Patent ID: 7271733

Claim:
A system for determining at least one parameter of at least one member ( 1 ) rotating with respect to a fixed structure ( 2 ), said system comprising, for each rotating member ( 1 ), an assembly comprising: a transponder ( 3 ) rotationally fixed to the rotating member ( 1 ), the transponder being able to measure the parameter or parameters to be determined; a coder ( 5 ) rotationally fixed to the rotating member ( 1 ), the coder comprising a reference singularity whose angular position is indexed with respect to the angular position of the transponder ( 3 ) on the rotating member ( 1 ); a sensor ( 6 ) fixed to the fixed structure ( 2 ), the sensor being disposed opposite to and at a reading distance from the coder ( 5 ), the sensor being able to deliver a rotation pulse signal comprising a reference pulse corresponding to the detection of the reference singularity; a detection device ( 4 ) for detecting the parameter or parameters issuing from the transponder ( 3 ), the device being fixed to the fixed structure ( 2 ) and comprising a communication means able to send an excitation signal to the transponder ( 3 ) and to receive the measurement or measurements, said communication means having a transmission/reception cone; a device for measuring the speed of rotation of the rotating member ( 1 ); said system also comprising: an activation device ( 7 ) which is connected to each sensor ( 6 ), to each detection device ( 4 ) and to each speed measurement device, the activation device being able, when a reference pulse issuing from the sensor ( 6 ) of an assembly is recorded, to activate the assembly detection device ( 4 ) at a moment which is a function of the indexed position of the transponder ( 3 ) and of the measured speed, so that the transponder ( 3 ) of the assembly is in the transmission/reception cone of the communication means of the detection device.