Optical time-of-flight range imaging proves to be an emerging technology for a wide field of professional and consumer applications

Citation

(2002), "Optical time-of-flight range imaging proves to be an emerging technology for a wide field of professional and consumer applications", Sensor Review, Vol. 22 No. 2. https://doi.org/10.1108/sr.2002.08722bab.008

Optical time-of-flight range imaging proves to be an emerging technology for a wide field of professional and consumer applications

Keywords: Distance measurement, Optical sensors

The Swiss Center for Electronics and Microtechnology, CSEM, is a leading R&D institution for optical time-of-flight (TOF) range imaging. After eight years of basic and applied research, the physical and technological limitations of this technology are well understood today, and the performance of CSEM's range cameras now reach the physical limits. This prompted several international companies recently to sign R&D contracts with CSEM, for the joint investigation of professional and consumer applications in the fields of security, safety, surveillance, automotive, robotics and automatic manufacturing (Plate 2).

Plate 2 Time-of-flight 3D imaging sensing range camera – a unique technology developed at CSEM

Optical TOF range cameras work with a modulated visible or infrared light source. The emitted light pulses are reflected by the objects in a scene, traveling back to the camera, where their precise time of arrival is measured locally in each "smart" pixel of a custom image sensor. In contrast to conventional cameras, TOF range cameras cannot only determine the local brightness in a scene but also the complete distance map (the 3D model) of the camera's environment. The distance resolution is limited by the amount of available reflected light and the timing precision of the camera's electronics. Today's TOF range cameras already exhibit a distance resolution of a few centimeters over a measurement range of up to some tens of meters, while working at video speed. Thanks to the continuing advances of solid-state technology, the measurement precision will soon be in the millimeter range, and the TOF range cameras will be miniaturized to a size not much larger than today's webcams.

"Our world is a three-dimensional one, and it can only be properly imaged with range cameras", says Peter Seitz, executive vice president of CSEM's Photonics division and extraordinary professor for optoelectronics at the University of Neuchatel, Switzerland. "Once TOF range cameras are small and affordable enough, they will be as ubiquitous as today's electronic still and video cameras, in a growing number of professional and consumer applications".

Several large, internationally operating companies are currently investigating the potential of this emerging technology for a wide range of applications, including security and surveillance, safety in public and private transportation (especially in automotive environments), autonomous robotics and safety in robotic fabrication, as well as in automatic fabrication manufacturing and quality control. Several more fields of applications are being proposed, such as 3D face recognition, full body shape acquisition for utilization in retail and service industries, smart toys sensing their environment, medical imaging within the body and on its surface, care-taking of young, handicapped or elderly persons, interior modeling and architecture, as well as multimedia and professional film- making.

Contact: Mr. Sohail Malik, CSEM SA, Swiss Center for Electronics and Microtechnology, Badenerstrasse 569, CH-8048 Zürich, Switzerland. Tel: +41 1 497 14 11; E-mail: smk@ch.ch; Website: http://www.csem.ch/