3D-TOF sensors in the automobile

In recent years, pervasive computing has become an important topic in automobile industry. Besides well-known driving assistant systems such as ABS, ASR and ESP several small tools that support driving activities were developed. The most important reason for integrating new technologies is to increase the safety of passengers as well as road users. The Centre Suisse d'Electronique et de Microtechnique SA (CSEM) Zurich presented the CMOS/CCD real-time range-imaging technology, a measurement principle with a wide field of applications in automobiles. The measuring system is based on the time-of-flight measurement principle using actively modulated radiation. Thereby, the radiation is emitted by the camera's illumination system, reflected by objects in the field of view and finally imaged on the CMOS/CCD sensor by the optics. From the acquired radiation, the phase delay and hence the target distance is derived within each individual pixel. From these distance measurements, three-dimensional coordinates can then be calculated. The imaging sensor acquires its environment data in a high-frequency mode and is therefore appropriate for real-time applications. The basis for decisions which contribute to the increased safety is thus available. In this contribution, first the operational principle of the sensor technology is outlined. Further, some implementations of the technology are presented. At the laboratories of the Institute of Geodesy and Photogrammetry (IGP) at ETH Zurich an implementation of the above mentioned measurement principle, the SwissRanger, was investigated in detail. Special attention was focused on the characteristics of this sensor and its calibration. Finally, sample applications within the automobile are introduced.