In the last years 3D-Vision systems based on the Time-Of-Flight (TOF) principle have gained more importance than Stereo Vision (SV). TOF offers a direct depth-data acquisition, whereas SV involves a great amount of computational power for a comparable 3D data set. Due to the enormous progress in TOF-techniques, nowadays 3D cameras can be manufactured and be used for many practical applications. Hence there is a great demand for new accurate algorithms for 3D object recognition and classification. This paper presents a new strategy and algorithm designed for a fast and solid object classification. A challenging example - accurate classification of a (half-) sphere - demonstrates the performance of the developed algorithm. Finally, the transition from a general model of the system to specific applications such as Intelligent Airbag Control and Robot Assistance in Surgery are introduced. The paper concludes with the current research results in the above mentioned fields.
Many concepts for incoherent optical distance measurement, based on the time-of-flight (TOF) principle, are discussed in the past, but they differ in complexity and accuracy. The used modulation techniques and evaluations methods require different signal sources, which are controllable in frequency or phase delay in high precision. Development effort and outlay of TOF-systems will be reduced with the use of standard logic devices. The restrictions of these devices permit a limited number of phase or frequency steps, but the combination of standard logic devices and the principle of Phase-Shift Interferometry (PSI) offers the possibility to design a plain and precise system, at very low cost. Over the past 20 years many evaluation algorithms for PSI have been presented in different applications. The phase angle of an ideal interferogram is determinable with only three or four sampling values, but the usage of more sampling values will suppress emitter and detector non-linearities, phase shift errors and noise generally. This paper will present the design of the optimal phase-shift algorithm based on Fourier analysis of the complete recorded interferogram.