VDI - Optische Technologien in der KFZ-Technik, 2. Fachtagung in Leonberg, 17./18. Mai 2006, Vortragsfolien von Prof. Dr. Schwarte

Rudolf Schwarte, Zhigang Zhang, Bernd Buxbaum: Neue 3D-Bildsensoren für das Technische 3D-Sehen
(volles PDF-Dok., 707 KB)

Ambient Intelligence bezeichnet eine hilfreiche, sich den Bedürfnissen der Menschen anpassende Lebens- und Arbeitswelt, in der technische Systeme schützende und helfende Funktionen übernehmen. Solch eine fruchtbare Partnerschaft mit den Menschen stellt ein erstrebenswertes aber höchst anspruchsvolles Entwicklungsziel dar und erfordert technische Systeme hoher Sensor-, Aktor- und Computer-Intelligenz.
So wie das 3D-Sehen in seiner ganzen Komplexität der schnellen Modellierung und Kognition der Umgebung die wichtigste Sensorik des Menschen darstellt, ist unschwer die wohl wichtigste Sensorik seines technischen Gegenübers auszumachen: Technisches 3D-Sehen in Echtzeit – wie der Mensch es für seine Bewegung und Handhabung in natürlichen Umgebungen gewohnt ist. Dieses Ziel wird weltweit intensiv bearbeitetet, insbesondere in Hinblick auf die Sicherheitstechnik, autonome Robotik und Mensch-Maschine-Schnittstelle.
Ohne die schnelle Erfassung, Digitalisierung und Modellierung der dynamischen 3D-Umwelt fehlt unseren technischen Systemen die notwendige Autonomie. Sie sind praktisch „blind“. Alle Versuche, vor allem auf Basis von Stereovision oder Laserscannern z. B. zum autonomen Fahren von Robotern in natürlichen Umgebungen, konnten diese Aufgabe nicht zufrieden stellend lösen.
Im Folgenden wird ein experimentell verifizierter Lösungsweg für diese Problematik vorgestellt. Tausende paralleler Laserradars in PMD (Photonic Mixer Device)-Technologie erfassen gleichzeitig Tausende von Raumpunkten über Echolaufzeiten als 3D-Snapshot. Als 3D-Videokamera vermessen sie eine dynamische 3D-Szene fortlaufend mit Videobildrate vom Nahbereich bis in den 10m-Bereich bei einer Auflösung im mm-Bereich - je nach der Empfangsoptik und Sendeleistung der modulierten Laser- oder LED-Beleuchtung.
Funktionsweise und Anwendungen der PMD-Schlüsseltechnologien, die diesen Fortschritt ermöglichen, werden erläutert – auch unter Betrachtung der erwarteten technischen, wirtschaftlichen und gesellschaftlichen Vorteile, die diese Innovation in nahezu allen Lebensbereichen bietet.


Rudolf Schwarte: Real Time 3D-perception by TOF-echoing 3D-Video Cameras
(volles PDF-Dok., 673 KB)

We are faced with urgent needs of fast 3D-perception of moving sceneries in various fields, like
• Human-Safety, Industrial Automation, 3D-Man Machine Interfacing,
• Autonomous Mobile Robots, e.g. for Service, Assembling, Exploration & Rescue,
• Accident-free Driving, Precrash, Automatic Stop&Go, Traffic Control etc.
Evolution created ingenious concepts and systems for fast 3D-perception and evaluation for the sake of orientation and goal-directed reaction in dynamic 3D-environments. So far our understanding and still more our technical solutions seem to be miles behind the evolutionary state-of-the-art, e.g., of the 3D-sonar TOF (time-of-flight) systems of dolphins or of the 3D-stereo vision systems of advanced mammals and of human beings.
In our technical evolution we are pursuing similar concepts, but neither our two-camera stereo vision systems nor our echo TOF (time-of-flight)-based ultrasonic-, microwave- and laser-radar systems are able to provide comparable performance to the natural standard examples in real-time 3D-environment perception.
Finally an innovation to be described gives us the chance to solve the technical challenge of high speed 3D-capturing dynamic environments. After two decades of laser-radar research in 1996 a key component was found [1], providing an amazing way to reduce the volume of the laser-radar receiver by a factor of more than 1 : 100.000, including a dramatic improvement of all measurement specifications.
The purpose of this paper is to describe this proved multi-channel laser-radar technology which enables thousands of high-sensitive laser-radar receivers to be integrated on a fingernail-sized CMOS-chip for fast 3D-perception. Furthermore, the consequences of this innovation have to be illustrated with respect to the increasing autonomy of technical systems, to the huge number of applications and to the substantial scientific, economic and social impact.
These extraordinary capabilities rely on a smart photodiode-inherent mixing-process. We called this specialized photo diode with two controllable photo-current outputs PMD (Photonic Mixer Device). That’s why the opto-electronic mixing process of optical and modulation signals is accomplished directly in the photonic state before the photo-current is read out, followed by an integration process to get the OE-correlation function which stands for the optical echo delay. As outlined, PMD enables to realize 3D-cameras respectively 3D-video cameras for high speed 3D-perception in dynamic environments, today using up to 20.000 PMD-pixel.


Rudolf Schwarte: Ultra-fast Analog and Digital OE-Multichannel Signal Processing using PMD/OEP-Technologies
(volles PDF-Dok., 327 KB)

This paper introduces the operation principles of new versatile opto-electronic semiconductor components called OEP (Opto-Electronic Processor). These are sophisticated PMD (Photonic Mixer Device)-combinations which provide a large range of new powerful, low-cost, incoherent, and extremely fast OE-devices, e.g. enabling picosecond-3D-sampling, OE- and OO-digital logic like all-optical XOR, AND, NOR, furthermore OE/OO-analog signal processing, like OE-PLL and DLL-operations, optical interconnection and routing, OE-multiplexing and demultiplexing, OE-AD-Conversion, time-resolved spectroscopy, etc.


H. Kraft, J. Frey, T. Moeller, M. Albrecht, M. Grothof, B. Schink, H. Hess, B. Buxbaum: 3D-Camera of High 3D-Frame Rate, Depth-Resolution and Background Light Elimination Based on Improved PMD (Photonic Mixer Device)-Technologies
(volles PDF-Dok., 926 KB)

The knowledge of three-dimensional data is essential for many control and navigation applications. Especially in the industrial and automotive environment a fast and reliable acquisition of 3D data has become a main requirement for future developments.
This contribution describes novel 3D camera modules used in Time-of-Flight measurement systems for 3D imaging applications. The key components are array and line sensors which can measure the distance to the target pixelwise in parallel, i.e. without scanning. Therefore these cameras have the advantages of fast imaging and high lateral resolution combined with the depth information of the captured scene. The sensors consist of smart pixels, called the Photonic Mixer Device (PMD) which enables fast optical sensing and demodulation of incoherent light signals in one component.
To realize a Photonic Mixer Device there are different techniques currently under investigation. Sensors are conceivable working with different types of electromagnetic waves, e.g. light, microwaves or ultrasound. In this paper two types of optical 3D-cameras with different PMDs are described. Each camera consists of a sensor chip, a modulated optical transmitter, control and processing electronics and software package. One camera is realized with standard CMOS technology based on Photogate (PG) PMD. The other sensor uses a different type of PMD, called Metal-Semiconductor-Metal (MSM) PMD.
Beginning from the description of both PMD types and their characteristics the system concept is shown. Based on realized cameras the sensor architectures and system environment are described. Finally measurements are presented to show the performance of the cameras in terms of accuracy, resolution and suppression of background illumination.


R. Schwarte, Z. Zhang, M. Grothof, J. Frey, H. Kraft, T. Moeller, H. Hess, B. Buxbaum, T. Ringbeck, Z. Xu: OEP (Opto Electronic Processor) for Extremely Fast Multi-Channel Analog and Digital OE-Signal-Processing
(volles PDF-Dok., 563 KB)

Optoelectronics and photonics become key technologies more and more, being particularly the most ambitious and innovative technologies in communications and sensor techniques, automation and safety. In this context there is a lasting demand for improvements in order to fasten and to simplify opto-electronic processing and interconnection techniques as well as photonic measurement techniques.
This paper presents new procedures and components for low cost and high speed optoelectronic analog and digital signal processing and interfacing. Following examples demonstrate new capabilities of multi-channel light processing and measurement performing low noise, high dynamics, pico-second time resolution, high sensitivity and electronically controlled pure optical signal processing.
A new component PMD (Photonic Mixer Device) introduced an advantageous standard into fast 3D-imaging by applying a detector-inherent mixing and correlation process. Meanwhile the PMD technology achieved a mature state, e.g. enabling frame rates of 100 3D-images at 256 PMD-pixels per second. The University of Siegen Institutes INV and ZESS and the Siegen firms PMDTechnologies and S-TEC GmbH are looking forward to a road map of increasing pixel numbers to more than 10.000 PMD-pixel (look at paper 4.2 in this OPTO 2004 proceedings). In parallel to this way we developed new similar photonic technology as exciting as the PMD-technology: We found that a PMD-combination, i.e. OE- integrated components using the inherently mixing and switching PMD-principle, is ideally suited for new high speed analog and digital optoelectronic signal processing capabilities. This new device is called OEP Opto-Electronic Processor. It is composed of PMD-structures in Schottky technology and will offer an extraordinary high bandwidth or bit rate in the 10 to 30 GHz / Gbit/s - range.
Schottky-PMD technology in GaAs- or silicon enables this extremely high speed based on the Schottky-MSM (Metal Semiconductor Metal)-Photodiode which is known to enable a bandwidth of more than 100 GHz.

Copyright © Institut RST · Universität Siegen · Juni 2006 · alexander.prusakuni-siegen.de