École Nationale d'Ingénieurs de Tarbes

The most widely used technique for generating whole-body motions on a humanoid robot accounting for various tasks and constraints is inverse kinematics. Based on the task-function approach, this class of methods enables the coordination of robot movements to execute several tasks in parallel and account for the sensor feedback in real time, thanks to the low computation cost. To some extent, it also enables us to deal with some of the robot constraints (e.g., joint limits or visibility) and manage the quasi-static balance of the robot. In order to fully use the whole range of possible motions, this paper proposes extending the task-function approach to handle the full dynamics of the robot multibody along with any constraint written as equality or inequality of the state and control variables. The definition of multiple objectives is made possible by ordering them inside a strict hierarchy. Several models of contact with the environment can be implemented in the framework. We propose a reduced formulation of the multiple rigid planar contact that keeps a low computation cost. The efficiency of this approach is illustrated by presenting several multicontact dynamic motions in simulation and on the real HRP-2 robot.

This article presents the benefits of using field-programmable gate array (FPGA)-based controllers for power electronics and drive applications. For this purpose, an algorithm perspective is first proposed, where it is stated that, depending on the intrinsic parallelism properties as well as level of complexity, it makes sense to implement each control algorithm on a specific hardware and/or software architecture to get the best performances in terms of execution time or the best ratio performance versus cost. Then, an application perspective is proposed where the constraints specifically linked to the control of power converters are discussed.

We propose a systematic modeling of the nonholonomic mobile manipulators built from a robotic arm mounted on a wheeled mobile platform. We use the models derived to generalize the standard definition of manipulability to the case of mobile manipulators. The effects of mounting a robotic arm on a nonholonomic platform are shown through the analysis of the manipulability thus defined. Several applications are evoked, particularly applications to control. The optimization of criteria inherited from manipulability considerations are given to generate the controls of our system when its end effector motion is imposed.

Abstract Job-shop scheduling through simulation uses various kinds of dispatching rules such as SPT or the slack time rule. Each of these rules aims at satisfying a single criterion although workshop management is a multi-criteria problem. This paper proposes a way to use fuzzy logic in order to build aggregated rules allowing to obtain a compromise between the satisfaction of several criteria. When the criteria of performance change with the evolution of the production environment, these aggregated rules can be parametrized in order to modify the respective influence of the elementary rules they are composed of.

ABSTRACT In this paper, the distribution and status of the Spanish Ibex, Capra pyrenaica (Mammalia: Artiodactyla), are revised. The whole Iberian population numbers nearly 50 000, distributed in more than 50 nuclei, and has generally increased during the last decades. Nevertheless, within this wider context, different conditions apply to different populations, including recent extinction (the Pyrenean population), recovery from recent severe epizooty of sarcoptic mange (e.g. the Sierras de Cazorla and Segura y Las Villas range population) and populations at high densities (e.g. Gredos mountain range and Sierra de Grazalema Natural Park, among others). The main factors affecting the conservation of this species are also reported and discussed. On the basis of current information we propose the status of ‘vulnerable’ for the Spanish Ibex.

Machining is a material removal process that alters the dynamic properties during machining operations. The peripheral milling of a thin-walled structure generates vibration of the workpiece and this influences the quality of the machined surface. A reduction of tool life and spindle life can also be experienced when machining is subjected to vibration. In this paper, the linearized stability lobes theory allows us to determine critical and optimal cutting conditions for which vibration is not apparent in the milling of thin-walled workpieces. The evolution of the mechanical parameters of the cutting tool, machine tool and workpiece during the milling operation are not taken into account. The critical and optimal cutting conditions depend on dynamic properties of the workpiece. It is illustrated how the stability lobes theory is used to evaluate the variation of the dynamic properties of the thin-walled workpiece. We use both modal measurement and finite element method to establish a 3D representation of stability lobes. The 3D representation allows us to identify spindle speed values at which the variation of spindle speed is initiated to improve the surface finish of the workpiece.

For generations, the process of cost estimation has been manual, time-consuming and error-prone. Emerging Building Information Modelling (BIM) can exploit standard measurement methods to automate cost estimation process and improve inaccuracies. Structuring standard measurement methods in an ontologically and machine readable format for a BIM software can greatly facilitate the process of improving inaccuracies in cost estimation. This study explores the development of an ontology based on New Rules of Measurement (NRM) for cost estimation during the tendering stages. The methodology adopted is methontology, one of the most widely used ontology engineering methodologies. To ensure the ontology is fit for purpose, cost estimation experts are employed to check the semantics, descriptive logic-based reasoners are used to syntactically check the ontology and a leading 4D BIM modelling software is used on a case study building to test/validate the proposed ontology.

COVID-19 lockdowns in early 2020 reduced human mobility, providing an opportunity to disentangle its effects on animals from those of landscape modifications. Using GPS data, we compared movements and road avoidance of 2300 terrestrial mammals (43 species) during the lockdowns to the same period in 2019. Individual responses were variable with no change in average movements or road avoidance behavior, likely due to variable lockdown conditions. However, under strict lockdowns 10-day 95th percentile displacements increased by 73%, suggesting increased landscape permeability. Animals' 1-hour 95th percentile displacements declined by 12% and animals were 36% closer to roads in areas of high human footprint, indicating reduced avoidance during lockdowns. Overall, lockdowns rapidly altered some spatial behaviors, highlighting variable but substantial impacts of human mobility on wildlife worldwide.

Summary Background Few data are available on the incidence, risk factors and contamination pathways involved in acute indigenous hepatitis E in developed countries. Aims To draw up an overall picture of hepatitis E cases, to confirm whether or not the majority of the cases were indigenous and to attempt to identify the risk factors and contamination pathways involved in hepatitis E. Methods This study was performed in the framework of a national network (ANGH) including 96 participating centres. The 19 centres with at least one case of acute HEV reported a total number of 53 cases. Results A decreasing South‐to‐North geographic gradient was observed. A nonspecific clinical profile was observed in many cases. Acute hepatitis E was of indigenous origin in 90% of the patients. The most relevant and/or frequent possible risk factors among the 47 indigenous metropolitan cases were water consumption from a personal water supply, uncooked shellfish consumption and the recent acquisition of a pet pig. Conclusions This national survey confirmed that acute indigenous hepatitis E is an emerging disease in developed countries such as France, and suggests that various risk factors are responsible for acute indigenous hepatitis E contamination in non‐endemic countries.

We extend the standard definition of manipulability to the case of a nonholonomic mobile manipulator built from an n joint robotic arm and a nonholonomic mobile platform. The effects of mounting the arm on a nonholonomic platform are shown through the analysis of the manipulability thus defined. Applications of criteria inherited from manipulability considerations are given to justify design and to generate the controls of our system.

Temperature prediction of a battery plays a significant role in terms of energy efficiency and safety of electric vehicles, as well as several kinds of electric and electronic devices. In this regard, it is crucial to identify an adequate model to study the thermal behavior of a battery. This article reports a comparative study on thermal modeling approaches by using a LiCoO2 26650 lithium-ion battery, and provides a methodology to characterize electrothermal phenomena. Three approaches have been implemented numerically—a thermal lumped model, a 3D computational fluid dynamics model, and an electrochemical model based on Newman, Tiedemann, Gu and Kim formulation. The last two methods were solved using ANSYS Fluent software. Simulations were validated with experimental measurements of the cell surface temperature at constant current discharge and under a highway driving cycle. Results show that the three models are consistent with actual temperature measurements. The electrochemical method has the lower error at 0.5C. Nevertheless, this model provides the higher error ( 1.3∘C) at 1.5C, where the maximum temperature increase of the cell was 18.1∘C. Under the driving cycle, all the models are in the same order of error. Lumped model is suitable to simulate a wide range of battery operating conditions. Furthermore, this work was expanded to study heat generation, voltage and heat transfer coefficient under natural convection.

An IR-femtosecond laser ablation ICPMS coupling was used to investigate the influence of the high repetition rate on elemental fractionation effects for the analysis of silicate glass SRM NIST 610. First, elemental fractionation inherent to the ICP was minimised by working on wet plasma conditions which had greater tolerance to mass loading and demonstrated a higher robustness compared to dry plasma conditions. Because of the use of a narrow laser beam producing small craters (17 µm in diameter), a special arrangement of pulses was used to perform resulting craters of 100 µm diameter. The ablation strategy developed in this work consisted in a series of concentric circle trajectories ablated at high repetition rates by moving the laser beam rapidly thanks to a scanning beam device. Two scanner speeds (0.25 mm s−1 and 1.5 mm s−1), five laser repetition rates (from 0.1 kHz to 10 kHz) and three fluence values (5 J cm−2, 14 J cm−2, and 25 J cm−2) were investigated in detail. For this purpose, critical elemental ratios (namely 238U/232Th, 208Pb/238U, and 66Zn/65Cu) of aerosols produced by fs-LA of silicate glass were studied to evaluate the impact of the different laser parameters on elemental fractionation. No heating zones or preferential evaporation of elements were found depending on the repetition rate employed. However, particle-size-fractionation was measured during the ablation of the sample surface, and this effect was reduced by using a high repetition rate as well as a high scanner speed which allow the dilution of the large particles coming from the surface layer with finer particles coming to deeper levels. Additionally, the ablation rate induced by the selected ablation strategy had a low influence on fractionation effects due to the high robustness of the ICP plasma and, on the other hand, fractionation indices were not particularly affected by the laser repetition rate although they could be improved by the use of high fluence values. Finally, it could be stressed that no differences on the structure of the aerosol particles collected on membrane filters were found depending on the ablation parameters.

This article examines the language of numbers as it is used in talk within a contemporary organization to provide a better understanding of the ways speech acts, performed during the construction of accounts, contribute to the process of organizing. Based on an in-depth case study of the site budgetary control process in a French construction firm, it shows that the business of doing calculations through talk generates respective obligations and, in turn, plays a central role in the constitution of the organization. Hence, this article shows how accounting, in all of its manifestations, produces the organization and does not simply occur within it.

In the present ever-changing environment, sales and operations planning (S&OP) is a key process for providing visibility to the enterprise. Besides, it supports a transversal decision process, which co-ordinates different functions either in the company or between companies, in a supply chain (SC) environment. In the literature, S&OP models are mainly focusing on sales, production and inventory. This paper proposes a wider S&OP model built with three levels (sales, operations and supply). It provides a better support for integration inside the company, but also for integration of the company in the SC. Some simulation results are presented, describing the S&OP propagation along a SC, and the related collaboration requirements to be satisfied between the networked companies.

SUMMARY The work presented in this paper aims at providing a unified modelling framework for the reactive control of wheeled mobile manipulators (WMM). Where most work in the literature often provides models, sometimes simplified, of a given type of WMM, an extensive description of obtaining explicit kinematic and dynamic models of those systems is given. This modelling framework is particularly well suited for reactive control approaches, which, in the case of mobile manipulation missions, are often necessary to handle the complexity of the tasks to be fulfilled, the dynamic aspect of the extended workspace and the uncertainties on the knowledge of the environment. A flexible reactive framework is thus also provided, allowing the sequencing of operational tasks (in our case, tasks described in the end-effector frame) whose natures are different but also an on-line switching mechanism between constraints that are to be satisfied using the system redundancy. This framework has been successfully implemented in simulation and on a real robot. Some of the obtained results are presented.

The aim of this correlational study was to: (1) characterize the composition of cow's milk farmhouse cheeses in terms of average contents and variability in fatty acids, retinol, -tocopherol, folate, -carotene, xanthophylls, calcium, phosphorus, magnesium, potassium, zinc, sodium chloride and total antioxidant capacity (TAC) and (2) identify herd characteristics and feeding practices associated with differences in cheese composition. Three hundred and six farmhouse pressed cheeses, produced under real herd management conditions throughout the year, were collected. The conditions of milk production were identified beforehand by means of surveys. The farmhouse cheese was characterized by a high variability in composition. The nature of the basic fodder ration (pasture vs. preserved forages, in particular) explained a great part of the variability in the fat-soluble components in the cheese. The cheese fat was richer in C4:0, C18:0, cis-9 C18:1, trans-11 C18:1, cis-9, trans-11 C18:2 (CLA), -carotene, xanthophylls, retinol, -tocopherol and TAC and poorer in C10:0, C14:0 and C16:0 with the pasture-based rations compared with the preservedforage-based rations. In the grazing period, it was the poorest in C6:0 to C14:0, -carotene and retinol and the richest in cis-9 C18:1, C18:2 n-6 and C18:3 n-3 with the alpine pasture. It was higher in trans-11 C18:1, CLA, -carotene and xanthophylls and lower in C16:0 with a first-use pasture compared with a pasture of higher use rank. A higher percentage of concentrate was associated with higher levels of C14:0 and C16:0 and lower levels of trans-11 C18:1, CLA, C18:2 n-6, C18:3 n-3, xanthophylls and retinol. In the indoor feeding period, the cheese fat was the poorest in trans-11 C18:1, CLA, C18:3 n-3 and -carotene with the maize-based rations, while the vitamin A and E supplementation was associated with higher retinol and -tocopherol contents, respectively. Herd characteristics did not markedly affect the cheese composition, except the breed. In particular, Abondance and Montbliarde breeds were associated with higher CLA percentage in the cheese than the

The ball burnishing process is done to improve the surface finish of workpieces that have been previously machined. In this article we present the results of tests performed with this process that was applied to workpieces with a convex or concave surface of two different materials: aluminum A92017 and steel G10380. An experiment to do the tests was designed. The results of measurements of surface roughness are presented in this paper as well. These results are compared to those measured in the workpieces before being burnished. After that conclusions are drawn about the improvement of surface roughness applied to the workpieces through the ball burnishing process. The main innovation of this paper is that we work with concave and convex geometries. We also obtain a table of recomended parameter values for the process.

International audience

We report the discovery of companions to 5 nearby late M dwarfs (>M5), LHS1901, LHS4009, LHS6167, LP869-26 and WT460, and we confirm that the recently discovered mid-T brown dwarf companion to SCR1845-6357 is physically bound to that star. These discoveries result from our adaptive optics survey of all M dwarfs within 12 pc. The new companions have spectral types M5 to L1, and orbital separations between 1 and 10 AU. They add significantly to the number of late M dwarfs binaries in the immediate solar neighbourhood, and will improve the multiplicity statistics of late M dwarfs. The expected periods range from 3 to 130 years. Several pairs thus have good potential for accurate mass determination in this poorly sampled mass range.

Addressing issues related to multi-label classification is relevant in many fields of applications. In this work. We present a multi-label classification architecture based on Multi-Branch Neural Network Model (MBNN) that permits the network to encode data from multiple semi-parallel subnetworks or layers outputs separately. Different types of neural networks can be used in the MBNN, but the proposal is made with Convolutional Neural Networks subnetworks, trained, and joined in classifying the outputs (i.e., labels). The proposed work makes it possible to perform incremental changes on existing Multitask Learning architectures for an adaptation to the multi-label classification. These transformations lead us to define two new architectures (neural network multi-outputs and neural network multi-features) using the feature extractors from the pre-trained neural networks. The empirical and statistical results verify that the proposed multibranch neural network architecture performs better than other simple multi-label classification architectures. Later, the “network with multi-features” obtained the highest classification score than other deep neural networks with 83.31% of the f1-score for the Amazon rainforest dataset. The f1-score values are 88.81% for Pascal VOC 2007 dataset, 87.71% for Nuswide, and 88.64% for Pascal VOC 2012.