An eddy current proximity sensor online self-test method and self-test circuit

Abstract

The invention provides an eddy-current-type proximity-sensor online self-checking method and a self-checking circuit. An online self-checking circuit with approach self-checking and far-away self-checking modes used for testing whether each function unit of an eddy-current-type proximity sensor is under a normal operating condition is included. The online self-checking circuit comprises a test circuit portion and a self-checking circuit portion. According to the online self-checking circuit, a condition that a circuit signal of the test circuit portion generates a difference with an output signal under an original state when a distance between a target and a probe changes is determined so as to complete self-checking. The test circuit portion comprises a test circuit power supply, an oscillating circuit, a demodulation circuit, a return difference circuit and a power amplifier circuit. The self-checking circuit portion comprises a self-checking circuit power supply, an excitation unit and a fault determination unit, wherein the excitation unit and the fault determination unit are connected to the self-checking circuit power supply respectively. By using the online self-checking circuit, the structure is simple, the self-checking method is easy to realized, high reliability is possessed and simultaneously a good self-checking effect is possessed too.

Description

technical field [0001] The invention relates to the technical field of eddy current sensing, in particular to an online self-inspection method and a self-inspection circuit of an eddy-current proximity sensor. Background technique [0002] The eddy current proximity sensor is a sensor that uses the eddy current effect to work. Because of its simple structure, high sensitivity, wide frequency response range, and not affected by oil and other media, it can perform non-contact measurement and has a wide range of applications. It has been paid attention to since it came out, and is widely used in non-electrical measurement of position, displacement, vibration, thickness, speed, hardness, etc., as well as non-destructive flaw detection and other fields. The eddy current proximity sensor is an important part of the aircraft landing gear system and the door switch monitoring system. Stricter requirements were put forward. Foreign eddy current proximity sensors have been used in l...

AI Technical Summary

Problems solved by technology

[0004] In view of this, the main purpose of the present invention is to provide a method for realizing the online self-test of the eddy current proximity sensor and a self-test circuit through a hardware circuit according to the problem that the eddy current proximity sensor cannot perform self-test

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