Crane Hoisting Control for Boom Tip and Hook Alignment
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Solution Overview
Problem
Existing cranes struggle to effectively manage positional shifts between the boom tip portion and the hook during the hoisting of a suspended load, particularly after the start of the hoisting process.
Innovation Solution
A crane system equipped with a position adjustment control unit that adjusts the position of the boom tip and hook to maintain alignment throughout the hoisting process, using a controller to perform position control and instruct workers through a display unit, ensuring the boom tip and hook remain close in a vertical direction until the load is lifted off the ground.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the hook is not positioned immediately above the center of gravity of the suspended load at the start of hoisting, then the hoisting operation can be performed, but a positional shift between the boom tip portion and the hook occurs after the start of hoisting
Solution Approach 1:
The control device performs preliminary position adjustment control before the start of hoisting by calculating the required adjustment amount based on the initial positional relationship between the boom tip portion and hook, and controlling the boom and hook to achieve proper alignment before hoisting begins. This prevents positional shift during hoisting operation.
2Manufacturing precision
If position adjustment control is performed continuously during hoisting, then positional shift is reduced, but the complexity of the control system increases
Solution Approach 1:
The control device calculates and determines the adjustment amount before the start of hoisting operation, and then maintains the adjusted position during hoisting. This preliminary determination approach reduces the need for continuous complex control calculations during the hoisting process, thereby managing system complexity while maintaining position alignment.
Solution Approach 2:
The control device detects the actual position of the boom tip portion and hook, calculates the positional relationship, and determines the required adjustment amount based on this feedback. This feedback mechanism enables precise position alignment control without requiring overly complex continuous adjustment systems.
Data Source
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AI summary
A positional shift between a boom tip and a hook (34) occurring after the start of a hoisting motion is reduced. There is provided a crane (1) that hoists a suspended load (L) through a boom (4) and a hook (34) from a tip of the boom (4). The crane (1) performs position adjustment control for causing the position of the hook (34) and the position of the tip of the boom (4) to be close to each other as viewed in a vertical direction until the suspended load (L) is separated from a ground surface from the start of a hoisting motion. In the position adjustment control, any one of upward and downward derricking motions of the boom (4) can be performed and the adjustment of the speed of the hoisting motion of the hook (34) can also be performed according to the relative movement direction of the hook (34) with respect to a crane body (3).