Measurement method for aviation-specific proximity sensor

摘要

A measurement method for an aviation-specific inductive proximity sensor (IPS for short) includes steps of: 1) building a measurement circuit, wherein an IPS comprises an internal resistance r and an inductance L; 2) building a look-up table, wherein the step 2) specifically comprises steps of: sampling a first voltage measured value U1 corresponding to a first constant delay time T1 with the ADC; sampling a second voltage measured value U2 corresponding to a second constant delay time T2 with the ADC; then obtaining voltage discharge formulas U1(T1, R, r, L) and U2(T2, R, r, L) of an r-L circuit; and 3) compressing the look-up table, utilizing the compressed look-up table for calculation during measurement. The present invention ensures that the system works within a standard temperature range, and improves measurement stability, reliability, and real-time performance. Furthermore, there is no floating point calculation, which saves CPU or MCU hardware resources.

主权项

1. A measurement method for an aviation-specific inductive proximity sensor (IPS for short), comprising steps of:
1) building a measurement circuit, wherein an IPS comprises an internal resistance r and an inductance L, an value of the internal resistance r increases when environmental temperature increases, a value of the inductance L relates to a distance between the IPS and metal target; the measurement circuit of the IPS comprises a current-limiting resistance R, the IPS and a controlled switch connected in series; an analog-digital converter (ADC for short) is placed at a voltage measurement node between the current-limiting resistance R and the internal resistance r; 2) building a look-up table, wherein the step 2) specifically comprises steps of: sampling a first voltage measured value U1 corresponding to a first constant delay time T1 with the ADC; sampling a second voltage measured value U2 corresponding to a second constant delay time T2 with the ADC; then obtaining voltage discharge formulas U1(T1, R, r, L) and U2(T2, R, r, L) of an r-L circuit, wherein T1, T2, and R are constants; uniting the two formulas for building the look-up table of the internal resistance r and the inductance L corresponding to the U1 and U2; and 3) compressing the look-up table, utilizing the compressed look-up table for calculation during measurement.