1999. 
gorithms, 
shape by 
ical Report 
rlag, Band 2., 
o N 
mputer 
ling using 
Joint Geodetic 
t 
led Image 
Washington 
je Understood 
'ern Analysis 
and McMillan, 
'H 2000, 
rence Series, 
3D Natural 
age and Video 
Reconstruction 
sion and Pattern 
d Schafer, R. , 
e reconstruction 
on Volume 
id beyond): a 
lowna, British 
attern 
Computer 
attern 
5,1998. 
ic Real-World 
ference on Virtual 
332. 
FLEXIBLE 3-D MODELLING OF HOSTILE ENVIRONMENTS WITH CONSTRAINED 
VIEWPOINT AND MULTIPLE UNKNOWNS 
Christophe Leroux *, Philippe Even", Anne Lottin", Rodolphe Gelin *, 
Jean Marc Idasiak*, Jean François Boissonneau “, Michel Jeanjacques à 
, LIST/SRSI, CEA-FAR, 92265 Fontenay-Aux-Roses, France (Christophe.Leroux,Anne.Lottin)@cea.fr 
LORIA, Campus Scientifique, BP 239, 54506 Vandœuvre-lès-Nancy, France Philippe.Even@loria. fr 
A * DDCO/SDAD, CEA VALRHO BP 17171 30207 Bagnols-sur-Céze Jean-Marc.Idasiak(a)cea.fr 
DEN/SAC/DRSN CEA FAR PB 6 92265 Fontenay-aux-Roses (boissonneaujf,Michel.Jeanjacques)(a)cea.fr 
Commission V, WG V/2 
KEY WORDS: 3-D modelling, Reconstruction, User interfaces, Image registration, Industry applications 
ABSTRACT: 
This paper describes the 3D geometric modelling of a nuclear waste room using the interactive vision software Pyramide. Pyramide 
was developed at CEA a few years ago for robotics applications. Therefore, models provided can be used straight to prepare and 
execute telerobotics missions. Modelling with Pyramide is made from video images. The software is strongly oriented to provide 
interactive functions. This allows the operator to adapt its modelling strategy according to the circumstances. Pyramide appeared to 
be well suited to this modelling application in reason of its versatility. Constraints on the modelling were indeed very strong: great 
number of parts, highly reflective material, restrained access and radioactive environment. Pyramide allowed to adapt modelling 
strategy and to take into account at the same time, a-priori knowledge on the scene, data captured on-line and unpredictable situation. 
RESUME: 
Cet article décrit la modélisation géométrique 3D d'une salle d'effluents, à l'aide du logiciel de vision interactif Pyramide. Pyramide 
a été développé au CEA il y a quelques années pour des applications de robotique. Le modèle fourni peut être utilisé directement 
pour préparer et exécuter des missions de téléopération. Les fonctions de Pyramide sont fortement orientées sur la modélisation 
interactive en ligne. Ceci permet à l’opérateur d’orienter sa stratégie de modélisation en fonction des circonstances. Pyramide est 
apparu bien adapté à cette application de modélisation, en raison de sa versatilité. Les contraintes sur la modélisation étaient en effet 
très fortes : grand nombre de pièces, matériau réfléchissant, faible éclairage, accès très contraint et environnement radioactif. 
Pyramide a permis d’adapter la stratégie de modélisation en permettant de prendre en compte à la fois des informations a priori sur la 
scène, des informations acquises en ligne et des situations imprévisibles. 
1. INTRODUCTION exposure and human interventions, using of robotics or 
mechanical devices is strongly encouraged. Using such devices 
This paper reports the 3D modelling of a nuclear waste room means that lot of attention must paid to prepare and then control 
using the interactive vision software Pyramide. It highlights the the execution of tasks. One key point is to have a good 
potentiality of a high level of interaction approach to model a representation of the actual situation. This can be provided by 
room with strong environmental constraints: cluttered an accurate 3D model. 
environment, highly reflective surfaces, weak lighting, 
restrained access and radioactivity. It also points out the 22 Environment 
achieved flexibility of this software to adapt the modelling 
strategy to a-priori knowledge on the environment and on-line The environment to model is a nuclear waste room, where 
data acquisition. human access is strictly forbidden. The room has been sealed 
after its construction. It is only accessible through a 160mm 
In the first part of this document, we will describe the diameter hole in the ceiling. Ceiling is a 700mm concrete slab. 
environmental constraints of the modelling. We will then This hole is the only way to set a correspondence between the 
present the chosen solution. The following section will be interior and the exterior of the room. 
dedicated to the modelling. We will conclude giving some 
remarks on the results obtained and on its usability. 
2. ENVIRONMENTAL CONSTRAINTS 
2.1 Context 
Nuclear building decommissioning requires realising tasks with 
the maximum safety. It concerns first the safety of the staff. It 
concerns as well the security of the equipment. In order to limit 
The room is completely dark. No light is available. 
The room dimensions are 6m x 3m x 2.5m approximately. It 
contains three stainless steel tanks labelled A, B and C and two 
other tanks made in some dark non-metallic material. The cell 
contains as well stainless steel pipes running along the ceiling 
and the walls, some electro-valves situated above the tanks, 
filters attached to the walls and a heat exchanger bolted on the 
ceiling. The relative position of these parts to the access hole is 
not well known. 
—175—