COSMER Laboratory – RNSR 201522018X
EA 7398 – Mechanical and Robotic Systems
The COSMER lab participated in the IROS conference at Abu Dhabi in Oct. 2024, where Charly Péraud presented his work described in two papers:
IMU-based Monitoring of Buoy-Ballast System through Cable Dynamics Simulation
Workshop ROMADO: Cable Lobe Detection in a ROV/USV Tethered System Using IMUs and
Compliant Buoy-Ballast Equipment.
The Doctoral Studies Office is pleased to inform you that
Ms Juliette DRUPT
Doctoral student at the COSMER laboratory, part of the Doctoral School 548 “Mer & Sciences” (France)
will submit her thesis in order to obtain the degree of Doctor
under the supervision of
Vincent HUGEL,Professor, University of Toulon (France), Thesis Director
&
Mme Claire DUNE, Maitre de conférences, Université de Toulon (France), Thesis co-supervisor
Andrew COMPORT, Research Fellow, CNRS (France), Thesis co-supervisor
Discipline: Automatics, Signal, Productics, Robotics
on the theme
“Localization of an underwater robot chain“.
Wednesday, November 29, 2023 at 10:00 a.m.
At Université de Toulon – Campus La Garde – Bâtiment M – Amphi M.01
before a jury composed of :
Abstract
Because real-time wireless communications are impossible underwater, underwater remotely operated vehicles (ROVs) are connected to a surface station by a physical link. Recent works investigate limiting the mechanical effects exerted by this cable by using intermediary ROVs to control its shape. This configuration is called an underwater robot chain and is the focus of the current thesis, which investigates its self-localization using embedded sensors.
While ROV localization with respect to its environment can be estimated from its embedded sensors, the cable can be taken as an advantage to localize the ROV at its end point given a knowledge of the cable’s 3D state. Two complementary approaches are studied: the proprioceptive localization of the chain based on an estimation of the 3D state of its cable parts using inertial measurements, and exteroceptive, multi-agent localization with respect to the environment using visual simultaneous localization and mapping techniques.
Keywords: underwater robotics, deformable objects, VSLAM.
The COSMER lab participated in the 11th edition of the ECMR conference. Cédric Anthierens presented the thesis work of Ornella Tortorici, and Vincent Hugel chaired the session, which was dedicated to robotics applications.
Detailed program.
The papers of the conference are available on request.
The Doctoral Studies Office is pleased to inform you that
Mr. Lewis ANDURAND
Doctoral student at the COSMER laboratory
laboratory, attached to Doctoral School 548 “Mer & Sciences” (France)
will submit his dissertation in view of obtaining the Grade de Docteur
under the supervision of
Vincent HUGEL, Professor, University of Toulon (France)
Co-supervised by
Sébastien CAMPOCASSO, Associate Professor, University of Toulon (France)
&
Matthieu MUSEAU, Associate Professor, Grenoble-Alpes University (France)
Discipline: Solid Mechanics, Mechanical Engineering, Productics, Transport and Civil Engineering
Specialty: Additive Manufacturing
on the theme
“Development of a versatile trajectory generation method for the production of multi-axis DED parts from faceted surfaces”.
Thursday, August 31, 2023 at 09:30 a.m.
At Université de Toulon – Campus La Garde – Bâtiment M – Amphi M.01
before a jury composed of :
Development of a Versatile Path Generation Method for the Manufacturing of Parts by Multi-Axis DED Processes from Meshed Surfaces
Abstract:
Additive manufacturing is a category of processes that allows the production of mechanical parts by the adding of material. Directed Energy Deposition (DED) processes can be combined with multi-axis robots and are a promising option to obtain parts with complex structures. However, the path generation methods and the machine structures used remain an issue. With innovations in these areas, the industrial possibilities would increase tenfold.
This thesis presents a numerical and systematic path generation method based on meshed surfaces and adapted to DED processes. The method was validated through simulations on minimal triply periodic surfaces and allows the creation of a first deposition path that meets the distance constraint between the part and the tool. This first path can be combined with region prioritization feedback to obtain a final path adapted to the physical warnings provided by the robot, the manufacturing material and the tool.
Keywords : Path Generation, Additive Manufacturing, Directed Energy Deposition, Computer Aided Manufacturing
M. Hervé BARTHELEMY, Professor, University of Toulon (France), Codirecteur de thèse
supervised by M. Cédric ANTHIERENS, Assistant Professor, University of Toulon (France)
will defend her thesis to obtain the degree of Doctor
Discipline : « Automatic, Signal, Productics, Robotics »
on the thème
Monday December 13, 2021 at 1:30 pm
at University of Toulon – Campus La Garde – Amphi Building M
in front of the following jury
Abstract
Remotely operated underwater robots (ROV) are connected by an umbilical to communicate with their control station on the surface. This umbilical has a safety advantage as a physical link to the robot but also impacts the system by transmitting forces and disturbances to the ROV, increasing the risk of snags and limiting its working range. This thesis focuses on the active management of umbilical connected to small ROVs in order to limit their impact on the system.
The forces transmitted by the cable to the ROV are studied as a function of different parameters thanks to the chain model and then thanks to the construction of a finite solids model under Matlab Simulink. A simple method of estimating the torsional stiffness and bending stiffness coefficients of the cable is proposed to parameterize these models.
A solution to control the cable distribution by a reel based on its instrumentation with a passive compliance system and a bending sensor is then proposed. This solution is evaluated through simulations of the complete system under Vortex and tank tests of the ROV with its cable instrumented and controlled by the reel. The experiments showed the feasibility of the automatic control of the cable at a reasonable length adapted to the movements of the ROV thanks to its instrumentation.
Key words : Underwater robotics, Mechatronic design, Active management of instrumented umbilical
Abstract
Design and control of actuated tether for underwater robots
Remotely operated vehicles in underwater (ROV) are connected by an umbilical to communicate with their control unit on the surface. This umbilical has a safety advantage as a physical link to the robot but also impacts the system by transmitting forces and disturbances to the ROV, thus increasing the risk of snags and limiting its working range. This thesis focuses on the active management of umbilicals connected to small ROVs in order to limit their impact on the system.
The forces transmitted by the cable to the ROV are studied as a function of different parameters using the catenary model and the construction of a finite solids model under Matlab Simulink. A simple method to estimate the torsional stiffness and bending stiffness coefficients of the cable is proposed in order to parameterize these models.
A solution to control the cable distribution by a winch using its instrumentation which is composed of a passive compliance system and a bending sensor is then proposed. This solution is evaluated through simulations of the complete system under Vortex and tank tests of the ROV with its instrumented cable controlled by the reel. The experiments showed the feasibility of the automatic control of the cable at a length adapted to the movements of the ROV thanks to its instrumentation.
Keywords: Underwater robotics, Mechatronic design, Active management of instrumented tether
Translated with www.DeepL.com/Translator (free version)
In June, the COSMER laboratory was at CIRS of the University of Girona. The objective of this mission was to use the robot
s and inftrastructures of CIRS to test the algorithms developed at COSMER with a dynamic motion tracking based on our Qualysis motion tracking system.
We acquired nearly 300 sequences in one week and carried out 6 different groups of experiments:
We thank the CIRS team for their welcome and help in setting up the experiments!
Keywords : Hydrodynamic parameters, SPH, Numerical method, Interaction, Fluid-solid, Fluid-structure, Incompressible flow, Underwater robotics.
Additive manufacturing of tubes by multi-axis robotized wire deposition :
Trajectory generation and optimization
Additive manufacturing through Directed Energy Deposition (DED) enables small batches
of parts to be rapidly manufactured. However, manufacturing trajectories usually used
for the manufacture of overhanging parts require the use of supports, material which
is not useful for the finished part and time consuming. If multi-axis trajectories can be
used to avoid them, they present generally a heterogeneous local inter-layer distance, thus
requiring a variation of the deposition parameters to adapt the layer height ; variation that
can be harmful to the mechanical characteristics of the final part. This thesis first proposes
a constant local inter-layer trajectory generation method for DED additive manufacturing
of tubular parts defined by parametric curves and which can have profile radius variations.
The proposed trajectories have been validated by robotized manufacturing trials of polymer
parts. Since the rotation about a coaxial deposition tool axis has no impact on the deposit,
the use of 6-axis robots offers a redundancy. Using this redundancy, a layer by layer
optimization of the trajectory in the robot space is then proposed. In a constrained robot
configuration, the trajectory optimization allows the manufacturing of parts that cannot
be manufactured in the usual way, and improves the geometrical quality of the parts with
a better repeatability.
Nicolas and Mathieu were in Girona in March to carry out experiments in the basins of the CIRS (Centre d’Investigació en Robòtica Submarina). These facilities are made available to foreign researchers as part of the EUMarineRobots project.
On this occasion, they answered questions from our Spanish colleagues.
From the 2nd to the 6th of March, a team of researchers and students of the Université de Toulon have been carrying out experiments at the facilities of the CIRS.
These tests allowed them to collect real data regarding the dynamic behaviour of SPARUS AUV which will be compared with the data from the simulator they are developing in order to improve their predictions.
This action has been possible thanks to the Trans-National Access (TNA) offered by the European project EUMarineRobots. The main objective of the EUMR project is to open up key national and regional marine robotics research infrastructures to all European researchers, from both academia and industry, ensuring their optimal use and joint development to establish a world-class marine robotics integrated infrastructure.
If you are a student, industrial researcher and academic or entrepreneur and you are interested in applying for a TNA to carry out experiments with Girona500 AUV or Sparus II AUV, you have time to apply until the 15th of April 2020!
https://www.eumarinerobots.eu/tna-3rdcall
(from https://vicorob.udg.edu/tna-experiments-in-the-vicorobs-infrastructures/)