Modeling and control of an anthropomorphic robotic hand

Mención Europea en el título de doctorThis thesis presents methods and tools for enabling the successful use of robotic hands. For highly dexterous and/or anthropomorphic robotic hands, these methods have to share some common goals, such as overcoming the potential complexity of the mechanical design and the ability of performing accurate tasks with low and efficient computational cost. A prerequisite for dexterity is to increase the workspace of the robotic hand. For this purpose, the robotic hand must be considered as a single multibody system. Solving the inverse kinematics problem of the whole robotic hand is an arduous task due to the high number of degrees of freedom involved and the possible mechanical limitations, singularities and other possible constraints. The redundancy has proven to be of a great usefulness for dealing with potential constraints. To be able to exploit the redundancy for dealing with constraints, the adopted method for solving the inverse kinematics must be robust and extendable. Obviously, addressing such complex problem, the method will certainly be computationally heavy. Thus, one of the aims of this thesis is to resolve the inverse kinematics problem of the whole robotic hand under constraints, taking into account the computational cost. To this end, this thesis extends and reduces the most recent Selectively Damped Least Squares method which is based on the computation of all singular values, to deal with constraints with a minimum computational cost. New estimation algorithm of singular values and their corresponding singular vectors is proposed to reduce the computational cost. The reduced extended selectively damped least squares method is simulated and experimentally evaluated using an anthropomorphic robotic hand as a test bed. On the other hand, dexterity depends not only on the accuracy of the position control, but also on the exerted forces. The tendon driven modern robotic hands, like the one used in this work, are strongly nonlinear dynamic systems, where motions and forces are transmitted remotely to the finger joints. The problem of modeling and control of position and force simultaneously at low level control is then considered. A new hybrid control structure based on the succession of two sliding mode controllers is proposed. The force is controlled by its own controller which does not need a contact model. The performance of the proposed controller is evaluated by performing the force control directly using the force sensor information of the fingertip, and indirectly using the torque control of the actuator. Finally, we expect that the applications of the methods presented in this thesis can be extended to cover different issues and research fields and in particular they can be used in a variety of algorithm that require the estimation of singular values.This work was partially supported by the European project HANDLE, FP7-231640, and by the Spanish ministry MICINN through FPI scholarship within the project DPI-2005-04302.Programa Oficial de Doctorado en Ingeniería Eléctrica, Electrónica y AutomáticaPresidente: Anis Sahbani.- Secretario: Fares Jawad Moh D Abu-Dakka.- Vocal: Claudio Ross

A new finger inverse kinematics method for an anthropomorphic hand

Proceedings of: 2011 IEEE International Conference on Robotics and Biomimetics (ROBIO), December 7-11, 2011, Phuket (Thailand)In this paper, a new method for solving the inverse kinematics of the fingers of an anthropomorphic hand is proposed. Our approach combines a Modified Selectively Damped Least Squares (MSDLS) and Jacobian Transpose (JT) methods. The main advantages of this method with respect to the ordinary SDLS are: optimal Cartesian increment, shorter computation time and better response near singularity configurations. The original JT method exhibits a strong shattering with small magnitudes which occurs near the goal position or in the case of unreachable positions. Like in the SDLS, a damping factor was applied to each input singular vector to filter the undesirable behavior. A comparative study between the MSDLS applied to the inverse Jacobian and JT matrix is developed to investigate manipulator performance in critical end-point positions of the index finger of a commercial anthropomorphic robotic hand and also to evaluate the impact of the increment length on computation time.European Community's Seventh Framework Progra

Electrophorèse des protéines sériques: étude de 410 profils électrophorétiques

L'électrophorèse des protéines sériques (EPS) est une analyse de routine dans la pratique quotidienne d'un laboratoire de biologie médicale. Le but de notre étude est d’analyser les différents profils électrophorétiques rencontrés dans notre pratique courante. Nous avons mené une étude transversale portant sur 410 échantillons sériques qui ont été collectés dans le cadre de l’analyse de routine au sein du laboratoire de biochimie du Centre Hospitalier Universitaire (CHU) Mohammed VI d’Oujda. L’électrophorèse des protéines sériques a été réalisée sur automate Capilarys2 Flex piercing de Sebia. 241 sérums de femmes et 169 sérums d’hommes ont été collectés. Âgés de 1 à 91 ans avec une moyenne d’âge de 49 ans. 19,5% des EPS étaient normales, l’hypo-albuminémie a été noté chez 34% des cas, un syndrome inflammatoire chronique dans 19,5% des cas, un syndrome néphrotique chez 2% des cas, 5,8% de nos patients avaient un bloc béta-gamma, une hypogammaglobulinémie a été observée dans 8,5% des cas, et 29 pics monoclonaux ont été notés, une bis-albuminémie a été objectivée chez 2 patients. Sur les 410 prélèvements: 92 immunofixations ont été réalisées dont 23 étaient positives (objectivant une gammapathie monoclonale). Cette étude met en évidence la variabilité des motifs de prescription d’une électrophorèse des protéines sériques, ainsi que l’importance des données cliniques pour une interprétation meilleure

Antioxidant activity, phenolic and flavonoid content in leaves, flowers, stems and seeds of mallow (Malva sylvestris L.) from North Western of Algeria

The nutraceutical composition (phenolics and flavonoids) of all leaves, flowers, stems and seeds of mallow, Malva sylvestris L., as well as their antioxidant properties were studied using in vitro methods: ferric reducing antioxidant power (FRAP) assay, by scavenging of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical and total antioxidant capacity (TAC) based on the reduction of molybdenum (VI) to molybdenum (V). Results show that all extracts possessed concentration-dependant antioxidant activity. Leaf extracts have a highest amount of total phenolics with 24.123 ± 0.718 mg GAE/g, and total flavonoids with 0.694 ± 0.017 mg RE/100 g. However, the seed extracts presented the lowest amount in the two assays used. In addition, the AcOEt (EC50 = 3.10 mg/ml) fraction showed the highest value of antioxidant activities for almost all parts of leaves.Keywords: Malva sylvestris L., antioxidant activity, ferric reducing antioxidant power (FRAP), 2,2-diphenyl-1- picrylhydrazyl (DPPH), total antioxidant capacity (TAC).African Journal of Biotechnology, Vol. 13(3), pp. 486-491, 15 January, 201

Comparative Study of Control Approaches Designed for a Quadrotor in a Visual Servoing Task without Observers

International audienceThe performance and characteristics of four controllers applied to a quadrotor UAV are analyzed in this paper. The compared control approaches are: PID, Linearizing Feedback, Backstepping Approach and Sliding Mode based control. A suitable and efficient structure is proposed for control laws implementation. Standard sensors are used and need of observer is avoided by use of IBVS. The comparative analysis is done for the UAV in Visual Servoing Task. It is based on tracking errors during transients and at steady state, and on the performance and robustness with respect to plant model, to environment perturbations (in sensors and actuators) and uncertainties

Séance du 12 janvier 1938

Séance du 12 janvier 1938. In: Bulletin de la Société entomologique de France, volume 43 (1-2), janvier 1938. pp. 2-8

La déesse Temusio

Blanchet Adrien. La déesse Temusio. In: Bulletin Monumental, tome 65, année 1901. p. 218