Paired ZF sampling for pulse running time filling level sensor

Patent metadata

Field	Value
Publication number	US-9494676-B2
Application number	US-62594607-A
Country	US
Kind code	B2
Filing date	Jan 23, 2007
Priority date	Feb 13, 2006
Publication date	Nov 15, 2016
Grant date	Nov 15, 2016

Abstract

A pulse running time filling level sensor includes a sampling device for sampling an IF signal at discrete instants and for converting the sampling values into digital sampling values, and a digital signal processing device for subsequent processing of the digital sampling values by calculating at least one new value characterizing the IF curve from respectively exactly two digital sampling values.

First claim

What is claimed is:

1. A pulse running time filling level sensor for digitizing and subsequent processing of an intermediate frequency signal for determining a filling level in a tank, comprising:
a sampling device pair sampling the intermediate frequency (IF) signal at pairs of discrete points in time, the sampling device converting sampling values into sampling pairs of digital sampling values, wherein the intermediate frequency signal comprises an amplitude modulated carrier wave having an intermediate frequency; and
a digital signal processing device subsequently processing of the digital sampling values through calculation of at least one characterizing value characterizing the IF signal from respectively exactly one of the digital sampling pairs, and
wherein the at least one characterizing value is an envelope value,
wherein the calculation of the envelope value for the respective sampling pairs is performed according to

HK
i

=

IF
⁢

⁢

1
i
2

+

(

IF
⁢

⁢

2
i

-

IF
⁢

⁢

1
i

*

cos
⁡

(

ω
*

(

ta
⁢

⁢

1
i

)

)

)

2

sin
⁡

(

ω
*

(

ta
⁢

⁢

1
i

)

)

2

wherein:
i: a non-negative integer, with i indicating respective ones of the sampling pairs;
HK i is an i-th envelope value for a respective, i-th, one of the sampling pairs;
IF 1 i : a respective first digital sampling value of a respective, i-th, one of the sampling pairs;
IF 2 i : a respective second digital sampling value of a respective, i-th, one of the sampling pairs;
ta 1 i : time interval between sampling of IF 1 i and IF 2 i ; and
ω: angular frequency of the carrier wave.

2. The method according to claim 1 , wherein the two digital sampling values within each pair are adjacent in time.

3. The method according to claim 2 , wherein the time interval of the two digital sampling values is one quarter of an IF frequency period.

4. A method for digitizing and subsequent processing of an intermediate frequency signal for level measuring using a pulse running time filling level sensor, comprising:
pair sampling the intermediate frequency (IF) signal at pairs of discrete points in time, wherein the intermediate frequency signal comprises an amplitude modulated carrier wave having an intermediate frequency;
converting the sampled IF signal into sampling pairs of digital sampling values; and
calculating from respectively exactly one of the sampling pairs at least one characterizing value characterizing the IF signal;
wherein the at least one characterizing value is an envelope value,
wherein the calculation of the envelope value for the respective sampling pairs is performed according to

HK
i

=

IF
⁢

⁢

1
i
2

+

(

IF
⁢

⁢

2
i

-

IF
⁢

⁢

1
i

*

cos
⁡

(

ω
*

Assignees

• Griessbaum Karl
• Fehrenbach Josef
• Welle Roland
• Haas Juergen
• Grieshaber Vega Kg

Inventors

• Griessbaum Karl
• Fehrenbach Josef
• Welle Roland
• Haas Juergen

Classifications

• G01S13/103

  particularities of the measurement of the distance (G01S13/12, G01S13/14, G01S13/16, G01S13/18 and G01S13/20 take precedence) · CPC title

• G01S7/285 Primary

  Receivers · CPC title

• G01S7/2922

  by using a controlled threshold · CPC title

• G01S13/88

  Radar or analogous systems specially adapted for specific applications (electromagnetic prospecting or detecting of objects, e.g. near-field detection, G01V3/00) · CPC title

• G01S15/88

  Sonar systems specially adapted for specific applications (seismic or acoustic prospecting or detecting G01V1/00) · CPC title