Eberhard Zeeb

Making Bertha Drive?An Autonomous Journey on a Historic Route

125 years after Bertha Benz completed the first overland journey in automotive history, the Mercedes Benz S-Class S 500 INTELLIGENT DRIVE followed the same route from Mannheim to Pforzheim, Germany, in fully autonomous manner. The autonomous vehicle was equipped with close-to-production sensor hardware and relied solely on vision and radar sensors in combination with accurate digital maps to obtain a comprehensive understanding of complex traffic situations. The historic Bertha Benz Memorial Route is particularly challenging for autonomous driving. The course taken by the autonomous vehicle had a length of 103 km and covered rural roads, 23 small villages and major cities (e.g. downtown Mannheim and Heidelberg). The route posed a large variety of difficult traffic scenarios including intersections with and without traffic lights, roundabouts, and narrow passages with oncoming traffic. This paper gives an overview of the autonomous vehicle and presents details on vision and radar-based perception, digital road maps and video-based self-localization, as well as motion planning in complex urban scenarios.

Optical data buses for automotive applications

Optical data links and bus systems are becoming increasingly attractive for automobiles. In 1998, a first optical data bus system, based on polymer optical fibers and visible light-emitting diodes was introduced in Mercedes-Benz cars to interconnect information and entertainment devices within the passenger compartment. Since 2002, media-oriented system transport (MOST) is the standard for an optical infotainment data bus system in the automotive industry. However, with increasing demands on network flexibility, robustness, safety-relevant functions, and data rate, the currently used technologies reach their limit. A new physical layer, based on 200-/spl mu/m polymer-cladded silica fibers and infrared-emitting vertical-cavity surface-emitting lasers, is a promising solution. This paper provides an overview about the state-of-the-art physical layer of standard MOST data bus systems, shows its limitations, and presents new optical-physical-layer concepts for next-generation data bus systems in cars.

Low-cost VCSEL-transceiver module for optical data busses

We have proposed and demonstrated a new low-cost, low insertion loss and compact optical transceiver module for optical data busses with reflective star topology. System experiments show the feasibility of these modules as transceivers in control data busses for mobile systems. We believe that the described mounting technique can also be applied to 50/125 /spl mu/m and 62.5/125 /spl mu/m silica and to plastic optical fiber based systems.

Optical transceiver module for star networks in cars

Here we present an optical transceiver concept for a reflective star bus system, showing favorable properties in respect to coupling efficiency and packaging. It is based on a hot embossed polymer substrate with two integrated micro-mirrors and a waveguide. On top of the substrate, above the mirrors, a vertical-cavity surface-emitting laser diode (VCSEL) and a photodiode chip are mounted with a flip-chip technique. At the end face of the waveguide a Polymer Clad Silica (PCS) fiber with a core diameter of 200 μm is attached in a groove. Thus an easy assembly of the individual components and a compact package is achieved. To evaluate and optimize the efficiency of the transceiver module we performed extended ray tracing calculations. Included are coupling efficiency between fiber and planar waveguide as well as coupling efficiencies between VCSEL and waveguide and between waveguide and photodiode, respectively. For a realistic estimation we took the transverse mode emission behavior of VCSELs at different supply currents and temperatures into account. Therefore we measured far-fields of VCSEL chips mounted on a heat sink for temperatures up to 85 °C and included the results in the simulations. The calculations indicate that the temperature dependant output power of the VCSEL is partly compensated by the variation in coupling efficiency. Measured VCSEL to fiber coupling efficiencies of about 60 % and out-coupling efficiencies to the photodiode of 70 % are achieved, in good agreement with calculations. Therefore our compact and low-cost concept shows at least 2 dB lower insertion losses compared to conventional 3 dB coupler solutions.

Planar star couplers for 200 /spl mu/m multimode PCS fibers

We have investigated the design and the fabrication of planar transmissive and reflective star couplers for 200 /spl mu/ polymer clad silica (PCS) fibres. We propose the design of potential low-cost planar optical star couplers and demonstrate prototypes with good optical performance.

Autonomes Fahren auf der historischen Bertha-Benz-Route

Zusammenfassung Im Jahre 1888 trat Bertha Benz die erste Überlandfahrt in der Geschichte des Automobils an. 125 Jahre später wiederholte die Mercedes Benz S-Klasse S 500 Intelligent Drive diese historische Fahrt von Mannheim nach Pforzheim – selbständig, ohne Fahrereingriff und im realen Verkehr. Die Bertha-Benz-Route ist 103 km lang und zeichnet sich durch eine breite Vielfalt von zu bewältigenden Fahrsituationen aus, die repräsentativ für den heutigen Alltagsverkehr sind. Die Strecke beinhaltet die Innenstädte von Mannheim und Heidelberg sowie die Durchfahrung von 23 Ortschaften und kleineren Städten. Zu den Situationen, die ein autonomes Fahrzeug auf der Bertha-Benz-Route beherrschen muss, gehören z. B. Kreisverkehre, Kreuzungen mit und ohne Ampelanlagen, Zebrastreifen, Überholen von Radfahrern oder enge Ortsdurchfahrten mit entgegenkommendem Verkehr. Eine Besonderheit des vorgestellten Projektes war die ausschließliche Verwendung seriennaher Sensorik. Kameras und Radarsensoren in Verbindung mit einer präzisen digitalen Karte ermöglichten die Erfassung des Fahrzeugumfelds auch in komplexen Situationen. Dieser Artikel liefert eine Systemübersicht des Fahrzeugs. Er beschreibt die kamerabasierte Umgebungswahrnehmung, die verwendeten digitalen Karten und die kartenrelative Selbstlokalisierung sowie die Manöverplanung in komplexen Verkehrsszenarien.

VCSEL based transmitter module for automotive temperature range between -55° C and +125° C

Robust, high speed optical data bus systems are increasingly required in automobiles, not only for entertainment applications within the passenger compartment but also for engine management systems and safety sensor networks. Optoelectronic components and modules intended to be used in cars have to withstand harsh environmental conditions, e.g. they have to be operational within a wide temperature range of up to - 55 °C to +1 25 °C for several thousand hours and at the same time they have to be of very low-cost. In this paper we describe a 500 MBit/s transmitter module based on a commercial available 850 nm vertical-cavity surface-emitting laser and a bias-T driving circuit. The optical output power of the module varies only by -0.5 dBm ± 1dB in the required temperature range without active temperature control. In addition we describe a packaging solution for the VCSEL transmitters allowing the operation of the module even in an extreme engine compartment environment, where short term temperature peaks above 125 °C appear.