Patent ID: 7106053

Claim:
A device for determining the absolute angular position of a turning device with respect to a fixed structure, said device comprising: an encoder adapted for rotation with the turning device, wherein said encoder includes a main multipolar track and a top turn track which are concentric, and said top turn track includes M angular distributed singularities; a fixed sensor arranged at a gap distance with regard to the encoder, the sensor including at least three sensing elements where at least two are positioned with regard to the main multipolar track so as to deliver two periodic signals S 1 , S 2 in quadrature and at least one is positioned with regard to the top turn track so as to deliver an electrical signal S 3 , the sensor further including an electronic circuit capable of delivering, starting from the signals S 1 , S 2 and S 3 , two squared digital position signals (A, B) in quadrature which are representative of the angular position of the turning device and one top turn signal (C) in the form of M pulses per revolution of the encoder; a processing device configured to process the signals (A, B, C) and including a means for counting, to determine, starting from an initial position, variations of the angular positions of the encoder; and means for measuring the angular position of the turning device with an angular uncertainty of Δθ in which the M singularities are each representative of an absolute angular position of the turning device and are distributed in the top turn track with an angular distribution between them which is greater than 2Δθ, wherein the processing device includes a means for updating the initial position, which upon detecting a pulse, discriminates the pulse detected as a function of the angular position coming from the means for measuring and assigns a value, with respect to the initial position, of the absolute angular position associated with said pulse.