Analysis and optimization of PMD-sensor data for rendezvous applications in space
Betreuer:
Huber, Felix, Univ.-Prof. Dr.rer.nat
Gutachter:
Huber, Felix, Univ.-Prof. Dr.rer.nat; D'Amico Simone, Assistant Prof. Dr.
Tag der mündlichen Prüfung:
17.06.2020
Jahr:
2020
Sprache:
Englisch
Stichwörter:
On-Orbit Servicing, PMD sesnor, pose estimation
Abstract:
In the last decade, people became more aware of the critical situation in space concerning
the space debris. Nowadays, there are plenty of uncontrolled objects located on different
orbits in the outer space. Some of them present the real hazards to the functioning
satellites and to the International Space Station. The researches all over the world are
working on optimal solutions for the space cleaning. There are projects which are directed
to repair the satellites and extend their operational lifetime, or totally remove a no more
useful space object from its orbit. Rendezvous is the one inevitable space operation all
these tasks need. We are able to execute a space operation with a target satellite only if
the servicer satellite approaches it. The goal of this thesis is to develop a visual navigation
system with the Photonic Mixer Device (PMD) sensor for the close rendezvous phase with
a non-cooperative target. The PMD sensor has never been used in space missions so far,
but it has already been tested on the ground.
In order to achieve the goal, this thesis provides two di
erent pipelines for the pose
acquisition and for the pose tracking using the images from the PMD sensor. In this
work we show that the use of the PMD's amplitude and depth images together brings a
great contribution to the visual navigation system. The pose acquisition is required in
order to initialize a pose (position and orientation) of the non-cooperative space object
before the tracking takes place. This task is very dicult, because we have to deal only
with the PMD images and the known 3D model of the target. We initialize the pose with
the depth image and thereafter improve the obtained pose with the amplitude image.
As soon as we have an initial estimation, the servicer starts to approach the target in a
frame-to-frame mode. The pose for every frame is estimated by a fusion of the states,
which are calculated with the developed techniques for the depth and the amplitude
images correspondingly. This technique shows a stable tracking with low errors of the
estimated pose even if there are some distortions in the depth image. This fact is very
important for the close rendezvous phase, because any failures in Guidance, Navigation
and Control (GNC) system can lead to an unpredictable behavior of the chaser, and in
end e
ect, create more space debris.
The techniques presented in this thesis are tested with real images of the PMD sensor.
The rendezvous simulations are executed and evaluated with a high accuracy hardware-inthe-
loop simulator. The tests of the visual navigation with a PMD sensor in a closed loop
show promising results. The servicer satellite can smoothly approach the non-cooperative
target by only using the PMD sensor for relative navigation. «
In the last decade, people became more aware of the critical situation in space concerning
the space debris. Nowadays, there are plenty of uncontrolled objects located on different
orbits in the outer space. Some of them present the real hazards to the functioning
satellites and to the International Space Station. The researches all over the world are
working on optimal solutions for the space cleaning. There are projects which are directed
to repair the satellites and extend their ope... »