Servo-control method and device

摘要

Method and device for servo-controlling the distance of an object from a transiting surface to be followed by said object and capable of reflecting microwaves, by exploiting a control signal, wherein a radiating unit fast with said object provides directive microwave radiation and a symmetrical detector compares the phases of the radiated microwaves and the reflected microwaves, said detector providing a control signal to a servo-control circuit. The device is namely intended to automatic metal-welding machines in which the welding member forms said object and a metal workpiece forms the reflecting surface to be followed at a predetermined distance by said welding member.