Differential Structure of Inductive Proximity Sensor

Area of Science:

• Aerospace Engineering
• Sensor Technology
• Measurement Science

Background:

• Inductive proximity sensors (IPS) offer non-contact, durable displacement measurement suitable for aviation.
• Aviation applications impose strict requirements, including temperature drift, computational limits, and RF emission constraints.
• Existing IPS methods face challenges in meeting these specialized aviation demands.

Purpose of the Study:

• To propose a novel differential structured IPS measurement method for aviation applications.
• To address limitations of conventional IPS, such as temperature drift and computational intensity.
• To enhance accuracy, reliability, and compliance with aviation environmental standards.

Main Methods:

• A differential IPS structure with distinct sensing coils was developed.
• Numerical separation of resistance and inductance components was employed for improved temperature adaptation.
• A dimension-reduced look-up table method was integrated to minimize computational complexity.
• A low-current pulse excitation technique was utilized to reduce RF emissions.

Main Results:

• The differential IPS achieved numerical decoupling of the sensing coil's vector impedance using 61 look-up table units.
• Measuring sensitivity significantly increased from 135.5 LSB/0.10 mm to 1201.4 LSB/0.10 mm.
• Linear approximation distance error was reduced from 99.376 μm to -3.240 μm.

Conclusions:

• The proposed differential structured IPS method effectively overcomes temperature drift and computational limitations.
• The enhanced sensitivity and accuracy make it highly suitable for demanding aviation displacement measurements.
• This technique offers significant advantages over existing similar measurement methods in the aerospace field.