Robert Schneider

Development of future short range radar technology

First cars equipped with 24 GHz short range radar (SRR) systems in combination with 77 GHz long range radar (LRR) system enter the market in autumn 2005 enabling new safety and comfort functions. In Europe the 24 GHz ultra wideband (UWB) frequency band is temporally allowed only till end of June 2013 with a limitation of the car pare penetration of 7%. From middle of 2013 new cars have to be equipped with SRR sensors which operate in the frequency band of 79 GHz (77 GHz to 81 GHz). The development of the 79 GHz SRR technology within the German government (BMBF) funded project KOKON is described

Impact of road surfaces on millimeter-wave propagation

Future intelligent transportation systems (ITSs) will deeply rely on millimeter waves for communication and sensing purposes. This results in the need of a precise description of the propagation properties at these frequencies. In this paper, the propagation mechanisms reflection and diffraction of millimeter waves at realistic road surfaces and geometries are investigated theoretically and validated by measurements at 77 GHz. The effect of guided waves underneath a vehicles underbody is observed, which can be exploited in a favorable way for range extension in obstructed sight situations. It is also shown that the local curvature of common road surfaces leads to focusing and defocusing effects of the transmitted energy, resulting in an increased signal fluctuation. Furthermore, the importance of diffraction phenomena at road crests is stressed, which were formerly neglected but may play an important role in security sensitive applications like collision avoidance systems etc.

Interference from 24-GHz automotive radars to passive microwave earth remote sensing satellites

The automotive industry is currently considering the introduction of short-range radars (SRR) operating near 24 GHz for improving road traffic safety. SSRs are intended to observe the full azimuthal space cover around a vehicle using up to eight sensors. The sensors would operate in an ultrawideband (UWB) mode, occupying 3-5 GHz of bandwidth. Interference from SRR transmitters with passive microwave remote sensing satellites used for weather and climate monitoring could occur as the result of several coupling mechanisms, including direct coupling via the transmit antenna beam and scattering and diffraction of the transmitted signals from leading vehicles, buildings, and other nearby objects. In this study, we estimate the amount of coupling anticipated to occur from SRRs, including the direct and scattered contributions. The calculations are based on bistatic scattering measurements of a typical automobile and ray optical simulations of reflection and propagation in an urban environment. Using these calculations, the maximum allowable SRR transmitted power for interference levels acceptable for meteorological and climatological remote sensing applications are quantified. The study provides criteria for SRR operation with the Earth Exploration Satellite Service on a noninterference basis.

Radar image acquisition and interpretation for automotive applications

Future safety and comfort systems will require clearly enhanced capabilities for environmental sensing and traffic scene understanding. This paper points out the potential of millimeter-wave radar sensors with high spatial resolution and high sensitivity for this demanding task, and addresses some aspects of practical implementation. The enhanced perception capabilities of imaging radar in traffic environment are demonstrated, and methods of image processing based automatic scenario interpretation are described. This comprises road course prediction and object segmentation with corresponding applications.

Antenna Technology for Millimeter Wave Automotive Sensors

Automotive sensors for the detection and discrimination of other vehicles on the road, obstacles, and boundaries use miniature radar systems and are heavily dependent in their performance on the antenna system. In this contribution, the requirements for such antenna systems are reviewed and the various options of antenna technology are discussed. In particular, prominent and presently employed, as well as innovative antenna concepts for forward looking obstacle avoidance and autonomous cruise control are presented. In conclusion, antenna requirements are discussed in the light of key requirements of advanced future automobile sensor systems.

KOKON - Automotive high frequency technology at 77/79 GHz

In future all automotive long and short range radar systems in Europe have to operate in the frequency range 76-81 GHz due to the European radar frequency regulation. For the development of future low-cost, high-performance and highly reliable radar systems the joint project KOKON was initiated. This contribution introduces the objectives of KOKON and presents current results achieved including sensor specification with respect to automotive applications, chip technology development, and realization of first sensor prototypes.

Millimeter-wave imaging of traffic scenarios

Methods for the automatic interpretation of complex road traffic scenarios are currently developed on the basis of real measured data. The measurements are performed using a fully polarimetric instrumentation radar at 76 GHz. Results of those measurements will be presented, especially with respect to automatic image interpretation. The features of the measurement system are very similar to a prospective automotive radar with the exception of possible Doppler range and physical dimensions. In parallel to the measurement and algorithmic activities, a radar sensor for automotive applications using monolithic integrated millimeter-wave circuits (MMIC) is under development. Real aperture imaging is achieved with a focal plane multibeam array. The most important design criteria are low cost and compactness. System aspects of this radar sensor will be discussed including results of the millimeter-wave circuits.

Prototypic Realisation of Millimetre Wave Radar Imaging

In future novel driver assistance, comfort, and safety systems the needs for environmental sensing and traffic scene interpretation are increasing. The reliability of these systems will be mainly determined by the perception of the sensors and the capability of automatic data interpretation, and it will be a differentiating factor in the competition amongst automotive OEMs. Automotive radar is expected to be a key sensor technology for future active safety systems, especially due to its specific physical properties (direct acquisition of range and velocity). This contribution demonstrates the potential of radar sensors with high resolution in azimuth and range in traffic environment and addresses some aspects of their practical implementation. A prototype of an automotive instrumentation radar is presented, which allows on-line acquisition and real-time visualisation of radar images with an update rate of up to 10Hz. The imaging capabilities of high resolution radar in traffic environment will be pointed out with respect to new comfort and safety features. In addition practical realisation approaches will be discussed.

Object detection in traffic scenes by a colour video and radar data fusion approach

Object detection is one of the key functions in autonomous driving. For this purpose different sensor types-such as laser or millimeter-wave (MMW) radar-are in use but most systems are solely based on vision (Thomanek et al., 1994). In contrast, this paper presents a data fusion approach for joint radar video object detection.

A Polarimetric 76 GHz Radar-Sensor for Automotive Applications

There is an increasing interest in millimeter-wave radar sensors for automotive applications, besides passenger-comfort traffic-safety will be the main distinctive feature for car manufacturers in future markets. Radar systems at millimeter-wave frequencies allow small antennas with high resolution fitting well into the front of a passenger car. Over and above radar sensors for automotive applications like autonomous intelligent cruise control and collision avoidance radar open up a relevant volume market for millimeter-wave technology. In this paper the concept of an automotive imaging radar will be discussed. The sensor is a fully polarimetric, coherent 76 GHz radar having an electronically obtained lateral resolution based on a focal plane array concept. Using advanced GaAs-based circuits all the building blocks necessary for the realization of the radar have been designed, assembled, and tested. Furthermore the modules and the obtained results as well as the integration of the complete radar sensor will be described. A sequence of radar images of traffic scenarios has been measured and processed with specially developed algorithms.