摘要:
A method for compensating for propagation inhomogeneities in a time-domain reflectogram measured for a cable, characterised in that it comprises the following steps, carried out repeatedly: - Injecting (101) a test signal into said cable, - Measuring (102) the reflection of said test signal to form a time-domain reflectogram, - Identifying (103) at least one time portion of said time-domain reflectogram comprising at least one amplitude peak corresponding to a propagation inhomogeneity, - Subtracting (104), from the test signal, the identified time portion of said reflectogram divided by the reflection coefficient of the signal at the point of injection, and replacing the test signal with the result of the subtraction (104).
摘要:
The method comprises: - a step (503) of injecting at an instant Tinj a reference signal Sar at a point of injection of said assembly, said reference signal having been obtained beforehand by injection (500) of an initial signal Sinit at the level of the injection point at an instant Tinit, by a measurement of the reflected signal resulting from this injection, and by the temporal inversion (501) of said measured signal; - a step (504) of measuring a reflected signal Smes resulting from the propagation of the signal Sar in the assembly of at least one cable; - a step (505, 506) of determining the ageing of the assembly of at least one cable between the instant Tinit and the instant Tinj, said ageing being deduced from the measurement of the reflected signal Smes.
摘要:
A method for analysing a cable into which a first reference signal g is injected, characterised in that it consists of calculating the dynamic correlation between a measurement f of the reflection, against at least one irregularity of said cable, of said injected signal g and a second reference signal g p equal to the first reference signal g weighted by a modelling function of the propagation of a wave along said variable-frequency cable.
摘要:
The present invention relates to a method and a device for analysing electric cable networks in order to detect and locate defects in cables comprising at least one branching from N secondary sections extend. The method involves injecting into the network at a plurality of injections points Ei pseudo-random sequences of digital signals Pni(t) that are de-correlated from each other, and collecting at one or more observation points Sj the composite time signals Rj(t) generated by the circulation of the outputted sequence and the reflection thereof in the network impedance discontinuity. The method further comprises computing the correlation between the composite signals and the time-offset pseudo-random sequences and searching for the positions of correlation peaks in order to derive the location of the defects in the network while taking into account the signal propagation speed in the network.
摘要:
The invention relates to a method for generating a reflectometry signal for diagnosing defects affecting a transmission line or a transmission line network (110), said method being carried out by a diagnostic device (100) belonging to a distributed system comprising a plurality of diagnostic devices connected to said line or said network of lines (110), said method comprising the following steps: • Generating an electrical signal comprising a plurality of frequency carriers regularly distributed within a frequency band subdivided into sub-carriers such that each device of the distributed system uses different sub-carriers from the other devices of said system, • Injecting said electrical signal into said line or network of lines.
摘要:
An overlayer intended to cover an object in order to detect a fault on a surface of said object, characterised in that it comprises an assembly consisting of a plurality of current-conducting wire elements of different mechanical resistances and a means for insulating said conductive wire elements, each conductive wire element being arranged in such a way as to at least partially cover a surface of said object when the overlayer covers said object, each conductive wire element being arranged to allow same to be connected to a test device for detecting a fault affecting said conductive element.
摘要:
The invention relates to a method for detecting and locating defects by reflectometry in a wired electric network that comprises the following steps: feeding a test signal into a wire of said network; collecting the signal reflected on said wire and sampling said reflected signal at a frequency of Fe=1/Te; repeating N times the preceding steps, N being an integer; for each fed test signal, collecting n samples of the corresponding reflected signal, n being an integer; analysing the M=n*N collected samples in order to detect and locate a defect in the wired electric network. The method is characterised in that the collected samples are compared with a predefined adaptive threshold for each diagnosis, on the basis of the test signal fed into the tested wire.