Automatic control system for cable crane - has trolley moving transversely along main cable operated by hauling rope and container is suspended by rope below trolley driven respectively by two capstans

摘要

The first capstan (7) moves the hauling rope (4) to drive the trolley (3) between a transport start position (A) and a position (B) and back. A second capstan (8) draws and drops the suspension rope (5) to vertically raise and lower the container (6). The capstans are respectively driven by motors (7a,8a) and each has a brake and a rpm detector. The control system includes a sensing unit for detecting the wt. of a transport object including the trolley and the container, a sensing system for a transverse movement value and the speed of the trolley and a similar system for the container. A computer (24) derives a previously determined value of a deflection variable, on the basis of its track, which is given provisionally as a numerical value. This corresponds to the loaded total wt. at the main cable, detected by an angle sensor (28). A coordinate of a start point and a destination point and a transverse movement variable of the trolley and a vertical movement variable of the container is determined by an electronic rangefinder (30). Control of the driving motors is achieved on the basis of the computer programme. USE/ADVANTAGE - On dam building site for transporting concrete. Works automatically with high efficiency and precision, behaviour of main cable, trolley and container is modelled, and automatic working operation is carried out on this basis.