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Laribi M.A.,CNRS Pprime Institute | Essomba T.,Loire Valley University | Essomba T.,University of Orléans | Zeghloul S.,CNRS Pprime Institute | And 2 more authors.
Proceedings of the ASME Design Engineering Technical Conference | Year: 2011

This paper considers the practice of a tele-echography through a new slave holder robot for a remote echographic diagnostic application. This robot is integrated in a master-slave system called 'Robotic Platform for an Interactive Tele-echographic System'(PROSIT ANR French national project). The proposed approach is based on motion capture of an expert's gestures during the echography examination. The medical gestures were analyzed in terms of positions and velocities; the result has been used in the definition of the kinematics specifications of the proposed manipulator. The effective workspace size of a standard echography act, done by the medical expert, is determined through an experimental study. The evaluation of the workspace is based on the use of the Vicon Nexus motion capture system. The spherical parallel mechanism (SPM) has been selected because of its characteristics meeting the constraint requirements. In addition this architecture offers an excellent stiffness, high precision and is light weight. The design problem of a new parallel probe-holder robot according to the identified experimental workspace for the tele-echography system is presented. In this work, in order to increase the workspace volume of the manipulator, a minimal set of geometrical parameters of spherical parallel manipulators are optimized to find the maximum workspace. Seven independent design parameters have been identified. The optimal synthesis of spherical parallel manipulators is performed using a real-coded genetic algorithm(GA) based method. An optimal study of the orientation workspace is also presented. Copyright © 2011 by ASME.


Boutat D.,Loire Valley University | Saif M.,University of Windsor
IFAC Proceedings Volumes (IFAC-PapersOnline) | Year: 2013

This paper considers the nonlinear observer normal forms and their application in an ecological Predator-Prey system. These forms allow for the design of robust observers for Predator-Prey models where full measurement is not available. Thus, from a measured population of one specie (prey or predator), one can estimate the population that is not directly measured. © IFAC.


Essomba T.,Loire Valley University | Essomba T.,University of Poitiers | Nouaille L.,Loire Valley University | Laribi M.A.,University of Poitiers | And 2 more authors.
Applied Mechanics and Materials | Year: 2012

This paper deals with the design process of a particular mechatronic system: a teleechography robot. First, we describe the principle of robotized tele-echography and the prototypes already designed. Then, after having chosen the design process, we show two medical gestures analysis performed to define the required specifications of a tele-echography robot. Several kinematic synthesis allow demonstrating that the serial spherical wrist is the most adapted structure to this medical application. The kinematic performance of this structure is limited by the singularity position located at the centre of the workspace. An inclined spherical wrist structure is proposed to displace the singularity position in a less used workspace zone that the normal direction to the patient's skin. In the dimensional synthesis phase, this structure is optimized. Then, a collaborative design study with designers is presented to improve aesthetic and ergonomic of the robot. This step was very interesting because it brought innovative propositions. Finally, a detailed phase allows defining the PROSIT 1 robot. It was manufactured and will be soon tested in clinical environment. © (2012) Trans Tech Publications, Switzerland.


Zheng G.,French Institute for Research in Computer Science and Automation | Zheng G.,French National Center for Scientific Research | Barbot J.-P.,French Institute for Research in Computer Science and Automation | Barbot J.-P.,ENSEA Cergy | Boutat D.,Loire Valley University
Automatica | Year: 2013

Using the theory of non-commutative rings, this paper studies the delay identification of nonlinear time-delay systems with unknown inputs. A sufficient condition is given in order to deduce an output delay equation from the studied system. Then necessary and sufficient conditions are proposed to judge whether the deduced output delay equation can be used to identify delay involved in this equation. Two different cases are discussed for the dependent and independent outputs, respectively. The presented result is applied to identify delay in a biological system. © 2013 Elsevier Ltd. All rights reserved.


Yu L.,Wuhan University | Yu L.,ENSEA Cergy | Zheng G.,French Institute for Research in Computer Science and Automation | Boutat D.,Loire Valley University | And 2 more authors.
IET Control Theory and Applications | Year: 2011

This study investigates the observability and observer design for a class of single output switched systems with high frequency switching, where classical observers cannot be applied directly since the high frequency switching signals are not derivable. By assuming that these signals are integrable in the less restrictive way, and defining a new output, this study shows that algebraic observer can be adopted to estimate the states of the studied switched systems. Although the main idea is explained via normal forms, it can be easily extended to treat generic switched systems with high frequency switching. © 2011 The Institution of Engineering and Technology.


Hanus J.-L.,Loire Valley University | Magnain B.,Loire Valley University | Durand B.,INERIS | Alanis-Rodriguez J.,INERIS | Bailly P.,Loire Valley University
Mechanics and Industry | Year: 2012

Evaluation of the dynamic properties of quasi-brittle materials is of the utmost importance for assessing the vulnerability of structural components under dynamic loadings such as collision or explosion. To investigate the dynamic strength of (quasi)-brittle material, three-point bending tests are performed on a modified Split Hopkinson Pressure Bar. Such an apparatus is often used with pre-cracked specimen to determine the dynamic stress intensity factor of metallic materials. With quasi-brittle materials special care has to be paid to the processing of the test since fracture can occur at very low strains. The specimen remains in an out-of equilibrium state and fracture occurs before the support reactions appear as if it was a support-free impact test. A special non-equilibrium analytical approach has been developed to process the tests. Finite-element simulations are used to assess relevance of the proposed analysis for normalized short beams. Experimental results on brick and concrete samples showing a significant dynamic strength increase are presented. © AFM, EDP Sciences 2013.


Abdelhedi A.,Gabes University | Wided S.,Gabes University | Lassaad S.,Gabes University | Boutat D.,Loire Valley University
2015 World Congress on Information Technology and Computer Applications, WCITCA 2015 | Year: 2015

In this paper, we design exponentially convergent observer for the systems with distributed parameters. A Volterra integral transformation is used to change the coordinates of the error dynamics into exponentially stable target systems using the backstepping procedure. The gains of the observer, which are attained by solving a Partial Differential Equations (PDE) system with output injection, will guarantee the exponential convergence of the observer. What is more, the design method is applied to a SIR epidemic system to consider the sensitive population. © 2015 IEEE.


Zheng G.,French Institute for Research in Computer Science and Automation | Zheng G.,École Centrale Lille | Boutat D.,Loire Valley University
Chinese Control Conference, CCC | Year: 2014

In this paper, we investigate the problem of adaptive observer for simultaneous estimation of state and parameter for a class of nonlinear systems which is of the output depending normal form. Necessary condition for the existence of such an observer is derived. An academic example is given in order to illustrate the effectiveness of the proposed results. © 2014 TCCT, CAA.


Tami R.,Loire Valley University | Boutat D.,Loire Valley University | Zheng G.,French Institute for Research in Computer Science and Automation
Automatica | Year: 2013

This paper concerns the design of a nonlinear observer through a transformation of a nonlinear system into an observer form that supports a high gain observer. Sufficient geometrical condition is deduced to guarantee the existence of change of coordinates allowing the transformation of a nonlinear system into the proposed normal form. The result is highlighted by studying the Susceptible Exposed Infected and Recovered (SEIR) model. © 2013 Published by Elsevier Ltd.


Boutat D.,Loire Valley University
Proceedings of the IEEE Conference on Decision and Control | Year: 2013

This paper provides a class of single-output nonlinear systems that are transformable by means of a suitable extension and a change of coordinates into output-depending extended nonlinear observer normal forms. In addition, this class of dynamical systems provides us with examples of systems that can be transformed using several auxiliary dynamics. © 2013 IEEE.

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