Multiple hanging points crane electric control method

Abstract

The present invention discloses an electrical control method and a device for a multi-suspension-point crane. The control method comprises the following steps: a. preparation mode: a high and low voltage distribution system, a main driving system and a control system, etc can be detected to check whether fault is existed; b. steel wire rope pre-tensioning mode: each lifting motor adopts torque control and gives out torque given valve, and then a weighing sensor can check whether the steel wire rope is tightened; c. hovering mode: each lifting motor adopts speed control, the controller sets motor torque limiting valve, load hoist can be underwent and centroid position of loaded object can be calculated; d. joint lifting mode: each lifting motor adopts speed control, the torque limiting value of the motor is the same as that in hovering mode, and constantly monitoring and correction can ensure smooth lifting of hanging piece. The electrical control method improves control level of automatic operation and operation efficiency and reduces error of manual operation. The technology can be used for various cranes with the need of synchronous control and has broad application prospect.

Description

Technical field [0001] The invention relates to an ultra-large tonnage crane, in particular to an electrical control scheme for a multi-lifting point crane for integral docking and manufacturing of offshore drilling platforms. Background technique [0002] At present, the electric synchronous control of the hoisting mechanism is up to 4 hoisting points, and the hoisting load is uniform load. The steel wire rope of the reel is wound in a single layer. The control method is relatively simple. The four hoisting systems can use the same speed given signal. To ensure the speed synchronization control of the four winch systems. At the same time, the external position detection is used to judge whether the height of the 4 hoisting points is out of tolerance. Once the allowable value is exceeded, the out-of-tolerance mechanism will be followed by the additional setting of the drive device, and finally the speed of the 4 sets of hoisting systems will be synchronized and Location synchroni...

AI Technical Summary

Problems solved by technology

However, this simple hoisting mechanism cannot satisfy the smooth lifting of large-tonnage equipment, so a super-large-tonnage multi-lift point bridge crane is needed for hoisting to meet the requirements of large-scale assembly projects such as overall hoisting of drilling platforms. At present, there is no such kind in the world. For cranes of different types and lifting methods, there is no similar design of the electrical control system for reference. Multiple lifting points are not a simple addition of lifting mechanisms. Due to uneven loads, the output of each motor is different, and a lifting mechanism is also required. The speed can be asynchronous; and the hoisting system reel wire rope is wound in multiple layers. Compared with the speed of the same motor, the linear speed of each layer of reel is different, and the pulling force on the wire rope is different. If the distribution of force is unreasonable, it may Some motors do not work hard, some motors are overloaded and the system cannot run stably, etc. Therefore, multiple sets of hoisting systems jointly lift loads to form a complex multi-lift point super-static system, and the force distribution is better than 4 lifting points. The control is much more complicated, and stability and synchronization are extremely important. If these problems are not resolved, there will be great safety hazards in the lifting process

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