Contribution on the control and the reactif pilot of wheeled mobile robots

Dans cette thèse nous avons contribué à la commande floue de deux types de robots mobiles : deux robots de type unicycle (Khepera II et fauteuil roulant). Ensuite, nous avons utilisé une architecture de pilotage réactive permettant d’intégrer la commande floue ainsi qu’un algorithme d’évitement d’obstacles réactif utilisant la théorie de Zones de Déformation Virtuelles (ZDV). Des résultats de simulation et expérimentales ont permis de valider l’approche développée.In this thesis we contributed on developing a fuzzy control of two types of mobile robots : two unicycle robots (Khepera II and wheelchair). Then, we used a reactive pilotingarchitecture insuring the integration of both the fuzzy controller and an obstacle avoidance algorithm using the deformable virtual zones theory (DVZ). Simulation and experimental results validate the developed approach

An effective fuzzy-DVZ controller for an omnidirectional mobile robot

International audienceThis paper presents a fuzzy-logic controller and navigation algorithm for guiding an omnidirectional robot. Based on introduced start and reference points, with respect to the inverse kinematic model, the fuzzy logic controller is used to steer the robot to follow the planned poses so as to reach the target point. Our contribution consist on extending a behavioral approach basing on Deformable Virtual Zone (DVZ) for the case of an omnidirectional robot. Furthermore the DVZ algorithm is computed with the fuzzy controller to ensure robot navigation in environments with narrow obstacles and corners. Simulation tests taking into consideration the kinematics of an omnidirectional robot (ROMNI), demonstrate that the robot can successfully navigates within a reasonable amount of time

Evaluation of User Interface Performing a DVZ-Fuzzy Logic Pilot for Powered Wheelchair

This paper presents the preliminary tests of an adapted user interface that performs an hybrid fuzzy-Deformable Virtual Zone(DVZ) pilot. The proposed concept uses a safely guidance algorithm for the powered wheelchair user and a laser range sensor to avoid collision. An adapted user interface is developed so that the accessibility and the mobility of disable or aged people especially those suffering from low cognitive abilities will be enhanced. Trials with the proposed algorithm detected obstacles and avoid them in 80% of trials with different objects and generated safe paths for the interface user

An Effective DVZ-Fuzzy Logic Pilot for a Mobile Robot using Generic Architecture

International audienceThis paper proposes a discussion of a generic controller basing on an hybrid fuzzy-DVZ algorithm that drives a robotic wheelchair to a desired target and remains free of collision. Furthermore, it overcomes a corner situation constraint present in a number of obstacle avoidance strategies present in the literature. This algorithm is reactive and generic, but the obtained experimental paths are not optimized and to do so we have used a collaborative assistance using a 2D interface with 'virtual moving targets'. Results are demonstrated in experimental tests

DVZ-based Obstacle Avoidance Control of a Wheelchair Mobile Robot

International audienceThis paper adresses the control problem of unicycle mobile robot evolving in unknown environments using reactive behaviours. The deformable Virtual Zone (DVZ) principle is used to resolve this problem through defining a safety zone around the vehicle. This approach presents fast control laws that react depending on the presence of an obstacle in the safety zone. Experimental tests are carried out on a wheelchair mobile robot and proved the effectiveness of the studied method

Differentiation of Fanconi anemia and aplastic anemia using mitomycin C test in Tunisia

International audienceFanconi anemia (FA) is a recessive chromosomal instability syndrome that is clinically characterized by multiple symptoms. Chromosome breakage hypersensitivity to alkylating agents is the gold standard test for FA diagnosis. In this study, we provide a detailed laboratory protocol for accurate assessment of FA diagnosis based on mitomycin C (MMC) test. Induced chromosomal breakage study was successful in 171 out of 205 aplastic anemia (AA) patients. According to the sensitivity of MMC at 50 ng/ml, 38 patients (22.22%) were diagnosed as affected and 132 patients (77.17%) as unaffected. Somatic mosaicism was suspected in an 11-year-old patient with a FA phenotype. Twenty-six siblings of FA patients were also evaluated and five of them (19.23%) were diagnosed as FA. From this study, a standard protocol for diagnosis of FA was developed. It is routinely used as a diagnostic test of FA in Tunisia