Efficient models configuration for an electric vehicle energy management software

International audienceEnergy management of electric vehicles has been the focus of recent research to allow optimal engine and battery usage. Many efforts have been realised to use the trip knowledge - or a prediction of it - to provide the best vehicle efficiency. Yet few works take into account the embedded devices and the vehicle global Quality of Service. The ORQA framework has a vehicle systemic approach, its purpose is to generate an architecture to counter the range anxiety and offer the best quality effort based on the driver preferences. The work described in this paper is about the off-line configuration of the ORQA framework to match a target vehicle characteristics and abilities. With a more precise configuration, the on-line execution of ORQA is optimised. Two leads are presented to reduce the computation time needed to explore the solution space on-line. The final result is an energy management software tuned for a specific targeted vehicle which offers a driving strategy and a control of the embedded devices matching the driver destination and preferences

Integration of physical models in the ORQA framework for electric vehicle energy management

International audienceThe energy management of electric vehicles is located in the storage system. It considers only the storage physical constituents and adapts the demand of the drive-chain technologies but is blind to other parts of the vehicle. Furthermore it has a very focused approach - to optimise the vehicle movement - and misses the driver's pragmatical needs. ORQA is a framework dedicated to the modelling of the vehicle consuming devices complementing the embedded systems models. It characterises each consuming device by its energetic needs and the quality levels it offers from a driver perspective. ORQA is realised by a system-level energy manager which looks for a driving strategy matching the driver needs and constraints. As the components used in ORQA are generic devices, the consumption of the devices is an approximation of their real consumptions. This paper presents the adaptation of the ORQA framework to have a closer estimation of the consuming devices. We propose the use of physical models issued from mechatronic systems for the main devices, drive-chain and energy storage, and discuss the benefits and constraints

ORQA: Modeling Energy and Quality of Service within AUTOSAR Models

International audienceElectric vehicles embed a low amount of energy, so their devices need to be managed efficiently to optimize the vehicle autonomy. A vehicle management is achieved by the embedded systems, modeled following the AUTOSAR standard. AUTOSAR covers most of the automotive concerns, but it lacks energy consumption and user-oriented Quality of Service models. This paper presents ORQA, a framework to model and manage the electric vehicle devices through energy consumption and user-oriented Quality of Service. At design time, the architects choose and tune the actual vehicle device models through their power requirements and, if appropriate, quality levels. The generated implementation is then embedded in the existing AUTOSAR models. Thus, at run-time, the vehicle's system is able to evaluate the global consumption of a trip and to propose the user a specific driving strategy. The optional devices are managed throughout the trip, based on the driver preferences. ORQA is illustrated with a classic use-case: a work to home trip

Modèles et transformations de modèles pour l'introduction de la consommation énergétique dans le standard AUTOSAR

National audienceDans un véhicule automobile électrique, la connaissance et la maitrise des consommations énergétiques est primordiale pour une gestion optimale de l'autonomie du véhicule. La gestion logicielle des équipements s'appuie sur une architecture AUTOSAR à base de composants. AUTOSAR ne permet pas actuellement de modéliser les aspects énergétiques des divers équipements. Pour pallier ce manque, ce papier propose un premier modèle de consommations liées à l'utilisation des équipements automobiles. Ce modèle est utilisé pour générer -- à partir d'un architecture fonctionnelle AUTOSAR -- un modèle d'architecture AUTOSAR enrichi de politiques de contrôle de la consommation énergétique. Nous illustrons cette proposition avec une étude de cas (gestion du plafonnier d'un véhicule)

Measure transformation and efficient quadrature in reduced-dimensional stochastic modeling of coupled problems

Coupled problems with various combinations of multiple physics, scales, and domains are found in numerous areas of science and engineering. A key challenge in the formulation and implementation of corresponding coupled numerical models is to facilitate the communication of information across physics, scale, and domain interfaces, as well as between the iterations of solvers used for response computations. In a probabilistic context, any information that is to be communicated between subproblems or iterations should be characterized by an appropriate probabilistic representation. Although the number of sources of uncertainty can be expected to be large in most coupled problems, our contention is that exchanged probabilistic information often resides in a considerably lower dimensional space than the sources themselves. In this work, we thus use a dimension-reduction technique for obtaining the representation of the exchanged information. The main subject of this work is the investigation of a measure-transformation technique that allows implementations to exploit this dimension reduction to achieve computational gains. The effectiveness of the proposed dimension-reduction and measure-transformation methodology is demonstrated through a multiphysics problem relevant to nuclear engineering

Shiatsu and Acupressure: Two Different and Distinct Techniques

Background: Although shiatsu has been taught in specialized schools in Japan since 1940, there is a limited amount of research for its practice. As a result, authors substitute shiatsu with acupressure to use available research on acupressure. It is the position of the authors that, while the two share common aspects, they are substantively different. This project was undertaken to describe technical differences and advocate for a clear distinction, especially in research studies and academic discussions.Methods: To understand whether it is appropriate to include acupressure studies in the evidence for shiatsu an analysis of the references included in a frequently cited systematic review was conducted to collect information about the protocols. In addition, a preliminary exploration of shiatsu practitioners’ perceptions about the differences between shiatsu and acupressure is described. This exploration used videos of shiatsu and acupressure techniques and asked practitioners to comment on their perception of similarity.Discussion: The results identified several key technical differences between the two, including type of pressure applied, the positioning of the thumb, and the way in which body weight is used. Researchers should separate shiatsu and acupressure in their designs and purposively choose one or the other. To facilitate such clarification, we have proposed a definition for shiatsu that may facilitate the differentiation between these two techniques.Conclusion: The authors hope to stimulate discussion about the differences between shiatsu and acupressure, and to question the appropriateness of using acupressure studies as evidence of the efficacy of shiatsu. A true understanding of the efficacy of shiatsu cannot be determined until studies use a common definition of shiatsu and discontinue substituting acupressure research for evidence of shiatsu efficacy. When this happens, it is proposed that a clearer picture of the safety, efficacy, and mechanism of action of both shiatsu and acupressure will emerge

On the construction of general cubature formula by flat extensions

International audienceWe describe a new method to compute general cubature formulae. The problem is initially transformed into the computation of truncated Hankel operators with flat extensions. We then analyse the algebraic properties associated to flat extensions and show how to recover the cubature points and weights from the truncated Hankel operator. We next present an algorithm to test the flat extension property and to additionally compute the decomposition. To generate cubature formulae with a minimal number of points, we propose a new relaxation hierarchy of convex optimization problems minimizing the nuclear norm of the Hankel operators. For a suitably high order of convex relaxation, the minimizer of the optimization problem corresponds to a cubature formula. Furthermore cubature formulae with a minimal number of points are associated to faces of the convex sets. We illustrate our method on some examples, and for each we obtain a new minimal cubature formula

A dynamic inequality generation scheme for polynomial programming

Hierarchies of semidefinite programs have been used to approximate or even solve polynomial programs. This approach rapidly becomes computationally expensive and is often tractable only for problems of small size. In this paper, we propose a dynamic inequality generation scheme to generate valid polynomial inequalities for general polynomial programs. When used iteratively, this scheme improves the bounds without incurring an exponential growth in the size of the relaxation. As a result, the proposed scheme is in principle scalable to large general polynomial programming problems. When all the variables of the problem are non-negative or when all the variables are binary, the general algorithm is specialized to a more efficient algorithm. In the case of binary polynomial programs, we show special cases for which the proposed scheme converges to the global optimal solution. We also present several examples illustrating the computational behavior of the scheme and provide comparisons with Lasserre’s approach and, for the binary linear case, with the lift-and-project method of Balas, Ceria, and Cornuejols

Об областьях однолистности некоторых классов аналитических функций

[Tchakaloff L.; Chakalov Lyubomir; Tchakaloff Lubomir; Tschakaloff Ljubomir; Tschakaloff Lubomir; Čakalov Ljubomir; Čakalov Lyubomir; Чакалов Любомир]Bulgarian. Russian, French summar