Electric Wheelchair Navigation Simulators: why, when, how?

International audienc

Contribution à l'Amélioration de la Perception Visuelle pour une Navigation Autonome du Fauteuil Roulant le M.A.R.H M

Cet article décrit un concept de fauteuil roulant autonome appelé le M.A.R.H (comme la figure 1), (Mobile d’Autonomie Robotisé pour Handicapé), de part sa constitution, son mode de fonctionnement et la prise en compte de la sécurité de la personne transportée. Il est l’aboutissement de plusieurs années de réflexion menées avec les ergothérapeutes et les services de rééducation de l’IRF Pomponiana Olbia de Hyères (Var) , et plus particulièrement Monsieur Jean-Pierre BELHEU

Vision par Ordinateur et Robotique d'Assistance (application au projet M.A.R.H. , Mobile Autonome Robotisé pour Handicapés)

TOULON-BU Centrale (830622101) / SudocSudocFranceF

Utilisation des Réseaux de Petri Architecturaux pour la modélisation des algorithmes de commande d'une plateforme technologique d'aide aux handicapés

International audiencePour évaluer les capacités fonctionnelles d'une personne handicapée et les compensations nécessaires à la commande d'un fauteuil roulant électrique, une plateforme technologique a été réalisée sur la base des conseils d'un ergothérapeute. Elle a été réalisée avec du matériel standard, comme il est souhaitable de le faire chaque fois que c'est possible pour réduire les coûts financiers. Différentes commandes ont été implantées et sont personnalisables en fonction des spécificités de chaque personne. Elles sont faciles à installer car elles sont modulaires et interchangeables. L'électronique embarquée est intégrée dans des circuits programmables de type FPGA. La programmation est faite en langage VHDL et est obtenue directement à partir de la modélisation des algorithmes par Réseaux de Petri Architecturaux pour obtenir une adéquation algorithme architecture optimisée

A petri net modelling of a neural human machine interface

International audienceFor some disabled people, the use of a wheelchair can be difficult, due to weak physical capacities or cognitive troubles. So, the human-machine interface must be modular, configurable and easy to implement. It must bring reliability and use non specific material as often as possible. Therefore, the FRACAH project (Fauteuil Roulant A Commande Adaptee au Handicap) has been developed. Its lever is handled by an artificial neural network that records functional limitations of the hand, and then compensates them. Petri nets have been used in order to obtain an easy FPGA implementation of the control. Some examples of obtained results are given

A Genetic Algorithm Application to Stereo Calibration

International audienceIn this paper, we propose a method, which adopts a global optimization algorithm based on a hybrid scheme. It consists of a genetic algorithm (GA) combined with a local search process. In the GA phase, an efficient fitness evaluation procedure based on a non-linear camera model is proposed. The local search step is a non-linear local approach using the Levenbergh-Marquardt algorithm. The experimental results show that the proposed method performs very well in terms of robustness to outliers and quality of camera parameters estimation

A camera self-calibration technique for mobile wheelchairs

International audienceThe Robotic systems for disabled people, aims at bringing a piloting assistance to powered wheelchairs in answer to the needs of mobility aid using dynamic vision techniques from mobile robotics. People start to design the robot with the fastest computers to process the information, together with high quality camera to serve as its eye, and precise mechanical motion control. The main working mode for this purpose is a contribution to dynamic vision, in the aim to improve a visio-space behavior of handicapped children. A self-calibration technique of a visual sensor is described: self-calibration implying the adoption of methods allowing to calibrate automatically a camera without using of special calibration set-ups. This paper examines what can be done within a Euclidean calibration, when the internal parameters must remain constant any more. So, we look at a Euclidean basis being a projective and one where some constraints must be observed. This work shows theoretically along with real experiments, how it is possible to completely calibrate a camera in line, that is to determine the intrinsic parameters and the relative displacement between two or three images, without any a priori knowledge of the scenes. The infinite homography computing method is used to estimate intrinsic and extrinsic parameters. This procedure consists of a closed-form solution, followed by a nonlinear refinement based on a bundle adjustment criterion

A camera self-calibration technique for mobile wheelchairs

International audienceThe Robotic systems for disabled people, aims at bringing a piloting assistance to powered wheelchairs in answer to the needs of mobility aid using dynamic vision techniques from mobile robotics. People start to design the robot with the fastest computers to process the information, together with high quality camera to serve as its eye, and precise mechanical motion control. The main working mode for this purpose is a contribution to dynamic vision, in the aim to improve a visio-space behavior of handicapped children. A self-calibration technique of a visual sensor is described: self-calibration implying the adoption of methods allowing to calibrate automatically a camera without using of special calibration set-ups. This paper examines what can be done within a Euclidean calibration, when the internal parameters must remain constant any more. So, we look at a Euclidean basis being a projective and one where some constraints must be observed. This work shows theoretically along with real experiments, how it is possible to completely calibrate a camera in line, that is to determine the intrinsic parameters and the relative displacement between two or three images, without any a priori knowledge of the scenes. The infinite homography computing method is used to estimate intrinsic and extrinsic parameters. This procedure consists of a closed-form solution, followed by a nonlinear refinement based on a bundle adjustment criterion

A global optimization algorithm for stereo calibration

International audienceThe aim of this paper is to propose an efficient solution to the codesign of a stereo calibration operation based on a hybrid approach using genetic algorithms and a nonlinear local search process. This solution can then be easily described by data flow Petri nets, for an implementation through a hardware description language

A camera self-calibration technique for mobile wheelchairs

International audienceThe Robotic systems for disabled people, aims at bringing a piloting assistance to powered wheelchairs in answer to the needs of mobility aid using dynamic vision techniques from mobile robotics. People start to design the robot with the fastest computers to process the information, together with high quality camera to serve as its eye, and precise mechanical motion control. The main working mode for this purpose is a contribution to dynamic vision, in the aim to improve a visio-space behavior of handicapped children. A self-calibration technique of a visual sensor is described: self-calibration implying the adoption of methods allowing to calibrate automatically a camera without using of special calibration set-ups. This paper examines what can be done within a Euclidean calibration, when the internal parameters must remain constant any more. So, we look at a Euclidean basis being a projective and one where some constraints must be observed. This work shows theoretically along with real experiments, how it is possible to completely calibrate a camera in line, that is to determine the intrinsic parameters and the relative displacement between two or three images, without any a priori knowledge of the scenes. The infinite homography computing method is used to estimate intrinsic and extrinsic parameters. This procedure consists of a closed-form solution, followed by a nonlinear refinement based on a bundle adjustment criterion