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CN-121994319-A - Method for operating an ultrasonic flow measurement device and ultrasonic flow measurement device

CN121994319ACN 121994319 ACN121994319 ACN 121994319ACN-121994319-A

Abstract

A method of operating an ultrasonic flow measurement device is described, which comprises an ultrasonic transducer and a control and evaluation unit, which obtains an indirect value of the flow from a signal run time by evaluating an ultrasonic signal during a measurement run. The method can flexibly respond to changing measurement conditions by controlling an ultrasonic transducer by a control and evaluation unit, which emits a wideband ultrasonic signal, by obtaining an optimal measurement frequency range in an evaluation step, by frequency-filtering the received wideband ultrasonic signal into a plurality of measurement frequency ranges of the wideband ultrasonic signal, by calculating a mass value for each of the plurality of measurement frequency ranges from the frequency-filtered ultrasonic signal of the measurement frequency range and determining the measurement frequency range in which the highest mass value is obtained as the optimal measurement frequency range, and by using a signal run time, which is obtained from the optimal measurement frequency range after frequency-filtering the received wideband ultrasonic signal, when at least an indirect value for the flow is obtained.

Inventors

  • W. Sipper
  • E. Van Dijk

Assignees

  • 克洛纳有限公司

Dates

Publication Date
20260508
Application Date
20251104
Priority Date
20241106

Claims (15)

  1. 1. Method for operating an ultrasonic flow measurement device (2) for measuring a flow through a measuring tube (4) flowing through a medium (3), wherein the ultrasonic flow measurement device (2) comprises at least one transmitting ultrasonic transducer (5) for transmitting an ultrasonic signal (6) and at least one receiving ultrasonic transducer (7) for receiving an ultrasonic signal (6) and a control and evaluation unit (8), wherein the ultrasonic transducers (5, 7) are arranged in such a way that they implement an ultrasonic measuring path (9) in the medium (3), and wherein the control and evaluation unit (8) actuates the transmitting ultrasonic transducer (5) in such a way that it transmits the ultrasonic signal (6), the receiving ultrasonic transducer (7) receives the transmitted ultrasonic signal (6) and the control and evaluation unit (8) acquires at least one indirect flow value (Vp) for the measuring tube (4) for the acquired operating time t_t of the ultrasonic signal (6) in a measuring operation (14), It is characterized in that the method comprises the steps of, The control and evaluation unit (8) controls the transmitting ultrasound transducer (5) in such a way that a broadband ultrasound signal (USb, tx) is emitted, In the evaluation step (10), an optimal measurement frequency range (M_opt) is determined by frequency filtering (11) the received wideband ultrasonic signal (USb, rx) into a plurality of measurement frequency ranges (M) of the received wideband ultrasonic signal, by additionally calculating (12) at least one quality value (Q) from the frequency-filtered ultrasonic signals (USb, rx, f) of the associated measurement frequency ranges (M) for a plurality of the measurement frequency ranges (M) and obtaining the highest quality value (Q) as the optimal measurement frequency range (M_opt), respectively, and -Using a signal run time (t_sig) obtained from the optimal measurement frequency range (m_opt) after frequency filtering (11) of the received broadband ultrasonic signal (USb, rx) when obtaining the at least indirect value for the flow rate (Vp).
  2. 2. The method (1) according to claim 1, characterized in that the evaluation step (10) is performed each time the at least indirect value of the flow (Vp) for the medium (3) is determined in order to obtain an optimal measurement frequency range (m_opt), or that the evaluation step (10) is performed after a plurality of determinations of the at least indirect value of the flow (Vp) for the medium (3) in order to obtain an optimal measurement frequency range (m_opt), or that the evaluation step (10) is triggered by an external signal of the ultrasonic flow measurement device (2) in order to obtain an optimal measurement frequency range (m_opt).
  3. 3. Method (1) according to claim 1 or 2, characterized in that the broadband ultrasonic signal (USb, tx) is generated by exciting the transmitting ultrasonic transducer (5) with a superposition of periodic time signals of a plurality of different frequencies, in particular wherein the periodic time signals are harmonic signals.
  4. 4. Method (1) according to claim 1 or 2, characterized in that the broadband ultrasonic signal (USb, tx) is generated by exciting the transmitting ultrasonic transducer (5) with a rectangular signal or with a periodic rectangular signal sequence (15), in particular wherein the fundamental frequency of the periodic rectangular signal sequence (15) corresponds to the fundamental mode of vibration of the transmitting ultrasonic transducer (5).
  5. 5. Method (1) according to any one of claims 1 to 4, characterized in that the received broadband ultrasonic signal (USb, rx) is frequency filtered (11) into a plurality of measured frequency ranges (M) of the received broadband ultrasonic signal (USb, rx) by using at least one analog or digital band-pass filter (13), in particular wherein the digital band-pass filter (13) is implemented as a Finite Impulse Response (FIR) or Infinite Impulse Response (IIR) filter.
  6. 6. Method (1) according to any one of claims 1 to 5, characterized in that the quality value (Q) for the measurement frequency range (M) is obtained by obtaining a signal run time (t_sig) of the frequency-filtered ultrasonic signal (USb, rx, f) and by obtaining a run time deviation (delta_t_sig) from the comparison run time (t_sig, ref), wherein a smaller run time deviation (delta_t_sig) corresponds to a higher quality value (Q).
  7. 7. Method (1) according to claim 6, characterized in that the comparison run time (t_sig, ref) is a signal run time from a predetermined measurement frequency range (M), or the comparison run time (t_sig, ref) is an average of the signal run times (t_sig) from the predetermined measurement frequency range (M), in particular an average of the signal run times (t_sig) from all measurement frequency ranges (M).
  8. 8. Method (1) according to any one of claims 1 to 7, characterized in that a quality value (Q) for the measured frequency range (M) of the received wideband ultrasonic signal (USb, rx) is obtained between the received frequency-filtered wideband ultrasonic signal (USb, rx, f) and the corresponding reference signal (USref) by calculating a signal deviation (delta_usb) in the considered time interval, wherein a smaller signal deviation corresponds to a higher quality value (Q).
  9. 9. Method (1) according to claim 8, characterized in that the signal deviation (delta_usb) is calculated by comparing the corresponding vibration amplitudes.
  10. 10. Method (1) according to any one of claims 1 to 9, characterized in that a quality value (Q) for the measured frequency range (M) of the received wideband ultrasonic signal (USb, rx) is obtained between the received frequency-filtered wideband ultrasonic signal (USb, rx, f) and the respective reference signal (USref) by calculating at least one frequency deviation (delta_f) in the considered time interval, wherein a smaller frequency deviation (delta_f) corresponds to a higher quality value.
  11. 11. Method (1) according to claim 10, characterized in that the instantaneous signal frequencies of the signals compared with each other in the time zone are calculated by applying a hilbert transformation to the signals, in particular wherein the quality value (Q) is an average of a plurality of calculated frequency deviations (delta_f) in the considered time interval.
  12. 12. Method (1) according to any one of claims 1 to 11, characterized in that a quality value (Q) for the frequency range (M) of the received wideband ultrasonic signal (USb, rx) is obtained by calculating at least one signal/noise ratio (SNR) of the received wideband ultrasonic signal (USb, rx) in the considered time interval, wherein a larger signal/noise ratio (SNR) corresponds to a higher quality value (Q).
  13. 13. The method (1) according to claim 12, characterized in that the signal/noise ratio (SNR) is calculated from the peak-to-peak value of a pure noise signal (noise) and the peak-to-peak value of a useful signal with noise interference (signal + noise).
  14. 14. An ultrasonic flow measurement device (2) having a measuring tube (4) for measuring a flow through the measuring tube (4) flowing through a medium (3), having at least one transmitting ultrasonic transducer (5) for transmitting an ultrasonic signal (6) and at least one receiving ultrasonic transducer (7) for receiving an ultrasonic signal (6), and having a control and evaluation unit (8), wherein the ultrasonic transducers (5, 7) are arranged in such a way that they implement an ultrasonic measuring path (9) in the medium (3), and wherein the control and evaluation unit (8) actuates the transmitting ultrasonic transducer (5) in such a way that it emits the ultrasonic signal (6), the receiving ultrasonic transducer (7) receives the emitted ultrasonic signal (6) and the control and evaluation unit (8) determines at least one indirect flow value (Vp) for the measuring tube (4) by evaluating the signal operating time (t) of the emitted and received ultrasonic signal (6) from the signal (6) in the measuring operation (14), It is characterized in that the method comprises the steps of, The control and evaluation unit (8) controls the transmitting ultrasound transducer (5) in such a way that a broadband ultrasound signal (USb, tx) is emitted, The control and evaluation unit (8) in an evaluation step (10) acquires an optimal measurement frequency range (M_opt) by frequency filtering (11) the received wideband ultrasonic signal (USb, rx) into a plurality of measurement frequency ranges (M) of the received wideband ultrasonic signal (USb, rx), by additionally calculating (12) at least one quality value (Q) from the frequency-filtered ultrasonic signals (USb, rx, f) of the associated measurement frequency ranges (M) for a plurality of the measurement frequency ranges (M) and obtaining the highest quality value (Q) as the optimal measurement frequency range (M_opt), respectively, and determines the measurement frequency range (M) of the highest quality value (Q) as the optimal measurement frequency range (M_opt) A signal run time (t_sig) is used when the at least indirect value for the flow (Vp) is acquired, which signal run time is acquired from the optimal measurement frequency range (m_opt) after frequency filtering (11) of the received broadband ultrasonic signal (USb, rx).
  15. 15. The ultrasonic flow measurement device (2) according to claim 14, characterized in that the control and evaluation unit (8) implements the method (1) according to the characterizing part of at least one of claims 2 to 13 in operation of the ultrasonic flow measurement device (2).

Description

Method for operating an ultrasonic flow measurement device and ultrasonic flow measurement device Technical Field The invention relates to a method for operating an ultrasonic flow measuring device for measuring a flow through a measuring tube through which a medium flows, wherein the ultrasonic flow measuring device comprises at least one active ultrasonic transducer for emitting an ultrasonic signal and at least one active ultrasonic transducer for receiving an ultrasonic signal and a control and evaluation unit, wherein the ultrasonic transducer is arranged in such a way that it implements an ultrasonic measuring path in the medium, and wherein the control and evaluation unit actuates the active ultrasonic transducer in such a way that it emits an ultrasonic signal, the active ultrasonic transducer receives the emitted ultrasonic signal, and the control and evaluation unit acquires at least one indirect value for the flow of the medium through the measuring tube by evaluating the emitted and received ultrasonic signal from the acquired signal operating time of the ultrasonic signal during a measuring operation. The invention also relates to an ultrasonic flow measurement device of this type. Background Flow measurements in the case of using ultrasound have been known for a long time. Depending on which measurement method is used exactly (e.g. time-of-flight measurement, time-of-flight difference measurement (in and against the flow direction), frequency measurement/doppler effect), the flow measurement is however always based on the follow-up of the ultrasonic waves in the medium flowing through the measuring tube, the flow velocity of which medium should be detected. From the signal travel time of the ultrasonic signals, the (average) flow velocity of the medium along the ultrasonic measuring path and thus indirectly also the flow rate of the medium through the measuring tube can be deduced. Typically, the transmitting ultrasound transducer is excited very narrowly, preferably at a unique certain frequency. This has advantages with regard to energy use (eigenvalues of the piezoelectric actuator/sensor in the ultrasound transducer) and in the case of signal evaluation, the shape and attenuation of the emitted ultrasound signal can also be influenced specifically, for example, by selecting a certain frequency. This approach is problematic when, for example, the speed of sound of the medium slightly varies at the boundary conditions under which the certain frequency is selected. Disclosure of Invention The object of the present invention is to improve the method for operating an ultrasonic flow measurement device described at the outset and the ultrasonic flow measurement device described at the outset in such a way that a robust response to changing operating conditions can be achieved during the measurement. In the method described above, the task that has been deduced is first achieved by the control and evaluation unit actuating the transmitting ultrasound transducer in such a way that a broadband ultrasound signal is emitted. In the evaluation step, an optimal measuring frequency range is acquired in that the received wideband ultrasonic signal is frequency-filtered into a plurality of measuring frequency ranges of the received wideband ultrasonic signal. In the evaluation step, at least one quality value is furthermore calculated from the frequency-filtered ultrasonic signals of the associated measuring frequency ranges for a plurality of measuring frequency ranges, and the measuring frequency range in which the highest quality value is obtained is determined as the optimal measuring frequency range. The method steps make clear why a broadband ultrasonic signal can be understood. The broadband ultrasound signal must in any case have frequency contributions (Frequenzanteile, sometimes referred to as frequency components) in a continuous or locally distributed manner over a certain frequency range, so that the claimed frequency filtering into a plurality of measurement frequency ranges can be effected in a meaningful way, i.e. there can be frequency contributions in the examined range. In determining the at least indirect value for the flow rate, then in a conventional measurement operation a signal run time is thus used, which is obtained from the optimum measurement frequency range after the frequency filtering of the received wideband ultrasound signal. The wideband ultrasonic signal is thus operated at all times not only in the evaluation step (in which the optimum measuring frequency range is acquired) but also in the normal measuring operation (in which the wideband ultrasonic signal is frequency-filtered onto the optimum measuring frequency range and the signal operating time is then acquired from the frequency-filtered ultrasonic signal). By operating consistently with a broadband ultrasonic signal, the emitted ultrasonic signal always contains a suitable frequency, which is advantageous even i