Crane Hook Position Control for Vertical Lift-Off
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Solution Overview
Problem
Existing crane lift-off methods require manual adjustment of the hook position by the operator, which is skill-dependent and challenging, especially when the load is not visible, leading to potential side pulling and swing of the load.
Innovation Solution
A control method that automatically adjusts the hook position before lift-off using a control device with sensors and actuators to tension all sling wire ropes, ensuring the load is lifted vertically with respect to its center-of-gravity position.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If manual hook position adjustment is used before lift-off, then the operator can control the positioning, but the operator's workload increases and skill dependency arises
Solution Approach 1:
The system automatically adjusts the hook position by detecting wire rope tensions and controlling the winch accordingly, eliminating the need for manual operator intervention. The crane system serves itself by using sensor data to autonomously position the hook for optimal lift-off
Solution Approach 2:
The system continuously monitors the tension of each wire rope through sensors and uses this feedback to automatically adjust the hook position. The control device receives tension signals and modifies winch operation to achieve balanced tensioning of all wire ropes
2Manufacturing precision
If manual hook positioning is performed, then the operator can adjust the position, but side pulling and swing of the load occur due to imprecise positioning
Solution Approach 1:
The control device receives tension detection signals from sensors monitoring each wire rope and automatically adjusts the hook position based on this feedback. This closed-loop control ensures precise positioning that prevents side pulling and load swing during lift-off
Solution Approach 2:
The system replaces manual mechanical positioning with an automated control system that uses sensor data and electronic control to achieve precise hook positioning. This substitution eliminates the imprecision inherent in manual operation
3Adaptability or versatility
If the operator manually adjusts the hook position, then the positioning can be adapted to different loads, but the operator needs advanced skills especially when the load is not visible
Solution Approach 1:
The system automatically adapts to different load configurations by detecting wire rope tensions and autonomously adjusting the hook position. This eliminates the need for operator skill in judging load position, especially when the load is not visible to the operator
Solution Approach 2:
The patent replaces the operator's visual assessment and manual adjustment skills with automated sensors and control systems that objectively detect wire rope tensions and calculate the optimal hook position regardless of load visibility
Data Source
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AI summary
The purpose of the present invention is to provide a method for controlling a crane, with which the position of a hook is automatically adjusted before lift-off. To that end, provided is a control method for controlling a crane where a freely-derricking telescopic boom 8 is provided to a swivel base, a main hook 10a is suspended with a main wire rope 14 from a distal end section of the telescopic boom 8, and a suspended load W is suspended on a main hook 10a with slinging wire ropes 100, 101, wherein post-slinging lift-off is preceded by a hook position adjustment control involving repeating: a first process where the control device controls so as to reel in the main wire rope 14 to a position where the main wire rope 14 is tensed; and a second process where the control device controls so as to move the distal end section of the telescopic boom 8 in the same direction of a horizontal direction component V2 of the movement of the main hook 10a in the first process.