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EP-4741777-A1 - ULTRASONIC SENSOR DEVICE

EP4741777A1EP 4741777 A1EP4741777 A1EP 4741777A1EP-4741777-A1

Abstract

An ultrasonic sensor device for determining the flow rate of a medium comprises an ultrasonic transducer and an evaluation unit. The ultrasonic transducer is configured to receive a first ultrasonic signal transmitted by the medium at a first time point and a second ultrasonic signal transmitted by the medium at a second time point. The evaluation unit is configured to determine the envelope of the first ultrasonic signal and the phase profile of the second ultrasonic signal. The evaluation unit is further configured to determine a first transit time based on the envelope of the first ultrasonic signal, a second transit time based on the phase profile of the second ultrasonic signal, and the flow rate of the medium based on the first and second transit times.

Inventors

  • Kuri, Florian
  • Weigold, William

Assignees

  • SICK AG

Dates

Publication Date
20260513
Application Date
20241111

Claims (15)

  1. Ultrasonic sensor device (100) for determining a flow rate of a medium (106), comprising an ultrasound transducer (102) configured to receive a first ultrasound signal (108) transmitted by a medium (106) at a first time point and a second ultrasound signal (110) transmitted by the medium (106) at a second time point; and an evaluation unit (114), trained for this purpose, to determine an envelope (410) of the first ultrasound signal (108); to determine a phase profile (512) of the second ultrasound signal (110); to determine an initial transit time (416) based on the envelope (410) of the first ultrasound signal (108); to determine a second transit time (516) based on the phase profile (512) of the second ultrasound signal (110); and to determine a flow rate of the medium (106) based on the first run time (416) and the second run time (516).
  2. Ultrasonic sensor device (100) according to claim 1, further comprising a second ultrasound transducer (104) designed to emit the first ultrasound signal (108) at the first time and the second ultrasound signal (110) at the second time, wherein the ultrasound transducer (102) and the second ultrasound transducer (104) are arranged facing each other.
  3. Ultrasonic sensor device (100) according to claim 1 or 2, further comprising a control unit (116) designed to control the ultrasound transducer (102), to receive the first ultrasound signal (108) and the second ultrasound signal (110), wherein the first ultrasound signal (108) and the second ultrasound signal (110) are received alternately, or wherein the first ultrasound signal (108) is received again only after an integer number of cycles after the second ultrasound signal (110), in particular after 10 cycles.
  4. Ultrasonic sensor device (100) according to at least one of claims 1 to 3, wherein the evaluation unit (114) is designed to transform the first ultrasound signal (108) from a time domain into a first analytical signal in a frequency domain and the second ultrasound signal (110) from the time domain into a second analytical signal in the frequency domain.
  5. Ultrasonic sensor device (100) according to claim 4, wherein the evaluation unit (114) is configured to filter the first analytical signal and the second analytical signal, where a first filter width for filtering the first analytical signal is larger than a second filter width for filtering the second analytical signal.
  6. Ultrasonic sensor device (100) according to claim 5, wherein the evaluation unit (114) is configured to process the first filtered to transform the analytical signal and the second filtered analytical signal from the frequency domain into the time domain.
  7. Ultrasonic sensor device (100) according to at least one of claims 1 to 6, wherein the evaluation unit (114) is designed to to determine a maximum (414) of the envelope (410) of the first ultrasound signal (108), to determine at least two zero crossings (514-1, 514-2, 514-3, ... 514-N) of the phase response (512) of the second ultrasound signal (110), to determine the first transit time (416) based on the maximum (414) of the envelope (410) of the first ultrasound signal (108), and to determine the second transit time (516) based on the at least two zero crossings (514-1, 514-2, 514-3, ... 514-N) of the phase profile (512) of the second ultrasound signal (110).
  8. Ultrasonic sensor device (100) according to claim 7, wherein the evaluation unit (114) is designed to to determine the maximum (414) of the envelope (410) of the first ultrasound signal (108) using a parabola, wherein a vertex of the parabola coincides with the maximum (414) of the envelope (410).
  9. Ultrasonic sensor device (100) according to at least one of claims 1 to 8, wherein the evaluation unit (114) is configured to correct the second transit time (516) of the second ultrasound signal (110) based on the first transit time (416) of the first ultrasound signal (108), wherein the flow rate of the medium (106) is the corrected second transit time.
  10. Method for determining the flow rate of a medium (106) using an ultrasonic sensor device (100) according to any one of claims 1 to 9, comprising: Receiving (602) a first ultrasound signal (108) transmitted by a medium (106) at a first time point; Receiving (604) a second ultrasound signal (110) transmitted by the medium (106) at a second time; Determining (606) an envelope (410) of the first ultrasound signal (108); Determining (608) a phase profile (512) of the second ultrasound signal (110); Determining (610) a first transit time (416) based on the envelope (410) of the first ultrasound signal (108); Determine (612) a second transit time (516) based on the phase profile (512) of the second ultrasound signal (110); and Determine (614) a flow rate of the medium (106) based on the first run time (416) and the second run time (516).
  11. Method according to claim 10, wherein the first ultrasound signal (108) comprises a smaller number of transmit pulses than the second ultrasound signal (110).
  12. Method according to at least one of claims 10 or 11, wherein the first ultrasound signal (108) comprises one signal period and the second ultrasound signal (110) comprises a plurality of signal periods.
  13. Method according to at least one of claims 10 to 12, wherein a first transmission frequency of the first ultrasound signal (108) is different from a second transmission frequency of the second ultrasound signal (110).
  14. Method according to at least one of claims 10 to 13, wherein the first ultrasound signal (108) and the second ultrasound signal (110) are received alternately, or wherein the first ultrasound signal (108) is received again only after an integer number of cycles after the second ultrasound signal (110), in particular after 10 cycles.
  15. Ultrasonic sensor system, comprehensive a plurality of ultrasonic sensor devices (100) according to at least one of claims 1 to 9, wherein at least two ultrasound transducers (102, 104) are arranged facing each other in a wall of a channel (118) in which the medium (106) flows.

Description

The invention relates to an ultrasonic sensor device and a method for determining the flow rate of a medium. Flow velocities of a medium in a channel or pipeline can be determined in various ways. For example, the flow velocity can be determined using ultrasonic sensors. This involves calculating the flow velocity of the medium based on the time difference between two oppositely emitted and received ultrasonic signals. However, the accuracy of the flow velocity determined in this way is highly dependent on the quality, and especially on the accuracy of the timing, of the ultrasonic signals. It is therefore the object of the present invention to provide an ultrasonic sensor device with which the determination of the flow rate of a medium can be improved. The problem is solved by an ultrasonic sensor device for determining the flow rate of a medium according to claim 1, by a method according to claim 10 for determining the flow rate of the medium using the ultrasonic sensor device, and by an ultrasonic sensor system with the features of claim 15. Advantageous embodiments of the ultrasonic sensor device and the method are described in the dependent claims, the description, and the drawings. The ultrasonic sensor device according to the invention serves to determine the flow rate of a medium. The ultrasonic sensor device comprises an ultrasonic transducer configured to receive a first ultrasonic signal transmitted in or with a medium at a first time point and a second ultrasonic signal transmitted in or with the medium at a second time point. The ultrasonic sensor device further comprises an evaluation unit configured to determine an envelope, in particular only, of the first ultrasonic signal, a phase profile, in particular only, of the second ultrasonic signal, a first transit time based on the envelope of the first ultrasonic signal, a second transit time based on the phase profile of the second ultrasonic signal, and a flow rate of the medium based on the first transit time and the second transit time. In the ultrasonic sensor device according to the invention, two different ultrasonic signals are used to determine the flow rate of the medium. The respective advantageous properties of the two different ultrasonic signals are utilized in this process. The medium can be a fluid, such as a liquid or a gas. The medium can flow through a channel or pipe at the flow rate to be determined. The flow rate indicates how fast, or at what speed, the medium flows through the channel or pipe. The ultrasound transducer, or a first ultrasound transducer, can be operated as a transmitter or receiver and is therefore designed to both send and receive ultrasound signals. The ultrasound signal emitted by the ultrasound transducer, or another ultrasound transducer, can be transmitted through the medium. This can mean that the ultrasound signal The signal can be transmitted through the medium from one ultrasound transducer to another ultrasound transducer. The first ultrasound signal can be shorter than the second. This can mean that the transmission duration of the first ultrasound signal is shorter than that of the second. It can also mean that the first ultrasound signal decays more quickly than the second. In particular, the number of transmission pulses of the first ultrasound signal can be smaller than the number of transmission pulses of the second. Specifically, the number of transmission pulses of the first ultrasound signal can be, preferably at least, 10 times smaller, 5 times smaller, or 3 times smaller than the number of transmission pulses of the second ultrasound signal. Alternatively or additionally, the transmission duration of the second ultrasound signal can be, preferably at least, 10 times longer, 5 times longer, or 3 times longer than the transmission duration of the first ultrasound signal. Furthermore, the signal level of the first ultrasound signal can be lower than the signal level of the second ultrasound signal. The first ultrasound signal can comprise only one signal period, whereas the second ultrasound signal can comprise a multitude of signal periods, in particular any number of signal periods. Generally, the number of signal periods of the first ultrasound signal can differ from the number of signal periods of the second ultrasound signal. Accordingly, the number of zero crossings in the phase profile of the first ultrasound signal can be fewer than the number of zero crossings in the phase profile of the second ultrasound signal. The first and second time points can indicate the respective points in time at which the first and second ultrasound signals are received by the ultrasound transducer. However, it is also possible that the first time point indicates a duration during which the first ultrasound signal is received by the ultrasound transducer, and the second time point indicates a duration during which the signal is received. during which the second ultrasound signal is received by the