Electromagnetic actuator having a processing unit intended to act on drive means as a function of a mechanical load applied to the said actuator, actuator comprising: - a movable armature mounted inside a magnetic fixed yoke, the said movable armature being movable between an open position and a closed position, - at least one excitation coil linked to the drive means, - the said processing unit having: - means for determining a variation of flux (Φ) in the excitation coil, on the basis of a measurement of the instantaneous voltage (u) and of the instantaneous electric current (i) flowing around the said coil, - means for determining a variation of inductance in the excitation coil, on the basis of a measurement of variation of flux (φ), - means for determining the position (x) of the movable armature with respect to the fixed yoke, determination on the basis of a correlation between the said position (x), the inductance and the instantaneous current (i) in the excitation coil, - means for measuring a total resistance of the excitation coil on the basis of a reference electric current (Iref) and/or of a reference voltage (Uref), actuator, characterized in that the processing unit comprises autoadaptative supervision means having: - means for determining an elementary thermal energy (R.i2.dt) as a function of the total resistance of the excitation coil and of the instantaneous electric current (i), - means for determining an elementary electrical energy (u.i.dt) as a function of the instantaneous voltage (u) and of the instantaneous electric current (i), - means for determining an elementary electromagnetic energy equal to the difference between the instantaneous electrical energy (u.i.dt) and the instantaneous thermal energy (R.i2.dt) - means for determining an elementary mechanical energy (∂Φ(i,x)/i.dx) equal to the difference between the elementary electromagnetic energy ax and an elementary magnetic energy, - the elementary magnetic energy (∂Φ(i,x)/i.dx) being dependent on ai the partial derivative of the flux with respect to the instantaneous current (i), - means for determining a mechanical load applied to the actuator as a function of the difference between the elementary mechanical energy (∂Φ(i,x)/i.dx) and the variation of kinetic energy (1/2mv2) with respect to time of the movable armature between the open position and the closed position, the velocity (v) obtained as derivative of the position (x) with respect to time; the drive means linked to the autoadaptative supervision means varying the intensity of the drive current (I+) for the coil as a function of the said mechanical load. - a movable armature mounted inside a magnetic fixed yoke, the said movable armature being movable between an open position and a closed position, - at least one excitation coil linked to the drive means, - the said processing unit having: - means for determining a variation of flux (Φ) in the excitation coil, on the basis of a measurement of the instantaneous voltage (u) and of the instantaneous electric current (i) flowing around the said coil, - means for determining a variation of inductance in the excitation coil, on the basis of a measurement of variation of flux (φ), - means for determining the position (x) of the movable armature with respect to the fixed yoke, determination on the basis of a correlation between the said position (x), the inductance and the instantaneous current (i) in the excitation coil, - means for measuring a total resistance of the excitation coil on the basis of a reference electric current (Iref) and/or of a reference voltage (Uref), - means for determining an elementary thermal energy (R.i2.dt) as a function of the total resistance of the excitation coil and of the instantaneous electric current (i), - means for determining an elementary electrical energy (u.i.dt) as a function of the instantaneous voltage (u) and of the instantaneous electric current (i), - means for determining an elementary electromagnetic energy equal to the difference between the instantaneous electrical energy (u.i.dt) and the instantaneous thermal energy (R.i2.dt) - means for determining an elementary mechanical energy (∂Φ(i,x)/i.dx) equal to the difference between the elementary electromagnetic energy ax and an elementary magnetic energy, - the elementary magnetic energy (∂Φ(i,x)/i.dx) being dependent on ai the partial derivative of the flux with respect to the instantaneous current (i), - means for determining a mechanical load applied to the actuator as a function of the difference between the elementary mechanical energy (∂Φ(i,x)/i.dx) and the variation of kinetic energy (1/2mv2) with respect to time of the movable armature between the open position and the closed position, the velocity (v) obtained as derivative of the position (x) with respect to time;