Point Cloud Cable Analysis for Deformed Slack Estimation

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Solution Overview

Problem

Existing methods for estimating the slack level and tension in cables, such as those used in utility poles, are inaccurate when the cable shape deviates from a quadratic or catenary curve due to external loads, leading to erroneous calculations.

Innovation Solution

A point cloud analysis device and method that divides the cable into regions based on deformation points, using a quadratic curve model to estimate the slack level and tension by detecting branch points and calculating the degree of division boundary, allowing for accurate estimation of cable shape deviations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a single quadratic curve model is used to represent the entire cable, then the device complexity is low, but the measurement precision of slack level and tension becomes inaccurate when the cable is deformed by external loads

Engineering Contradiction:
Improveslack level and tension estimation accuracyVSAvoidcable model complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The cable is divided into multiple regions along its length, with each region represented by a separate quadratic curve model. This segmentation allows the system to capture local deformations caused by external loads (such as service lines or intermediate branches) while maintaining the simplicity of quadratic models for each segment. The division points are automatically detected based on deviations from the expected cable shape, enabling accurate slack level and tension estimation without requiring a single complex model for the entire cable.

Inventive Principle:
Principle #1Segmentation

2Measurement precision

If field measurement work is performed to obtain slack level data, then the measurement precision is high, but the productivity and operation efficiency decrease due to the huge amount of manual work required

Engineering Contradiction:
Improveslack level measurement accuracyVSAvoidmaintenance work efficiency
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent replaces manual field measurement operations with an automated point cloud analysis system. The system uses three-dimensional coordinate information from mobile mapping systems to automatically detect cable positions, fit quadratic curve models, and calculate slack levels and tensions. This substitution eliminates the need for maintenance workers to physically measure cables in the field, dramatically improving productivity while maintaining measurement accuracy through automated computational methods.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Measurement precision

If manual measurement of slack level is performed, then the ease of operation is low due to extensive field work, but the measurement precision can be maintained

Engineering Contradiction:
Improveslack level accuracyVSAvoidmaintenance operation convenience
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The system performs self-service by automatically processing point cloud data to extract cable information, fit models, and calculate parameters without requiring manual field measurements. The automated pipeline includes point cloud acquisition, cable detection, quadratic curve fitting, and slack level calculation, all executed without human intervention in the field. This eliminates the operational burden on maintenance personnel while preserving measurement accuracy through systematic computational analysis.

Inventive Principle:
Principle #25Self-service

Data Source

PatentUS11922650B2Point cloud analysis device, estimation device, point cloud analysis method, and program
Publication Date: 2024.03.05 NIPPON TELEGRAPH & TELEPHONE CORP
  • US11922650B2 patent drawing
  • US11922650B2 patent drawing
  • US11922650B2 patent drawing

AI summary

It is possible to estimate a slack level accurately in consideration of a shape of a deformed cable. A point cloud analysis device sets a plurality of regions of interest obtained by window-searching a wire model including a quadratic curve model representing a cable obtained from a point cloud consisting of three-dimensional points on an object, the region of interest being divided into a first region and a second region. The point cloud analysis device compares information on the first region with information on the second region based on the point cloud included in the region of interest and the quadratic curve model for each of the plurality of regions of interest, calculates a degree of division boundary representing a degree to which a division position between the first region and the second region of the plurality of regions of interest is a branch point of the cable, and detects a division boundary point that is a branch point of a cable represented by the quadratic curve model based on the degree of division boundary calculated for each of the plurality of regions of interest.