haifa mehdi - Academia.edu (original) (raw)

Papers by haifa mehdi

Dans le domaine de la robotique, la commande des robots contraints est consideree, jusqu'a no... more Dans le domaine de la robotique, la commande des robots contraints est consideree, jusqu'a nos jours, l’un des problemes les plus cruciaux a resoudre. En effet, pour effectuer les taches qui leur sont assignees, un grand nombre de robots manipulateurs doivent entrer en contact avec leur environnement. Par ailleurs, ils necessitent non seulement une commande en position mais aussi en force ce qui peut provoquer une instabilite du systeme robotique contraint en generant une destruction de l’environnement et/ou du robot. La commande des systemes robotiques contraints est par ailleurs un probleme de commande multivariable et non lineaire inherent a deux objectifs conflictuels : toute position elimine la force associee dans une direction de l’espace operationnel et vis vers ca. Dans cette These, des solutions a ce probleme complexe sont proposees en utilisant des strategies de commande par raideur active et par impedance via de nouvelles conditions de stabilite asymptotique au sens d...

$Research paper thumbnail of Stabilization and tracking control of the inverted pendulum on a cart via a modified PSO fractional order PID controller$

The Inverted Pendulum in Control Theory and Robotics: From theory to new innovations, 2017

In this chapter, a fractional-order proportional integral derivative controller, PIλDμ, based sup... more In this chapter, a fractional-order proportional integral derivative controller, PIλDμ, based super-twisting observer for the cart inverted pendulum system is proposed. The mathematical model of the underactuated robotic system is derived using Lagrange equation and Grunwald-Letnikov fractional calculus with the physical parameters of a commercial device, the Googol Technology experimental Laboratory. PIλDμ parameters are optimized using a modified Particle Swarm intelligence optimization approach with the help of a multiobjective fitness function. A comparative analysis with the classical Particle Swarm Optimization algorithm shows the superiority of the proposed approach.

International Journal on Smart Sensing and Intelligent Systems, 2012

To improve the human arm function of disable patients after stroke, we propose in this paper a ne... more To improve the human arm function of disable patients after stroke, we propose in this paper a new design of a robot-assisted therapy. The robotic device must be attached to a human arm and mimics the motion of the shoulder, elbow and wrist joints. The functional training of the stroked upper limb is covered in motion and force via a safe compliant motion. The controller parameters are optimized by the therapist based on the human morphology parameters via an intelligent Control Interface where a Therapist-Patient Interface including the training mode configuration and the displaying the training data must motivate the patients during the assessment treatment progress.

International Journal of Advanced Robotic Systems, 2015

A new design of a robust impedance controller for constrained robotic manipulators is presented. ... more A new design of a robust impedance controller for constrained robotic manipulators is presented. The main objective is to stabilize asymptotically, in the task space, the robotic manipulator's end effectors into a desired position, via a desired contact force under model uncertainties and measurement noise. In this work, the proposed approach is enough straightforward for application without force and position control separation. Robust asymptotic stability in the approach is proved using a Hamiltonian-Lyapunov approach. Besides this, a state/parameter observer and an acceleration estimator are proposed to handle the problems of force estimation, disturbance rejection and acceleration measurement. To ensure high performance, a Particle Swarm Optimization (PSO) algorithm is used finally as an efficient and fast method for the offline fine-tuning of the controller's parameters. In designing the PSO method, the Mean of Root Squared Error (MRSE) is considered as a cost function in the Cartesian space. Finally, the example of the ABB-IRB 140 industrial robot with 6DOFs is used to validate the performances of the proposed approach.

International Journal of Social Robotics, 2011

In this paper, stiffness and impedance control concepts are used to solve position and force cont... more In this paper, stiffness and impedance control concepts are used to solve position and force control for robot-aided rehabilitation. New asymptotic stability conditions are proposed using a suitable Lyapunov approach and based on the relationship between the dynamics of the robot and its energy. The efficiency of the proposed approach is tested on a planar 3 DOF robot-aided rehabilitation constrained to a circular trajectory. The robotic device is configured to be safe and stable in compliant motion in contact with the human arm. It is also designed to be adapted easily to different subjects for performing different tasks. Force and control parameters are tuned using a non linear optimization strategy for which the stability conditions are considered as inequality constraints. Simulation results show that the robot could guide the upper limb of subjects in circular movements under predefined model of the external force and prove the stability and the performances of the compliant motion control strategy.

2011 11th International Conference on Intelligent Systems Design and Applications, 2011

In this paper, position/force stability conditions for constrained robotic manipulators are propo... more In this paper, position/force stability conditions for constrained robotic manipulators are proposed using a Lyapunov approach. The stiffness control concept is applied to design the force model whereas the controller parameters are optimized using Particle Swarm intelligence. The Mean of Root Squared Error (MRSE) is considered as a fitness function in the task space to design the Particle Swarm Optimization (PSO) algorithm. Simulation results prove the stability and the performances of the proposed approach on a 3DOF robotic arm constrained to a circular trajectory.

Lecture Notes in Computer Science, 2012

In this paper, new sufficient conditions for safe motion/force tracking control of robotic system... more In this paper, new sufficient conditions for safe motion/force tracking control of robotic systems under unknown environment are proposed. The asymptotic stability conditions are proved using a Lyapunov impedance approach and the relationship between the error dynamics of the robotic system and its energy. A 3DOF manipulator constrained to a circular trajectory is finally used to validate the stability, the robustness and the safety of the proposed approach.

2013 International Conference on Electrical Engineering and Software Applications, ICEESA 2013, 2013

In this paper, we present an improved proof of global asymptotic stability of constrained robotic... more In this paper, we present an improved proof of global asymptotic stability of constrained robotic systems under model uncertainties. The control objective is to make the robotic manipulator's end effector to track the reference trajectories in the task space. The proposed approach is an enough straightforward method without force and position control separation. It's based on the Lyapunov Hamiltonian method and the stiffness control strategy. The robustness of the suggested robust controller is proved via simulation results.

Robotica, 2014

SUMMARYA method for motion/force control of robot arms with model uncertainties is presented. Tra... more SUMMARYA method for motion/force control of robot arms with model uncertainties is presented. Tracking control of complex trajectories is guaranteed using a Lyapunov approach with high-precision performance ensured using a particle swarm optimization (PSO) algorithm. Tracking performance and robustness are simulated for a robotic device for limb rehabilitation that is designed to be adapted easily to different subjects by considering model parameter uncertainties. Controller parameters are optimized offline using the PSO algorithm with Lyapunov stability conditions considered as inequality constraints. Using the control scheme, the robot can guide limbs on smooth and non-smooth trajectories, under model uncertainties and measurement noise.

Procedia Engineering, 2012

In this paper, a novel robust tracking control law is proposed for constrained robots under unkno... more In this paper, a novel robust tracking control law is proposed for constrained robots under unknown stiffness environment. The stability and the robustness of the controller are proved using a Lyapunov-based approach where the relationship between the error dynamics of the robotic system and its energy is investigated. Finally, a 3DOF constrained robotic arm is used to prove the stability, the robustness and the safety of the proposed approach.

International Journal of Advanced Robotic Systems, 2011

This paper presents an efficient and fast method for fine tuning the controller parameters of rob... more This paper presents an efficient and fast method for fine tuning the controller parameters of robot manipulators in constrained motion. The stability of the robotic system is proved using a Lyapunov-based impedance approach whereas the optimal design of the controller parameters are tuned, in offline, by a Particle Swarm Optimization (PSO) algorithm. For designing the PSO method, different index performances are considered in both joint and Cartesian spaces. A 3DOF manipulator constrained to a circular trajectory is finally used to validate the performances of the proposed approach. The simulation results show the stability and the performances of the proposed approach.

Journal of Computer Science, 2010

Problem statement: The assistance of person with limited ability of arm movement is necessary for... more Problem statement: The assistance of person with limited ability of arm movement is necessary for rehabilitation reasons. This aid is required not only to cover the human performances of the arm in motion and force but also to have a strictly stable dynamics. In this study, we proposed a cooperative system between a disabled arm and a robotic manipulator to reach such objectives. Desired positions and contact forces were imposed by the disabled human whereas appropriate torques were applied by the manipulator to follow human intension. Approach: Various control strategies were proposed during recent years to solve position/force control problem. The impedance control concept was used in this study. A relationship between the dynamics of the robot and its energy was developed to derive stability conditions of the robotic system at the constrained motion phase using a suitable Lyapunov approach. Results: New sufficient conditions of asymptotic stability were developed. To prove the efficiency of the proposed approach, a prototype of a human arm coupled to cooperative constrained robotic manipulator was used. The simulation results showed the stability and the performances of the proposed approach. Conclusion: Results showed the possibility of their use in a real context of rehabilitation of injured and disabled people.