Magnetic Encoder Layout for Stable Position Signals Under Field Noise
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Solution Overview
Problem
Existing encoder devices using magnetic wires face challenges in generating stable electric signals due to noise from unnecessary magnetic fields, affecting the reliability of position detection.
Innovation Solution
An encoder device with a magnetosensitive part disposed orthogonally to the magnet's side surface and magnet field lines, utilizing a magnetosensitive part with a length direction orthogonal to tangential magnet field lines to generate electric signals, and a power supply system that switches power based on generated electric signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a magnetic wire is used to generate electric signals in an encoder device, then position detection can be achieved, but noise from unnecessary magnetic fields degrades signal stability and detection reliability
Solution Approach 1:
The magnetosensitive part is positioned at a specific location spaced apart from the side surface of the magnet, and its length direction is oriented orthogonal to tangential directions of magnetic field lines. This localized positioning and orientation optimization ensures that the magnetosensitive part responds primarily to the intended magnetic field changes while minimizing exposure to unnecessary magnetic field noise, thereby improving signal stability and position detection reliability.
2Measurement precision
If the magnetosensitive part is disposed close to the magnet to improve detection sensitivity, then measurement precision improves, but exposure to harmful magnetic field noise increases
Solution Approach 1:
Instead of simply moving the magnetosensitive part closer to or farther from the magnet along the radial direction, the invention optimizes the position by spacing it apart from the side surface and orienting its length direction orthogonal to tangential magnetic field lines. This dimensional optimization in both position and orientation allows the system to achieve adequate detection sensitivity while minimizing exposure to harmful magnetic field noise.
3Reliability
If power is continuously supplied to maintain system operation, then system availability is maintained, but energy consumption increases during normal operation
Solution Approach 1:
The power supply unit switches power supply to the position detection unit based on the electric signals generated by the magnetosensitive part. Instead of continuous power supply, the system periodically supplies power when detection is needed, as indicated by the generated electric signals. This periodic power supply approach maintains system availability when required while reducing overall energy consumption during normal 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 solution provides stable electric signals by minimizing noise interference, ensuring reliable position detection even in power supply emergencies.
Implementation Method 1
an electric signal generation unit for generating an electric signal, based on a magnetic characteristic of a magnetosensitive part, the electric signal generation unit having the magnetosensitive part whose magnetic characteristic is changed by a change in magnetic field associated with relative movement to the magnet
Data Source
AI summary
An encoder device including a position detection unit for detecting position information of a moving part; a magnet having a plurality of polarities along a moving direction of the moving part; and an electric signal generation unit for generating an electric signal, based on a magnetic characteristic of a magnetosensitive part, the electric signal generation unit having the magnetosensitive part whose magnetic characteristic is changed by a change in magnetic field associated with relative movement to the magnet, wherein the magnetosensitive part is disposed so that the magnetosensitive part is spaced apart from a side surface of the magnet in a direction orthogonal to the moving direction and a length direction of the magnetosensitive part is orthogonal to tangential directions of at least some of magnetic field lines of the magnet.