Abstract: A method for positioning a node within a wireless sensor network in which each node measures RSSs from its neighboring nodes. Path loss parameters of a channel between a regular node and a neighboring node are first obtained. Distances separating each regular node from its neighboring nodes are then estimated on the basis of the measured RSSs, the allocated path loss parameters. Each distance estimate is further corrected by a systematic bias depending upon the actual sensitivity of the receiver. The positions of the regular nodes are estimated from the distance estimates thus corrected.

Abstract: The invention relates to environmental characterization on the basis of an Ultra Wide Band (UWB) radiofrequency communication network. Pulses are emitted and the waveform received is compared with predicted waveforms corresponding to well determined interactions between the wave and its environment. The comparison is done by searching for maximum temporal correlation. The interactions can be notably reflections of the wave on walls or obstacles. The deformations are very dependent on the nature of the materials and directions in which the pulses are emitted and received. If predicted waveforms are stored for various pairs of direction of emission and of reception, it is possible through these correlation operations to find where a wall which gave rise to a reflection is situated.

Abstract: A method and a system are provided which are able to utilize indirect paths of signals of UWB type to locate a wireless communication node possessed by a body. The present method and system can notably apply to cooperative body networks implementing several wireless nodes able to communicate with one another.

Abstract: A method and a device for cooperative location of a first node possessed by a first mobile body comprising several nodes able to transmit and/or receive a signal by wireless means, comprises a step of measurements of distances separating the first node from second nodes, each of the second nodes being possessed by one of the following entities chosen from among: the first mobile body, a remote fixed apparatus and a second mobile body both situated within transmission range of the said mobile body, at least two nodes from among all the second nodes used to perform the distance measurements being possessed by two entities of distinct types and/or by the second mobile body, a step making it possible to utilize the measurements so as to locate at least the first node at least in relation to some of the second nodes.

Abstract: Device for determining a characteristic of a trajectory formed of successive positions of a triaxial accelerometer (3A) rigidly tied to a mobile element (EM), between a first instant of immobility (t0) and a second instant of immobility (tn) of the triaxial accelerometer (3A), subsequent to said first instant of immobility (t0), said device comprising, furthermore, a triaxial additional sensor for measuring a vector of a substantially constant vector field between said first and second instants of immobility (t0,tn), in a fixed global reference frame (GE) tied to the terrestrial reference frame, said additional sensor being rigidly tied to said mobile element (EM) and fixed in the reference frame of the accelerometer (3A), and control means (CMD).

Abstract: The invention relates to environmental characterization on the basis of an Ultra Wide Band (UWB) radiofrequency communication network. Pulses are emitted and the waveform received is compared with predicted waveforms corresponding to well determined interactions between the wave and its environment. The comparison is done by searching for maximum temporal correlation. The interactions can be notably reflections of the wave on walls or obstacles. The deformations are very dependent on the nature of the materials and directions in which the pulses are emitted and received. If predicted waveforms are stored for various pairs of direction of emission and of reception, it is possible through these correlation operations to find where a wall which gave rise to a reflection is situated.

Abstract: A method for locating a UWB transmitter, without a previously-set reference, using at least one first set of at least three UWB searching transceivers, including first, second, and third transceivers. The method a) synchronizes the three UWB searching transceivers, arranged at three different points, and estimates the relative position of these three points; b) receives, by the three transceivers, signals transmitted by the transmitter to be located; and c) calculates the relative position, with respect to the three searching transceivers, of the transmitter to be located according to the time of travel of the signals, transmitted by the transmitter to be located, to the three searching transceivers.

Abstract: A multi-duct diffusion exhaust device for a turbomachine. The exhaust device including an annular inlet, an outer casing shaped symmetrically overall with respect to an axis, one or more internal partitions defining several roughly concentric ducts for an exhaust stream to flow through, and an absorbent coating capable of absorbing some of the acoustic energy generated by the flow. The absorbent coating being provided on at least one of a surface of one internal partition and an interior surface of the outer casing. The absorbent coating having a thickness that is tailored along a length of the exhaust device to optimize the flow in the ducts by maintaining progressive diffusion and avoiding detachment near stationary surfaces.

Abstract: Multi-duct exhaust device for a turbomachine, of the multi-duct type with an annular inlet 4, comprising an outer casing 3 shaped symmetrically overall with respect to an axis and one or more internal partitions 5 defining several roughly concentric ducts 7, 8 for the exhaust stream to flow through, characterized in that an absorbent coating 14, 15, 17, capable of absorbing some of the acoustic energy generated by the flow is provided on at least one surface of one internal partition 5 and/or on the interior surface of the outer casing 3.