Der Photomischdetektor zur schnellen 3D-Vermessung für ...

Abstract
The present doctoral thesis describes simulative and experimental investigations of the
innovative photonic mixer device (PMD) technology and associated applications in
future automobiles.
Generally speaking the photonic mixer device is an optoelectronic component which
enables the onchip correlation of an amplitude-modulated optical signal with an electrical
reference signal. This functionality is the basic of both distance measurement
based on the time-of-flight principle and optical data transmission. Regarding a complete
realization in CMOS-technology, this sensor principle allows a highly integrated,
fast and low cost 3D-solid-state camera.
Concerning the field of multi-dimensional ranging application this work shows at
first a possible way to model a complete PMD-camera system with Matlab/Simulink.
All necessary equations for calculating the optical power on a PMD-pixel depending
on the distance are displayed. Furthermore the optoelectronic mixing process is modeled
including consideration of an effective background light suppression. Various signal
processing tasks and evaluation algorithms complete the implementation of the mentioned
PMD-model. The result of this approach is a powerful simulation tool which
allows the performance analysis of PMD-cameras in certain 3D-vision applications.
Another focus of this work lies on PMD-applications in the interior and the exterior
of automobiles. Regarding interior protection for occupants the major task is an intelligent
airbag deployment. For this functionality it is essential to know if the passenger
seat is occupied or not and whether the object is a person or maybe a baby in a child
seat. In this context the present thesis deals with the aspects of image processing with
neural networks and polynomial classificators for pattern recognition of various simulated
passenger seat configurations. Furthermore the boundary conditions of a dynamic
out of position detection are explained and the experimental setup of a PMD-sensor
for this application is demonstrated.
Relating to exterior applications in the range of security and convenience, this thesis
is primarily concerned with precrash-detection and automated stop&go. Thereby the
major task was to develop an applicative modulation procedure which considers on the
one hand the general boundary conditions of an active infrared sensor, e.g. the laser
safety rules, and on the other hand the non-ambiguous distance evaluation independent
from the influence of other equivalent sensors nearby.
In the field of optical communication the PMD-technology applied to MSM-diodes
provides a correlated mixer device for fast multi-access applications. In this work the
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