Patent ID: 8831855

Claim:
A monitoring method for monitoring a servo-control loop ( 3 ) of an actuator system ( 2 ) for actuating variable-geometry components of a turbojet, the actuator system ( 2 ) comprising at least a servovalve ( 25 ), and first and second actuators ( 21 , 22 ), said method comprising: an estimation step E 20 of estimating a plurality of monitoring parameters m 1 -m 17 from operating data d 4 -d 14 of the servo-control loop ( 3 ); an evaluation step E 30 of evaluating a plurality of indicators i_EVS, i_EVA, i_EVB, i_CID, i_CINT, i_EPA, i_EPB, i_SOMA, i_SOMB, and i_EWRAP from the monitoring parameters; an evaluation step E 40 for evaluating at least one signature matrix, each signature matrix being representative of the values of at least some of the indicators; and a detection and location step E 50 of detecting and locating a degradation affecting the servo-control loop as a function of said at least one signature matrix; wherein, during the estimation step E 20 , an estimate is made of a plurality of parameters selected from at least one of the following categories: a category of parameters representative of positions VSV 1 , VSV 2 , VSVsel of the actuators ( 21 , 22 ); a category of parameters representative of coefficients of autoregressive models used for predicting actuator positions as a function of a control current iCMD of the servovalve ( 25 ); and a category of parameters representative of the control current iCMD of the servovalve ( 25 ) or an integral current of the servo-control loop ( 3 ).