Caliper Pig Sensor Arms Using Hall Effect for Pipeline Deformation Detection
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Solution Overview
Problem
Existing caliper pigs for pipeline inspection lack high-resolution, low-power sensor systems capable of detecting geometrical deformations such as dents, ovalities, and bend radius with high-frequency response, which is essential for maintaining pipeline integrity.
Innovation Solution
A caliper pig design featuring a sensor arm assembly with a primary caliper sensor ring, circumferentially distributed sensor arms, each equipped with a magnet, dual-axis Hall effect Integrated Circuit (IC), and a resilient member, enabling accurate detection of angle deflection and deformation in pipelines.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional sensor systems are used in caliper pigs, then the device complexity is reduced, but the measurement precision and frequency response are insufficient for detecting geometrical deformations
Solution Approach 1:
The patent replaces conventional mechanical contact sensors with a magnetic field-based sensing system. A permanent magnet is mounted on the sensor arm, and a Hall effect sensor detects changes in the magnetic field as the arm deflects. This substitution eliminates complex mechanical linkages and contact mechanisms, achieving high measurement precision while reducing device complexity.
Solution Approach 2:
The patent introduces a magnetic field as an intermediary between the sensor arm deflection and the detection system. The permanent magnet converts mechanical deflection into magnetic field variations, which the Hall effect sensor then measures. This intermediary enables precise detection of geometrical deformations without direct mechanical contact or complex transmission mechanisms.
2Measurement precision
If high-power sensor systems are used to improve detection capability, then the measurement precision improves, but the energy consumption increases
Solution Approach 1:
The Hall effect sensor system requires minimal electrical power compared to conventional active sensors. The permanent magnet provides a passive magnetic field that requires no power, and the Hall effect sensor operates at low power while detecting magnetic field changes with high precision. This achieves high measurement precision with low energy consumption.
Solution Approach 2:
The permanent magnet continuously generates the magnetic field without requiring external power, and the Hall effect sensor passively detects field changes. The system essentially powers itself through the motion-induced magnetic field variations, eliminating the need for high-power active sensing components.
3Speed
If low-frequency response sensors are used, then the device complexity is reduced, but the ability to detect high-speed deformations is compromised
Solution Approach 1:
The Hall effect sensor has inherently high frequency response capability, able to detect rapid changes in magnetic field. Combined with the permanent magnet and simple sensor arm mechanism, this achieves high-speed deformation detection without complex mechanical scanning or high-frequency mechanical components.
Solution Approach 2:
The magnetic field acts as a high-frequency intermediary that can rapidly respond to sensor arm deflections. The Hall effect sensor detects these magnetic field changes with high temporal resolution, enabling fast detection of geometrical deformations without mechanical inertia or complex signal processing.
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 caliper pig achieves high-resolution, low-power sensing with high-frequency response, effectively detecting pipeline deformations and maintaining pipeline integrity by providing accurate data on geometrical deformities.
Implementation Method 1
Each of the plurality of sensor arms includes a sensing unit comprising a dual-axis Hall effect Integrated Circuit (IC). The sensing unit is configured to detect a change in magnetic field produced by the magnet to generate an output signal indicative of an angle of deflection
Implementation Method 2
Each of the plurality of sensor arms includes a sensing arm comprising a wheel, a connecting arm, and a resilient member, where the sensing arm is adapted to be in contact with an internal surface of the pipeline. The wheel and the resilient member enable the sensing arm to move resiliently based on contour of the internal surface of the pipeline
Data Source
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AI summary
A caliper pig for detecting geometrical deformation of a pipeline is disclosed. The caliper pig includes a body and a first sensor arm assembly. The first sensor arm assembly includes a primary caliper sensor ring adapted to be mounted on the body. Further, the first sensor arm assembly includes a plurality of sensor arms adapted circumferentially distributed on the primary caliper sensor ring. Each of the plurality of sensor arms includes a sensing arm adapted to be in contact with an internal surface of the pipeline and a pair of magnets adapted to rotate along the sensing arm. Each of the plurality of sensor arms includes a sensing unit configured to detect a change in magnetic field based on the movement of the sensing arm. The sensing unit is configured to generate an output indicative of an angle of deflection of the sensing arm while traversing on the internal surface of the pipeline.