Crane Winch Deceleration Control for Irregular Winding Prevention
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Solution Overview
Problem
Existing cranes face issues with irregular winding of suspension ropes due to rapid deceleration, leading to temporary drops of suspended loads and reduced efficiency in load handling.
Innovation Solution
A crane system with a load measurement device to derive an allowable deceleration rate based on the suspended load, controlling the winch to decelerate the rope within this rate, thereby preventing irregular winding without significantly impacting efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If rapid deceleration of the winding of the suspension rope is used, then the work efficiency is improved, but irregular winding occurs causing temporary sudden drop of the suspended load
Solution Approach 1:
The patent applies dynamics by making the deceleration rate adjustable rather than fixed. The control device dynamically adjusts the deceleration rate based on real-time load measurements, allowing rapid deceleration when load is sufficient and reduced deceleration when load is light, thus preventing irregular winding while maintaining work efficiency.
Solution Approach 2:
The patent changes the parameter of deceleration rate from a constant value to a variable value that depends on the load. By deriving an allowable deceleration rate from the measured load and adjusting the control parameters accordingly, the system prevents irregular winding caused by excessive deceleration while maintaining productivity.
2Reliability
If slow deceleration of the winding of the suspension rope is used, then irregular winding is prevented, but the efficiency in carrying the suspended load deteriorates
Solution Approach 1:
The patent changes the deceleration rate parameter based on load conditions. When the load is light, the allowable deceleration rate is reduced to prevent irregular winding. When the load is sufficient, a higher deceleration rate is permitted to maintain work efficiency. This dynamic parameter adjustment resolves the contradiction between reliability and productivity.
Solution Approach 2:
The system dynamically adapts the deceleration rate to current operating conditions rather than using a fixed slow deceleration rate. This allows the crane to maintain high efficiency during normal operation while preventing irregular winding during critical low-load phases.
3Device complexity
If a fixed allowable deceleration rate is used, then the control is simple, but the system cannot adapt to varying load conditions causing either irregular winding or reduced efficiency
Solution Approach 1:
The patent implements feedback by continuously measuring the load on the suspension rope and using this information to adjust the allowable deceleration rate. The load measurement device provides real-time feedback to the control device, which then adapts the deceleration rate accordingly, achieving both adaptability and reasonable control complexity.
Solution Approach 2:
The control system serves itself by automatically adjusting the deceleration rate based on load conditions without requiring manual intervention. The system monitors its own operating conditions and self-regulates the deceleration rate to prevent irregular winding while maintaining efficiency.
Data Source
AI summary
Provided is a crane and a control method capable of preventing an irregular winding from being caused, without significant deterioration in work efficiency. The crane includes an allowable deceleration rate derivation unit and a winch control unit. The allowable deceleration rate derivation unit derives an allowable deceleration rate representing an allowable value of the deceleration rate of the winding of a suspension rope, from a measured load that is a suspension load measured by a load measurement device. The allowable deceleration rate derivation unit derives the allowable deceleration rate that is decreased with a decrease in the measured load. The winch control unit makes the winding of the suspension rope by a winch device decelerated at a deceleration rate limited within a range equal to or less than the allowable deceleration rate.