DEVICE FOR ADJUSTING A NOMINAL VALUE OF THE DIMENSION OF AN ACTUATOR, THE LONGITUDINAL DIMENSION OF WHICH CAN BE CHANGED BY APPLYING AN EXTERNAL ELECTROMAGNETIC OR ELECTROSTATIC FIELD

摘要

A device for adjusting a nominal value of the dimension of an actuator, the longitudinal dimension of which can be changed by applying an external electromagnetic or electrostatic field, the magnitude of the external electromagnetic or electrostatic field being associated with the longitudinal dimension of the actuator, or soft-magnetic and highly magnetoelastic layer being connected to the actuator in such a manner that a change in length of the actuator produces a change in the mechanical stress in the layer. The change in mechanical stress in the layer produces a change in the value of an inductance, the mechanical stress in the layer being inferred from the magnitude of the inductance in sensor electronics and the longitudinal dimension of the actuator being inferred from the mechanical stress in the layer. The longitudinal dimension of the actuator is compared with a predetermined nominal value in a comparison device and a correcting variable is output by a control device when a difference between the longitudinal dimension of the actuator and the predetermined nominal value is detected by the comparison device. The correcting variable is predetermined in such a manner that the detected difference disappears.