A Displacement Sensing Method Based on Permanent Magnet and Magnetic Flux Measurement.

Area of Science:

• Physics
• Materials Science
• Electrical Engineering

Background:

• Accurate displacement sensing is crucial in various engineering applications.
• Existing methods may face limitations in cost, linearity, or material compatibility.

Purpose of the Study:

• To propose and validate a novel displacement sensing method utilizing magnetic flux measurement.
• To design and analyze a bridge-structured magnetic circuit for enhanced sensor performance.

Main Methods:

• Development of a bridge-structured magnetic circuit using permanent magnets and ferromagnetic cores.
• Analysis via equivalent magnetic circuit modeling and 3D finite element simulations.
• Prototyping a sensor with permanent magnets (excitation), a Hall sensor (reception), and ferromagnetic cores.

Main Results:

• Magnetic flux density demonstrated a linear relationship with the reciprocal of displacement plus a constant.
• Experimental validation confirmed high linearity (correlation coefficient > 0.9995) across measurement ranges.
• The sensor showed compatibility with various ferromagnetic materials, with a maximum error under 5%.

Conclusions:

• The proposed magnetic flux-based displacement sensor offers a cost-effective and highly linear sensing solution.
• The sensor's performance is validated through simulations and experimental results.
• A key limitation is the requirement for the test object to be made of ferromagnetic materials.