12-13-2021 PhD Defense of Ornella Tortorici

The Office of doctoral Studies is pleased to inform you that
Mrs Ornella TORTORICI
PhD candidate at COSMER & IM2NP laboratories with Doctoral School 548 « Sea & Sciences »
Under the supervision of M. Vincent HUGEL, Professor, Université de Toulon (France)
&

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

Design and automatic control of an instrumented umbilical for underwater robots
 

Monday December 13, 2021 at 1:30 pm

at University of Toulon – Campus La Garde – Amphi Building M

in front of the following jury

 

  • M. Benoit CLEMENT, Professor, ENSTA Bretagne, reviewer
  • M. Vincent CREUZE, Assistant professor, University of Montpellier , reviewer
  • M. Gérard POISSON, Professor, IUT de BOURGES, examiner
  • M. Cédric ANTHIERENS, Assistant professor, University of Toulon, co-supervisor
  • M. Hervé BARTHELEMY, Professor, University of Toulon, supervisor
  • M. Vincent HUGEL, Professor, University of Toulon, co-supervisor
  • Mme Elisabeth MURISASCO, Professor, University of Toulon, invited

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)