Crane Pendulum Damping via Inertial Measurement Unit
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Solution Overview
Problem
Existing crane systems face challenges in effectively damping pendulum movements, particularly with double pendulum oscillations caused by elongated slinging devices, which complicates load positioning and increases operational risks due to the complexity of predicting and controlling these movements.
Innovation Solution
The implementation of an inertial measurement unit (IMU) attached to the sling or load, providing acceleration and rotation rate signals, combined with a Kalman filter observer, allows for precise determination of load position and deflection without requiring knowledge of sling length or load inertia, enabling effective sway damping and improved operational safety.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If manual control of crane drives is used to move the load quickly between target points, then productivity is improved, but pendulum oscillations increase and operational safety deteriorates
Solution Approach 1:
The control device receives feedback signals from sensors detecting load position and pendulum movements, and automatically adjusts drive device operation to dampen oscillations while maintaining transport speed, resolving the contradiction between productivity and safety
Solution Approach 2:
The patent replaces manual mechanical control with an automated control system that uses sensor data and control algorithms to manage crane operation, eliminating the need for operator skill while improving both speed and safety
2Adaptability or versatility
If elongated lifting slings are used to suspend loads, then adaptability is improved, but double pendulum movements increase and control difficulty worsens
Solution Approach 1:
Sensors detect the complex double pendulum movements caused by elongated slings, and the control device uses this feedback to calculate and execute compensating drive adjustments, maintaining simplicity of operation despite increased system complexity
Solution Approach 2:
The control system dynamically adjusts drive parameters based on real-time detection of sling length and load position, adapting to varying configurations without requiring complex manual control procedures
3Reliability
If automated pendulum damping control is implemented, then operational safety is improved, but device complexity increases
Solution Approach 1:
The control device performs multiple functions including safety monitoring, pendulum detection, automatic damping control, and drive coordination within a single integrated system, improving safety without proportionally increasing overall system complexity
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
This solution enables precise control of crane movements, reducing pendulum oscillations and enhancing operational safety by accurately determining load position and deflection, even with varying loads and sling lengths, and can be retrofitted to existing cranes without complex modifications.
Implementation Method 1
at least one additional pendulum sensor in the form of an inertial measurement device attached to the lifting device (12) or directly to the load (11), which provides acceleration and rotation rate signals indicative of translational accelerations and rotation rates of the load (11)
Data Source
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AI summary
The invention relates to a crane, in particular a revolving tower crane or boom crane, having a hoisting cable (7) which extends from a crane boom (2) and carries a load hook (8), wherein a sling (12) having a load (11) fixed thereto is rigged to the load hook (8), which load hangs down, spaced apart from the load hook (8), and having a determination device (60) for determining the position and/or excursion of the load (11), and an electronic control apparatus (3) for controlling drive devices for moving crane elements and relocating the load hook (8) according to the detected position and/or excursion of the load (11), wherein the determination device (60) has first determining means (63; 65) for determining a position and/or excursion of the load hook (8) and furthermore an inertial measurement device (66, 67) which is attached to the sling (12) and/or the load (11) and which has acceleration and rotation rate sensor means for providing acceleration and rotation rate signals and second determination means for determining and/or estimating an excursion and/or position of the load (11) from the acceleration and rotation rate signals of the inertial measurement device (66, 67), which is attached to the sling (12) and/or to the load (11), and from the signals of the indicated first determination means (63, 65) which characterize the position and/or excursion of the load hook (8).