Method for processing a signal supplied by a bi-directional sensor and corresponding device

A method for processing a signal (CRK) provided by a bidirectional sensor detecting the transit of teeth of a target with a view to generating an angular clock of an internal combustion engine with the aid of a first electronic component (2) receiving the signal originating from the bidirectional sensor, said first component (2) exhibiting means for determining, in a signal exhibiting low-level segments and high-level segments, whether the length of a segment of a given level is or is not greater than a predefined threshold (THMI), and the signal (CRK) provided by the bidirectional sensor being a signal in the form of slots comprising at least low-level segments, high-level segments, and intermediate-level segments, each slot corresponding to the transit of a tooth of a target in front of the sensor and the signal also comprising characteristics making it possible to determine the direction of transit of the tooth, wherein the method comprises the following steps:

• generation of a first signal (CRK_CNT) utilizing all the slots of the signal provided by the sensor but exhibiting only segments corresponding to a first level and segments corresponding to a second level,
• generation of a second signal (CRK_FW) utilizing the slots of the signal provided by the sensor and corresponding to a first direction of transit of a tooth in front of the sensor, and exhibiting a constant level during the rotation of the target in the second direction of transit,
• generation of a third signal (CRK_BW) utilizing the slots of the signal provided by the sensor and corresponding to the second direction of transit of a tooth in front of the sensor, and exhibiting a constant level during the rotation of the target in the first direction of transit,
• connection of the first signal (CRK_CNT) to the input of the first electronic component (2),
• connection of the second signal (CRK_FW) and of the third signal (CRK_BW) to a second electronic component (GTM, 24, 26),
• detection by the second electronic component (GTM, 24, 26) of rising and/or falling edges of the second signal (CRK_FW) and of the third signal (CRK_BW),
• change of the value of the predefined threshold (THMI) in the first component (2) when the second electronic component (GTM, 24, 26) detects an edge on one of the two signals connected to the second component whereas the previous edge has been detected on the other signal, the threshold value being able to take either a first predefined value termed the maximum value or a second value, termed the predefined minimum value, in such a way that the length of the slots is always on one and the same side of the corresponding threshold.