Assisted parking and portal falling system for dam top portal crane and control method

The invention discloses an assisted parking and portal falling system for a dam top portal crane and a control method. In order to overcome the problem of huge improvement cost and poor independence and expandability as an added electric control loop and a mechanical structure are coupled with an original dam top portal crane, the system comprises a man-machine interaction module, a central control module, an assisted portal falling module and an assisted parking module, wherein the man-machine interaction module displays a position, a state and a monitoring image of the original portal cranesystem and inputs an operating command; the central control module is connected to the original portal crane system by Ethernet to control parking and portal falling work; the assisted portal fallingmodule comprises a jacking mechanism fixedly arranged on a middle oblique beam to align a dam portal in an assisted manner and fall a gate; and the assisted parking module comprises an encoder and a proximity switch arranged o