High-precision liquid level sensor measuring system and measuring method

Abstract

The invention discloses a high-precision liquid level sensor measuring system and method, and the method comprises the steps: controlling a single-pole single-throw switch through a square wave signal to achieve the modulation of a DC voltage reference signal, and outputting an AC square wave excitation signal with a high-precision amplitude; the excitation end cable capacitance suppression circuit is used for realizing a suppression function on distributed capacitance in front of a cable; the acquisition end protection and suppression cable capacitance circuit and the multi-channel time-sharing acquisition control unit are used to realize the suppression function of the rear distributed capacitance of the cable; a self-balancing current bridge circuit is used for realizing negative feedback control and conversion of a current signal passing through a tested capacitor, and outputting a direct-current voltage signal, so that the acquisition precision and the anti-interference function are improved; a demodulation principle is used to realize holding sampling of an AC voltage signal, and negative feedback balance bridge arm voltage switching is realized. According to the technical scheme, the problems that an existing capacitive oil quantity sensor is prone to being affected by the environment during capacitance collection, the collection precision is poor, universality is not high, and cost is high are solved.

Description

technical field [0001] The invention relates to but not limited to the technical field of monitoring and control, especially a high-precision liquid level sensor measurement system and measurement method. Background technique [0002] Capacitive sensors are generally used for the accurate collection of aviation fuel volume and lubricating oil level, which can easily convert the liquid level into capacitance to realize the monitoring and control of the liquid level. For example, in aircraft status monitoring and control, the fuel level is monitored to provide accurate fuel quantity information and overrun warning information for the engine control system and aircraft system, which is related to the correct control of the engine and flight safety. It is of great significance to the aviation field. [0003] At present, capacitive fuel sensors are mostly used in aviation. The traditional conditioning method generally has the problem of charge leakage, poor anti-interference abi...

AI Technical Summary

Problems solved by technology

[0008] The purpose of the present invention is: to solve the problems existing in the first, second and third methods, the embodiment of the present invention proposes a high-precision liquid level sensor measurement system and measurement method to solve the problem of capacitive acquisition of the existing capacitive oil sensor It is easily affected by the environment, and problems such as poor acquisition accuracy, poor versatility, and high cost

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