Swing angle measuring apparatus for swing free operation of crane

摘要

A swing angle measuring apparatus generates feedback signals for closed loop regulation of a load swinging motion in operation of a crane. The swing angle measuring apparatus measures two-dimensional swing angles, and includes a rope fixed to a hoisting device, two laser displacement sensors, laser reflecting plates, and a rectangular box attached to a hoisting device. Two steel reflecting plates are installed on the periphery of the fixed rope. Two laser displacement sensors are installed in a rectangular box such that the heading of the sensors are configured to perpendicularly intersect the faces of the laser reflecting plates. The configuration of the displacement sensors and the reflecting plates can be reversed. The rectangular box is attached to the hoisting device, and the laser reflecting plates are placed at an offset distance away from the face of the laser displacement sensors, at which a sensor signal of 0 volts is obtained. The swing angle of the rope or cable is determined from the distance between the laser displacement sensors and the laser reflecting plates.