Crane Load Shaking Suppression via Notch Filter Segmentation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional cranes face challenges in conveying loads along a suitable locus while effectively suppressing load shaking, particularly due to geometrically non-linear loci resulting from combined traveling and traverse input operations, which can lead to continued shaking despite resonance frequency filtering.
Innovation Solution
A crane system equipped with a detection unit for attitude information, a target signal generation unit, a filter unit, and a control unit that generates and applies a notch filter to control signals for the driving devices, ensuring the load is conveyed along a suitable locus by filtering and attenuating specific frequency components to minimize shaking.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a time delay filter is applied to suppress resonance frequency components in traveling and traverse input signals, then load vibration is reduced, but the combined locus becomes geometrically non-linear causing continued shaking
Solution Approach 1:
The patent segments the control signals into independent traveling and traverse components, applying the notch filter to each component separately before combination. This segmentation prevents the geometric non-linearity issue that occurs when filtering combined signals, as each filtered signal maintains its original linear relationship with the corresponding driving device output.
Solution Approach 2:
The patent applies the notch filter preliminarily to each input signal (traveling and traverse) before they are combined to control the driving devices. This preliminary filtering action ensures that resonance frequency components are removed from each signal individually, preventing the generation of geometrically non-linear loci that would cause continued shaking.
2Stability of the object's composition
If manual operation is used to cancel load shaking by turning or raising the boom, then load stability is improved, but conveyance efficiency is affected by operator skill level
Solution Approach 1:
The patent implements self-service control by automatically generating speed command signals that incorporate notch filter processing. The system autonomously suppresses resonance frequency components without requiring manual intervention from the operator, eliminating the dependency on operator skill level while maintaining load stability during conveyance.
Solution Approach 2:
The patent employs feedback control by calculating the resonance frequency of the load based on detected parameters (such as suspended length) and using this feedback to adjust the notch filter characteristics. This closed-loop approach ensures continuous adaptation to changing load conditions, maintaining stability without manual operation.
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
This crane is provided with: a operable functional part that is supported on a pair of lower bases in a state where it can be turned, raised, and elongated/contracted; a driving device that drives the operable functional part; a detection unit that detects information about the attitude of the operable functional part; a target signal generation unit that generates a target signal regarding the moving direction and the moving speed of a suspended load on the basis of information about an operation input for instructing the moving direction and the moving speed of the suspended load; a filter unit that generates a filtering target signal by filtering the target signal; a control signal generation unit that generates a speed control signal for controlling the operation speed of the driving device on the basis of the information about the attitude and the filtering target signal; and a control unit that controls the driving device on the basis of the speed control signal.