Crane Control Filtering for Load Swing and Operability Balance
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Solution Overview
Problem
Existing cranes struggle to balance manipulability and vibration reduction based on the operational state, as they rely solely on the number of lever switches to adjust vibration filters, leading to inconsistent performance.
Innovation Solution
A crane that generates a filtered control signal for actuators, adjusting the frequency attenuation based on manual or automatic control, operational state, load position, and weight, to prioritize either manipulability or vibration reduction as needed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a time lag filter is applied to reduce vibration, then the vibration reduction effect is improved, but the manipulability of the crane deteriorates
Solution Approach 1:
The patent applies dynamics by making the filter characteristics changeable based on operational conditions. The control device dynamically adjusts the vibration reduction rate and frequency band according to whether the operation is manual or automatic, and the magnitude of operations. This allows the system to optimize between manipulability and vibration reduction in real-time based on the current operational state.
Solution Approach 2:
The patent changes parameters (filter characteristics) based on operational state. Specifically, it adjusts the vibration reduction rate and frequency band parameters according to whether manual or automatic control is active, and according to the magnitude of operations. This parameter adaptation resolves the contradiction by having different filter settings for different operational contexts.
2Object-affected harmful factors
If the vibration reduction rate is increased to improve vibration reduction effect, then the manipulability deteriorates due to excessive filtering
Solution Approach 1:
The system dynamically adjusts the vibration reduction rate based on operational magnitude. When operation magnitude is large, a higher vibration reduction rate is applied; when operation magnitude is small, a lower rate is used to preserve manipulability. This dynamic adjustment resolves the contradiction adaptively.
Solution Approach 2:
The control device changes the vibration reduction rate parameter according to the magnitude of operations detected. This parameter change allows the system to apply stronger filtering when needed (large operations) and weaker filtering when manipulability is prioritized (small operations), resolving the contradiction through context-dependent parameter adjustment.
3Object-affected harmful factors
If the frequency band for vibration attenuation is widened, then the vibration reduction effect is improved, but the manipulability deteriorates due to loss of operational precision
Solution Approach 1:
The patent applies dynamics by making the frequency band width changeable based on operational mode. In automatic control mode, a wider frequency band is applied for maximum vibration reduction. In manual control mode, a narrower frequency band is used to preserve operational precision and manipulability. This dynamic adaptation resolves the contradiction.
Solution Approach 2:
The control device changes the frequency band parameter based on whether manual or automatic control is active. This parameter change allows the system to optimize vibration reduction in automatic mode while maintaining manipulability in manual mode, resolving the contradiction through mode-dependent parameter adjustment.
4Device complexity
If the crane relies solely on the number of lever switches to adjust vibration filters, then the device complexity is reduced, but the adaptability to different operational states deteriorates
Solution Approach 1:
The patent applies feedback by detecting the operational state (manual/automatic mode and operation magnitude) and using this information to automatically adjust filter characteristics. The control device receives feedback about current operations and adapts the vibration reduction parameters accordingly, resolving the contradiction between simplicity and adaptability through intelligent feedback-based adjustment.
Solution Approach 2:
The control system performs self-service by automatically adjusting its own filter characteristics based on detected operational conditions. Rather than requiring external complex control systems, the crane's own control device monitors and adapts the vibration reduction parameters, achieving high adaptability without proportionally increasing device complexity.
Data Source
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AI summary
Provided is a crane making it possible to obtain operability and vibration suppression effect corresponding to an operating state. A crane 1 calculates the resonance frequency ω(n) of the fluctuation of a suspended load W determined from the hanging length of a main wire rope 14 or a sub wire rope 16, generates a control signal C(n) for a swing hydraulic motor 8 and an undulating hydraulic cylinder 12, which are actuators, in accordance with the operation of a turning operation tool 18, a hoisting operation tool 19 and the like, and generates a filtering control signal Cd(n) for the actuators in which a frequency component in an arbitrary frequency range has been attenuated from the control signal C(n) at an arbitrary ratio in reference to the resonance frequency ω(n). When the swing hydraulic motor 8 and the undulating hydraulic cylinder 12 are controlled by the operation of the respective operation tool and when the swing hydraulic motor 8 and the undulating hydraulic cylinder 12 are controlled regardless of the operation of the respective operation tool, the frequency range of the frequency component to be attenuated and the attenuation ratio are switched to different settings.