Title KLASIFIKACIJA OBJEKATA I
ODREDIVANJE KORESPONDENCIJA
DIJELOVA UNUTAR KLASA OBJEKATA
NA DUBINSKIM SLIKAMA U SVRHU
ROBOTSKE MANIPULACIJE
Title (english) Object classication and intra-class part correspondence determination in depth
images for robot manipulation
Author Petra Đurović
Mentor Robert Cupec (mentor)
Committee member Irena Galić (predsjednik povjerenstva)
Granter Josip Juraj Strossmayer University of Osijek Faculty of Electrical Engineering, Computer Science and Information Technology Osijek (Department of Computer Engineering and Automation) (Chair of Automation and Robotics) Osijek
Defense date and country 2020-09-14, Croatia
Scientific / art field, discipline and subdiscipline TECHNICAL SCIENCES Electrical Engineering Automation and Robotics
Universal decimal classification (UDC ) 004 - Computer science and technology. Computing. Data processing
Abstract Motivacija za istrazivanje predstavljeno u ovoj disertaciji jest razvoj inteligentnih robota
koji djeluju u nestrukturiranim unutarnjim prostorima, poput kucanstava, bolnica ili skola.
Pri tome, takvi roboti rukuju predmetima koje prethodno nisu vidjeli. Za takvo autonomno
kretanje i manipulaciju, robotskom je sustavu potreban odgovarajuci percepcijski senzor.
Uporaba RGB-D kamere u ulozi senzora pruza trodimenzionalnu informaciju o okolini robotskog
manipulatora. Iz slike snimljene RGB-D kamerom mogu se dobiti informacije o
obliku i velicini predmeta na sceni, korisne u algoritmima za prepoznavanje i klasikaciju
prvi puta videnih predmeta, kao i u algoritmima semanticke segmentacije. Segmentacija
objekta na semanticke dijelove korisna je za odredivanje dijela objekta koji je zbog svoje
svrhe ili geometrijskih svojstava, prikladan za razlicite radne operacije. RGB-D kamera daje
i informacije o polozaju predmeta i njegovih dijelova na sceni, koje se, zajedno s vizualnim
obiljezjima robotske ruke, mogu upotrijebiti u vizualnom vodenju i planiranju radnih
operacija.
Cilj istrazivanja opisanog u ovoj disertaciji je razvoj metoda za klasikaciju objekata na
sceni snimljenoj RGB-D kamerom, metode za semanticku segmentaciju objekata i metode
vizualnog vodenja. Namjena ovih metoda je integracija u autonomni robotski sustav s rukom
i kamerom koji prepoznaje i manipulira prvi puta videnim objektima.
Istrazivanje opisano u ovoj disertaciji nastoji upotpuniti nedostatke postojecih metoda.
Najcesci je nedostatak metoda klasikacije objekata sto ne estimiraju polozaj objekata potreban
za primjene u robotskoj manipulaciji. Nadalje, problem segmentacije na dijelove i
odredivanje korespondencija izmedu dijelova objekata iste klase u svrhu robotske manipulacije
je relativno neistrazen, a izvodenje automatiziranih postupaka semantickog oznacavanja
velikih skupova objekata zahtijeva ljudske i vremenske resurse. Naposljetku, nedostatak su
i dugotrajne metode umjeravanja robotske ruke i kamere koje je tesko prilagoditi za automatizirani
rad u stvarnom vremenu kao i nedovoljan broj prikladnih metoda za vizualno
107
Sazetak
vodenje cjenovno dostupnih robota. Nabrojeni nedostatci dovode do potrebe za razvojem
novih metoda.
Tijekom istrazivanja razvijene su cetiri nove metode:
1. Metoda vizualnog vodenja za SCARA robote koji koriste dubinsku kameru
u boji kao jedini senzor. Metoda koristi marker pricvrscen blizu alata robota, koji
omogucuje odredivanje trenutne pozicije alata pomocu RGB-D kamere te informaciju o dominantnoj
ravnini u radnom prostoru robota dobivenu iz RGB-D slike. Umjeravanje sustava
robot-kamera se izvodi jednim pokretom robotske ruke.
2. Metoda klasikacije objekata na dubinskim slikama zasnovana na poravnanju
konveksne ljuske. Za dani objekt prikazan na RGB-D slici, metoda odreduje najslicnijeg
pripadnika odredene klase objekata. Metoda omogucuje odredivanje polozaja objekta na
sceni u odnosu na referentni objekt dane klase. Ucenje se provodi na bazi 3D modela objekata
razvrstanih u nekoliko klasa.
3. Metoda klasikacije objekata na dubinskim slikama zasnovana na poliedar-
skim modelima klasa oblika. Za dani objekt, metoda odreduje parametre najslicnijeg
pripadnika odredene klase oblika. Ucenje se provodi na bazi 3D modela objekata razvrstanih
u nekoliko klasa. Metoda omogucuje odredivanje polozaja objekta te korespondencija
izmedu dijelova povrsine objekata iste klase.
4. Metoda odredivanja korespondencija dijelova unutar klasa objekata zasnovana
na poliedarskim modelima klasa oblika. Metoda pridruzuje segmentima razmatranih
objekata semanticku oznaku na temelju malog broja anotiranih reprezentativnih objekata i
omogucuje prosirenje baze objekata u stvarnom vremenu.
Razvijena metoda vizualnog vodenja eksperimentalno je ispitana nizom pokusa navodenja
robota iznad zeljene pozicije i hvatanjem jednostavnih predmeta. Uspjesnost metoda klasi-
kacije objekata na dubinskim slikama i odredivanja dijelova na referentnim skupovima 3D
objekata usporedene su s drugim referentnim metodama te je u disertaciji opisana analaiza
rezultata usporedbe.
Abstract (english) Abstract
Object classication and intra-class part correspondence determination in depth
images for robot manipulation
The motivation for the research presented in this dissertation is development of intelligent
robots capable of operating in unstructured environment such as houses, hospitals
and schools. Such robots are expected to manipulate with previously unseen objects. In
order to facilitate autonomous locomotion and manipulation, a robot system requires an
appropriate perception sensor. RGB-D camera as a sensor provides 3D information about
the robot's environment. The information about the shape and size of objects on a scene,
obtained by the RGB-D camera, is useful in object recognition and classication algorithms,
as well as in algorithms for semantic segmentation. Segmentation of objects into semantic
parts is required in order to identify the object parts, relevant for dierent robot operations.
Furthermore, RGB-D cameras provide information about the object pose and the pose of
its parts, which is, along with the robot arm visual features, utilized in visual servoing and
robot operation planning.
The goal of the research presented in this dissertation, was to develop methods for object
classication in RGB-D scenes, semantic object segmentation and visual servoing. The
purpose of these methods is integration in an autonomous robot system with an arm and a
camera, capable of recognizing and manipulating with previously unseen objects.
The research presented in this thesis attempts to overcome the existing methods limitations.
A common drawback of the existing object classication methods is not estimating
the object's pose required for application in robot manipulation. Furthermore, there is a
relatively small number of research regarding semantic part segmentation and part correspondence
determination for robot manipulation tasks, while the part annotation of large
object datasets is labour-intensive. Finally, the lack of hand-eye calibration methods suitable
for real time recalibration as well as visual servoing methods suitable for low cost robots
109
Abstract
are common
aws of the state-of-the-art approaches. The mentioned drawbacks encourage
the development of novel approaches.
During the research, four novel methods are developed:
1. A visual servoing method for SCARA robots using an RGB-D camera as
the only sensor. This method utilizes a marker, placed at the robot end eector, which
determines the current robot tool position, and dominant plane information obtained by the
RGB-D camera. Hand-eye calibration is performed by a single robot arm movement.
2. A method for object classication in depth images based on convex hull
alignment. For a given object in an RGB-D image, this method determines the most
similar object belonging to a particular class. The method estimates the object position
with respect to the referent object from the same class. The learning is based on a 3D model
database, sorted into classes.
3. A method for object classication in depth images based on polyhedral shape
class models. For a given object, this method determines the parameters of the most
similar object belonging to the particular class. Analogously to the previous proposed object
classication method, the learning is based on a 3D model database, sorted into classes. This
method estimates the pose of the object and the correspondences between intra-class object
surfaces.
4. A method for determination of part correspondences within object classes
based on polyhedral shape class models. This method assigns the semantic labels
to the considered objects' segments, based on a small number of annotated representative
objects and enables real time database expansion.
The developed visual servoing approach is experimentally tested by performing positioning
and simple objects' grasping experiments. The accuracy of the proposed classication
methods are experimentally evaluated and compered to several state-of-the-art approaches
using a publicaly available benchmark dataset. The accuracy of the part association method
is evaluated using a set of 3D object models of several classes.
Keywords
vizualno vodenje
umjeravanje robotske ruke i kamere
robotska manipulacija
klasikacija objekata
korespondencije dijelova objekata
3D senzori
Keywords (english)
visual servoing
hand-eye calibration
robotic manipulation
object classication
object part correspondences
3D sensors
Language croatian
URN:NBN urn:nbn:hr:200:538658
Promotion 2020-07-28
Study programme Title: Postgraduate doctoral study programme; specializations in: branch Power Engineering and Communications, branch Informatics Course: branch Power Engineering and Communications Study programme type: university Study level: postgraduate Academic / professional title: doktor/doktorica znanosti, područje tehničkih znanosti, polje elektrotehnika (doktor/doktorica znanosti, područje tehničkih znanosti, polje elektrotehnika)
Type of resource Text
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Created on 2020-10-07 14:00:17