Method for measuring the flow velocity of a medium

Patent metadata

Field	Value
Publication number	US-11255956-B2
Application number	US-201916418511-A
Country	US
Kind code	B2
Filing date	May 21, 2019
Priority date	May 30, 2018
Publication date	Feb 22, 2022
Grant date	Feb 22, 2022

Abstract

Method for measuring the flow velocity of a medium in an open channel with a radar meter, wherein a primary emission direction of the radar meter forms with a direction of a surface of the medium a first angle from 20° to 80° and with a flow direction of the medium a second angle between 0° and 80°, comprising the following steps:Sending a transmission signal with a plurality of frequency ramps,Receiving a reception signal per frequency ramp of the transmission signal,Saving the reception signals,Performing a first spectral analysis of the reception signals,Performing a second spectral analysis of several receiving signals or output signals of the first spectral analysis,Determining a flow velocity based on the phase change yielded from the output signals of the second spectral analysis in at least one distance in the distance range.

First claim

We claim:

1. A method for measuring the flow velocity of a medium in an open channel with a radar meter, wherein the radar meter is arranged and aligned in such a way that a primary emission direction of the radar meter forms with a direction of a surface normal of the medium a first angle between 20° and 80°, and with a flow direction of the medium a second angle between 0° and 80°, comprising the following steps:
Sending a transmission signal with a plurality of frequency ramps,
Receiving a reception signal per frequency ramp of the transmission signal,
Saving the reception signals,
Performing a first spectral analysis of the reception signals,
Performing a second spectral analysis of several receiving signals or output signals of the first spectral analysis,
Determining a flow velocity based on a phase change using the output signals of the second spectral analysis in at least one distance in a distance range, such distance range comprising a range from a minimum distance up to a maximum distance resulting on account of a distance of the surface of the medium from the radar meter in a main emission direction and the first angle and second angle, wherein the flow velocity is determined on account of an average phase change in the distance range, a level of the medium in the channel is determined, and the distance range is adjusted based on the determined level.

2. The method of claim 1 , wherein the spectral analysis is a fast Fourier transformation.

3. The method of claim 1 , wherein a transmission signal with at least 25 frequency ramps is transmitted.

4. The method of claim 1 , wherein a transmission portal comprises a plurality of frequency ramps.

5. The method of claim 4 , wherein the transmission signal contains 128, 256 or 512 frequency ramps.

6. The method of claim 1 , wherein a frequency ramp has a duration between 1 μs and 1000 μs.

7. The method of claim 1 , wherein a start frequency f 1 and/or a slope and/or an increment of the frequency ramps varies.

8. The method of claim 1 , wherein the first angle is determined by a position sensor.

9. The method of claim 1 , wherein a transmission signal with at least 300 frequency ramps is transmitted.

10. The method of claim 1 , wherein a frequency ramp has a duration of between 100 μs and 200 μs.

Assignees

• Grieshaber Vega Kg

Inventors

• Corbe Bernhard
• Welle Roland
• Waelde Steffen

Classifications

• G01F23/284

  Electromagnetic waves · CPC title

• G01S7/288

  Coherent receivers · CPC title

• G01S7/2883

  using FFT processing · CPC title

• G01P5/00

  Measuring speed of fluids, e.g. of air stream; Measuring speed of bodies relative to fluids, e.g. of ship, of aircraft (application of speed-measuring devices for measuring volume of fluid G01F) · CPC title

• G01S13/343

  using sawtooth modulation · CPC title