Crane Control with Optical Cable Angle Measurement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing crane control systems fail to accurately align the crane cable perpendicular to the gravitational direction before lifting, leading to undesired oscillations due to manual alignment difficulties and lack of consideration for cable field twisting, especially in boom cranes.
Innovation Solution
A crane control system equipped with sensor units and gyroscope units that determine the cable angle relative to the gravitational direction, allowing for precise alignment and automatic damping of oscillations, while also accounting for cable field twisting through multiple sensor units and followers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If manual alignment of the crane cable is performed before lifting, then the crane operator can position the cable, but alignment precision is poor and time-consuming
Solution Approach 1:
The patent replaces manual mechanical alignment with an automated optical measurement system. A measurement camera system captures images of the cable and boom, and a evaluation unit automatically calculates the cable angle relative to the boom and determines alignment status, eliminating the need for manual alignment operations.
Solution Approach 2:
The patent uses a measurement camera system to create an optical copy/image of the cable and boom configuration. By analyzing this visual copy rather than direct mechanical measurement, the system achieves precise alignment detection without physical contact or manual intervention.
2Measurement precision
If measurement camera systems are arranged behind the cable checkpoint to determine cable angle, then cable angle measurement is possible, but the system cannot be used in boom cranes where the cable exit point changes with cable angle
Solution Approach 1:
The patent transitions from measuring cable angle in a fixed reference frame to measuring the angle between the cable and boom in a moving reference frame. By capturing images of both the cable and boom and calculating their relative angle, the system adapts to the changing cable exit point in boom cranes.
Solution Approach 2:
The patent creates a universal measurement system that works across different crane types. The evaluation unit calculates the cable angle relative to the boom and compares it against stored reference values specific to each crane type, enabling the same system to accurately measure alignment for both trolley cranes and boom cranes.
3Measurement precision
If mechanical measurement pick-ups are used to determine cable angle relative to the boom, then cable angle can be measured, but measurement accuracy is poor and results are wrong in case of crane deformation
Solution Approach 1:
The patent replaces mechanical measurement pick-ups with an optical measurement system. The measurement camera captures images of the cable and boom, and the evaluation unit calculates angles through image processing, eliminating mechanical contact points that are susceptible to deformation errors.
Solution Approach 2:
The patent introduces an image-based intermediary measurement method. Instead of directly measuring physical distances and angles with mechanical sensors, the system uses visual images as an intermediary to calculate cable and boom positions and angles, providing immunity to mechanical deformation.
4Productivity
If the cable is not aligned perpendicular before lifting, then lifting can proceed, but undesired oscillations occur during load movement
Solution Approach 1:
The patent performs preliminary alignment verification before lifting begins. The evaluation unit checks whether the cable is properly aligned with the boom using optical measurement, and only allows lifting to proceed when alignment criteria are met, preventing oscillations before they occur.
Solution Approach 2:
The patent implements a feedback control system where the measurement camera continuously monitors cable and boom positions, the evaluation unit calculates alignment status, and the system provides feedback to control whether lifting should proceed. This closed-loop feedback prevents oscillations by ensuring proper alignment before and during the lifting operation.
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
The system ensures safer and easier alignment of the crane, reduces oscillations, and prevents overload by providing real-time feedback and automatic adjustments, enhancing operational safety and efficiency.
Implementation Method 1
sensor unit for determining a cable angle relative to the direction of gravitational force
Implementation Method 2
gyroscope units are used for determining the load oscillation, which are arranged in the hook of the crane and determine the angular velocity of the cable
Implementation Method 3
The cable angle is determined via an observer circuit which integrates the movement of the cable
Implementation Method 4
load oscillation damping for damping spherical pendular oscillations of the load
Data Source
AI summary
The present invention shows a crane control of a crane which includes at least one cable for lifting a load, wherein at least one sensor unit is provided for determining a cable angle relative to the direction of gravitational force. Furthermore, there is shown a crane control for driving the positioners of a crane which includes at least one first and one second strand of cables for lifting the load, with a load oscillation damping for damping spherical pendular oscillations of the load, wherein first and second sensor units are provided, which are associated to the first and second strands of cables, in order to determine the respective cable angles and/or cable angular velocities, and the load oscillation damping includes a control in which the cable angles and/or cable angular velocities determined by the first and second sensor units are considered. Furthermore, a corresponding crane and a method are shown.