Barrier actuator with obstacle detection, e.g. for garage door, has motor with shifted characteristic curve to allow rapid detection of changes in movement of barrier

摘要

An AC motor has a rotor connected to the barrier (24) to move it. A controller controls the movement of the barrier by controlling changes in operating variables represented by motor signals for changing the excitation of the motor. The motor exhibits a raised characteristic curve representing the relationship between detected operating variables and torque, to improve the rapid detection of changes in a movement of the barrier by the controller by detecting changes in the operating variables.