Hoisting Anti-Sway Optimization with Double-Pendulum Modeling
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Solution Overview
Problem
Existing anti-sway algorithms for hoisting appliances struggle to effectively control secondary sway phenomena, which have higher frequencies and are difficult to suppress, leading to reduced efficiency and safety issues during load transportation.
Innovation Solution
An anti-sway algorithm optimization method using a double pendulum model to determine updated length and mass parameters, combined with lowpass filtering to reject secondary sway frequencies, and highpass filtering to detect and stop the appliance when secondary sway exceeds a threshold.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing anti-sway algorithms are used to control primary sway, then primary sway is reduced, but secondary sway remains uncontrolled and reduces effectiveness
Solution Approach 1:
The patent segments the sway control problem into two distinct frequency components: primary sway (lower frequency) and secondary sway (higher frequency). By using a dual-filter approach with different cutoff frequencies, the system separately processes and controls each sway component, allowing the anti-sway algorithm to effectively address primary sway while the highpass filter detects and allows stopping for secondary sway conditions.
2Productivity
If the hoisting appliance operates continuously to maintain productivity, then productivity increases, but secondary sway may occur and reduce safety
Solution Approach 1:
The patent implements a feedback mechanism where the highpass filter continuously monitors for secondary sway conditions. When secondary sway is detected (exceeding a threshold), the system provides feedback to stop the hoisting appliance, preventing unsafe operations. This feedback loop maintains safety while minimizing interruptions to productivity by only stopping when necessary.
3Reliability
If the appliance stops to wait for secondary sway to stop on its own, then safety is maintained, but productivity decreases
Solution Approach 1:
The patent applies preliminary action by detecting secondary sway conditions in advance through the highpass filter before they become hazardous. The system proactively stops the appliance when secondary sway thresholds are exceeded, preventing unsafe load deposition. This approach minimizes downtime by only stopping when necessary while ensuring safety is maintained.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enhances the ability to control both primary and secondary sway, improving the efficiency and safety of load transportation by effectively damping secondary sway and allowing safe deposition of loads.
Implementation Method 1
filtering a signal representative of a measured angle of the load with respect to a vertical Z-axis as a function of time by a lowpass filter designed to reject said secondary sway frequencies
Implementation Method 2
applying said recorded speed parameters to a model of a double pendulum system associated with the hoisting appliance to generate corresponding angle parameters of the load
Data Source
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AI summary
For optimizing an anti-sway algorithm for the transport of a load (6) by a hoisting appliance spanning a hoisting area and comprising a trolley (2), a reeving system and a tool (4) handling the load, a control device is able to: record (S1a) operating parameters of the hoisting appliance comprising a speed parameter of the trolley and an angle parameter of the load with respect to a vertical Z-axis, apply (Sib) the recorded speed parameters to a model of a double pendulum system associated with the hoisting appliance to generate corresponding angle parameters of the load, perform (S1c) a statistical identification method to iteratively determine updated values for length and mass parameters of the model which minimize a difference between the recorded and generated angle parameters, calculate (S1d) primary and secondary sway frequencies of the hoisting appliance based on the updated values for length and mass parameters of the model, during operation of the hoisting appliance, filter (S2) a signal representative of a measured angle of the load by a lowpass filter designed to reject the secondary sway frequencies, transport (S3) the load in the hoisting area by applying the anti-sway algorithm to the filtered signal.