Patent ID: 8314518

Claim:
A method for monitoring the output of an electromechanical actuator of the rotolinear type for the purposes of detection of a gradual seizing of said actuator, said actuator comprising: a casing, electric motor means for driving in rotation including at least one induction winding, at least one nut supported for rotation in bearings of said casing and driven in rotation by said motor means, at least one actuator rod arranged coaxially with said nut, said nut and said actuator rod being coupled in rotation by axial helical meshing means, means for blocking said actuator rod in rotation with respect to said casing so that the rotation of said nut leads to a linear displacement of said actuator rod, a means provided on said casing for fastening said casing to a fixed or displaceable component, and a means provided on said actuator rod for fastening a free end of said actuator rod to a component which is respectively displaceable or fixed, the method comprising the following steps: a) the intensity of an electric current powering said induction winding is measured, said intensity being representative of a motor torque, and a stress representative of an axial stress to which said actuator rod is subjected, is measured, b) from these measurements, the axial stress to which said actuator rod is subjected/motor torque ratio, which is representative of an overall output of said actuator and representative of the present state of said actuator is calculated, c) an evaluation of the actuator's present state of health of the actuator is produced which is based on the present state of said actuator and optionally on previous stored states of said actuator and on outer parameters, wherein in Step a) a torque representative of an antirotation torque between said means for blocking in rotation and said actuator rod is also measured, and in Step b) the [antirotation torque/motor torque] ratio which is representative of the state of said bearings for mounting said nut for rotation on said casing and/or the [antirotation torque/axial stress to which said actuator rod is subjected] ratio which is representative of the state of said respective cooperating axial helical meshing means of said nut and said actuator rod is/are also calculated.