FUEL BALL DETECTING METHOD AND SYSTEM WITH SELF-DIAGNOSIS FUNCTION

摘要

A fuel ball detecting method and system with a self-diagnosis function are provided. The method includes: exciting a first detecting coil and a second detecting coil of a fuel ball sensor disposed outside a pipeline; obtaining a first voltage signal U1 from the first detecting coil and a second voltage signal U2 from the second detecting coil; processing U1 and U2 by differential amplification, band pass filtering, phase sensitive detection and low pass filtering by a signal processor to obtain a fuel ball waveform signal U0; determining whether the fuel ball passes the pipeline according to U0 by a single chip microcomputer; determining whether the first and the second detecting coils, the signal processor and the single chip microcomputer work normally; outputting a result showing whether the fuel ball passes the pipeline, when the first and the second detecting coils, the signal processor and the single chip microcomputer work normally.

主权项

1. A fuel ball detecting method with a self-diagnosis function, comprising:
exciting a first detecting coil and a second detecting coil of a fuel ball sensor disposed outside a pipeline by a sinusoidal alternating current, wherein the first detecting coil and the second detecting coil wind around the pipeline and are set upstream and downstream the pipeline respectively; obtaining a first voltage signal U1 from the first detecting coil and a second voltage signal U2 from the second detecting coil; processing the first voltage signal U1 and the second voltage signal U2 by differential amplification, band pass filtering, phase sensitive detection and low pass filtering by a signal processor so as to obtain a fuel ball waveform signal U0; determining whether the fuel ball passes the pipeline according to U0 by a single chip microcomputer; determining whether the first detecting coil, the second detecting coil, the signal processor and the single chip microcomputer work normally; and outputting a result showing whether the fuel ball passes the pipeline, when the first detecting coil, the second detecting coil, the signal processor and the single chip microcomputer work normally, wherein determining whether the first detecting coil, the second detecting coil, the signal processor and the single chip microcomputer work normally comprises: determining whether the first detecting coil and the second detecting coil work normally by detecting voltages across the first detecting coil and the second detecting coil, and outputting a first high level signal, when the first detecting coil and the second detecting coil work normally; determining whether the signal processor works normally via a photocoupler disposed on a power source terminal of the signal processor, and outputting a second high level signal when the signal processor works normally; determining whether the single chip microcomputer works normally by detecting a square wave output from the single chip microcomputer, and outputting a third high level signal when the single chip microcomputer works normally; processing the first high level signal, the second high level signal and the third high level signal by AND operation to get a self-diagnosis output signal; and determining that the first detecting coil, the second detecting coil, the signal processor and the single chip microcomputer work normally when the self-diagnosis output signal is a high level signal.