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In order to design efficient electric motors for automotive applications, it is necessary to consider the constraints from different physics: size, weight, torque density, temperature, and mechanical stress due to high speed and vibration limits. A new methodology taking into account all these aspects will be presented in this paper. A design of experiments (DOE) analysis is carried out in order to build a surface of response and then optimize the motor, fulfilling the different constraints by only modifying the rotor shape.

Thermal characterization of electrical machines is a critical task that must be performed early in the design stages. To get accurate results, just considering the magnetic and thermal features of the machine alone may not be enough. The current harmonics, usually produced by control algorithms and electrical converters, play a critical role in the losses and, therefore, in the machine’s thermal and magnetic performances. In this paper, multiphysics 2D FEM simulation is used to model a PMSM (Permanent Magnet Synchronous Machine) in two different scenarios: fed with sinusoidal currents or fed by a converter and controlled using a PWM (Pulse Width Modulation). Both, thermal steady state and transient analysis will be carried out. A complete experimental validation was performed for both cases, i.e. with sinusoidal currents and with currents generated by converter with PWM. Finally, a detailed comparison between simulation results and experimental tests is presented.

Vibratory characterization of electrical machines is an important task that should be performed early in the design stages. Treat it as an afterthought may lead to high vibration and noise levels incompatible with the application requirements.In this paper, multiphysics FEM simulation is used to model a PMSM (Permanent Magnet Synchronous Machine) from both, the magnetic and vibratory point of view.A 2D magnetic simulation is carried out to get the excitation forces over the stator. In parallel, a 3D modal simulation will reproduce an Experimental Modal Analysis (EMA), identifying machine’s vibration modes. Finally, the Maxwell forces obtained by the magnetic simulation will be used as input to run an Operation Modal Analysis (OMA) which output is the vibration levels in the machine’s housing.Magnetic, EMA and OMA simulations has been validated through prototype testing. A detailed comparison between simulation results and experiments is presented.

International audience; It is of primary interest for biologists to be able to visualize the dynamics of proteins within the cell. In this paper, we propose a new mapping method to robustly estimate dynamics in the entire cell from particle tracks. To obtain satisfyingdiffusion and drift maps, we use a spatiotemporal kernel estimator. Trajectory classification data is used as input andallows to automatically label particle movements into three classes: confined motion (or subdiffusion), Brownian motion, and directed motion (or superdiffusion). We then use this information to calculate diffusion coefficient and drift mapsseparately on each class of motion.

International audience; In this invited communication, we perform a review on Fully-Aperiodic Large Pitch Fibers. Major advantages and drawbacks of this design are presented first as well as the synthesis method, which enables the success of their fabrication. Some laser experiments are then detailed in order to prove the relevance of the aperiodic fiber concept. Very last experimental results and some prospects will be finally shown during the conference.

This paper proposes a framework to make the programming of cobots faster, user-friendly and flexible for assembly tasks. The work focusses on an industrial case of a small (

This study presents key features to develop an efficient tele-rehabilitation platform to support the recovery process in patients after hip replacement surgery. The tool is designed on the concepts of therapeutic education and serious games, in order to enhance the self-rehabilitation. Also, the system is built on a modular architecture to ensure its scalability and adaptation to other physical therapeutic programs. The assessment module integrated in the platform and implemented in dynamic time warping allows for a fair discrimination of the quality of the exercises performed by the users, especially when the motion acquisition is not affected by occlusion. An important contribution of this work is to propose a method that can assess both the range of motion and the compensation movements that may be involved in each exercise.

This paper relates to the study of the evolution of the short-circuit fault in the stator winding and rotor bar breakage fault in a squirrel-cage induction motor. Amplitudes of harmonics of the stator currents and of the magnetic field in the motor proximity are evaluated through dedicated 3D finite element models of the motor. The evolutions of the short-circuit fault and of the bar breakage based on changing of the amplitude of particular harmonics of the stator currents or of the magnetic field are analyzed.

This paper addresses a major challenge in traffic engineering: the selection of a set of paths that minimizes routing cost for a random traffic matrix. We introduce the concept of pathbook: a small set of paths to which we restrict routing. The use of pathbook accelerates centralized traffic engineering algorithms, and therefore is appealing for instantiating, configuring, and optimizing large software-based networks. However, restricting routing to a few paths may lead to higher cost or infeasibility. To this end, we introduce the problem of pathbook design, wherein we search for a pathbook of constrained size that minimizes the expected routing cost of the random traffic matrix, which represents a prediction of the future traffic. The pathbook design problem is of combinatorial nature, and we show that it is NP-hard. We then study its convex relaxation for which we propose an optimal algorithm based on the projected subgradient method. For large networks, the subgradient vector is of prohibitive dimensions, hence we propose a coordinate-descent method using the Gauss-Southwell rule, which prescribes a move along the direction of largest subgradient element. We test the performance of our solution on dynamic traffic matrices from GEANT and find that our Gauss-Southwell pathbooks can accelerate standard methods by two orders of magnitude.

We propose an algorithmic framework for network slicing based on column generation. It aims at efficiently maximizing the number of accepted slices while minimizing the cost of embedding virtual networks. It can address key QoS and high reliability constraints for 5G networks and it extensively uses parallelization to quickly solve a relaxed version of the problem and round it to a near-optimal integer solution. This poster presents performance results on small and large problem instances.

This paper relates to the detection of the short-circuit faults in the stator winding of induction motors. Amplitudes of harmonics of the stator currents and of the magnetic field outside the motor are evaluated through the finite element analyses of the 3D electromagnetic field in time domain. In the perspective of early faults detection, the evolution of short-circuit faults based on changing of the amplitude of particular harmonics of the stator currents or of the magnetic field is studied.

Load-balancing and network optimization in SDN networks require efficient flow splitting during the path computation phase. The way flow splitting is typically implemented in switches is to map the output of an hash function computed on the headers of incoming flows to the content stored in a Ternary Content Addressable Memory (TCAM), a very efficient but scarce resource. Although a large TCAM budget means that the flow distribution can more accurately model a fractional ideal, the distribution of flow volume amongst the paths is constrained in reality to use only a limited number of TCAM rows. In this paper, we present a flow splitting algorithm that maximizes the total number of demands allocated in the network according to the TCAM size constraints and, at the same time, minimize the total routing cost. Although the problem is NP-hard, we show through simulations that we can achieve good approximations of the optimal solution in a reasonable amount of time.

This paper deals with the non-invasive online monitoring of the evolution of a rotor bar breakage in a squirrel-cage induction motor. The investigation of the magnetic field outside the motor based on a dedicated finite element model takes into account the rms value and the amplitudes of particular harmonics of the output voltage of coil sensors. The early detection of the broken bar fault should be based on the exceeding of imposed limits in the change of the rms value or of the amplitude of selected harmonics of the output voltage.

Accurate coverage maps are an important tool for network planning and operation but it is often impossible to obtain these maps completely from measurements. In this paper we describe two new methods that enable operators to minimize the cost for obtaining a complete coverage map at high accuracy. Our first method applies the Singular Value Thresholding (SVT) algorithm to reconstruct a complete map from a sparse matrix of coverage data. We then use the Query by Committee (QbC) rationale to identify the areas where further measurements would maximize accuracy of the completed map. This second method allows operators to plan their drive tests such that a given budget is spent at highest efficiency. Our numerical examples illustrate that our proposed completion technique outperforms relevant state of the art and that QbC further enhances reconstruction accuracy.

Rhythmic and discrete movements are two fundamental motor primitives being - at least partially - controlled by different neural pathways. After a stroke, both primitives can be impaired. However, current upper-limb therapies - both conventional and robot-assisted - train mainly discrete functional movements. In order to recover the complete motor repertoire, training both movements should be offered with dedicated exercises. The paper elaborates a new performance-based robotic assistance to train rhythmic movements with a rehabilitation robot. More precisely, it develops and validates a performance-based smoothness assistance. The developed assistance aims at smoothing the movement being performed, based on a real-time estimate of the movement smoothness.

International audience; A lot of interest has recently arisen in the analysis of multiple-choice "cuckoo hashing" schemes. In this context, a main performance criterion is the load threshold under which the hashing scheme is able to build a valid hashtable with high probability in the limit of large systems; various techniques have successfully been used to answer this question (differential equations, combinatorics, cavity method) for increasing levels of generality of the model. However, the hashing scheme analysed so far is quite utopic in that it requires to generate a lot of independent, fully random choices. Schemes with reduced randomness exists, such as "double hashing", which is expected to provide similar asymptotic results as the ideal scheme, yet they have been more resistant to analysis so far. In this paper, we point out that the approach via the cavity method extends quite naturally to the analysis of double hashing and allows to compute the corresponding threshold. The path followed is to show that the graph induced by the double hashing scheme has the same local weak limit as the one obtained with full randomness.

This paper studies the influence of the magnetic nonlinear frames in the detection of the short-circuit faults based on the investigation of the magnetic field in the induction motors neighboring. The conclusions are based on the comparison of the finite element results obtained with three models: without frame, an ideal closed frame with very important shielding effect, and a frame with two opposite windows, whose radiative behavior is not so different than in the case of real frames.

In order to address their considerable impacts on both energy efficiency and performance requirements, eddy currents modeling and its accuracy are discussed from a thermodynamic approach. A dedicated error criterion is first described in a general framework, i.e., without any assumption about the potential formulation, including possible body motion, and independent from the dimension of the problem. After implementation, preliminary validation is given on an induction heating problem and an induction machine. As expected, the thermodynamic functional provides the global convergence of the calculation within an iterative procedure, whereas the conservation of the electromagnetic power is assessed locally to highlight the ill-checked elements.

Recognizing a person from a distance is important to establish meaningful social interaction and to provide additional cues regarding the situations experienced by a robot. To do so, face recognition and speaker identification are biometrics commonly used, with identification performance that are influenced by the distance between the person and the robot. This paper presents a system that combines these biometrics with human metrology (HM) to increase identification performance and range. HM measures are derived from 2D silhouettes extracted online using a dynamic background subtraction approach, processing in parallel 45 front features and 24 side features in 400 ms compared to 38 front and 22 side features extracted in sequence in 30 sec by using the approach presented by Lin and Wang [1]. By having each modality identify a set of up to five possible candidates, results suggest that combining modalities provide better performance compared to what each individual modality provides, from a wider range of distances.

Based on finite element models of a squirrel cage induction motor, on the frequency domain analysis of steady state motor operation and on the step by step in time domain analysis of the transient of electromagnetic field, dynamics and transient heating of the rotor, this paper represents an almost complete evaluation of the influence of the shape of rotor bars cross-section on motor operation characteristics. The evaluation of the rotor heating transient during the motor in-load start-up through a dedicated multiphysic model reflects three coupled phenomena - transient electromagnetic field, rotor dynamics and transient rotor heating.