39 research outputs found
Algebraic nonlinear estimation and flatness-based lateral/longitudinal control for automotive vehicles
6 pagesInternational audienceA combined longitudinal and lateral vehicle control is presented. It employs flatness-based control and new algebraic estimation techniques for the numerical differentiation of noisy signals. This nonlinear control is designed for automatic path-tracking via vehicle steering angle and driving/braking wheel torque. It combines the control of the lateral and longitudinal movements in order to ensure an accurate tracking of straight or curved trajectories. It can also be used to perform a combined lane-keeping and steering control during critical driving situations such as obstacle avoidance, stop-and-go control, lane-change maneuvers or any other maneuvers. Promising results have been obtained using the noisy experimental data acquired by a laboratory vehicle under high dynamic loads and characterized by high lateral accelerations
Modulowatt : description d'un système innovant de recharge de véhicule électrique
National audienceCe papier présente l'architecture d'un système innovant de recharge de véhicules électriques. Ce système tente de répondre d'une façon systémique aux éléments freins à l'introduction du véhicule électrique dans l'espace urbain. Basé sur le concept de connexion automatique mains libres, le système Modulowatt (infrastructure de recharge + système embarqué dans les véhicules) propose un domaine d'applications à plusieurs innovations étudiées dans le cadre des systèmes de transports intelligents comme la conduite autonome, la communication V2I et V2V, la perception, etc. Ce papier présente une partie de ces innovations réalisée dans le cadre d'un démonstrateur présentée au salon de l'automobile 2010 de Paris
A Hybrid Control for Automatic Docking of Electric Vehicles for recharging
International audienceIn this paper, we present the architecture of an innovative docking station for electric vehicles recharging and a hybrid control scheme for automatic docking of the vehicles. This work is a part of on-going project concerning the development of a smart charging station for electric vehicles equipped with an automated arm, which connect the vehicle to the charging station, and an infrared beacon system for localizing the automatically maneuvering vehicle in the docking area. The proposed control scheme combines time-optimal (bang-bang) control with continuous time-invariant nonlinear control, which stabilizes the vehicle to a small neighborhood of the docking point. Simulation and experimental results illustrate the effectiveness of the proposed controller
Preparation and investigation of high purity Ge-Te-AgI glasses for optical application
International audienceThe method for the preparation of high purity Ge-Te-AgI glasses with low content of the limiting impurities has been developed. The method includes the synthesis of GeTe4 glass using chemical distillation purification, loading AgI and GeTe4 into silica glass reactor by evaporation in all-sealed glass vacuumed system, melting the (GeTe4)100 − x(AgI)x (x = 0-20) glass into muffle rocking furnace at 850 °С, quenching the glass in water with subsequent annealing and cooling. The prepared glass samples were investigated by energy-dispersive X-ray microanalysis, DSC, FTIR-spectroscopy, Raman spectroscopy, and laser calorimetry. The high purity (GeTe4)100 − x(AgI)x (x = 0-20) glass samples are characterized by good transparency in the spectral range of 2-20 μm, glass transition temperature of 140-160 °С, Tc − Tg difference of more than 100 °С, and a very low content of the limiting impurities. Some glass compositions with AgI content between 10 and 20 at.% manifest a good thermal stability against crystallization
The development of advanced optical fibers for long-​wave infrared transmission
International audienceLong-​wave IR fibers are used in an increasing no. of applications ranging from thermal imaging to bio-​sensing. However, the design of optical fiber with low-​loss in the far-​IR requires a combination of properties including good rheol. characteristics for fiber drawing and low phonon energy for wide optical transparency, which are often mutually exclusive and can only be achieved through fine materials engineering. This paper presents strategies for obtaining low loss fibers in the far-​IR based on telluride glasses. The compn. of the glasses is systematically investigated to obtained fibers with minimal losses. The fiber attenuation is shown to depend strongly on extrinsic impurity but also on intrinsic charge carrier populations in these low band-​gap amorphous semiconductor materials
Commande sans modèle de la vitesse longitudinale d'un véhicule électrique
International audienceWe present for the longitudinal control of an electrical vehicle a "model-free'' control strategy, which is illustrated by convincing experimental results. The physical control is a coefficient rate of the maximal voltage of the battery. The chassis and the engine dynamical equations exhibit complex unknown parameters and/or neglected terms. The proposed ``intelligent'' PI controller, which utilizes new algebraic techniques for estimating derivatives of noisy signals, permits to bypass those parameter and model uncertainties, without the necessity of identifying them
An on-demand personal automated transport system: The CityMobil demonstration in La Rochelle
International audienceThe objective of the CityMobil project is to achieve a more effective organisation of urban transport, resulting in a more rational use of motorised traffic with less congestion and pollution, safer driving, a higher quality of living and an enhanced integration with spatial development. This objective is brought closer by developing integrated traffic solutions: advanced concepts for innovative autonomous and automated road vehicles for passengers and goods, embedded in an advanced spatial setting. This paper presents the automated road vehicles service demonstration to be held in La Rochelle in 2011
Optimising ‘cash flows’:Converting corporate finance to hard currency
Following recent works that have underlined the increasing search for liquidity in economic exchange, this article studies how illiquid forms of money are converted into liquid forms by corporate finance actors. In the name of ‘shareholder value’, the various forms of value generated by companies (such as ‘trade credit’) tend to be increasingly transformed into liquid forms of money that are easily distributable to shareholders (‘cash flows’). Describing this phenomenon as an example of what anthropologists of money call ‘conversion’, this paper highlights how such a conversion process was necessary for the historical development of ‘shareholder value’ policies in corporate finance. Considering documentary sources and interviews with consultants, auditors, and private equity fund managers involved in ‘cash flow’ optimisation practices, this paper details this conversion phenomenon and shows how it has relied on the historical elaboration of specific metrological, technical, legal, and moral norms