Radar sensors for the digital traffic infrastructure
In march 2017, the Federal Ministry of Transport and Digital Infrastructure, abbreviated BMVI, has brought the research programme "Digital Test Field Autobahn" into life. A primary focus of this programme lies on automated and cross-linked driving. In this framework, research on an infrastructure of cooperative radar sensors along a test track at the Autobahn A9 (project KoRA9) will be funded between 09/2017 and 06/2019. The project goal is an exemplary operation of stationary radar sensors for the purposes of traffic flow management and the support of automated driving. KoRA9 is a joint project of Siemens, Infineon, Intel, the Technical University of Munich and the University of Applied Sciences Augsburg. Our working group is responsible for the signal processing of the radar signals, which incorporates the detection, the tracking and the prediction as well as a classification of objects such as road users and obstacles, including the pilot use at the Autobahn A9.
Beyond an increasing number of mobile radar sensors already deployed on board of automobiles, the advent of automated driving and its support through an infrastructure of cross-linked stationary radar sensors will further contribute to the risk of mutual interference. Therefore, another focus of our works lies in methods that help establish smooth coexistence of mobile and stationary radar sensors.
Gigabit transmission over rotary joints
The transfer of electrical power and / or signals between rotating and stationary parts (rotors and stators) is accomplished by so-called rotary joints. Common applications are magnetic resonance scanners, windmills or building cranes, etc., where the demand for higher data rates is ever increasing, as it does in general. The use of wireless technology such as WiFi seems obvious at first sight, however, electromagnetic interference or the availability of frequencies present obstacles. The use of fibre-optical solutions can usually be ruled out, too, since the rotational centre of the rotary joint must be kept clear to carry the axis.
The scientific work focuses on ideas for the development, simulation and production of rotors and stators of rotary joints different in size for contactless data transmission at different data rate requirements. A particular goal is to realise standardised data interfaces, like e. g. 10 GBT.
Gigabit transmission over twisted-pair cables
Even for very high data rates such as several 10 Gbit/s, the use of twisted copper-wire pairs (twisted-pair cables) can be a cost-efficient alternative to fibre optic cables. In automotive applications e. g., twisted-pair cables offer frequency bandwidths of several GHz for data transmission, due to their short lengths. (For comparison: VDSL lines exploit 30 MHz of bandwidth at data rates of e. g. 50 Mbit/s, only.)
In the GHz range, the properties of twisted-pair cables are not well-known. A signal transmitted within a line can yield similar signal levels in adjacent lines, due to strong crosstalk. Cables can behave like antennas, which may cause massive interference in the onboard electronics of a vehicle. Another challenge is the measuring techniques for characterisation of these cables: A common quad cable consisting of 4 wires has a resulting 8 ports, while standard network analysers used in the desired frequency range are equipped with 2 ports, by default. The aforementioned frequency bandwidth of several GHz offers great potential of transmission capacity, however, its exploitation requires sampling rates of several GHz and a high bit resolution at the same time.
Therefore, our research focuses on the development of calibration procedures for error correction of twisted-pair cable measurements, on the development of simulation models of such cables, and on the transmission technology in order to generate, sample and process the required signals within a bandwidth of several GHz.
Laboratory for high frequency engineering
The working group high frequency systems performs most of its research activities in the laboratory of high frequency engineering of the faculty of electrical engineering. For this purpose, the laboratory equipment undergoes frequent modernisation measures, which is for the benefit of teaching activities, too.