3D Time-of-flight distance measurement with custom - Universität ...

centimeter accuracy. With the single exception of the demodulation pixel array
itself, only standard electronic and optical components have been used in these
range cameras. For a resolution of 5 centimeters, an optical power of 600 fW per
pixel is sufficient, assuming an integration time of 50 ms (20 Hz frame rate of 3D
images). This low optical power implies that only 0.06 electrons are generated per
modulation period (Tmod=50 ns at 20 MHz modulation frequency).
Furthermore, we present an in-depth analysis of the influences of non-linearities in
the electronics, aliasing effects, integration time and modulation functions. Also, an
optical power budget and a prediction for the range accuracy is derived as a
function of the ratio of active illumination to background illumination. The validity of
this equation is confirmed by both computer simulations and experimental
measurements with real devices. Thus, we are able to predict the range accuracy
for given integration time, optical power, target distance and reflectance.
With this work we demonstrate the first successful realization of an all-solid-state
3D TOF range-camera without moving parts that is based on a dedicated
customized PhotoASIC. The measured performance is very close to the theoretical
limits. We clearly demonstrate that optical 3D-TOF is an excellent, cost-effective
tool for all modern vision problems, where the relative position or motion of objects
need to be monitored.
VII