by multipath propagation effects resulting in a location accuracy that is often not very reliable. More accurate ranging techniques such as Time Difference of Arrival (TDOA) could be integrated into IEEE 802.11 g/n/ac chip sets requiring hardware modificat...
Conference Paper
Full-text available
Inertial navigation systems are frequently employed in robotic applications. It is well known that if they are used without the assistance of a reference system, position failures can increase rapidly in the course of time. This article presents various zero-velocity detection routines to reduce the position instability of robots equipped with unai...
Conference Paper
Full-text available
Estimating motion velocity state is crucial in dealing with inertial navigation systems (INS) or in situations where backing of an INS by other technologies is difficult or impossible. This study therefore investigates time sequences delivered by embedded inertial sensors in order to draw conclusions about the motion state of moving objects. Variou...
Conference Paper
Full-text available
Resource conserving weight, material and energy savings, achievement of compliance with new environmental and safety requirements, cost-efficient retrofitting of already existing monitoring and control systems, improvement of labor productivity, inventory optimization, mobile operation and tracking, remote control and maintenance or alleviation and...
Article
Zusammenfassung Ist der Bewegungszustand autonom agierender inertialer Navigationssysteme (INS) bekannt, lässt sich die Positioniergenauigkeit durch die Anwendung sog. Zero Velocity Updates (ZUPT) deutlich erhöhen. Verschwindet das Nutzsignal der Sensoren allerdings im Rauschen, was insbesondere bei langsamen Bewegungen der Fall ist, so hat die Sch...
Article
Zusammenfassung In der vorliegenden Arbeit wird ein kurzer Abriss zur energieautarken Sensorik im Automobil gegeben. Hierzu wird auf die Vielfalt der Sensoren im heutigen Kraftfahrzeug eingegangen und eine Motivation bezüglich der Substitution hin zu energieautarken Sensoren aufgezeigt. Des Weiteren werden potentielle Nutzenergien und die Möglichke...
Conference Paper
Full-text available
Performance evaluation of five TOA/TDOA estimation algorithms (IFT, group delay, ESPRIT, MUSIC, MinNorm) is carried out employing stochastic radio channel modeling. Mean errors and standard deviations for IEEE802.11g/n/ac standards are calculated as a function of coherence bandwidth and Rician K-factor. It can be shown that super-resolution techniq...
Conference Paper
Full-text available
Die Kenntnis des Bewegungszustands autonom agierender inertialer Navigati-onssysteme (INS) ist vorteilhaft für eine exakte Ortsbestimmung. Gelingt es eine (langsame) Bewegung von Stillstand sicher zu unterscheiden, lassen sich über der Zeit akkumulierte Geschwindigkeitsabweichungen in sog. Zero Velocity Update (ZUPT)-Phasen zurücksetzen, so dass ei...
Article
Robustness and reliability of wireless systems for factory automation applications mainly depend on their ability to cope with fast fading radio channels in metal-rich environments, their immunity against classical industrial interferers like switch mode power supplies, contactors or relays and their coexistence behavior in the presence of other wi...
Article
Identification and sensor systems based on surface acoustic waves exhibit intriguing properties which have hitherto remained unexploited by semiconductor-based systems. They offer a long readout distance of up to more than 20 meters with purely passive surface acoustic wave (SAW) devices. SAW devices operate with no battery or wiring, withstand ext...
Article
Today modern cars are equipped with many electronic systems so that it is necessary to look at the quiescent current when the car is not in use and energy has to be delivered from the battery. One way to keep the quiescent current low is to replace conventional electronic systems like an intrusion detection system by an energy autonomous one. The a...
Article
In automation applications many different wireless technologies and standards are in use. Generally, these do not have a possibility for RF-intercommunication and active coexistence. One way to improve coexistence to another wireless system is to reduce transmission times and to use as less transmission power as possible. Therefore it is advantageo...
Chapter
In time-critical applications a fast transmission of control data between rotating parts of a machine is required for proper system operation. This chapter presents an ultra-fast data transmission using ultra-wideband (UWB) technology for a continuous sub-microsecond communication in rotating systems. A slotted waveguide ring allows a reliable and...
Article
Zusammenfassung Die exakte Charakterisierung von Hochfrequenzfiltern mit Isolationen bis zu −60 dB stellt eine große messtechnische Herausforderung dar. Hierfür müssen die elektromagnetischen Wechselwirkungen der Messaufnahmen mit den Hochfrequenzbauelementen exakt analysiert und anschließend durch Anpassung der Messaufnahmengeometrien auf ein Mini...
Article
Zusammenfassung Die Wellenausbreitung im industriellen Umfeld kann durch frequenzselektive und zeitvariante Funkkanäle mit hoher Signaldynamik beschrieben werden. Aus diesen können deterministische Muster extrahiert werden, welche bei der Auslegung von Funksystemen zur Steigerung der Robustheit und Leistungsfähigkeit oder zur Verringerung des Energ...
Conference Paper
Full-text available
Funk in der Fertigung zur drahtlosen Sensor/Aktor-Ansteuerung muss gleichzeitig vielen Anforderungen gerecht werden. Drei besonders wichtige Merkmale sind: kurze Reaktionszeiten im Bereich von 5 ms – 10 ms, Paketfehlerraten im Bereich von 10-9 und Koexistenz mit anderen, in der Fertigung eingesetzten Funksystemen, wie z.B. WLAN, Bluetooth oder Wire...
Article
A microwave rotary joint using a slotted waveguide ring for wideband and ultra-wideband signals is presented and analyzed in this paper, An analytical description of the channel model is derived and compared to full-wave three-dimensional electromagnetic field simulation results as well as to measurement results of a fabricated prototype. Experimen...