Crane Dynamic Lift-Off Control Device Vibration Suppression
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Solution Overview
Problem
Conventional dynamic lift-off control devices require complex control using two actuators, leading to prolonged dynamic lift-off times due to the need to maintain a constant work radius.
Innovation Solution
A dynamic lift-off control device that includes a boom, a winch, a load weight measurement means, and a control unit that calculates the change in derricking angle based on the time change in measured load weight, allowing the boom to be raised to compensate for the change.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If two actuators are used in combination to maintain constant work radius during dynamic lift-off, then load vibration is suppressed, but dynamic lift-off time increases due to complicated control
Solution Approach 1:
The patent extracts the work radius maintenance function from the dynamic lift-off control process. By allowing the work radius to change temporarily during lift-off and compensating only for boom deflection, the system eliminates the need for complex two-actuator coordination while still suppressing load vibration through targeted deflection compensation.
Solution Approach 2:
The control approach is segmented into two independent components: (1) winch hoisting to provide lifting force, and (2) boom raising to compensate for deflection. This segmentation allows each actuator to perform a simplified function rather than coordinating complex movements, reducing control complexity and lift-off time.
2Stability of the object's composition
If work radius is kept constant during dynamic lift-off, then load stability is improved, but control complexity increases requiring two actuators
Solution Approach 1:
The patent extracts the work radius constraint from the control system, allowing the work radius to vary naturally during dynamic lift-off. Only boom deflection compensation is maintained, which provides sufficient load stability without requiring complex multi-actuator coordination to maintain constant work radius.
Solution Approach 2:
The system transitions from a static work radius constraint to a dynamic approach where the work radius is allowed to change temporarily. The boom position is dynamically adjusted only to the extent needed for deflection compensation, simplifying control while maintaining adequate stability.
3Object-affected harmful factors
If complex control with two actuators is used for dynamic lift-off, then load vibration is suppressed, but operation time increases
Solution Approach 1:
The control process is segmented into independent winch hoisting and boom raising operations. The winch provides lifting force while the boom compensates for deflection, allowing parallel execution of functions that previously required sequential coordination, thereby reducing overall operation time while maintaining vibration suppression.
Solution Approach 2:
The boom is raised in anticipation of deflection changes during the lift-off process. By pre-compensating for expected deflection through continuous monitoring and adjustment, the system prevents vibration rather than correcting it afterward, reducing the total time required for stable lift-off.
Data Source
AI summary
The present invention provides a dynamic lift-off control device and a crane with which it is possible to quickly perform dynamic lift-off of a suspended load while suppressing vibration of the load. This dynamic lift-off control device D comprises: a boom (14); a winch (13); a load weight measurement means (22); and a controller (40) serving as a control unit, the controller (40) controlling operations of the boom (14) and the winch (13), deriving, when performing dynamic lift-off of the suspended load by hoisting the winch (13), an amount of change in a derricking angle of the boom (14) on the basis of the time change in the measured load weight, and raising the boom (14) so as to compensate for the amount of change.