Electromagnet Position Sensing System for Piston Measurement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing position measurement systems face limitations in measuring the position of isolated moving objects, such as pistons in engines, due to the need for mechanical connections, size constraints, and sensitivity to external magnetic disturbances, especially from ferromagnetic objects, which affect accuracy and linearity.
Innovation Solution
A position sensing system utilizing an electromagnet to generate an alternating magnetic field, combined with magnetic sensors and a processor for real-time position estimation, which models the magnetic field around the object and adapts to disturbances, allowing non-intrusive measurement without requiring a mechanical connection or a permanent magnet on the moving object.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If magnetic sensors are placed adjacent to the moving object to measure position, then position measurement is enabled, but the required short gap between the magnetic sensor and the moving object limits the applicability in cases where thicker isolation is required
Solution Approach 1:
The patent transitions from a 2D planar magnetic field measurement approach to a 3D volumetric magnetic field analysis. By using multiple magnetic sensors arranged in three dimensions and analyzing the magnetic field distribution throughout a volume rather than at a single point, the system can measure position through thicker isolating materials while maintaining measurement precision.
2Measurement precision
If an array of magnetic sensor devices is placed adjacent to the moving object to provide continuous position measurement, then continuous position measurement is enabled, but the size of the sensor increases with the increase in the range of measurement
Solution Approach 1:
The patent employs three-dimensional magnetic field analysis with sensors distributed in space, allowing continuous position measurement across a large range without proportionally increasing sensor array length. The volumetric field analysis enables the system to measure positions throughout a 3D space using a more compact sensor configuration.
3Measurement precision
If permanent magnet based position sensors are used, then position measurement is provided, but the position measurement can have significant errors due to disturbances from ferromagnetic objects
Solution Approach 1:
The patent uses multiple magnetic sensors to continuously monitor the magnetic field environment and detect disturbances caused by ferromagnetic objects. By analyzing changes in the magnetic field pattern across the sensor array, the system can identify and compensate for disturbances, maintaining measurement accuracy in the presence of ferromagnetic interference.
Solution Approach 2:
The patent introduces a computational model of the magnetic field as an intermediary between the physical magnetic sensors and the position measurement. This model allows the system to distinguish between magnetic field changes caused by the target object's position and those caused by external ferromagnetic disturbances, enabling accurate position measurement despite interference.
4Measurement precision
If mechanical connection is made between the sensor and the moving object to enable position measurement, then position measurement is enabled, but modification of the design and assembly are required
Solution Approach 1:
The patent replaces mechanical connection-based position measurement with a magnetic field-based measurement system. Magnetic sensors detect the position of the moving object through magnetic field interactions without requiring physical contact or mechanical linkages, thereby eliminating the need for design modifications and assembly of mechanical components.
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 provides robust, real-time position measurement with high accuracy and immunity to ferromagnetic disturbances, reducing errors and enabling flexible installation on existing systems without increasing sensor size, even in harsh environments.
Implementation Method 1
an electromagnet to generate an alternating magnetic field
Implementation Method 2
at least one magnetic sensor configured to measure an intensity of a magnetic field that is based on the alternating magnetic field
Data Source
AI summary
A position sensing system for measuring a position of a moving object includes an electromagnet configured to generate an alternating magnetic field, and a magnetic sensor configured to measure an intensity of a first magnetic field that is based on the alternating magnetic field. A controller is configured to estimate a position of the moving object based on the measured intensity of the first magnetic field.