Ultrasonic fuel flow measurement system and method

Abstract

The fuel flow measurement system includes an ultrasonic fuel flow sensor. The fuel flow sensor includes a first transducer and a second transducer. The first transducer is excited at multiple different excitation frequencies, and during excitation, voltage, current, and the phase difference between the voltage and current are sensed at the first transducer. Data points are generated based on the sensed readings, and a model is fitted to the data points to determine a complex impedance spectrum. The complex impedance spectrum indicates the range of excitation frequencies within the peak resonant frequency range of the first transducer. One or more characteristics of the excitation signal guided to the second transducer are set based on the determined complex impedance spectrum. In this way, the signal-to-noise ratio of the ultrasonic signal emitted by the second transducer and received by the first transducer can be maximized.

Description

[0001] Cross-references to related applications

[0002] This application claims the benefit of U.S. Provisional Application No. 63 / 182,382, filed April 30, 2021, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure generally relates to fuel flow measurement systems and methods thereof, and more specifically, to fuel flow measurement systems with ultrasonic fuel flow sensors and their tuning methods. Background Technology

[0004] Fuel flow measurement systems are critical to many industries, including the automotive, oil and gas, power, and aerospace industries. Such systems are important because they determine how much fuel is directed to, consumed by, or transported by vehicles or machinery, or, alternatively, how much fuel is passing through pipes or conduits. In many high-mass-flow applications, even minute inaccuracies in fuel flow measurement can result in lost revenue.

[0005] Ultrasonic fuel flow sensors can be used for fuel flow measurement and are widely applicable due to their accuracy and non-invasive arrangement. An ultrasonic fuel flow sensor may include one or more transducers arranged to emit ultrasonic signals. Traditionally, the excitation frequency of such transducers is rarely tuned and is based on phase optimization techniques. Improved techniques for tuning the excitation frequency of such transducers to enhance the overall accuracy and consistency of the fuel flow sensor would be a welcome addition to the field. Summary of the Invention

[0006] The aspects and advantages of this disclosure will be set forth in part in the description which follows, or may be apparent from the description, or may be learned by practice of this disclosure.

[0007] In one exemplary embodiment of this disclosure, a system is provided. The system includes an ultrasonic flow sensor having a first transducer and a second transducer. The first transducer is excited at different frequencies, and voltage, current, and the phase difference between them are measured at the first transducer. Data points are generated based on these readings, and a model is fitted to the data points. By fitting the model to the data points, a peak resonant frequency associated with the first transducer can be determined. Frequencies within a predetermined range of the peak resonant frequency are considered to be the complex impedance spectrum associated with the first transducer. One or more characteristics of the excitation signal directed to the second transducer are set at least in part based on the complex impedance spectrum associated with the first transducer. In this way, the signal-to-noise ratio of the ultrasonic signal emitted by the second transducer and received by the first transducer is maximized or nearly maximized.

[0008] These and other features, aspects, and advantages of this disclosure will become more readily understood with reference to the following description and the appended claims. The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments of the disclosure and, together with the description, serve to explain the principles of the disclosure. Attached Figure Description

[0009] The complete and effective disclosure of this disclosure, including its best mode, is set forth in the description with reference to the accompanying drawings, and is intended for use by those skilled in the art, wherein:

[0010] Figure 1 This is a block diagram of an example fuel flow measurement system configured for an aircraft engine;

[0011] Figure 2 yes Figure 1 A schematic diagram of the ultrasonic fuel flow sensor in the fuel flow measurement system;

[0012] Figure 3 yes Figure 1 A schematic diagram of an ultrasonic fuel flow sensor for a fuel flow measurement system is shown, depicting a first and second transducer that are excited one at a time at multiple different frequencies.

[0013] Figure 4A , 4B The 4Cs respectively describe the stimulation methods used for, such as Figure 3 The first excitation signal, the second excitation signal, and the third excitation signal of the first transducer are shown.

[0014] Figure 5 It is a flowchart depicting an example of how the excitation signal directed to the second transducer can be set or updated;

[0015] Figure 6 It is a graph depicting the data points associated with the first dataset plotted on a complex impedance contrast excitation frequency graph, and also shows the model fitted to the data points;

[0016] Figure 7 It is a graph depicting the data points associated with the subsequent first dataset plotted on a complex impedance contrast excitation frequency graph, and also shows the model fitted to the data points associated with the subsequent first dataset;

[0017] Figure 8 It is a flowchart depicting an example way in which the excitation signal directed to the first transducer can be set or updated;

[0018] Figure 9 It is a graph depicting the data points associated with a second dataset plotted on a complex impedance versus excitation frequency graph, and also shows the model fitted to the data points;

[0019] Figure 10 It is a graph depicting the data points associated with a subsequent second dataset plotted on a complex impedance contrast excitation frequency graph, and also shows the model fitted to the data points associated with the subsequent second dataset;

[0020] Figure 11 It is a graph depicting an example of how a model can be shifted or fitted based on changes in the fuel flowing through the duct;

[0021] Figure 12 yes Figure 1 A schematic diagram of an ultrasonic fuel flow sensor for a fuel flow measurement system is shown, depicting a first transducer simultaneously excited at multiple different frequencies and a second transducer simultaneously excited at multiple different frequencies.

[0022] Figure 13 An example excitation signal is described, depicting the characteristics of a combination of three excitation signals;

[0023] Figure 14 This is a schematic diagram of an ultrasonic fuel flow sensor that includes a fuel flow measurement system with two pairs of transducers.

[0024] Figure 15 This is a schematic diagram of an ultrasonic fuel flow sensor that includes two pairs of transducers for measuring fuel flow, one of which is offset.

[0025] Figure 16 This is a flowchart of a method for tuning one or more transducers of an ultrasonic fuel flow sensor according to an exemplary aspect of this disclosure;

[0026] Figure 17A , 17B 17C and 17D provide schematic diagrams of an ultrasonic fuel flow sensor for a fuel flow measurement system and depict a sequence of ultrasonic signals emitted by a first transducer of the ultrasonic fuel flow sensor according to an exemplary aspect of this disclosure.

[0027] Figure 18A , 18B 18C and 18D provide Figure 17A , 17B A schematic diagram of ultrasonic fuel flow sensors 17C and 17D is shown, and the sequence of ultrasonic signals emitted by the second transducer of the ultrasonic fuel flow sensor is depicted.

[0028] Figure 19 A decay model fitted to the first data point plotted on the amplitude-to-distance graph is described;

[0029] Figure 20The attenuation model fitted to the first and second data points plotted on the amplitude contrast distance chart is described;

[0030] Figure 21 A graph depicting the composite function compared to multiple baseline functions is presented;

[0031] Figure 22 A set of synthesis functions generated based on multiple synthesis functions is schematically depicted, each synthesis function corresponding to a different excitation frequency;

[0032] Figure 23 This is a flowchart of a method for classifying the medium type of a medium flowing through a duct using one or more transducers of an ultrasonic fuel flow sensor, according to an exemplary aspect of this disclosure.

[0033] Figure 24 This is a schematic diagram of an ultrasonic fuel flow sensor for a fuel flow measurement system according to an exemplary aspect of the present disclosure, the ultrasonic fuel flow sensor being operable to detect contaminants in a medium flowing through a duct;

[0034] Figure 25 This is a flowchart of a method for determining the presence of contaminants in a medium flowing through a duct using one or more transducers of an ultrasonic fuel flow sensor, according to an exemplary aspect of this disclosure.

[0035] Figure 26 This is a schematic diagram of an ultrasonic fuel flow sensor assembly according to an exemplary aspect of this disclosure;

[0036] Figure 27 It is a flowchart depicting an example way to determine one or more amplitude response transfer functions;

[0037] Figure 28 A predefined model was described and fitted to data points plotted on an amplitude-to-frequency graph to determine the amplitude response transfer function;

[0038] Figure 29 This is a flowchart of a method for determining the amplitude response transfer function associated with a fuel flow sensor assembly according to an exemplary aspect of this disclosure; and

[0039] Figure 30 This is a block diagram of an example computing system based on an example aspect of this disclosure. Detailed Implementation

[0040] Reference will now be made in detail to the present embodiments of this disclosure, one or more examples of which are illustrated in the accompanying drawings. The detailed description uses numbers and letters to designate features in the drawings. Similar or analogous reference numerals in the drawings and description have been used to designate similar or analogous portions of this disclosure.

[0041] The term "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any implementation described herein as "exemplary" is not necessarily to be construed as preferred or superior to other implementations. Furthermore, unless explicitly stated otherwise, all embodiments described herein should be considered exemplary.

[0042] As used herein, the terms “first,” “second,” and “third” are used interchangeably to distinguish one component from another and are not intended to indicate the location or importance of the individual components.

[0043] The terms "front" and "rear" refer to relative positions within a gas turbine engine or vehicle, and specifically to the normal operating posture of the gas turbine engine or vehicle. For example, in the case of a gas turbine engine, "front" refers to the position closer to the engine inlet, while "rear" refers to the position closer to the engine nozzle or exhaust port.

[0044] The terms "upstream" and "downstream" refer to the relative directions of fluid flow within a fluid path. For example, "upstream" refers to the direction from which the fluid flows, and "downstream" refers to the direction in which the fluid flows.

[0045] The terms “connection,” “fixation,” “attachment,” etc., refer to direct connection, fixation, or attachment, as well as indirect connection, fixation, or attachment via one or more intermediate components or features, unless otherwise stated herein.

[0046] The singular forms “a,” “one,” and “the” include plural references unless the context clearly indicates otherwise.

[0047] The approximate language used throughout the specification and claims is applied to modify any quantitative expression that allows for variation without altering its associated essential function. Therefore, values ​​modified by one or more terms such as “about,” “approximately,” and “substantially” are not limited to the specified precise values. In at least some cases, approximate language may correspond to the precision of the instrument used to measure the value, or the precision of the method or machine used to construct or manufacture the component and / or system. For example, approximate language may refer to a margin of 1%, 2%, 4%, 10%, 15%, or 20%. These approximate ranges may apply to a single value, define one or both endpoints of the numerical range, and / or the margin between the endpoints.

[0048] Throughout this specification and claims, scope limitations are combined and interchanged, and such scopes are identified and include all subscopes contained herein, unless otherwise indicated by context or language. For example, all scopes disclosed herein include endpoints, and endpoints may be combined independently of each other.

[0049] Furthermore, as used herein, the term "real-time" refers to execution within the controller's time step to provide new input (e.g., measurement or calculation) for each controller update.

[0050] This disclosure generally relates to a fuel flow measurement system having an ultrasonic fuel flow sensor. In one example aspect, the ultrasonic fuel flow sensor has at least two transducers, including a first transducer and a second transducer spaced apart from the first transducer. The first transducer is arranged to guide an ultrasonic signal through fuel flowing through a conduit to the second transducer. The second transducer is arranged to guide the ultrasonic signal through fuel flowing through a conduit to the first transducer.

[0051] It is noteworthy that the inventors of this disclosure have invented novel and non-obvious techniques for setting or updating one or more characteristics of an excitation signal for a transducer used to excite a fuel flow sensor using information associated with another transducer. In particular, the inventors have invented techniques for setting or updating one or more characteristics of one or more excitation signals directed to a second transducer, at least in part based on a determined complex impedance spectrum associated with a first transducer. In this respect, the signal-to-noise ratio (SNR) of the ultrasonic signal emitted by the second transducer and received by the first transducer can be maximized or nearly maximized.

[0052] Specifically, to determine the complex impedance spectrum associated with the first transducer, the first transducer is excited at multiple different frequencies. When excited at these frequencies, the voltage and current at the first sensor are sensed and recorded. The phase difference between the voltage and current is also recorded. Data points are generated, at least in part, based on the sensed data, and a model is fitted to these data points. Fitting the model to the data points allows the determination of the minimum impedance, corresponding to the peak resonant frequency associated with the first transducer. The complex impedance spectrum can be determined, at least in part, based on the peak resonant frequency associated with the first transducer. The determined complex impedance spectrum indicates a range of favorable excitation frequencies for exciting the second transducer to maximize the SNR of the ultrasonic signal emitted by the second transducer and received by the first transducer.

[0053] Such technology can also be used to set or update one or more characteristics of one or more excitation signals guided to the first transducer, thereby maximizing the SNR of the ultrasonic signal emitted by the first transducer and received by the second transducer. The characteristics of the excitation signals guided to the first and / or second transducers can be set and / or updated in real time or near real time. This also allows the fuel flow sensor to capture readings consistently and accurately, even as fuel flow conditions through the duct change. This accuracy and consistency can lead to accurate fuel velocity readings, which in turn leads to accurate volumetric flow rate calculations. Accurate volumetric flow rate calculations, in turn, can lead to accurate fuel mass flow rate predictions.

[0054] Referring now to the accompanying drawings, where the same numbers represent the same elements throughout all the drawings. Figure 1 This is a block diagram of an example fuel flow measurement system 100 according to at least some aspects of this disclosure. For example, the fuel flow measurement system 100 may be configured to measure fuel flowing to an aircraft engine. The fuel flow measurement system 100 includes one or more fuel flow sensors, including an ultrasonic fuel flow sensor 200. The fuel flow measurement system 100 also includes an electronics enclosure 110, which includes one or more processors 120 and one or more memory devices 130, such as one or more non-transitory computer-readable media.

[0055] One or more processors 120 are communicatively coupled to the fuel flow sensor 200 and the database 140. The processors 120 may receive and / or output data to the fuel flow sensor 200 and may receive and / or output data to the database 140. The database 140 may store various types of data, including but not limited to information related to frequency-amplitude ratio diagrams, K-factors, fuel density curves for various fuels, including but not limited to Jet-A, JP-4, JP-5, JP-8, hydrogen (gas or liquid), liquefied natural gas (LNG), sustainable aviation fuels (such as synthetic kerosene fuel), etc. The database 140 may also store information related to the geometry of the conduit along which the fuel flow sensor 200 is located (e.g., the cross-sectional area of ​​the conduit), the path length between the transducers of the fuel flow sensor 200, etc. It should be understood that such information may also be stored on one or more memory devices 130 of the electronics enclosure 110. In some embodiments, the fuel flow measurement system 100 may optionally include a fuel temperature sensor 180 for sensing the temperature of the fuel flowing through the conduit and / or a fuel pressure sensor 190 for sensing the pressure of the fuel flowing through the conduit. Data from these sensors 180 and 190 can be provided to components in the electronic box 110.

[0056] Typically, one or more processors 120 of the fuel flow measurement system 100 are configured to calculate and output the mass flow rate 150 of fuel flowing through a duct (e.g., a fuel line). For example, the mass flow rate 150 can be output via a data bus to an electronic engine controller 160 associated with the gas turbine engine 170, such as... Figure 1 As shown. The electronic engine controller 160 can control the gas turbine engine 170 using the mass flow rate 150.

[0057] Figure 2 yes Figure 1A schematic diagram of an ultrasonic fuel flow sensor 200 in a fuel flow measurement system 100 is shown. As illustrated, the ultrasonic fuel flow sensor 200 includes a first transducer 210 and a second transducer 220. The first transducer 210 and the second transducer 220 are positioned within a conduit 202 arranged to allow fuel to flow through it. In this embodiment, the first transducer 210 is positioned upstream of the second transducer 220. In this respect, the fuel flowing through the conduit 202... Figure 2 The fluid flows from left to right, indicated by arrow F. The first transducer 210 is spaced apart from the second transducer 220. Specifically, the first transducer 210 and the second transducer 220 are spaced apart by a length L, which is the distance between the surfaces of the first transducer 210 and the second transducer 220. Furthermore, in this embodiment, the first transducer 210 and the second transducer 220 are spaced apart from each other in a direction parallel to the flow axis of the fluid flowing through the conduit 202. The first transducer 210 and the second transducer 220 are generally aligned with the flow axis. However, in alternative embodiments, the first transducer 210 and the second transducer 220 do not need to be aligned with the flow axis. For example, in some embodiments, the first transducer 210 and the second transducer 220 may be offset from the flow axis, for example, such that the first transducer 210 and the second transducer 220 operate diagonally relative to the flow axis.

[0058] The first transducer 210 can be excited to guide the ultrasonic signal US1 through the conduit 202. More specifically, one or more processors 120 can cause the first signal generator 212 to generate one or more excitation signals ES1 and pulse them. The first signal generator 212 may include any suitable type of electronics for generating one or more excitation signals, including switches, transistors, gate drivers, etc. The first signal generator 212 may be electrically connected to a suitable power supply. Although the first signal generator 212 is shown as separate from the electronics housing 110, in alternative embodiments, the first signal generator 212 may be a component of the electronics housing 110.

[0059] The excitation signal ES1 pulsed by the first signal generator 212 can be amplified by the driver 214, and the driver 214 in Figure 2The amplifier is schematically represented in the diagram. Driver 214 may include one or more amplifiers. The amplified excitation signal ES1 may be directed to the first transducer 210. The excitation signal ES1 may excite an active element (e.g., a piezoelectric or ferroelectric material) of the first transducer 210, causing the first transducer 210 to convert the electrical energy provided in the excitation signal ES1 into ultrasonic energy. In this way, the excitation signal ES1 causes the first transducer 210 to direct the ultrasonic signal US1 through the fuel flowing through the conduit 202. In this embodiment, the first transducer 210 may be arranged to direct the ultrasonic signal US1 downstream to a second transducer 220. In other embodiments, the first transducer 210 may be arranged to direct the ultrasonic signal US1 to other objects within the conduit 202, such as air bubbles entrained in the fuel.

[0060] Similarly, the second transducer 220 can be excited to guide an ultrasonic signal through the conduit 202. Specifically, one or more processors 120 can cause the second signal generator 222 to generate one or more excitation signals ES2 and pulse them. The second signal generator 222 can include any suitable type of electronics for generating one or more excitation signals, including switches, transistors, gate drivers, etc. The second signal generator 222 can be electrically connected to a suitable power supply. Although the second signal generator 222 is shown as separate from the electronics box 110, in alternative embodiments, the second signal generator 222 can be a component of the electronics box 110. Furthermore, in some embodiments, the first signal generator 212 and the second signal generator 222 can be combined into a single unit.

[0061] The pulsed excitation signal ES2 can be amplified by driver 224, and driver 224 in Figure 2 The amplifier is schematically represented in the diagram. Driver 224 may include one or more amplifiers. The amplified excitation signal ES2 may be directed to the second transducer 220. The amplified excitation signal ES2 may excite an active element (e.g., a piezoelectric or ferroelectric material) of the second transducer 220, causing the second transducer 220 to convert the electrical energy provided in the excitation signal ES2 into ultrasonic energy. In this way, the excitation signal ES2 causes the second transducer 220 to direct the ultrasonic signal US2 through the fuel flowing through the conduit 202. For example, the second transducer 220 may be arranged to direct the ultrasonic signal US2 upstream to the first transducer 210. In other embodiments, the second transducer 220 may be arranged to direct the ultrasonic signal US2 to other objects within the conduit 202.

[0062] The volumetric flow rate of fuel flowing through conduit 202 can be captured by fuel flow sensor 200 in the following example manner. The time required for an ultrasonic signal US1 emitted by first transducer 210 to travel from first transducer 210 to second transducer 220 can be sensed and recorded. That is, the time of flight (TOF) of ultrasonic signal US1 can be sensed and recorded. Similarly, the time required for an ultrasonic signal US2 emitted by second transducer 220 to travel from second transducer 220 to first transducer 210 can be sensed and recorded. That is, the TOF of ultrasonic signal US2 can be sensed and recorded. One or more processors 120 can determine the average velocity of ultrasonic signal US1 based at least in part on the recorded TOF and length L of ultrasonic signal US1. Similarly, one or more processors 120 can determine the average velocity of ultrasonic signal US2 based at least in part on the recorded TOF and length L of ultrasonic signal US2. Typically, the average velocity represents the speed of sound in the medium flowing through conduit 202, in this example, the medium is fuel.

[0063] Using a determined average velocity, one or more processors 120 can calculate the difference between the average velocity of ultrasonic signal US1 and the average velocity of ultrasonic signal US2. As will be understood, all other variables remaining constant, the average velocity of ultrasonic signal US1 will be faster than the average velocity of ultrasonic signal US2, i.e., because ultrasonic signal US2 travels upstream through the fuel, while ultrasonic signal US1 travels downstream through the fuel. The difference between the average velocity of ultrasonic signal US1 and the average velocity of ultrasonic signal US2 gives the fuel flow rate through conduit 202.

[0064] In other embodiments, the upstream TOF is directly compared with the downstream TOF to determine the fuel flow rate, without the need to calculate and compare the average TOF or average velocity.

[0065] The volumetric flow rate of fuel flowing through conduit 202 can be determined by one or more processors 120, at least in part, based on a determined fuel flow rate and the cross-sectional vector area of ​​conduit 202. The cross-sectional vector area of ​​conduit 202 can be known. The one or more processors 120 can then determine the mass flow rate of fuel flowing through conduit 202. The mass flow rate can be determined by one or more processors 120, at least in part, based on the determined volumetric flow rate and one or more known fuel characteristics and fuel temperature and / or pressure. Figure 1 As shown, the mass flow rate 150 can be output by one or more processors 120, for example, to an electronic engine controller 160 associated with the gas turbine engine 170.

[0066] According to aspects of the invention disclosed herein, one or more characteristics of one or more excitation signals directed to a transducer can be set and / or updated in real time to maximize the signal-to-noise ratio (SNR or S / N) of the ultrasonic signals received by transducers spaced apart from the excited transducer. Specifically, as will be explained in more detail below, the excitation frequency, amplitude, and / or phase of one or more excitation signals directed to a first transducer can be set or updated in real time, at least in part, based on the complex impedance spectrum of a second transducer receiving the ultrasonic signals from the first transducer. Similarly, the excitation frequency, amplitude, and / or phase of one or more excitation signals directed to a second transducer can be set or updated in real time, at least in part, based on the complex impedance spectrum of a first transducer receiving the ultrasonic signals from the second transducer. Real-time updating of the excitation frequency, amplitude, and phase of the excitation signals can result in consistently accurate readings (e.g., TOF readings associated with the ultrasonic signals emitted by the transducers). Therefore, this can allow for more accurate volumetric flow rate estimation, and consequently, more accurate fuel mass flow rate prediction.

[0067] refer to Figure 1 and 2 In one example, the excitation frequency, amplitude, and phase of the excitation signal ES1 guided to the first transducer 210 can be set and / or updated in real time, and similarly, the excitation frequency, amplitude, and phase of the excitation signal ES2 guided to the second transducer 220 can be set and / or updated in real time. In other words, the excitation signals ES1 and ES2 guided to the first and second transducers 210 and 220 can be tuned in real time to maximize the SNR of the ultrasonic signals US1 and US2. One or more characteristics of the excitation signals ES1 and ES2 (e.g., frequency, amplitude, and / or phase) can be updated in the following example manner.

[0068] To initiate a tuning or update process, one or more processors 120 may excite the first transducer 210 one at a time at multiple frequencies. For example, one or more processors 120 may excite the first transducer 210 at a first excitation frequency at a first time, at a second excitation frequency at a second time, and at a third excitation frequency at a third time, wherein the first, second, and third excitation frequencies are different from each other and these times are different from each other. In other embodiments, one or more processors 120 may excite the first transducer 210 at fewer than three excitation frequencies (e.g., two excitation frequencies) or more than three excitation frequencies (e.g., five excitation frequencies).

[0069] As an example, such as Figure 3As shown, at a first time, the first signal generator 212 can generate and pulse a first excitation signal ES1-1 having a first excitation frequency, a first amplitude, and a first phase. At a second time, the first signal generator 212 can generate and pulse a second excitation signal ES1-2 having a second excitation frequency, a second amplitude, and a second phase. At a third time, the first signal generator 212 can generate and pulse a third excitation signal ES1-3 having a third excitation frequency, a third amplitude, and a third phase. The second time is later than the first time, and the third time is later than the second time. Each excitation signal ES1-1, ES1-2, and ES1-3 can have different amplitudes or phases, or they can have the same amplitude or phase.

[0070] Figure 4A The first excitation signal ES1-1 with a first excitation frequency and a first amplitude is described. Figure 4B The second excitation signal ES1-2 with a second excitation frequency and a second amplitude is described, and Figure 4C A third excitation signal ES1-3 with a third excitation frequency and a third amplitude is depicted. As shown, the frequencies of the first excitation signal ES1-1, the second excitation signal ES1-2, and the third excitation signal ES1-3 are different from each other. The amplitudes of the first excitation signal ES1-1, the second excitation signal ES1-2, and the third excitation signal ES1-3 are the same, but in other embodiments, they need not be the same. Furthermore, as noted, each excitation signal ES1-1, ES1-2, ES1-3 has a phase, which may be the same as or different from each other.

[0071] Similar to the first transducer 210, one or more processors 120 can cause the second transducer 220 to be excited one at a time at multiple frequencies. For example, one or more processors 120 can cause the first transducer 210 to be excited at a first excitation frequency at a first time, at a second excitation frequency at a second time, and at a third excitation frequency at a third time, wherein the first, second, and third excitation frequencies are different from each other and these times are different from each other. In other embodiments, one or more processors 120 can cause the second transducer 220 to be excited at fewer than three excitation frequencies (e.g., two excitation frequencies) or more than three excitation frequencies (e.g., five excitation frequencies).

[0072] For example, such as Figure 3As shown, at a first time, the second signal generator 222 can generate and pulse a first excitation signal ES2-1 having a first excitation frequency, a first amplitude, and a first phase. At a second time, the second signal generator 222 can generate and pulse a second excitation signal ES2-2 having a second excitation frequency, a second amplitude, and a second phase. At a third time, the second signal generator 222 can generate and pulse a third excitation signal ES2-3 having a third excitation frequency, a third amplitude, and a third phase. The second time is later than the first time, and the third time is later than the second time. As described, the frequencies of the first excitation signal ES2-1, the second excitation signal ES2-2, and the third excitation signal ES2-3 are different from each other. The amplitudes of the first excitation signal ES2-1, the second excitation signal ES2-2, and the third excitation signal ES2-3 can be the same or different from each other. Furthermore, the phases of the first excitation signal ES2-1, the second excitation signal ES2-2, and the third excitation signal ES2-3 can be the same or different.

[0073] In some embodiments, the first transducer 210 may be excited at multiple different frequencies or for a given excitation pulse at a time. For example, the excitation signal directed to the first transducer 210 may be a broadband signal transmitting multiple excitation signals, each with a different frequency. In this respect, the excitation signal may include continuous frequencies. In some cases, the excitation signal in the form of a broadband signal may be divided into specific frequency ranges, such that the first transducer 210 may be excited at a specific time within a specific frequency range or for a specific pulse. The second transducer 220 may also be excited at multiple different frequencies or for a given excitation pulse at a time.

[0074] When the first transducer 210 is excited at multiple different excitation frequencies, the current, voltage, and phase difference between the current and voltage at the first transducer 210 are sensed and recorded for each excitation frequency. Specifically, when the first transducer 210 is excited at a first excitation frequency, the current, voltage, and phase difference at the first transducer 210 are sensed. When the first transducer 210 is excited at a second excitation frequency, the current, voltage, and phase difference at the first transducer 210 are sensed again. When the first transducer 210 is excited at a third excitation frequency, the current, voltage, and phase difference at the first transducer 210 are sensed again. The sensed current, voltage, and phase difference associated with each excitation frequency can be transmitted to the electronics box 110 for storage, for example, by one or more of its memory devices 130.

[0075] Current, voltage, and the phase difference between current and voltage can be sensed by the first sensor 216. The first sensor 216 may include any suitable type of component or circuitry for sensing the current, voltage, and phase difference at the first transducer 210. Although the first sensor 216 is positioned at... Figure 3The first sensor 216 is located on (e.g., mounted on or inside) the first transducer 210, but can be positioned anywhere along the first bus 218 that electrically connects the driver 214 and the first transducer 210. In this way, the first sensor 216 can sense current, voltage, and phase difference at the first transducer 210, regardless of whether it is physically located on the first transducer 210. In some alternative embodiments, for example, the first sensor 216 may be positioned outside the conduit 202 along the first bus 218 downstream of the driver 214.

[0076] Similarly, when the second transducer 220 is excited at multiple different excitation frequencies, the current, voltage, and phase difference between the current and voltage at the second transducer 220 are sensed and recorded for each excitation frequency. Specifically, when the second transducer 220 is excited at a first excitation frequency, the current, voltage, and phase difference at the second transducer 220 are sensed. When the second transducer 220 is excited at a second excitation frequency, the current, voltage, and phase difference at the second transducer 220 are sensed again. When the second transducer 220 is excited at a third excitation frequency, the current, voltage, and phase difference at the second transducer 220 are sensed again. The sensed current, voltage, and phase difference associated with each excitation frequency can be transmitted to the electronics box 110 for storage, for example, by one or more of its memory devices.

[0077] Current, voltage, and the phase difference between current and voltage can be sensed by the second sensor 226. The second sensor 226 may include any suitable type of component or circuitry for sensing the current, voltage, and phase difference at the second transducer 220. Although the second sensor 226 is positioned at... Figure 3 The first transducer 210 and the second transducer 220 are located on (e.g., mounted on or inside) the second transducer 220, but the second sensor 226 can be positioned anywhere along the second bus 228 that electrically connects the driver 224 and the second transducer 220. In this way, the second sensor 226 can sense the current, voltage, and phase difference at the second transducer 220, regardless of whether the second sensor 226 is physically located on the second transducer 220. In some alternative embodiments, for example, the second sensor 226 can be positioned outside the conduit 202 along the second bus 228 electrically downstream of the driver 224. The first transducer 210 and the second transducer 220 can be excited simultaneously or with a time offset by their respective excitation signals.

[0078] Next, one or more processors 120 can determine the complex impedance spectrum associated with the first transducer 210 and the complex impedance spectrum associated with the second transducer 220.

[0079] Specifically, one or more processors 120 may determine the complex impedance spectrum associated with the first transducer 210, at least in part, based on fitting a model to a first dataset, wherein for each excitation frequency at which the first transducer 210 is excited, the first dataset includes i) a ratio representing the relationship between voltage and current at the first transducer 210, and ii) the phase difference between voltage and current at the first transducer 210. The model may be a Butterworth Van Dyke model or other suitable models, such as any suitable lumped-element electrical equivalent circuit model.

[0080] For example, besides Figure 1 In addition to 4, we are now also referring to Figure 5 and 6 One or more processors 120 can fit model 300 to the first dataset 310. For this example, model 300 is a Butterworth van Dyke model. Figure 5 The best-described first dataset 310 includes data obtained at the first excitation frequency. Current at the first transducer 210 during excitation ,Voltage and current and voltage phase difference between The first excitation frequency It is the frequency of the first excitation signal ES1-1. The first dataset 310 also includes the frequency when the second excitation frequency is used. Current at the first transducer 210 during excitation ,Voltage and current and voltage phase difference between The second excitation frequency This is the frequency of the second excitation signal ES1-2. Furthermore, the first dataset 310 includes data generated at the third excitation frequency. Current at the first transducer 210 during excitation ,Voltage and current and voltage phase difference between The third excitation frequency This refers to the frequency of the third excitation signal ES1-3. In this respect, the first dataset 310 includes or describes the ratio (i.e., complex impedance) indicating the relationship between voltage and current at the first transducer 210 and the phase difference between voltage and current at the first transducer 210 for each excitation frequency at which the first transducer 210 is excited. The phase difference helps the model 300 fit to the first dataset 310.

[0081] When fitting model 300 to the first dataset 310, one or more processors 120 can generate data points, at least in part, based on data from the first dataset 310. Each data point is defined by a complex impedance and an excitation frequency. Specifically, for a given excitation frequency, the complex impedance can be calculated. For example, voltage. and current It can be used to calculate the frequency of the first excitation. The associated complex impedance is used to generate the first data point D1. Voltage and current It can be used to calculate the second excitation frequency. The associated complex impedance is used to generate the second data point D2. Additionally, the voltage... and current It can be used to calculate the third excitation frequency. 3. The associated complex impedance is used to generate a third data point D3. In this way, data points can be generated for each excitation frequency at which the first transducer 210 is excited.

[0082] As data points D1, D2, and D3 are generated, one or more processors 120 can fit the model 300 to the data points D1, D2, and D3, such as... Figure 6 As shown. By fitting model 300 to the first dataset 310, or more specifically to data points D1, D2, D3, one or more processors 120 can determine the complex impedance spectrum CIS-1 associated with the first transducer 210. Typically, the complex impedance spectrum CIS-1 represents an excitation frequency range within which one or more excitation frequencies can be set to excite the second transducer 220, thereby maximizing the SNR of the ultrasonic signal US1 received by the second transducer 220.

[0083] In some embodiments, in determining the complex impedance spectrum CIS-1 associated with the first transducer 210 based at least in part on fitting model 300 to a first dataset 310, one or more processors 120 are configured to determine the peak resonant frequency associated with the first transducer 210. The peak resonant frequency associated with the first transducer 210 The phase difference at that point is zero or close to zero. For example... Figure 6 As shown, in this example embodiment, the peak resonant frequency is... Approximately 8 MHz. One or more processors 120 can determine the peak resonant frequency by identifying which frequency corresponds to the minimum impedance MI. That is, fitting model 300 to data points D1, D2, D3 allows one or more processors 120 to determine the minimum impedance MI, and as described, the frequency corresponding to the minimum impedance MI is the peak resonant frequency associated with the first transducer 210. .

[0084] In some embodiments, model 300 is fitted to data points D1, D2, D3 such that the minimum impedance MI and therefore the peak resonant frequency Within a predetermined design range of the design resonant frequency of the first transducer 210. In some cases, the first transducer 210 may have more than one natural frequency or resonant frequency, and in this case, the resonant frequency of interest is the pre-selected or designed peak resonant frequency of the first transducer 210. Therefore, model 300 is intelligently fitted according to these constraints.

[0085] Determining the peak resonant frequency associated with the first transducer 210 Subsequently, one or more processors 120 can determine the peak resonant frequency. The excitation frequency range within the predetermined range. At the peak resonant frequency... The predetermined range of excitation frequencies corresponds to the complex impedance spectrum CIS-1 associated with the first transducer 210. In some example embodiments, the predetermined range may be set to a fixed range. As an example, the predetermined range may include frequencies within 2 MHz of the peak resonant frequency. As another example, the predetermined range may include frequencies within 1 MHz of the peak resonant frequency.

[0086] In other example embodiments, a predetermined range can be set at least in part based on a receive threshold TR. The receive threshold TR can be set to any suitable pre-selected impedance value. Figure 6 In this configuration, the receiver threshold TR is set to 10 ohms. Impedance values ​​less than or equal to 10 ohms are considered less than or equal to the receiver threshold TR. The receiver threshold TR indicates how the lower and upper limits of a predetermined range can be set. As an example, less than the peak resonant frequency... The frequency corresponding to the first instance where model 300 intersects with the reception threshold TR can be set to the frequency corresponding to the lower limit of a predetermined range, for example, Figure 6 Approximately 7 MHz. Furthermore, it is greater than the peak resonant frequency. The frequency corresponding to the first instance where model 300 intersects with the reception threshold TR can be set to the frequency corresponding to the upper limit of a predetermined range, for example, Figure 6 Approximately 9 MHz. Therefore, for this embodiment, the complex impedance spectrum CIS-1 will correspond to a range spanning from 7 MHz to 9 MHz.

[0087] In some further example embodiments, one or more processors 120 may set a transmission threshold TS associated with the second transducer 220. The transmission threshold TS may be set to any suitable pre-selected impedance value. Figure 6In this configuration, the transmit threshold TS is set to approximately 50 ohms. Impedance values ​​less than or equal to 50 ohms are considered to be less than or equal to the transmit threshold TS. The transmit threshold TS can provide an upper limit for the appropriate impedance at the second transducer 220. Therefore, the excitation frequency that would cause the impedance at the second transducer 220 to exceed the transmit threshold TS is not selected as a frequency that can be included in the complex impedance spectrum CIS-1.

[0088] As described above, one or more processors 120 can determine the complex impedance spectrum associated with the second transducer 220. Typically, the complex impedance spectrum associated with the second transducer 220 can be determined in the same or similar manner as the determination of the complex impedance spectrum associated with the first transducer 210 described above. Specifically, one or more processors 120 can determine the complex impedance spectrum associated with the second transducer 220 based at least in part on fitting a model to a second dataset, wherein, for each excitation frequency at which the second transducer 220 is excited, the second dataset includes i) a ratio indicating the relationship between voltage and current at the second transducer 220, and ii) the phase difference between voltage and current at the second transducer 220. The model can be a Butterworth van Dyke model or other suitable models, such as any suitable lumped-element electrical equivalent circuit model. In some embodiments, the model 300 associated with the first transducer 210 can be specifically designed for the first transducer 210, while the model associated with the second transducer 220 can be specifically designed for the second transducer 220. In other embodiments, the same model may be used for both the first transducer 210 and the second transducer 220.

[0089] Now besides Figure 1 -4, also refer to Figure 8 One or more processors 120 can fit model 300 to a second dataset 320. For example... Figure 8 The best-described second dataset 320 includes data obtained at the first excitation frequency. Current at the second transducer 220 during excitation ,Voltage and current and voltage phase difference between The first excitation frequency It is the frequency of the first excitation signal ES2-1. The second dataset 320 also includes the frequency when the second excitation frequency is used. Current at the second transducer 220 during excitation ,Voltage and current and voltage phase difference between The second excitation frequency This is the frequency of the second excitation signal ES2-2. Furthermore, the second dataset 320 includes data generated at the third excitation frequency. Current at the second transducer 220 during excitation ,Voltage and current and voltage phase difference between The third excitation frequency It is the frequency of the third excitation signal ES2-3. In this respect, the second dataset 320 includes or describes the ratio (i.e., complex impedance) indicating the relationship between voltage and current at the second transducer 220 for each excitation frequency that excites the second transducer 220, and the phase difference between voltage and current at the second transducer 220.

[0090] When fitting model 300 to the second dataset 320, one or more processors 120 can generate data points, at least partially, based on data from the second dataset 320. Each data point is defined by a complex impedance and an excitation frequency. Specifically, for a given excitation frequency, the complex impedance can be calculated. For example, voltage. and current It can be used to calculate the frequency of the first excitation. The associated complex impedance is used to generate the first data point D1. Voltage and current It can be used to calculate the second excitation frequency. The associated complex impedance is used to generate the second data point D2. Additionally, the voltage... and current It can be used to calculate the third excitation frequency. The associated complex impedance is used to generate a third data point D3. In this way, data points can be generated for each excitation frequency at which the second transducer 220 is excited. The phase difference helps to fit the model 300 to the second dataset 320.

[0091] As data points D1, D2, and D3 are generated, one or more processors 120 can fit the model 300 to the data points D1, D2, and D3, such as... Figure 9 As shown. By fitting model 300 to the second dataset 320, or more specifically to data points D1, D2, D3, one or more processors 120 can determine the complex impedance spectrum CIS-2 associated with the second transducer 220. Typically, the complex impedance spectrum CIS-2 represents an excitation frequency range within which one or more excitation frequencies can be set to excite the first transducer 210, thereby maximizing the SNR of the ultrasonic signal US2 received by the first transducer 220.

[0092] In some embodiments, in determining the complex impedance spectrum CIS-2 associated with the second transducer 220 based at least in part on fitting model 300 to a second dataset 320, one or more processors 120 are configured to determine the peak resonant frequency associated with the second transducer 220. The peak resonant frequency associated with the second transducer 220 The phase difference at that point is zero or close to zero. For example... Figure 9 As shown, in this example embodiment, the peak resonant frequency is... Approximately 8 MHz. One or more processors 120 can determine the peak resonant frequency by identifying which frequency corresponds to the minimum impedance MI. That is, fitting model 300 to data points D1, D2, D3 allows one or more processors 120 to determine the minimum impedance MI, and as described, the frequency corresponding to the minimum impedance MI is the peak resonant frequency associated with the second transducer 220. .

[0093] In some embodiments, model 300 is fitted to data points D1, D2, D3 such that the minimum impedance MI and therefore the peak resonant frequency Within a predetermined design range for the design resonant frequency of the second transducer 220. In some cases, the second transducer 220 may have more than one natural frequency or resonant frequency, and in such cases, the resonant frequency of interest is the pre-selected or designed peak resonant frequency of the second transducer 220. Therefore, model 300 is intelligently fitted according to these constraints.

[0094] Determining the peak resonant frequency associated with the second transducer 220 Subsequently, one or more processors 120 can determine the peak resonant frequency. The excitation frequency range within the predetermined range. At the peak resonant frequency... The predetermined range of excitation frequencies corresponds to the complex impedance spectrum CIS-2 associated with the second transducer 220. In some example embodiments, the predetermined range may be set to a fixed range. As an example, the predetermined range may include frequencies within 2 MHz of the peak resonant frequency. As another example, the predetermined range may include frequencies within 1 MHz of the peak resonant frequency.

[0095] In other example embodiments, a predetermined range can be set at least in part based on a receive threshold TR. The receive threshold TR can be set to any suitable pre-selected impedance value. Figure 9In this configuration, the receiver threshold TR is set to 10 ohms. Impedance values ​​less than or equal to 10 ohms are considered less than or equal to the receiver threshold TR. The receiver threshold TR indicates how the lower and upper limits of a predetermined range can be set. As an example, less than the peak resonant frequency... The frequency corresponding to the first instance where model 300 intersects with the reception threshold TR can be set to the frequency corresponding to the lower limit of a predetermined range, for example, Figure 9 Approximately 8 MHz. Furthermore, it is greater than the peak resonant frequency. The frequency corresponding to the first instance where model 300 intersects with the reception threshold TR can be set to the frequency corresponding to the upper limit of a predetermined range, for example, Figure 9 Approximately 10 MHz. Therefore, for this embodiment, the complex impedance spectrum CIS-2 will correspond to a range spanning from 8 MHz to 10 MHz.

[0096] In yet another example embodiment, one or more processors 120 may set a transmission threshold TS associated with the first transducer 210. The transmission threshold TS may be set to any suitable pre-selected impedance value. Figure 9 For example, the transmit threshold TS is set to approximately 50 ohms. Impedance values ​​less than or equal to 50 ohms are considered to be less than or equal to the transmit threshold TS. The transmit threshold TS can provide an upper limit for the appropriate impedance at the first transducer 210. Therefore, the excitation frequency that would cause the impedance at the first transducer 210 to exceed the transmit threshold TS would not be selected as a frequency that can be included in the complex impedance spectrum CIS-2.

[0097] The determined complex impedance spectrum CIS-1 associated with the first transducer 210 can be used to set or update the excitation signal directed to the second transducer 220, and the determined complex impedance spectrum CIS-2 associated with the second transducer 220 can be used to set or update the excitation signal directed to the first transducer 210.

[0098] Specifically, one or more processors 120 may set or update one or more characteristics of one or more excitation signals to be directed to the second transducer 220, at least in part, based on the complex impedance spectrum CIS-1 associated with the first transducer 210. Similarly, one or more processors 120 may set or update one or more characteristics of one or more excitation signals to be directed to the first transducer 210, at least in part, based on the complex impedance spectrum CIS-2 associated with the second transducer 220.

[0099] For example, such as Figure 5As shown in the figure, the output of fitting model 300 to the first dataset 310 is a complex impedance spectrum CIS-1, which, as described above, indicates an excitation frequency range within which one or more excitation frequencies can be set to excite the second transducer 220 to maximize the SNR of the ultrasonic signal US2 received by the first transducer 210. As shown, the complex impedance spectrum CIS-1 is input to a second excitation control unit 322. The second excitation control unit 322 may be a set of computer-readable instructions or logic executable by one or more processors 120. When executing the second excitation control unit 322, one or more processors 120 may set one or more characteristics of one or more excitation signals to be directed to the second transducer 220.

[0100] Specifically, when the second excitation control unit 322 is executed, one or more processors 120 can set the excitation frequency of the first excitation signal ES2-1 to be guided to the second transducer 220. ,amplitude and phase One or more processors 120 can set the excitation frequency of the second excitation signal ES2-2 to be directed to the second transducer 220. ,amplitude and phase Furthermore, one or more processors 120 can set the excitation frequency of the third excitation signal ES2-3 to be directed to the second transducer 220. ,amplitude and phase The excitation frequencies of excitation signals ES2-1, ES2-2, and ES2-3. 1, 2, Each of these can be a frequency within the complex impedance spectrum CIS-1 associated with the first transducer 210. Therefore, the excitation frequencies of the excitation signals ES2-1, ES2-2, and ES2-3 are... 1, 2, It can be in or spans from 7 MHz to 9 MHz (i.e., Figure 6 The complex impedance spectrum CIS-1 is depicted in the diagram. The characteristics of excitation signals ES2-1, ES2-2, and ES2-3 can be input to a second signal generator 222. The second signal generator 222 can generate excitation signals ES2-1, ES2-2, and ES2-3 with the indicated characteristics. The generated excitation signals ES2-1, ES2-2, and ES2-3 can be driven by driver 224 (…). Figure 3 The amplified signal is then directed to the second transducer 220.

[0101] As noted, one or more processors 120 may set or update one or more characteristics of one or more excitation signals to be directed to the first transducer 210 based at least in part on the complex impedance spectrum CIS-2 associated with the second transducer 220.

[0102] For example, such as Figure 8 As shown in the figure, the output of fitting model 300 to the second dataset 320 is a complex impedance spectrum CIS-2, which, as described above, indicates an excitation frequency range within which one or more excitation frequencies can be set to excite the first transducer 210 to maximize the SNR of the ultrasonic signal US1 received by the second transducer 220. As shown, the complex impedance spectrum CIS-2 is input to a first excitation control unit 312. The first excitation control unit 312 may be a set of computer-readable instructions or logic executable by one or more processors 120. When executing the first excitation control unit 312, one or more processors 120 may set one or more characteristics of one or more excitation signals to be directed to the first transducer 210.

[0103] Specifically, when the first excitation control unit 312 is executed, one or more processors 120 can set the excitation frequency of the first excitation signal ES1-1 to be guided to the first transducer 210. ,amplitude and phase One or more processors 120 can set the excitation frequency of the second excitation signal ES1-2 to be directed to the first transducer 210. ,amplitude and phase Furthermore, one or more processors 120 can set the excitation frequency of the third excitation signal ES1-3 to be directed to the first transducer 210. ,amplitude and phase The excitation frequencies of excitation signals ES1-1, ES1-2, and ES1-3. 1, 2, Each of these can be a frequency within the complex impedance spectrum CIS-2 associated with the second transducer 220. Therefore, the excitation frequencies of the excitation signals ES1-1, ES1-2, and ES1-3 are... 1, 2, It can be in or spans from 8 MHz to 10 MHz (i.e., Figure 9The complex impedance spectrum CIS-2 is depicted in the figure. The characteristics of excitation signals ES1-1, ES1-2, and ES1-3 can be input to the first signal generator 212. The first signal generator 212 can generate excitation signals ES1-1, ES1-2, and ES1-3 with the indicated characteristics. The generated excitation signals ES1-1, ES1-2, and ES1-3 can be driven by driver 214 ( Figure 3 It is amplified and guided to the first transducer 210.

[0104] In some embodiments, when the second excitation control unit 322 is executed, one or more processors 120 may set the frequency of at least one excitation signal ES2-1, ES2-2, ES2-3 directed to the second transducer 220 to the peak resonant frequency associated with the first transducer 210. (For example, Figure 6 The peak resonant frequency depicted in Furthermore, in some embodiments, one or more processors 120 may set the frequency of at least one excitation signal ES2-1, ES2-2, ES2-3 directed to the second transducer 220 to be less than the peak resonant frequency associated with the first transducer 210. The frequencies of at least one excitation signal ES2-1, ES2-2, ES2-3 to be guided to the second transducer 220 are set to be greater than the peak resonant frequency associated with the first transducer 210. .

[0105] Similarly, in some embodiments, when the first excitation control unit 312 is executed, one or more processors 120 may set the frequency of at least one excitation signal ES1-1, ES1-2, ES1-3 directed to the first transducer 210 to the peak resonant frequency associated with the second transducer 220. (For example, Figure 9 The peak resonant frequency depicted in Furthermore, in some embodiments, one or more processors 120 may set the frequency of at least one excitation signal ES1-1, ES1-2, ES1-3 directed to the first transducer 210 to be less than the peak resonant frequency associated with the second transducer 220. Furthermore, the frequencies of at least one excitation signal ES1-1, ES1-2, ES1-3 directed to the first transducer 210 are set to be greater than the peak resonant frequency associated with the second transducer 220. .

[0106] In some further embodiments, when executing the second excitation control unit 322, in addition to based on the complex impedance spectrum CIS-1 associated with the first transducer 210, one or more processors 120 may also set the frequencies of at least one excitation signal ES2-1, ES2-2, ES2-3 directed to the second transducer 220 based at least partially on the complex impedance associated with the driver 214 and / or the first signal generator 212 and / or other electrical components or circuits electrically upstream of the first transducer 210. In such an embodiment, as an example, the impedance associated with the driver 214 may be determined during calibration and input into the system 100 as a known constant. The known impedance can ultimately be used to adjust the complex impedance spectrum CIS-1 and / or the model 300.

[0107] As another example, when the first transducer 210 is excited at a given excitation frequency, the sensor can sense the current and voltage at the driver 214, as well as the phase difference between the current and voltage. The sensed readings can be used to generate data points, and a model can be fitted to the data points, for example, as described above. For example, the model could be a Butterworth van Dyke model. The complex impedance spectrum associated with the driver 214 can then be determined, for example, in the manner described above. In addition to the complex impedance spectrum CIS-1 associated with the first transducer 210, one or more processors 120 can also set or update one or more characteristics of one or more excitation signals to be directed to the second transducer 220, at least in part, based on the complex impedance spectrum associated with the driver 214.

[0108] Similarly, in some embodiments, when executing the first excitation control unit 312, in addition to based on the complex impedance spectrum CIS-2 associated with the second transducer 220, one or more processors 120 may also set the frequencies of at least one excitation signal ES1-1, ES1-2, ES1-3 directed to the first transducer 210 based at least in part on the complex impedance associated with the driver 224 and / or the second signal generator 222 and / or other electrical components or circuits electrically upstream of the second transducer 220. In such embodiments, as an example, the impedance associated with the driver 224 may be determined during calibration and input into the system 100 as a known constant. The known impedance can ultimately be used to adjust the complex impedance spectrum CIS-2 and / or the model 300.

[0109] As another example, when the second transducer 220 is excited at a given excitation frequency, the sensor can sense the current and voltage at the driver 224, as well as the phase difference between the current and voltage. The sensed readings can be used to generate data points, and a model can be fitted to the data points, for example, as described above. For example, the model could be a Butterworth van Dyke model. The complex impedance spectrum associated with the driver 214 can then be determined, for example, in the manner described above. In addition to the complex impedance spectrum CIS-2 associated with the second transducer 220, one or more processors 120 can also set or update one or more characteristics of one or more excitation signals to be directed to the first transducer 210, at least in part, based on the complex impedance spectrum associated with the driver 224.

[0110] After one or more processors 120 set or update one or more characteristics of one or more excitation signals ES2 directed to the second transducer 220 based at least in part on the complex impedance spectrum CIS-1 associated with the first transducer 210, the one or more processors 120 can cause the second transducer 220 to be excited by one or more second excitation signals ES2, such that the second transducer 220 directs the ultrasonic signal US2 to the first transducer 210 or directs the ultrasonic signal US2 to the first transducer 210. In some embodiments, the one or more second excitation signals ES2 directed to the second transducer 220 can cause the second transducer 220 to be excited at multiple excitation frequencies, for example... Figure 5 The ES2-1 described in ES2-2 and ES2-3 Multiple excitation frequencies that excite the second transducer 220 can each be the peak resonant frequencies associated with the first transducer 210 at a previous time step. Within the predetermined range.

[0111] For example, Figure 7 Depicting the fit to Figure 6 The model 300 for data points D1, D2, and D3 is fitted to the model 300 for data points D4, D5, and D6 at a time step after the associated time step. Data points D4, D5, and D6 are associated with the subsequent first dataset, where, when the second transducer 220 is used as... Figure 5 The excitation signals ES2-1, ES2-2, and ES2-3 shown are used to set the excitation frequency. , , 3. Upon excitation, data from records associated with the subsequent first dataset is sensed. It is noteworthy that the second transducer 220 is as follows: Figure 5 The excitation signals ES2-1, ES2-2, and ES2-3 shown are used to set the excitation frequency. , , 3. Excitation, such that each of the excitation frequencies associated with data points D4, D5, and D6 is the peak resonant frequency associated with the first transducer 210 at the previous time step. Within the predetermined range. Specifically, such as... Figure 7 As shown, each of data points D4, D5, and D6 has a peak resonant frequency associated with the first transducer 210 at a previous time step. Within a predetermined range (i.e., within the complex impedance spectrum CIS-1). Setting or updating the excitation frequency for exciting the second transducer 220 in this manner allows the first transducer 210 to operate at its peak resonant frequency. The sensor receives ultrasonic signals at or near the location of the transducer, thus maximizing the voltage at the first transducer 210 when such an ultrasonic signal US2 is received. This contributes to accurate sensor readings.

[0112] Similarly, after one or more processors 120 set or update one or more characteristics of one or more excitation signals ES1 directed to the first transducer 210 based at least in part on the complex impedance spectrum CIS-2 associated with the second transducer 220, the one or more processors 120 can cause the first transducer 210 to be excited by one or more first excitation signals ES1, such that the first transducer 210 directs the ultrasonic signal US1 at or to the second transducer 220. In some embodiments, as described above, one or more first excitation signals ES1 directed to the first transducer 210 can cause the first transducer 210 to be excited at multiple excitation frequencies, such as ES1-1 shown in FIG8. ES1-2 and ES1-3 Multiple excitation frequencies that excite the first transducer 210 can each be the peak resonant frequencies associated with the second transducer 220 at a previous time step. Within the predetermined range.

[0113] For example, Figure 10 Depicting the fit to Figure 9 The model 300 for data points D1, D2, and D3 is fitted to the model 300 for data points D4, D5, and D6 at a time step after the associated time step. Data points D4, D5, and D6 are associated with the subsequent second dataset, wherein, when the first transducer 210 is as follows... Figure 8 The excitation signals ES1-1, ES1-2, and ES1-3 shown are used to set the excitation frequency. , , 3. Upon excitation, data from records associated with a subsequent second dataset is sensed. Notably, the first transducer 210 is as follows: Figure 8 The excitation signals ES1-1, ES1-2, and ES1-3 shown are used to set the excitation frequency. , , 3. Excitation, such that each of the excitation frequencies associated with data points D4, D5, and D6 is the peak resonant frequency associated with the second transducer 220 at the previous time step. Within the predetermined range. Specifically, such as... Figure 10 As shown, each of data points D4, D5, and D6 has a peak resonant frequency associated with the second transducer 220 at a previous time step. Within a predetermined range (i.e., within the complex impedance spectrum CIS-2). Setting or updating the excitation frequency for exciting the first transducer 210 in this way allows the second transducer 220 to operate at its peak resonant frequency. The sensor receives ultrasonic signals at or near the location of the transducer, thus maximizing the voltage at the second transducer 220 when such an ultrasonic signal US1 is received. This contributes to accurate sensor readings.

[0114] The process described above for setting one or more characteristics of one or more excitation signals guided to the transducer can be repeated iteratively, such that the transmitting transducer is continuously excited in such a way that the SNR of the ultrasonic signal received by the receiving transducer is maximized or at least nearly maximized. That is, continuously updating the characteristics of the excitation signals guided to the transmitting transducer based on the complex impedance spectrum of the receiving transducer allows the voltage at the receiving transducer to be maximized or at least nearly maximized when the receiving transducer receives the ultrasonic signal transmitted by the transmitting transducer. In practice, the above technique can be repeated iteratively and continuously to set and / or update one or more characteristics of one or more excitation signals guided to the transmitting transducer in real time. This also allows for optimized setting of one or more characteristics of one or more excitation signals guided to the transmitting transducer, even if the condition and / or characteristics of the fuel flowing through the conduit where the transmitting and receiving transducers are arranged change.

[0115] For example, such as Figure 11 As shown, the model is displayed at three different time steps. The model is fitted at one time step (denoted by 300-1), another time step (denoted by 300-2), and yet another time step (denoted by 300-3). As illustrated, changes in fuel temperature cause a shift in the peak resonant frequency associated with the transducer. An increase in fuel temperature leads to an increase in the peak resonant frequency; for example, the model at 300-1 can shift to the right to 300-2, and the peak resonant frequency can correspondingly increase from... Move to Conversely, a decrease in fuel temperature leads to a decrease in the peak resonant frequency. Furthermore, changes in fuel pressure cause changes in the minimum impedance. For example, an increase in pressure leads to an increase in minimum impedance; for instance, when the model is moved to 300-3, the minimum impedance MI2 of the model at 300-2 can shift upwards to MI3. Conversely, a decrease in pressure leads to a decrease in minimum impedance. Therefore, iteratively updating the excitation frequency and amplitude of the excitation signal guided to the transmitting transducer based on the complex impedance spectrum of the receiving transducer can account for these variations, ultimately allowing for more accurate and consistent fuel mass flow rate predictions.

[0116] Apart from Figure 1 Still referencing Figure 12 and 13 In some embodiments, instead of exciting the first transducer 210 one at a time at different frequencies and the second transducer 220 one at a time at different frequencies as described above, one or more processors 120 can simultaneously exciting the first transducer 210 and / or the second transducer 220 at multiple different frequencies. For example, one or more processors 120 can simultaneously exciting the first transducer 210 and / or the second transducer 220 at a first excitation frequency, a second excitation frequency, and a third excitation frequency, wherein the first excitation frequency, the second excitation frequency, and the third excitation frequency are different from each other. In some embodiments, the first transducer 210 and / or the second transducer 220 can be excited by a broadband signal having multiple frequencies. Furthermore, in other embodiments, one or more processors 120 can simultaneously exciting the first transducer 210 and / or the second transducer 220 at fewer than three excitation frequencies (e.g., two excitation frequencies) or more than three excitation frequencies (e.g., five excitation frequencies). Figure 13 An example excitation signal ES1-S, comprising ES1-1, ES1-2, and ES1-3, is described to depict the characteristics of a combination of three excitation signals. The excitation signal ES1-S can be directed to the first transducer 210 to simultaneously excite the first transducer 210 at multiple different frequencies. As will be understood, it can be used as... Figure 13 A similar excitation signal is used to excite the second transducer 220.

[0117] Now for reference Figure 14 and 15 In some embodiments, the fuel flow sensor 200 may include more than two transducers. For example, for Figure 14 and 15 In the illustrated embodiment, the fuel flow sensor 200 includes four transducers: a first transducer 210, a second transducer 220, a third transducer 230, and a fourth transducer 240. Such an embodiment can provide electrical redundancy and other benefits. Furthermore, the conduit 202 defines an axial direction A, which is parallel to... Figure 14 and 15 The flow axis in the example embodiment.

[0118] exist Figure 14 In this configuration, the third transducer 230 is arranged flush with the first transducer 210 along the axial direction A, and the fourth transducer 240 is arranged flush with the second transducer 220 along the axial direction A. In this respect, the first transducer 210 and the third transducer 230 are axially aligned, and the second transducer 220 and the fourth transducer 240 are axially aligned. Figure 15 In contrast, the fourth transducer 240 is offset from the second transducer 220, for example, along the axial direction A, such that the length between the third transducer 230 and the fourth transducer 240 is greater than the length between the first transducer 210 and the second transducer 220. Embodiments with varying distances between transducer pairs can provide additional attenuation data, among other benefits.

[0119] It is worth noting that, for Figure 14 Implementation examples and Figure 15 In some embodiments, one or more characteristics of one or more excitation signals can be set or updated as described above. For example, one or more characteristics of one or more excitation signals directed to the first transducer 210 can be set or updated at least in part based on the complex impedance spectrum associated with the second transducer 220, and vice versa. Furthermore, one or more characteristics of one or more excitation signals directed to the third transducer 230 can be set or updated at least in part based on the complex impedance spectrum associated with the fourth transducer 240, and vice versa.

[0120] In this embodiment, the ultrasonic signal US1 emitted by the first transducer 210 and the ultrasonic signal US3 emitted by the third transducer 230 can be received by the second transducer 220 and the fourth transducer 240. Similarly, the ultrasonic signal US2 emitted by the second transducer 220 and the ultrasonic signal US4 emitted by the fourth transducer 240 can be received by the first transducer 210 and the third transducer 230. To ensure a satisfactory SNR for the ultrasonic signals, it should be noted that the first transducer 210 and the second transducer 220 have the same design resonant frequency, and the third transducer 230 and the fourth transducer 240 have the same design resonant frequency, wherein the design resonant frequencies of the first transducer 210 and the second transducer 220 are different from the design resonant frequencies of the third transducer 230 and the fourth transducer 240. This provides a design resonant frequency for each of the transducer pairs, which serves as the signature of each pair of transducers. These design resonant frequencies allow transducers 210, 220, 230, and 240 to distinguish between ultrasonic signals emitted from a paired pair and ultrasonic signals received from a non-paired pair.

[0121] Figure 16A flowchart of a method 400 for tuning one or more transducers of an ultrasonic fuel flow sensor according to an example aspect of this disclosure is provided. Although Figure 16 The flowchart depicts a method 400 implemented to tune the excitation frequencies of two transducers (i.e., TX1 and TX2), but it should be understood that method 400 can be used to tune any number of transducers of an ultrasonic flow sensor. For example, method 400 can be used to tune the excitation frequencies of one or more transducers of any fuel flow sensor provided herein.

[0122] In 402-1, method 400 includes exciting a first transducer TX1 with a plurality of different excitation frequencies, such that the first transducer TX1 directs one or more ultrasonic signals through a conduit to a second transducer TX2 spaced apart from the first transducer. In some embodiments, the plurality of different excitation frequencies directed to the first transducer TX1 may be randomly selected. In other embodiments, the plurality of different excitation frequencies may be selected such that the excitation frequencies are spaced apart from each other by a predetermined interval. In some further embodiments, the first transducer TX1 is excited by broadband signals at the plurality of different excitation frequencies.

[0123] Similarly, in 402-2, method 400 includes exciting a second transducer TX2 at multiple different excitation frequencies, such that the second transducer TX2 guides one or more ultrasonic signals to the first transducer TX1 through a conduit. The first transducer TX1 can be excited at multiple different frequencies one at a time, for example, as shown below. Figure 3 As shown, or simultaneously excite the first transducer TX1 at multiple different frequencies, for example, as Figure 12 As shown. Similarly, the second transducer TX2 can be excited one at a time or simultaneously at multiple different frequencies. In some embodiments, multiple different excitation frequencies directed to the second transducer TX2 can be randomly selected. In other embodiments, multiple different excitation frequencies can be selected such that the excitation frequencies are spaced apart from each other by a predetermined interval. The first transducer TX1 and the second transducer TX2 can be excited simultaneously. In some further embodiments, the second transducer TX2 is excited by broadband signals at multiple different excitation frequencies.

[0124] In 404-1, method 400 includes recording the current at the first transducer TX1 when the first transducer TX1 is excited at multiple different excitation frequencies. ,Voltage and current and voltage phase difference between In this respect, each frequency at which the first transducer TX1 is excited has an associated recording current. ,Voltage and phase difference This data associated with the first transducer TX1 can be compiled into a first dataset. Similarly, in 404-2, method 400 includes recording the current at the second transducer TX2 when the second transducer TX2 is excited at multiple different excitation frequencies. ,Voltage and current and voltage phase difference between In this respect, the second transducer TX2 is excited at each frequency with an associated recorded current. ,Voltage and phase difference This data associated with the second transducer TX2 can be compiled into a second dataset.

[0125] In 406-1, method 400 includes generating data points based at least in part on the data recorded in 404-1. Each data point may be defined by a complex impedance and an excitation frequency among a plurality of different excitation frequencies. For example, a first data point may be defined by a complex impedance and a first excitation frequency among a plurality of different excitation frequencies, a second data point may be defined by a complex impedance and a second excitation frequency among a plurality of different excitation frequencies, and so on for each excitation frequency. The generated data points may be plotted on a graph of complex impedance versus excitation frequency, for example as... Figure 6 As shown. The complex impedance associated with a given data point is determined at least in part based on the voltage-to-current ratio at the first transducer TX1 when the first transducer TX1 is excited at a given frequency among a plurality of different excitation frequencies. In a similar manner, in 406-2, method 400 includes generating data points at least in part based on the data recorded in 404-2. This can be implemented in the same manner as described above with respect to 406-1.

[0126] In 408-1, method 400 includes fitting the model to the generated data points plotted in 406-1. For example, the model could be a Butterworth van Dyke model. Figure 6 A model is depicted that is fitted to the data points associated with the first transducer. Similarly, in 408-2, method 400 includes fitting the model to the generated data points plotted in 406-2. Figure 6 A model is described that is fitted to the data points associated with the second transducer.

[0127] In 410-1, method 400 includes determining a complex impedance spectrum CIS-1 associated with the first transducer TX1, at least in part, based on fitting a model to data points associated with the first transducer TX1. In some embodiments, determining the complex impedance spectrum CIS-1 associated with the first transducer TX1 may include determining a peak resonant frequency associated with the first transducer TX1, wherein the peak resonant frequency corresponds to a minimum impedance determined by fitting a model to data points associated with the first transducer TX1. Furthermore, determining the complex impedance spectrum CIS-1 associated with the first transducer TX1 may include determining an excitation frequency range within a predetermined range of the peak resonant frequency. The excitation frequency range within the predetermined range of the peak resonant frequency is related to the complex impedance spectrum CIS-1 associated with the first transducer TX1.

[0128] Similarly, in 410-2, method 400 includes determining a complex impedance spectrum CIS-2 associated with the second transducer TX2, at least in part, based on fitting a model to data points associated with the second transducer TX2. In some embodiments, determining the complex impedance spectrum CIS-2 associated with the second transducer TX2 may include determining a peak resonant frequency associated with the second transducer TX2, wherein the peak resonant frequency corresponds to the minimum impedance determined by fitting a model to data points associated with the second transducer TX2. Furthermore, determining the complex impedance spectrum CIS-2 associated with the second transducer TX2 may include determining an excitation frequency range within a predetermined range of the peak resonant frequency. The excitation frequency range within the predetermined range of the peak resonant frequency is related to the complex impedance spectrum CIS-2 associated with the second transducer TX2.

[0129] In 412-1, method 400 includes setting one or more characteristics of one or more second excitation signals ES2 that are directed to the second transducer TX2, based at least in part on the complex impedance spectrum CIS-1 associated with the first transducer TX1. Figure 16 A complex impedance spectrum CIS-1 associated with a first transducer TX1 is schematically depicted. This CIS-1 is used to set one or more characteristics of one or more second excitation signals ES2 directed to a second transducer TX2. The one or more characteristics may include at least one of the excitation frequency, amplitude, and phase of the one or more second excitation signals ES2 directed to the second transducer TX2. The one or more excitation frequencies of the one or more second excitation signals ES2 may be set within the complex impedance spectrum CIS-1 associated with the first transducer TX1, or in other words, within a predetermined range of the peak resonant frequency associated with the first transducer TX1.

[0130] Similarly, in 412-2, method 400 includes setting one or more characteristics of one or more first excitation signals ES1 directed to the first transducer TX1 based at least in part on the complex impedance spectrum CIS-2 associated with the second transducer TX2. Figure 16 A complex impedance spectrum CIS-2 associated with a second transducer TX2 is schematically depicted. This CIS-2 is used to set one or more characteristics of one or more first excitation signals ES1 directed to a first transducer TX1. The one or more characteristics may include at least one of the excitation frequency, amplitude, and phase of the one or more first excitation signals ES1 directed to the first transducer TX1. The one or more excitation frequencies of the one or more first excitation signals ES1 may be set within the complex impedance spectrum CIS-2 associated with the second transducer TX2, or in other words, within a predetermined range of the peak resonant frequency associated with the second transducer TX2.

[0131] In 414-1, method 400 includes exciting a first transducer TX1 with one or more first excitation signals ES1 having one or more characteristics, such that the first transducer TX1 guides one or more ultrasonic signals to a second transducer TX2 through a conduit. Because the first transducer TX1 is excited with one or more first excitation signals ES1 having one or more set or updated characteristics, the SNR of the ultrasonic signal received by the second transducer TX2 can be maximized. In some embodiments, at least one frequency at which the first transducer TX1 is excited is related to the peak resonant frequency of the second transducer TX2.

[0132] Similarly, in 414-2, method 400 includes exciting a second transducer TX2 with one or more second excitation signals ES2 having one or more characteristics, such that the second transducer TX2 guides one or more ultrasonic signals to a first sensor TX1 through a conduit. Because the second transducer TX2 is excited with one or more second excitation signals ES2 having one or more set or updated characteristics, the SNR of the ultrasonic signal received by the first transducer TX1 can be maximized. In some embodiments, at least one frequency at which the second transducer TX2 is excited is related to the peak resonant frequency of the first transducer TX1.

[0133] like Figure 16 As further described, the above method 400 can be iterative, such that the excitation frequencies directed to the first transducer TX1 and the second transducer TX2 are iteratively set or updated, for example, in real time. This can also facilitate accurate sensor readings, among other benefits, despite constantly changing fuel conditions.

[0134] Now besides Figure 1In addition, referring to Figures 17 and 18, an example method will now be described in which the type of medium flowing through the duct can be determined by the ultrasonic fuel flow sensor 200 of the fuel flow measurement system.

[0135] One or more processors 120 are configured to excite a first transducer 210 at one or more first excitation frequencies via one or more first excitation signals ES1, such that the first transducer 210 directs a first ultrasonic signal US1 through a medium flowing through conduit 202 to a second transducer 220. In this example embodiment, the medium is fuel.

[0136] One or more processors 120 are further configured to determine the amplitude of the first ultrasonic signal US1 at two or more points along a first crossing path TP1 of the first ultrasonic signal US1 at one or more of one or more of one or more first excitation frequencies. For example, as Figure 17A As shown, the first traversal path TP1 includes at least a first segment S1 spanning between the first transducer 210 and the second transducer 220, and a second segment S2 spanning between the second transducer 220 and the first transducer 210. The first segment S1 and the second segment S2 span the same distance L, but they are directional, because the first segment S1 represents the segment corresponding to the first traversal path TP1 of the first ultrasonic signal US1 emitted by the first transducer 210 and traversing to the second transducer 220, while the second segment S2 represents the segment corresponding to the first traversal path TP1 of the first ultrasonic signal US1 echoing from the second transducer 220 and returning to the first transducer 210.

[0137] Therefore, when the first transducer 210 is excited by one or more first excitation signals ES1, a first ultrasonic signal US1 is emitted by the first transducer 210 and travels along the first segment S1 from the first transducer 210 to the second transducer 220, at least echoing from the second transducer 220 (the first ultrasonic signal US1 may also echo from other objects, such as the conduit 202 and other objects), and travels along the second segment S2 from the second transducer 220 to the first transducer 210. Figure 17A In the diagram, the first ultrasonic signal US1 is shown as being emitted from the first transducer 210. Figure 17B In the diagram, the first ultrasonic signal US1 is shown as being received by the second transducer 220 after traversing the first segment S1 along the first traversal path TP1. Figure 17C In this context, the first ultrasonic signal US1 is shown as echoing from the second transducer 220 back to the first transducer 210, represented by the echoing first ultrasonic signal US1-R. Figure 17D In the diagram, the echoing first ultrasonic signal US1-R is shown as being received by the first transducer 210 after crossing the second segment S2 along the first crossing path TP1.

[0138] As described above, the amplitude of the first ultrasonic signal US1 is sensed at two or more points along the first traversal path TP1 of the first ultrasonic signal US1. For this example embodiment, the two or more points along the first traversal path TP1 of the first ultrasonic signal US1 include: a first point P1, located at the first transducer 210 and corresponding to the first segment S1 of the first traversal path TP1; a second point P2, located at the second transducer 220 and corresponding to the transition point between the first segment S1 and the second segment S2 of the first traversal path TP1; and a third point P3, located at the first transducer 210 and corresponding to the second segment S2 of the first traversal path TP1. In this respect, both the first point P1 and the third point P3 correspond to the same location, namely the location of the first transducer 210. However, the first point P1 corresponds to the point along the first crossing path TP1 where the first ultrasonic signal US1 is initially emitted, while the third point P3 corresponds to the point along the first crossing path TP1 where the first ultrasonic signal US1 is received (or more specifically, the first ultrasonic signal US1-R that echoes after the first ultrasonic signal US1 has been echoed from the second transducer 220 at the second point P2 and returned to the first transducer 210).

[0139] For example, when the first transducer 210 emits the first ultrasonic signal US1, the amplitude of the first ultrasonic signal US1 can be sensed at a first point P1, or more precisely, at the first transducer 210. This can be achieved, for example, by sensing the voltage amplitude at the first transducer 210 when the first transducer 210 is excited at a specific excitation frequency. Then, when the first ultrasonic signal US1 reaches the second transducer 220, for example... Figure 17B As shown, the amplitude of the first ultrasonic signal US1 can be sensed at the second point P2. This is reflected in the echo from the second transducer 220, for example... Figure 17C As shown, and after traversing along the second segment S2 and reaching the first transducer 210, for example, as Figure 17D As shown, the amplitude of the first ultrasonic signal US1 can be sensed at the third point P3. The amplitude of the first ultrasonic signal US1 at each point can be sensed by sensing the amplitude of the voltage at a specific point or transducer.

[0140] One or more processors 120 are further configured to generate first data points based at least in part on the amplitude of the sensed first ultrasonic signal US1. Each first data point is defined by the amplitude of the first ultrasonic signal US1 at a given point among two or more points along the first traversal path TP1, the total distance the first ultrasonic signal US1 has traveled through the medium to the given point among the two or more points, and the frequency of one or more first excitation frequencies that excite the first transducer 210. For example, Figure 19 Three first data points, DP1-1, DP1-2, and DP1-3, are depicted. The first data points DP1-1, DP1-2, and DP1-3 all correspond to the same excitation frequency, but as shown in the figure, they correspond to different distances and have different amplitudes.

[0141] Specifically, the first data point DP1-1 corresponds to Figure 17A The amplitude of the ultrasonic signal US1 at the first point P1 is depicted. At the first point P1, the ultrasonic signal US1 has traveled a distance DX1. The second data point DP1-2 corresponds to the amplitude of the ultrasonic signal US1 at... Figure 17A The amplitude at the second point P2 is shown. At the second point P2, the ultrasonic signal US1 has traveled a distance DX2, or Figure 17A The distance L depicted in the figure. The third data point DP1-3 corresponds to the ultrasonic signal US1 at... Figure 17A The amplitude at point P3, the third point depicted. At point P3, the ultrasonic signal US1 has traveled a distance of DX3, or twice the distance L, or 2L. Figure 19 As shown, the amplitude of the ultrasonic signal US1 decreases as the distance traversed by the first ultrasonic signal US1 increases. In this way, Figure 19 The manner in which the first ultrasonic signal US1 attenuates during the first crossing path TP1 is described.

[0142] A first data point can be generated for each excitation frequency at which the first transducer 210 is excited. For example, when the first transducer 210 is excited by a first excitation frequency, a second excitation frequency, and a third excitation frequency, the first data point can be generated and plotted on a graph corresponding to the first excitation frequency, on a graph corresponding to the second excitation frequency, and on a graph corresponding to the third excitation frequency. In this respect, each graph corresponds to a specific excitation frequency.

[0143] As the first data points DP1-1, DP1-2, and DP1-3 are generated, one or more processors 120 are further configured to determine one or more features of the medium by fitting the attenuation model 350 to the first data points DP1-1, DP1-2, and DP1-3. Any suitable fitting technique, including one or more machine learning techniques, can be used to fit the attenuation model 350 to the data points DP1-1, DP1-2, and DP1-3. Figure 19 As shown, the attenuation model 350 is fitted to the first data points DP1-1, DP1-2, and DP1-3.

[0144] It is worth noting that the synthesis function RF(350) of the attenuation model fitted to the first data points DP1-1, DP1-2, and DP1-3 Figure 21 This is related to one or more characteristics of the medium. It can be understood that Stokes' law of sound attenuation states that the amplitude of a signal decreases with increasing speed over distance traveled. It decreases exponentially, at a rate of It is given by the following formula:

[0145] (Equation 1)

[0146] in It is the dynamic viscosity coefficient of the medium. angular frequency of the signal It is the density of the medium, and It is the speed of sound in the medium. In this respect, rate Depending on one or more characteristics of the medium. By fitting the attenuation model to the first data points DP1-1, DP1-2, DP1-3, it is possible to determine the attenuation rate without knowing the limiting rate. Specific parameters (e.g., the dynamic viscosity coefficient of the medium) and the density of the medium Determine the rate associated with the medium flowing through conduit 202 in the following case. Therefore, the composite function RF of the attenuation model 350 fitted to data points DP1-1, DP1-2, and DP1-3 indicates the rate associated with the medium flowing through conduit 202. or with rate Related, where the rate It is also related to one or more characteristics of the medium.

[0147] Using the determined synthesis function RF (i.e., the function corresponding to the attenuation model 350 fitted to the data points), one or more processors 120 are configured to classify the medium type based at least in part on a comparison between one or more features of the medium and one or more baseline features. For example, as Figure 21 As shown, a synthesis function RF can be compared with multiple baseline functions, each corresponding to a predetermined media type. In this example, the multiple baseline functions include a first baseline function BF-1, a second baseline function BF-2, and a third baseline function BF-3. The first baseline function BF-1 may correspond to a first predetermined media type, such as Jet-A, the second baseline function BF-2 may correspond to a second predetermined media type, such as JP-4, and the third baseline function BF-3 may correspond to a third predetermined media type, such as JP-5. As will be understood, in other embodiments, the multiple baseline functions may include more than three baseline functions or fewer than three functions.

[0148] In some embodiments, a predetermined medium type associated with the baseline function that most closely matches the synthesis function RF among a plurality of baseline functions is classified as the medium type of the medium flowing through conduit 202. That is, one or more processors 120 can classify the medium type of the medium flowing through conduit 202 as corresponding to the medium type of the baseline function that most closely matches the synthesis function RF. For example, as shown in the figure, in Figure 21 In this process, the second baseline function BF-2 among multiple baseline functions most closely matches the synthesis function RF. Therefore, the medium type of the medium flowing through conduit 202 is classified by one or more processors 120 as the medium type corresponding to the second baseline function BF-2. In other embodiments, one or more processors 120 may classify the medium type of the medium flowing through conduit 202 as a medium type according to one or more other criteria.

[0149] In some alternative embodiments, the curve or function of the synthesized function can be compared with a baseline curve or function stored in a lookup table or the like.

[0150] In some further embodiments, in addition to fitting to the first data point, the attenuation model 350 can also be fitted to data points generated based on the ultrasonic signal emitted by the second transducer 220.

[0151] More specifically, in some embodiments, one or more processors 120 are configured to cause the second transducer 220 to be excited by one or more second excitation signals ES2 at one or more second excitation frequencies, such that the second transducer 220 guides the second ultrasonic signal US2 through the medium flowing through the conduit 202 to the first transducer 210.

[0152] One or more processors 120 are further configured to determine the amplitude of the second ultrasonic signal US2 at two or more points along the second traversal path TP2 of the second ultrasonic signal US2 at one or more frequencies of one or more of one or more second excitation frequencies. For example, as Figure 18A As shown, the first crossing path TP1 includes at least a first segment S1 spanning between the second transducer 220 and the first transducer 210, and a second segment S2 spanning between the first transducer 210 and the second transducer 220. The first segment S1 and the second segment S2 span the same distance L, but they are directional, wherein the first segment S1 represents the segment of the second crossing path TP2 corresponding to the second ultrasonic signal US2 emitted by the second transducer 220 and crossing to the first transducer 210, and the second segment S2 represents the segment of the second crossing path TP2 corresponding to the second ultrasonic signal US2 echoing from the first transducer 210 and returning to the second transducer 220.

[0153] Therefore, when the second transducer 220 is excited by one or more second excitation signals ES2, the second ultrasonic signal US2 is emitted by the second transducer 220 and travels along the first segment S1 from the second transducer 220 to the first transducer 210, echoes from the first transducer 210 (the second ultrasonic signal US2 can also echo from other objects, such as the conduit 202 and other objects), and travels along the second segment S2 from the first transducer 210 to the second transducer 220. Figure 18A In the diagram, the second ultrasonic signal US2 is shown as being emitted from the second transducer 220. Figure 18B In the diagram, the second ultrasonic signal US2 is shown as being received by the first transducer 210 after traversing the first segment S1 along the second crossing path TP2. Figure 18C In this context, the second ultrasonic signal US2 is shown as echoing from the first transducer 210 back to the second transducer 220, represented by the echoing second ultrasonic signal US2-R. Figure 18D In the diagram, the echoing second ultrasonic signal US2-R is shown as being received by the second transducer 220 after crossing the second segment S2 along the second crossing path TP2.

[0154] As indicated, the amplitude of the second ultrasonic signal US2 is sensed at two or more points along the second traversal path TP2 of the second ultrasonic signal US2. For this example embodiment, the two or more points on the second traversal path TP2 of the second ultrasonic signal US2 include: a first point P1 located at the second transducer 220 and corresponding to the first segment S1 of the second traversal path TP2; a second point P2 located at the first transducer 210 and corresponding to the transition point between the first segment S1 and the second segment S2 of the second traversal path TP2; and a third point P3 located at the second transducer 220 and corresponding to the second segment S2 of the second traversal path TP2. In this respect, both the first point P1 and the third point P3 correspond to the same location, namely the location of the second transducer 220. However, the first point P1 corresponds to the point of initial emission of the second ultrasonic signal US2 along the second crossing path TP2, while the third point P3 corresponds to the point of reception of the second ultrasonic signal US2 (or more specifically, the second ultrasonic signal US2-R echoed after the second ultrasonic signal US2 has echoed from the first transducer 210 at the second point P2 and returned to the second transducer 220).

[0155] For example, when the second transducer 220 emits the second ultrasonic signal US2, the amplitude of the second ultrasonic signal US2 can be sensed at a first point P1, or more precisely, at the second transducer 220. This can be achieved, for example, by sensing the amplitude of the voltage at the second transducer 220 when the second transducer 220 is excited at a specific excitation frequency. Then, when the second ultrasonic signal US2 reaches the first transducer 210, for example as... Figure 18B As shown, the amplitude of the second ultrasonic signal US2 can be sensed at the second point P2. This is achieved by sensing the echo from the first transducer 210 (e.g., as shown in the image). Figure 18C As shown), and traverses along the second segment S2 and reaches the second transducer 220 (e.g., as shown). Figure 18D As shown), the amplitude of the second ultrasonic signal US2 can be sensed at the third point P3. The amplitude of the second ultrasonic signal US2 at each point can be sensed by sensing the voltage amplitude at a specific point or transducer.

[0156] One or more processors 120 are further configured to generate second data points based at least in part on the amplitude of the sensed second ultrasonic signal US2. Each second data point is defined by the amplitude of the second ultrasonic signal US2 at a given point among two or more points along the second traversal path TP2, the total distance the second ultrasonic signal US2 has traveled through the medium to the given point among the two or more points, and the frequency of one or more second excitation frequencies to which the second transducer 220 is excited. For example, Figure 20 Three second data points, DP2-1, DP2-2, and DP2-3, are plotted on a graph showing the amplitude comparison distance. The first data points, DP1-1, DP1-2, and DP1-3, are also plotted on... Figure 20 On the chart. The second data points DP2-1, DP2-2, and DP2-3 all correspond to the same excitation frequency, but as shown in the figure, they correspond to different distances and have different amplitudes.

[0157] Specifically, the first data point DP2-1 corresponds to the second ultrasonic signal US2 in Figure 18A The amplitude at the first point P1 is shown. At the first point P1, the second ultrasonic signal US2 has traveled a distance DX1. The second data point DP2-2 corresponds to the amplitude of the second ultrasonic signal US2 at... Figure 18A The amplitude at the second point P2 is shown. At the second point P2, the second ultrasonic signal US2 has traveled a distance DX2, or... Figure 18A The distance L shown. The third data point DP2-3 corresponds to the second ultrasonic signal US2 at... Figure 18AThe amplitude at the third point P3 is shown. At the third point P3, the second ultrasonic signal US2 has traveled a distance of DX3, or twice the distance L, or 2L. Figure 20 As shown, the amplitude of the second ultrasonic signal US2 decreases as the distance traveled by the second ultrasonic signal US2 increases. Similarly, as described above, the amplitude of the first ultrasonic signal US1 decreases as the distance traveled by the first ultrasonic signal US1 increases. In this way, Figure 20 The manner in which the first ultrasonic signal US1 and the second ultrasonic signal US2 attenuate during their respective first crossing path TP1 and second crossing path TP2 is described.

[0158] A second data point can be generated for each excitation frequency at which the second transducer 220 is excited. For example, when the second transducer 220 is excited by a first excitation frequency, a second excitation frequency, and a third excitation frequency, a second data point can be generated and plotted on a graph corresponding to the first excitation frequency, a second data point can be generated and plotted on a graph corresponding to the second excitation frequency, and a second data point can be generated and plotted on a graph corresponding to the third excitation frequency. In this respect, each graph corresponds to a specific excitation frequency.

[0159] Furthermore, when determining one or more characteristics of the medium as described above, one or more processors 120 can be configured to fit the attenuation model 350 to a second data point in addition to the first data point, for example, as Figure 20 As shown. This could potentially double the number of data points that the attenuation model 350 can fit. This could ultimately provide a more accurate media type classification.

[0160] As described above, data points can be generated for each excitation frequency that excites a given transducer. In some embodiments, the attenuation model 350 is fitted to the data points corresponding to a given excitation frequency, and the synthesis function corresponding to each excitation frequency can be averaged to present a collective synthesis function. For example, such as Figure 22 As shown, for example, by fitting the attenuation model 350 to the data points generated for a given excitation frequency, each excitation frequency of the excitation transducer can be determined. , , and The synthesis function RF. One or more processors 120 may generate a collective synthesis function RF-C based at least in part on the synthesis function RF associated with each excitation frequency. As an example, a suitable curve averaging algorithm may be used to average the synthesis function RF associated with each excitation frequency to give an average curve, or the collective synthesis function RF-C. In some embodiments, the collective synthesis function RF-C is compared with one or more baseline functions as described above. The medium type corresponding to the baseline function that best matches the collective synthesis function RF-C can be classified as the medium type of the medium flowing through the conduit 202.

[0161] Figure 23 A flowchart is provided for a method 600 for classifying the medium type of a medium flowing through a duct using at least two transducers of an ultrasonic fuel flow sensor, according to an example aspect of this disclosure. Method 600 can be implemented to determine the medium type.

[0162] In method 602, method 600 includes exciting a first transducer at one or more first excitation frequencies, such that the first transducer directs a first ultrasonic signal through a medium flowing through a conduit to a second transducer spaced apart from the first transducer. For example, as... Figure 17A As shown, the first transducer is excited by one or more excitation signals having one or more first excitation frequencies. In some embodiments, the first transducer is upstream of the second transducer, for example, as shown in the diagram. Figure 17A As shown in -D and 18A-D. In other embodiments, the first transducer is downstream of the second transducer.

[0163] In method 604, method 600 includes determining the amplitude of a first ultrasonic signal at two or more points along a first traversal path of the first ultrasonic signal at one or more frequencies of one or more first excitation frequencies. For example, the amplitude may be sensed at a first transducer when the first ultrasonic signal is emitted, at a second transducer when the ultrasonic signal is received, and then at the first transducer again after the first ultrasonic signal echoes from the second transducer and returns to the first transducer. In some embodiments, the amplitude may be sensed only initially at the first transducer and then at the second transducer. Therefore, in such embodiments, it is not necessary to consider the amplitude of the echoing ultrasonic signal.

[0164] In 606, method 600 includes determining one or more characteristics of the medium by fitting an attenuation model to first data points, each of the first data points being defined by: the amplitude of a first ultrasonic signal at a given point among two or more points along a first traversal path, the total distance the first ultrasonic signal has traversed the medium to the given point among the two or more points, and the frequency of one or more first excitation frequencies at which the first transducer is excited. For example, in some embodiments, the synthesis function of the attenuation model fitted to the first data points is related to one or more characteristics of the medium. Thus, in some embodiments, one or more characteristics of the medium are related to the rate defined by Equation 1. Related. In this regard, the rate associated with the medium flowing through conduit 202 is determined by fitting the attenuation model to the first data point. It is possible to not know the limit rate It is determined based on the specific parameters.

[0165] In some implementations, the first crossing path includes at least a first segment spanning between the first and second transducers and a second segment spanning between the second and first transducers, for example... Figure 17A As shown. When the first transducer is excited, the first ultrasonic signal travels along the first segment from the first transducer to the second transducer, echoes from the second transducer, and travels along the second segment from the second transducer back to the first transducer, for example, as... Figure 17A -D indicates the sequence. Furthermore, in such an embodiment, two or more points along the first crossing path of the first ultrasonic signal include a first point located at the first transducer and corresponding to the first segment of the first crossing path, a second point located at the second transducer and corresponding to the transition point between the first and second segments of the first crossing path, and a third point located at the first transducer and corresponding to the second segment of the first crossing path.

[0166] In 608, the method includes classifying the medium type based at least in part on a comparison between one or more features of the medium and one or more baseline features. In some embodiments, classifying the medium type based at least in part on a comparison between one or more features of the medium and one or more baseline features includes comparing a synthesis function with a plurality of baseline functions, each baseline function corresponding to a predetermined medium type. Furthermore, in some embodiments, the predetermined medium type associated with the baseline function that most closely matches the synthesis function among the plurality of baseline functions is classified as the medium type of the medium flowing through the conduit.

[0167] In some further embodiments, method 600 includes determining the amplitude of a first ultrasonic signal at two or more points along a first traversal path of the first ultrasonic signal for each of one or more first excitation frequencies. In such an embodiment, determining one or more characteristics of the medium at 606 by fitting an attenuation model to first data points includes fitting an attenuation model to first data points associated with each of the one or more first excitation frequencies to give a synthesis function associated with each of the one or more first excitation frequencies, and determining a collective synthesis function based at least in part on each of the synthesis functions. In such an embodiment, when classifying the medium type based at least in part on a comparison between one or more characteristics of the medium and one or more baseline characteristics, one or more processors are configured to compare the collective synthesis function with a plurality of baseline functions.

[0168] In some further embodiments, the second transducer may be excited simultaneously with the first transducer, such that readings associated with the second ultrasonic signal emitted by the second transducer can be used to ultimately classify the medium type flowing through the conduit. Specifically, in some embodiments, method 600 includes exciting the second transducer at one or more second excitation frequencies, such that the second transducer directs the second ultrasonic signal through the medium to the first transducer. Furthermore, method 60 includes determining the amplitude of the second ultrasonic signal at two or more points along a second crossing path of the second ultrasonic signal at one or more of the one or more second excitation frequencies. In such embodiments, when determining one or more characteristics of the medium, one or more processors are configured to fit an attenuation model to second data points in addition to first data points, each second data point being defined by: the amplitude of the second ultrasonic signal at a given point among the two or more points along the second crossing path, the total distance the second ultrasonic signal has traveled through the medium to the given point among the two or more points along the second crossing path, and the frequency of the one or more second excitation frequencies that excited the second transducer.

[0169] Furthermore, in such an embodiment, the second crossing path includes at least a first segment spanning between the second transducer and the first transducer, and a second segment spanning between the first transducer and the second transducer, wherein when the second transducer is excited, the second ultrasonic signal travels along the first segment from the second transducer to the first transducer, echoes from the first transducer, and travels along the second segment from the first transducer to the second transducer. Furthermore, in such an embodiment, two or more points along the second crossing path of the second ultrasonic signal include a first point located at the second transducer and corresponding to the first segment of the second crossing path, a second point located at the first transducer and corresponding to the transition point between the first and second segments of the second crossing path, and a third point located at the second transducer and corresponding to the second segment of the second crossing path.

[0170] Now for reference Figure 1 and 24 , Figure 24 This is a schematic diagram of an ultrasonic fuel flow sensor 200 for a fuel flow measurement system according to an exemplary aspect of this disclosure. The ultrasonic fuel flow sensor 200 is operable to detect contaminants in a medium flowing through a conduit 202. For this embodiment, as... Figure 24 As shown, one or more processors 120 are configured to cause the first transducer 210 to transmit an ultrasonic signal US1 to the second transducer 220 through a medium flowing through the conduit 202. The one or more processors 120 are further configured to determine the time of flight (TOF) of the ultrasonic signal US1, wherein the TOF indicates the time it takes for the ultrasonic signal US1 to travel through the medium and return to the first transducer 210.

[0171] In such an embodiment, one or more processors 120 may compare the time-of-flight (TOF) of the ultrasonic signal US1 with a baseline time of flight. For example, the baseline TOF may correspond to the expected time for the ultrasonic signal US1 to travel through the medium, echo from the second transducer 220, and return to the first transducer 210. Furthermore, one or more processors 120 may determine the presence of a contaminant in the medium based at least in part on the comparison between the TOF of the ultrasonic signal US1 and the baseline TOF. That is, the actual TOF of the ultrasonic signal US1 is compared with the baseline TOF.

[0172] In some embodiments, when the TOF of the ultrasonic signal US1 is within a predetermined time range of the baseline TOF, one or more processors 120 determine that no contaminant is present in the medium. Conversely, when the TOF of the ultrasonic signal US1 is not within the predetermined time range of the baseline TOF, one or more processors 120 determine that contaminant is indeed present in the medium. In such embodiments, one or more processors 120 may be configured to generate an alarm indicating the presence of contaminant in the medium.

[0173] For example, such as Figure 24 As shown, numerous bubbles of contaminant C are depicted within the medium of conduit 202. In this configuration, when the first transducer 210 emits an ultrasonic signal US1, the ultrasonic signal US1 can travel through the medium and echo from one of the bubbles or objects of contaminant C. The echoing ultrasonic signal, as... Figure 24 As shown in US1-R, the ultrasonic signal returns to the first transducer 210 more quickly when it echoes from the contaminant C to be received by the first transducer 210, rather than when it travels a length L, echoes from the second transducer 220, and again travels a length L to be received by the first transducer 210. In this way, when the ultrasonic signal echoes from the second transducer 220, the actual TOF of the ultrasonic signal is less than its expected TOF. In some embodiments, the expected baseline TOF is preselected or determined at least in part based on the medium type.

[0174] One example contaminant is boiling of the medium within conduit 202. Boiling can indicate that the medium is undergoing a phase change, which may be undesirable in some cases (e.g., coking of injected fuel) and desirable in others (e.g., converting cryogenically stored liquid hydrogen into gaseous hydrogen before combustion), depending on the medium or fuel. In this regard, detecting the presence of contaminants within the medium flowing through conduit 202 can be useful. For example, when a contaminant is detected, one or more processors associated with ultrasonic fuel flow sensor 200 can trigger a response that causes regulation of one or more upstream and / or downstream systems to control the state or phase of the medium flowing through conduit 202 (e.g., by sending an alarm to one or more controllers of one or more upstream and / or downstream systems). Example upstream and / or downstream systems include one or more heat exchangers, one or more pumps, one or more fluid compression devices, one or more radiators and / or heat sources, etc. As an example, when a contaminant is present in the medium flowing through conduit 202 (e.g., when boiling is detected in injected fuel), one or more controllable devices can be controlled to regulate one or more upstream and / or downstream systems to reduce or eliminate boiling of the medium. As another example, when a contaminant is detected in the medium flowing through conduit 202 (e.g., when cryogenically stored liquid hydrogen is detected to become gaseous hydrogen before combustion), one or more controllable devices can be controlled to maintain the operation of one or more upstream and / or downstream systems to continue preheating the hydrogen.

[0175] Furthermore, the absence of contaminants can be used to determine whether upstream and / or downstream systems are functioning properly. In this respect, the health status of upstream and / or downstream systems can be determined even when contaminants are not detected, and one or more controllable devices can be controlled to regulate or maintain the operation of such upstream and / or downstream systems based on whether the contaminant is desirable.

[0176] Figure 25 This is a flowchart of a method 700 for determining the presence of contaminants in a medium flowing through a duct using one or more transducers of an ultrasonic fuel flow sensor, according to an example aspect of this disclosure.

[0177] In method 702, method 700 includes causing a first transducer of an ultrasonic flow sensor to transmit an ultrasonic signal to a second transducer of the ultrasonic flow sensor through a medium flowing through a conduit. In some embodiments, the first transducer is located upstream of the second transducer. In other embodiments, the first transducer is located downstream of the second transducer.

[0178] In 704, method 700 includes determining the time of flight of an ultrasonic signal, the time of flight of the ultrasonic signal indicating the time taken for the ultrasonic signal to travel through the medium and return to the first transducer.

[0179] In 706, method 700 includes comparing the time of flight of the ultrasonic signal with a baseline time of flight. For example, the baseline time of flight may correspond to the expected time for the ultrasonic signal to travel through the medium, echo from the second transducer, and return to the first transducer.

[0180] In method 708, method 700 includes determining the presence of contaminants based at least in part on a comparison between the time of flight (TOF) of the ultrasonic signal and a baseline TOF. In some embodiments, when the TOF of the ultrasonic signal is within a predetermined time range of the baseline TOF, it is determined that no contaminants are present in the medium. Conversely, when the TOF of the ultrasonic signal is not within the predetermined time range of the baseline TOF, one or more processors may determine that contaminants are present in the medium. In some further embodiments, method 700 may include generating an alarm indicating the presence of contaminants in the medium. The alarm may be provided to maintenance personnel, crew members, entities, etc.

[0181] In some further embodiments, method 700 may include causing a second transducer to emit a second ultrasonic signal toward a first transducer through a medium flowing through a conduit. Method 700 may also include determining the time of flight (TOF) of the second ultrasonic signal, which indicates the time it takes for the second ultrasonic signal to travel through the medium and return to the second transducer. Furthermore, method 700 may include comparing the TOF of the second ultrasonic signal with a second baseline. For example, the second baseline TOF may correspond to the expected time for the second ultrasonic signal to travel through the medium, echo from the first transducer, and return to the second transducer. In such embodiments, in addition to comparing the TOF of the ultrasonic signal emitted by the first transducer with the baseline time, a comparison between the TOF of the second ultrasonic signal and the second baseline TOF may also be used. For example, when both comparisons indicate the presence of contaminants, an alarm indicating the same condition may be generated, for example, using a high confidence score. When only one comparison indicates the presence of contaminants, the alarm may indicate the presence of contaminants, transducer malfunction, and / or both. When neither comparison indicates the presence of contaminants in the medium, an alarm indicating the same condition may be generated, for example, using a high confidence score.

[0182] According to another aspect of this disclosure, a method is provided for setting the excitation frequency of one or more transducers of a fuel flow sensor assembly. In one example aspect, the method of setting the excitation frequency includes exciting the transducers of the fuel flow sensor assembly at one or more excitation frequencies such that the transducers guide one or more ultrasonic signals through a medium flowing through a duct. The amplitude of the one or more ultrasonic signals is measured or otherwise determined. The amplitude may be measured at another transducer spaced apart from the transmitting transducer and / or at the transmitting transducer after the ultrasonic signal echoes back to the transmitting transducer. Data points may be determined based on the determined amplitudes, wherein a given data point is defined by the amplitude and frequency of the ultrasonic signal. An amplitude response transfer function may be determined based on the one or more data points. For example, a predefined model (e.g., a predefined attenuation model) may be fitted to the data points, for example, based on their relative positions to each other and their amplitude magnitudes. The fitted predefined model may give a synthesized amplitude response transfer function. The excitation frequency to be set for the transmitting transducer may then be selected based on the amplitude response transfer function. As an example, the amplitude response transfer function may be used to select the excitation frequency as the frequency corresponding to the maximum amplitude response (determined not to be noise). As another example, the amplitude response transfer function can be used to select the excitation frequency as the frequency that provides the best signal-to-noise ratio (SNR).

[0183] Therefore, this method can be used to set the excitation frequency of one or more transducers based on amplitude responses captured at different frequencies. Advantageously, such a method can be used to continuously set or update the excitation frequency of a given transducer in real time at predetermined intervals, when conditions are met, etc., so that a given transducer of a fuel flow sensor assembly is set as needed, for example, optimized for a specific purpose, such as maximizing the SNR. As the inventors have discovered, this method may require less computational resources and may require sensing fewer parameters or features compared to conventional methods for setting the excitation frequency of transducers. In this respect, this method provides an efficient way to set the excitation frequency of a transducer in a fuel flow sensor assembly.

[0184] Figure 26 This is a schematic diagram of an ultrasonic fuel flow sensor assembly 204 according to an exemplary aspect of this disclosure. The ultrasonic fuel flow sensor assembly 204 includes an ultrasonic fuel flow sensor 200, which includes a first transducer 210 and a second transducer 220 spaced apart from the first transducer 210. The first transducer 210 and the second transducer 220 are positioned within a conduit 202, the conduit 202 being arranged to allow a medium (e.g., fuel) to flow through it. Figure 26 In the illustrated embodiment, the first transducer 210 is located upstream of the second transducer 220. In this respect, the fuel flowing through the conduit 202... Figure 26 The fluid flows from left to right, indicated by arrow F. The first transducer 210 is spaced apart from the second transducer 220. Specifically, the first transducer 210 and the second transducer 220 are spaced apart by a length L, which is the distance between the surfaces of the first transducer 210 and the second transducer 220. Furthermore, in this embodiment, the first transducer 210 and the second transducer 220 are spaced apart from each other in a direction parallel to the flow axis of the fluid flowing through the conduit 202. The first transducer 210 and the second transducer 220 are generally aligned with the flow axis. However, in alternative embodiments, the first transducer 210 and the second transducer 220 do not need to be aligned with the flow axis. For example, in some embodiments, the first transducer 210 and the second transducer 220 may be offset from the flow axis, for example, such that the first transducer 210 and the second transducer 220 operate diagonally relative to the flow axis. Furthermore, in other example embodiments, the second transducer 220 may be located upstream of the first transducer 210.

[0185] The ultrasonic fuel flow sensor assembly 204 also includes an electronics box, a first circuit 206, and a second circuit 208. The first circuit 206 includes multiple electrically connected first components, including a first transducer 210 (which is also part of the ultrasonic fuel flow sensor 200), a first signal generator 212, a first driver 214, and a first input / output circuit 112 of the electronics box 110. The second circuit 208 includes multiple electrically connected second components, including a second transducer 220 (which is also part of the ultrasonic fuel flow sensor 200), a second signal generator 222, a second driver 224, and a second input / output circuit 114 of the electronics box 110.

[0186] for Figure 26 In the illustrated embodiment, one or more processors 120 of the electronic box 110 are configured to excite the first transducer 210 at one or more first excitation frequencies ES1, such that the first transducer 210 guides one or more first ultrasonic signals US1 through a medium (e.g., fuel) flowing through the conduit 202. Figure 26 As shown, one or more first ultrasonic signals US1 are indicated to be directed toward the second transducer 220. One or more processors 120 of the electronics box 110 are also configured to determine, at one or more of one or more of one or more first excitation frequencies ES1, the amplitude of the one or more first ultrasonic signals US1 received at the second transducer 220, and / or the amplitude of the one or more first ultrasonic signals echoing back to the first transducer 210 (denoted by US1-R) and received by the first transducer 210. In this respect, for example, the attenuation of one or more first ultrasonic signals US1 can be determined at the second transducer 220 and / or at the first transducer 210 after echoing back to the first transducer 210.

[0187] Furthermore, one or more processors 120 of the electronic box 110 are configured to determine one or both of the following: i) a first amplitude response transfer function associated with the fuel flow sensor assembly 204 based at least in part on the amplitude of one or more first ultrasonic signals US1 received at the second transducer 220 at one or more frequencies; and ii) a third amplitude response transfer function associated with the fuel flow sensor assembly 204 based at least in part on the amplitude of one or more first ultrasonic signals (represented by US1-R) that echo back to the first transducer 210 at one or more frequencies and are received by the first transducer 210.

[0188] For example, such as Figure 27As shown, the amplitude received at the second transducer 220 at one or more frequencies of one or more first excitation frequencies ES1 is schematically depicted, where each box represents the amplitude of a first ultrasonic signal received at the second transducer 220 for a given first excitation frequency of one or more first excitation frequencies ES1. As illustrated, the amplitude received at the second transducer 220 at one or more frequencies of one or more first excitation frequencies ES1 is used to determine a first amplitude response transfer function TF1 associated with the fuel flow sensor assembly 204, or more specifically, to determine a first amplitude response transfer function TF1 for the first circuit 206 and the second circuit 208 associated with the fuel flow sensor assembly 204. In this respect, the first amplitude response transfer function TF1 models the amplitude response of the first circuit 206 and the second circuit 208 of the fuel flow sensor assembly 204 at one or more frequencies.

[0189] The first amplitude response transfer function TF1 can model the amplitude response of the first circuit 206 and the second circuit 208 as a function of frequency. In this respect, each data point of the first amplitude response transfer function TF1 represents the amplitude of the first ultrasonic signal US1 received at the second transducer 220 as a function of frequency. In an alternative embodiment, the first amplitude response transfer function TF1 can model the amplitude ratio as a function of frequency, where the amplitude ratio is the ratio of the amplitude of the first ultrasonic signal US1 received at the second transducer 220 to the amplitude of the first ultrasonic signal US1 at the first transducer 210 when excited, and vice versa. The shape of the first amplitude response transfer function TF1 depends on the given fuel flow sensor assembly 204, or more precisely, its arrangement, transducer characteristics, associated circuitry, etc.

[0190] In some embodiments, reference Figure 28 The first amplitude response transfer function TF1 can be determined by fitting a predefined function or predefined model TF1-M to one or more data points D-1, D-2, D-3, where each data point D-1, D-2, D-3 represents the amplitude value (or amplitude ratio) of the first ultrasonic signal US1 received at the second transducer 220 as a function of frequency. Figure 28 In the depiction example, the first data point D-1 corresponds to the amplitude of the first ultrasonic signal US1 received at the second transducer 220 at the first frequency f-1, the second data point D-2 corresponds to the amplitude of the first ultrasonic signal US1 received at the second transducer 220 at the second frequency f-2, and the third data point D-3 corresponds to the amplitude of the first ultrasonic signal US1 received at the second transducer 220 at the second frequency f-3. For example... Figure 28As shown, the pre-defined model TF1-M was fitted to data points D-1, D-2, and D-3 (in Figure 28 (Move downwards and to the left). The synthesis position of the predefined model TF1-M corresponds to the first amplitude response transfer function TF1. In an alternative embodiment, the first amplitude response transfer function TF1 can be determined by plotting data points D-1, D-2, and D-3, and then connecting the data points D-1, D-2, and D-3 into a line. The synthesis line corresponds to the determined first amplitude response transfer function TF1.

[0191] like Figure 27 Further illustrated, the amplitude of the first ultrasonic signal US1 received at the first transducer 210 at one or more frequencies of one or more first excitation frequencies ES1 is schematically depicted, where each box represents the amplitude received at the first transducer 210 for a given first excitation frequency of one or more first excitation frequencies ES1. As shown, the amplitude received at the first transducer 210 at one or more frequencies of one or more first excitation frequencies ES1 is used to determine a third amplitude response transfer function TF3 associated with the fuel flow sensor assembly 204, or more specifically, to determine a third amplitude response transfer function TF3 associated with the first circuit 206 of the fuel flow sensor assembly 204. In this respect, the third amplitude response transfer function TF3 models the amplitude response of the first circuit 206 (but not the second circuit 208) of the fuel flow sensor assembly 204.

[0192] The third amplitude response transfer function TF3 can model the amplitude response as a function of frequency. In this respect, each data point of the third amplitude response transfer function TF3 represents the value of the amplitude of the first ultrasonic signal US1 received at the first transducer 210 as a function of frequency. In an alternative embodiment, the third amplitude response transfer function TF can model the amplitude ratio as a function of frequency, where the amplitude ratio is the ratio of the amplitude of the first ultrasonic signal US1 received at the first transducer 210 to the amplitude of the first ultrasonic wave US1 at the first transducer 210 when excited, and vice versa. The shape of the third amplitude response transfer function TF3 depends on the given fuel flow sensor assembly 204. In some embodiments, the third amplitude response transfer function TF3 can be determined by fitting a predefined function or predefined model to one or more data points, where each data point represents the amplitude (or amplitude ratio) of the first ultrasonic signal US1 received at the second transducer 220 as a function of frequency. The predefined model can be fitted to the data points, as referenced above. Figure 28 The third amplitude response transfer function TF3 can also be determined in other suitable ways, such as any of those described here.

[0193] In some embodiments, reference Figure 26 and 27 One or more processors 120 of the electronics box 110 are configured to select the excitation frequency of the first transducer 210 based at least in part on a first amplitude response transfer function TF1 and / or a third amplitude response transfer function TF3. As an example, one or more processors 120 of the electronics box 110 may be configured to use the first amplitude response transfer function TF1 and / or the third amplitude response transfer function TF3 to select an excitation frequency that maximizes the signal-to-noise ratio of the fuel flow sensor assembly 204. As another example, one or more processors 120 of the electronics box 110 may be configured to select an excitation frequency that corresponds to the fuel flow sensor assembly 204 operating at a minimum power level while still providing a predetermined level of measurement accuracy (e.g., 95% accuracy).

[0194] In a further embodiment, one or more processors 120 of the electronics box 110 may be configured to select an excitation frequency as the frequency of the peak amplitude (maximum peak or peak corresponding to the maximum received amplitude) corresponding to a given amplitude response transfer function. For example, refer to Figure 28 One or more processors 120 of the electronic box 110 can be configured to select an excitation frequency, as the frequency corresponding to f-1, because this frequency corresponds to the peak amplitude of the first amplitude response transfer function TF1. In some cases, the peak amplitude of the amplitude response transfer function may not correspond to the measured data point, but rather to the maximum peak value of the amplitude response transfer function, regardless of whether the maximum peak value is a measured data point.

[0195] In other embodiments, one or more processors 120 of the electronics box 110 may be configured to select an excitation frequency as a frequency corresponding to a predetermined point along the amplitude response transfer function. For example, by testing, it can be determined that a specific predetermined point along the amplitude response transfer function provides the optimal balance between signal-to-noise ratio and the power required for operation. For example, refer to... Figure 28 One or more processors 120 of the electronic box 110 can be configured to select an excitation frequency as a frequency corresponding to f-1.5, since this frequency corresponds to a predetermined point PP of the first amplitude response transfer function TF1.

[0196] In some further embodiments, one or more processors 120 of the electronics box 110 are configured to track excitation frequencies selected at two or more different sampling times (e.g., at a first sampling time and at different second sampling times). The one or more processors 120 of the electronics box 110 are then configured to monitor the health of the fuel flow sensor assembly 204 at least in part based on the tracked excitation frequencies. For example, the health of the fuel flow sensor assembly 204 can be determined by determining the difference between a selected excitation frequency sampled at one of the two or more different sampling times and another selected excitation frequency sampled at another of the two or more different sampling times. A difference that meets a threshold can be used to determine unacceptable degradation of the fuel flow sensor assembly 204. The magnitude of this difference can be used to determine the priority of alarms provided to health systems, operators, etc.

[0197] In some alternative embodiments, instead of tracking the excitation frequency selected at two or more different sampling times, one or more processors 120 of the electronics box 110 are configured to track the signal-to-noise ratio (SNR) of the fuel flow sensor assembly 204 at two or more different sampling times (e.g., at a first sampling time and at different second sampling times). The one or more processors 120 of the electronics box 110 are then configured to monitor the health of the fuel flow sensor assembly 204 based at least in part on the tracked SNR. For example, the health of the fuel flow sensor assembly 204 can be determined by determining the difference between an SNR determined at one of the two or more different sampling times and another SNR determined at another of the two or more different sampling times. A difference that meets a threshold can be used to determine unacceptable degradation of the fuel flow sensor assembly 204. The magnitude of this difference can be used to determine the priority of alarms provided to health systems, operators, etc. In some cases, the fuel flow sensor assembly 204 may degrade even if the excitation frequency does not change over time, but the determined SNR changes, which may indicate degradation. Therefore, tracking the signal-to-noise ratio may be beneficial, in addition to or as an alternative to the chosen excitation frequency.

[0198] In some embodiments, one or more processors 120 of the electronic enclosure 110 are configured to combine a first amplitude response transfer function TF1 and a third amplitude response transfer function TF3 into a combined amplitude response transfer function TFC. In this manner, the combined amplitude response transfer function TFC can be based on a transfer function determined based on one or more amplitudes of one or more first ultrasonic signals US1 received at the second transducer 220 and a transfer function determined based on one or more amplitudes of one or more echoing first ultrasonic signals US1-R received at the first transducer 210. In this respect, the selected excitation frequency can be selected with improved accuracy.

[0199] In some further embodiments, such as Figure 26 As shown, one or more processors 120 of the electronic box 110 are configured to excite the second transducer 220 at one or more second excitation frequencies ES2, such that the second transducer 220 guides one or more second ultrasonic signals US2 through the medium flowing through the conduit 202. Figure 26 As shown, one or more second ultrasonic signals US2 are indicated to be directed toward the first transducer 210. One or more processors 120 of the electronics box 110 are also configured to determine, at one or more of one or more of one or more second excitation frequencies ES2, the amplitude of the one or more second ultrasonic signals US2 received at the first transducer 210, and / or the amplitude of the one or more second ultrasonic signals echoing back to the second transducer 220 (denoted by US2-R) and received by the second transducer 220. In this respect, for example, the attenuation of one or more second ultrasonic signals US2 can be determined at the first transducer 210 and / or at the second transducer 220 after echoing back to the second transducer 220.

[0200] Furthermore, one or more processors 120 of the electronic box 110 are configured to determine one or both of the following: i) a second amplitude response transfer function associated with the fuel flow sensor assembly 204 based at least in part on the amplitude of one or more second ultrasonic signals US2 received at the first transducer 210 at one or more of the one or more second excitation frequencies ES2; and ii) a fourth amplitude response transfer function associated with the fuel flow sensor assembly 204 based at least in part on the amplitude of one or more second ultrasonic signals (represented by US2-R) echoing back to the second transducer 220 at one or more of the one or more second excitation frequencies ES2 and received by the second transducer 220.

[0201] For example, such as Figure 27As shown, the amplitudes of one or more second ultrasonic signals US2 received at the first transducer 210 at one or more of one or more second excitation frequencies ES2 are schematically depicted, where each box represents the amplitude received at the first transducer 210 for a given second excitation frequency among the one or more second excitation frequencies ES2. As illustrated, the amplitudes received at the first transducer 210 at one or more of the one or more second excitation frequencies ES2 are used to determine the second amplitude response transfer function TF2 associated with the fuel flow sensor assembly 204, or more specifically, to determine the second amplitude response transfer function TF2 of the first circuit 206 and the second circuit 208 associated with the fuel flow sensor assembly 204. In this respect, the second amplitude response transfer function TF2 models the amplitude response of the first circuit 206 and the second circuit 208 of the fuel flow sensor assembly 204.

[0202] like Figure 27 Further illustrated, the amplitude of the second ultrasonic signal US2 echoed and received at the second transducer 220 at one or more of one or more second excitation frequencies ES2 is schematically depicted, where each box represents the amplitude received at the second transducer 220 for a given second excitation frequency among the one or more second excitation frequencies ES2. As shown, the amplitude received at the second transducer 220 at one or more of one or more of the one or more second excitation frequencies ES2 is used to determine a fourth amplitude response transfer function TF4 associated with the fuel flow sensor assembly 204, or more specifically, to determine a fourth amplitude response transfer function TF4 associated with the second circuit 208 of the fuel flow sensor assembly 204. In this respect, the fourth amplitude response transfer function TF4 models the amplitude response of the second circuit 208 (not the first circuit 206) of the fuel flow sensor assembly 204. The second amplitude response transfer function and the fourth amplitude response transfer function can be determined as described above with respect to the first amplitude response transfer function and the third amplitude response transfer function, respectively.

[0203] In some embodiments, reference Figure 26 and 27One or more processors 120 of the electronics box 110 are configured to select the excitation frequency for the second transducer 220 based at least in part on a second amplitude response transfer function TF2 and / or a fourth amplitude response transfer function TF4. As an example, one or more processors 120 of the electronics box 110 may be configured to use the second amplitude response transfer function TF2 and / or the fourth amplitude response transfer function TF4 to select the excitation frequency that maximizes the signal-to-noise ratio of the fuel flow sensor assembly 204. As another example, one or more processors 120 of the electronics box 110 may be configured to select the excitation frequency of the second transducer 220 that corresponds to a frequency at which the fuel flow sensor assembly 204 operates at a minimum power level but still provides a predetermined level of measurement accuracy (e.g., 95% accuracy). In some other embodiments, the excitation frequency of the second transducer 220 is selected to correspond to the peak amplitude of a given amplitude response transfer function, which may or may not be associated with the measurement data points. In a further embodiment, the excitation frequency of the second transducer 220 is selected to correspond to a predetermined point along the amplitude response transfer function.

[0204] In some further embodiments, one or more processors 120 of the electronics box 110 are configured to track excitation frequencies selected at two or more different sampling times (e.g., at a first sampling time and at different second sampling times). The one or more processors 120 of the electronics box 110 are then configured to monitor the health of the fuel flow sensor assembly 204 at least in part based on the tracked excitation frequencies. For example, the health of the fuel flow sensor assembly 204 can be determined by determining the difference between a selected excitation frequency sampled at one of the two or more different sampling times and another selected excitation frequency sampled at another of the two or more different sampling times. A difference that meets a threshold can be used to determine unacceptable degradation of the fuel flow sensor assembly 204. The magnitude of this difference can be used to determine the priority of alarms provided to health systems, operators, etc.

[0205] In some embodiments, one or more processors 120 of the electronic enclosure 110 are configured to combine the second amplitude response transfer function TF2 and the fourth amplitude response transfer function TF4 into a combined amplitude response transfer function TFC. In this way, the combined amplitude response transfer function TFC can be based on a transfer function determined based on one or more amplitudes of the second ultrasonic signal US2 received at the first transducer 210 and a transfer function determined based on one or more amplitudes of the echoed second ultrasonic signal US2 received at the second transducer 220. In this respect, the excitation frequency selected for the second transducer 220 can be selected with improved accuracy.

[0206] In some embodiments, one or more processors 120 of the electronic box 110 are configured to combine a third amplitude response transfer function TF3 and a fourth amplitude response transfer function TF4 into a combined amplitude response transfer function TCF. In other embodiments, one or more processors 120 of the electronic box 110 are configured to combine a first amplitude response transfer function TF1 and a second amplitude response transfer function TF2 into a combined amplitude response transfer function TCF. In still other embodiments, one or more processors 120 of the electronic box 110 are configured to combine at least one of the first TF1, the second TF2, and the third amplitude response transfer function TF3 and the fourth amplitude response transfer function TF4 into a combined amplitude response transfer function TCF. In some embodiments, any combination of the first, second, third, and fourth transfer functions TF1, TF2, TF3, and TF4 can be combined into a combined amplitude response transfer function TCF, such as... Figure 27 As shown. That is, the first, second, third, and fourth transfer functions TF1, TF2, TF3, and / or TF4 can be combined into TF1-TF2; TF1-TF3; TF1-TF4; TF2-TF3; TF2-TF4; TF3-TF4; TF1-TF2-TF3; TF1-TF2-TF4; TF1-TF3-TF4; TF2-TF3-TF4; and TF1-TF2-TF3-TF4.

[0207] Figure 29 This is a flowchart of a method 800 for determining the amplitude response transfer function associated with a fuel flow sensor assembly, based on an example aspect of this disclosure.

[0208] In method 802, method 800 includes exciting a first transducer of a fuel flow sensor assembly at one or more first excitation frequencies, such that the first transducer directs one or more first ultrasonic signals through a medium flowing through a duct. The first transducer can be excited at different times or at a single time by broadband signals transmitting multiple different excitation signals at different first excitation frequencies, each excitation signal having a different frequency.

[0209] In 804, method 800 includes determining, at one or more of one or more first excitation frequencies, the amplitude of one or more first ultrasonic signals received at a second transducer of a fuel flow sensor assembly and / or the amplitude of one or more first ultrasonic signals echoing back to and received by the first transducer.

[0210] In 806, method 800 includes determining one or both of the following: i) determining a first amplitude response transfer function associated with the fuel flow sensor assembly based at least in part on the amplitude of one or more first ultrasonic signals received at the second transducer; and ii) determining a third amplitude response transfer function associated with the fuel flow sensor assembly based at least in part on the amplitude of one or more first ultrasonic signals that echo back to and are received by the first transducer. The first amplitude response transfer function can be determined by fitting a predefined model to one or more data points, where each data point represents a measured amplitude of a first ultrasonic signal at the second transducer at a given frequency. The third amplitude response transfer function can be determined by fitting a predefined model to one or more data points, where each data point represents a measured amplitude of a first ultrasonic signal that echoes back to and is received by the first transducer at a given frequency.

[0211] A first amplitude response transfer function models the amplitude response of one or more first ultrasonic signals at a first circuit and a second circuit of the fuel flow sensor assembly. The first circuit includes multiple electrically connected first components, including a first transducer, a first signal generator, a first driver, and a first input / output circuit of an electronics box. The second circuit includes multiple electrically connected second components, including a second transducer, a second signal generator, a second driver, and a second input / output circuit of an electronics box. A third amplitude response transfer function models the amplitude response of one or more first ultrasonic signals at a first circuit of the fuel flow sensor assembly, but not at a second circuit.

[0212] At 808, method 800 includes selecting an excitation frequency for the first transducer using one or both of a first amplitude response transfer function and a third amplitude response transfer function. For example, in some embodiments, the excitation frequency is selected to maximize the signal-to-noise ratio of the fuel flow sensor assembly. In other embodiments, the excitation frequency is selected to correspond to a frequency at which the fuel flow sensor assembly operates at a minimum power level but still provides a predetermined level of measurement accuracy. In some other embodiments, the excitation frequency is selected to correspond to the peak amplitude of a given amplitude response transfer function, which may or may not be associated with a measurement data point. In a further embodiment, the excitation frequency is selected to correspond to a predetermined point along the amplitude response transfer function.

[0213] In some embodiments, the first transducer is located upstream of the second transducer. In other embodiments, the second transducer is located upstream of the first transducer.

[0214] In some other embodiments, method 800 may include tracking excitation frequencies selected at two or more different sampling times. In such embodiments, method 800 may further include monitoring the health of the fuel flow sensor assembly based at least in part on the tracked excitation frequencies. Furthermore, in such embodiments, the health of the fuel flow sensor assembly may be determined by determining the difference between an excitation frequency sampled at one of the two or more different sampling times and another excitation frequency sampled at another of the two or more different sampling times.

[0215] In some further embodiments, method 800 includes exciting a second transducer at one or more second excitation frequencies such that the second transducer guides a second ultrasonic signal through a medium flowing through a conduit. Furthermore, method 800 includes determining, at one or more of the one or more second excitation frequencies, the amplitude of the second ultrasonic signal received at the first transducer and / or the amplitude of the second ultrasonic signal echoed back to and received by the second transducer. Additionally, method 800 includes determining one or both of the following: i) determining a second amplitude response transfer function associated with the fuel flow sensor assembly based at least in part on the amplitude of the one or more second ultrasonic signals received at the first transducer; and ii) determining a fourth amplitude response transfer function associated with the fuel flow sensor assembly based at least in part on the amplitude of the one or more second ultrasonic signals echoed back to and received by the second transducer. The second amplitude response transfer function models the amplitude response of the second ultrasonic signal at the first and second circuits of the fuel flow sensor assembly. The fourth amplitude response transfer function models the amplitude response of the second ultrasonic signal at the second circuit of the fuel flow sensor assembly, but not at the first circuit.

[0216] In some embodiments, method 800 includes combining a first amplitude response transfer function and a third amplitude response transfer function into a combined amplitude response transfer function. In some embodiments, method 800 includes combining a second amplitude response transfer function and a fourth amplitude response transfer function into a combined amplitude response transfer function. In some embodiments, method 800 includes combining a third amplitude response transfer function and a fourth amplitude response transfer function into a combined amplitude response transfer function. In some embodiments, method 800 includes combining at least one of the first amplitude response transfer function, the second amplitude response transfer function, and the third and fourth amplitude response transfer functions into a combined amplitude response transfer function. In some embodiments, method 800 includes combining at least one of the third, fourth, and first and second amplitude response transfer functions into a combined amplitude response transfer function. In some embodiments, method 800 includes combining the first, second, third, and fourth amplitude response transfer functions into a combined amplitude response transfer function.

[0217] Figure 30 An example computing system 500 according to an exemplary embodiment of the present disclosure is provided. The electronics box 110 and / or the electric motor controller 160 disclosed herein may include one, some, or all of the components of the computing system 500. As shown, the computing system 500 may include one or more computing devices 510. The computing device 510 may include one or more processors 510A and one or more memory devices 510B. The one or more processors 510A may include any suitable processing device, such as a microprocessor, microcontroller, integrated circuit, logic device, and / or other suitable processing device. The one or more memory devices 510B may include one or more computer-readable media, including but not limited to non-transient computer-readable media, RAM, ROM, hard disk drives, flash drives, and / or other memory devices.

[0218] One or more memory devices 510B may store information accessible by one or more processors 510A, including computer-executable or computer-readable instructions 510C executable by one or more processors 510A. Instructions 510C may be any set of instructions that, when executed by one or more processors 510A, cause one or more processors 510A to perform operations. In some embodiments, instructions 510C may be executed by one or more processors 510A to cause one or more processors 510A to perform operations, such as any operations and functions configured for the computing system 500 and / or computing device 510. Instructions 510C may be software written in any suitable programming language or hardware and / or firmware. Additionally and / or alternatively, instructions 510C may be executed in logically and / or virtually decoupled threads on the processor 510A. Memory device 510B may further store data 510D accessible by processor 510A.

[0219] The computing device 510 may also include a network interface 510E for communicating, for example, with other components of the system 500 (e.g., via a network). The network interface 510E may include any suitable components for interfacing with one or more network interfaces, including, for example, a transmitter, receiver, port, controller, antenna, and / or other suitable components. One or more external devices, such as an external remote control, may be configured to receive one or more commands from or provide one or more commands to the computing device 510.

[0220] The techniques discussed herein refer to computer-based systems and the actions taken by and sent to and from computer-based systems. Those skilled in the art will recognize that the inherent flexibility of computer-based systems allows for a wide variety of possible configurations, combinations, and partitions of tasks and functions among components. For example, the processes discussed herein can be implemented using a single computing device or multiple computing devices working in combination. Databases, memory, instructions, and applications can be implemented on a single system or distributed across multiple systems. Distributed components can operate sequentially or in parallel.

[0221] While specific features of various embodiments may be shown in some figures but not in others, this is merely for convenience. Any feature of the figures may be referenced and / or claimed in accordance with the principles of this disclosure, in conjunction with any feature of any other figure.

[0222] This written description uses examples to disclose this disclosure, including best practices, and also enables any person skilled in the art to practice this disclosure, including making and using any device or system and performing any combined methods. The patent scope of this disclosure is defined by the claims, but may include other examples that would occur to a person skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that are not indistinguishable from the literal language of the claims, or if they include equivalent structural elements that are not substantially different from the literal language of the claims.

[0223] Further aspects are provided by the subject matter of the following clauses:

[0224] 1. A system comprising: a first transducer arranged to guide an ultrasonic signal through a conduit; a second transducer spaced apart from the first transducer and arranged to guide an ultrasonic signal through the conduit; and one or more processors configured to: excite the first transducer at a first excitation frequency and a second excitation frequency, the first excitation frequency and the second excitation frequency being different from each other; determine a complex impedance spectrum associated with the first transducer based at least in part on fitting a model to a first dataset, the first dataset indicating i) the voltage-to-current ratio at the first transducer when excited at the first excitation frequency and the voltage-to-current ratio at the first transducer when excited at the second excitation frequency, and ii) the phase difference between the voltage and the current at the first transducer when excited at the first excitation frequency and the phase difference between the voltage and the current at the first transducer when excited at the second excitation frequency; and set one or more characteristics of one or more second excitation signals to be guided to the second transducer based at least in part on the complex impedance spectrum associated with the first transducer.

[0225] 2. The system according to any of the preceding clauses, wherein the first transducer is excited one at a time by a first excitation signal at the first excitation frequency and a second excitation signal at the second excitation frequency.

[0226] 3. The system according to any of the preceding clauses, wherein the first transducer is simultaneously excited by a first excitation signal at the first excitation frequency and a second excitation signal at the second excitation frequency, the first excitation signal having a first phase and the second excitation signal having a second phase.

[0227] 4. The system according to any of the foregoing clauses, wherein the model is the Butterworth van Dyke model.

[0228] 5. The system according to any one of the preceding clauses, wherein the one or more processors are further configured to: excite the second transducer at a first excitation frequency and a second excitation frequency, the first excitation frequency and the second excitation frequency associated with the second transducer being different from each other; determine a complex impedance spectrum associated with the second transducer based at least in part on fitting a model to a second dataset, the second dataset indicating i) the voltage-to-current ratio at the second transducer when excited at the first excitation frequency, and the voltage-to-current ratio at the second transducer when excited at the second excitation frequency, and ii) the phase difference between the voltage and the current at the second transducer when excited at the first excitation frequency, and the phase difference between the voltage and the current at the second transducer when excited at the second excitation frequency; and set one or more characteristics of one or more first excitation signals directed to the first transducer based at least in part on the complex impedance spectrum associated with the second transducer.

[0229] 6. The system according to any of the preceding clauses, wherein the one or more processors are further configured to: excite the second transducer by the one or more second excitation signals such that the second transducer directs the ultrasonic signal to the first transducer; and excite the first transducer by the one or more first excitation signals such that the first transducer directs the ultrasonic signal to the second transducer.

[0230] 7. The system according to any one of the preceding clauses, wherein: i) the one or more second excitation signals directed to the second transducer cause the second transducer to be excited at a plurality of excitation frequencies, and wherein each of the plurality of excitation frequencies at which the second transducer is excited is within a predetermined range of a peak resonant frequency associated with the first transducer at a previous time step; and ii) the one or more first excitation signals directed to the first transducer cause the first transducer to be excited at a plurality of excitation frequencies, and wherein each of the plurality of excitation frequencies at which the first transducer is excited is within a predetermined range of a peak resonant frequency associated with the second transducer at a previous time step.

[0231] 8. The system according to any of the preceding clauses, wherein when determining the complex impedance spectrum associated with the first transducer based at least in part on fitting the model to the first dataset, the one or more processors are configured to: determine a peak resonant frequency associated with the first transducer, the peak resonant frequency corresponding to a minimum impedance determined by fitting the model to the first dataset; and determine an excitation frequency range within a predetermined range of the peak resonant frequency, wherein the excitation frequency range within the predetermined range of the peak resonant frequency is related to the complex impedance spectrum associated with the first transducer.

[0232] 9. The system according to any of the preceding clauses, wherein the lower and upper limits of the predetermined range are set at least in part based on a receiving threshold, the receiving threshold being set as a preselected impedance value.

[0233] 10. The system according to any of the preceding clauses, wherein when determining the complex impedance spectrum associated with the first transducer based at least in part on fitting the model to the first dataset, the one or more processors are configured to: generate a first data point defined by the complex impedance and the first excitation frequency, determining the complex impedance associated with the first data point based at least in part on the ratio of the voltage to the current at the first transducer when excited at the first excitation frequency; generate a second data point defined by the complex impedance and the second excitation frequency, determining the complex impedance associated with the second data point based at least in part on the ratio of the voltage to the current at the first transducer when excited at the second excitation frequency; and fit the model to at least the first data point and the second data point.

[0234] 11. The system according to any of the preceding clauses, wherein the one or more features include at least the excitation frequency and amplitude of the excitation signal to be guided to the second transducer.

[0235] 12. The system according to any of the preceding clauses, wherein the one or more characteristics of the one or more first excitation signals guided to the first transducer are set in real time based at least in part on the complex impedance spectrum associated with the second transducer.

[0236] 13. The system according to any of the preceding clauses, wherein the conduit defines an axial direction, and wherein the system further comprises: a third transducer arranged flush with the first transducer along the axial direction; a fourth transducer arranged flush with the second transducer along the axial direction; and wherein the first transducer and the second transducer have the same design resonant frequency, and the third transducer and the fourth transducer have the same design resonant frequency, wherein the design resonant frequencies of the first transducer and the second transducer are different from the design resonant frequencies of the third transducer and the fourth transducer.

[0237] 14. The system according to any one of the preceding clauses further includes: a third transducer; and a fourth transducer offset from the second transducer such that the signal path length between the third transducer and the fourth transducer is greater than the signal path length between the first transducer and the second transducer, and wherein the first transducer and the second transducer have the same design resonant frequency, and the third transducer and the fourth transducer have the same design resonant frequency, wherein the design resonant frequency of the first transducer and the second transducer is different from the design resonant frequency of the third transducer and the fourth transducer.

[0238] 15. A method comprising: exciting a first transducer at a plurality of different excitation frequencies such that the first transducer directs one or more ultrasonic signals through a conduit to a second transducer spaced apart from the first transducer; determining a complex impedance spectrum associated with the first transducer based at least in part on fitting a model to a first dataset, wherein for at least two of the plurality of different excitation frequencies, the first dataset indicates i) a ratio of voltage to current at the first transducer, and ii) a phase difference between the voltage and current at the first transducer when excited at a given excitation frequency of the plurality of different excitation frequencies; setting one or more characteristics of one or more second excitation signals directed to the second transducer based at least in part on the complex impedance spectrum associated with the first transducer; and exciting the second transducer with the one or more second excitation signals having the one or more characteristics such that the second transducer directs one or more ultrasonic signals through the conduit to the first transducer.

[0239] 16. The method according to any one of the preceding clauses, further comprising: exciting the second transducer at a plurality of different second excitation frequencies such that the second transducer directs one or more ultrasonic signals through the conduit to the first transducer; determining a complex impedance spectrum associated with the second transducer based at least in part on fitting the model to a second dataset, wherein for at least two of the plurality of different second excitation frequencies, the second dataset indicates i) a ratio of voltage to current at the second transducer, and ii) a phase difference between the voltage and current at the second transducer when excited at a given second excitation frequency of the plurality of different second excitation frequencies; setting one or more characteristics of one or more first excitation signals directed to the first transducer based at least in part on the complex impedance spectrum associated with the second transducer; and exciting the first transducer with the one or more first excitation signals having the one or more characteristics such that the first transducer directs one or more ultrasonic signals through the conduit to the second transducer.

[0240] 17. The method according to any of the preceding clauses, wherein determining the complex impedance spectrum associated with the first transducer based at least in part on fitting the model to the first dataset comprises: generating a first data point defined by the complex impedance and a first excitation frequency among the plurality of different excitation frequencies; determining the complex impedance associated with the first data point based at least in part on the ratio of the voltage to the current at the first transducer when excited at the first excitation frequency; generating a second data point defined by the complex impedance and a second excitation frequency among the plurality of different excitation frequencies; determining the complex impedance associated with the second data point based at least in part on the ratio of the voltage to the current at the first transducer when excited at the second excitation frequency; and fitting the model to at least the first data point and the second data point.

[0241] 18. The method according to any of the preceding clauses, wherein determining the complex impedance spectrum associated with the first transducer, based at least in part on fitting the model to the first dataset, comprises: determining a peak resonant frequency associated with the first transducer, the peak resonant frequency corresponding to a minimum impedance determined by fitting the model to the first dataset; and determining an excitation frequency range within a predetermined range of the peak resonant frequency, wherein the excitation frequency range within the predetermined range of the peak resonant frequency is associated with the complex impedance spectrum associated with the first transducer.

[0242] 19. A non-transitory computer-readable medium comprising computer-executable instructions, which, when executed by one or more processors of a fuel flow measurement system, cause the one or more processors to: excite a first transducer of a fuel flow sensor at a first excitation frequency and a second excitation frequency, such that the first transducer directs one or more ultrasonic signals through a conduit to a second transducer of the fuel flow sensor, the second transducer being spaced apart from the first transducer, the first excitation frequency and the second excitation frequency being different from each other; and determine a complex impedance spectrum associated with the first transducer based at least in part on fitting a model to a first dataset, the first... The dataset indicates i) the voltage-to-current ratio at the first transducer when excited at the first excitation frequency and the voltage-to-current ratio at the first transducer when excited at the second excitation frequency, and ii) the phase difference between the voltage and current at the first transducer when excited at the first excitation frequency and the phase difference between the voltage and current at the first transducer when excited at the second excitation frequency; and sets one or more characteristics of one or more second excitation signals directed to a second transducer spaced apart from the first transducer, based at least in part on the complex impedance spectrum associated with the first transducer.

[0243] 20. A non-transitory computer-readable medium according to any of the preceding clauses, wherein when the computer-executable instructions are executed by the one or more processors of the fuel flow measurement system, the one or more processors further cause the second transducer to: excite the second transducer at a first excitation frequency and a second excitation frequency, such that the second transducer guides one or more ultrasonic signals through the conduit to the first transducer, the first excitation frequency and the second excitation frequency at which the second transducer is excited being different from each other; determine a complex impedance spectrum associated with the second transducer based at least in part on fitting the model to a second dataset, the second dataset indicating i) the voltage-to-current ratio at the second transducer when excited at the first excitation frequency and the voltage-to-current ratio at the second transducer when excited at the second excitation frequency, and ii) the phase difference between the voltage and the current at the second transducer when excited at the first excitation frequency and the phase difference between the voltage and the current at the second transducer when excited at the second excitation frequency; and set one or more characteristics of the one or more first excitation signals guided to the first transducer based at least in part on the complex impedance spectrum associated with the second transducer.

[0244] 21. A system comprising: a first transducer; a second transducer spaced apart from the first transducer; and one or more processors configured to: excite the first transducer at one or more first excitation frequencies such that the first transducer guides the first ultrasonic signal through a medium flowing through a conduit to the second transducer; determine, at one or more frequencies of the one or more first excitation frequencies, the amplitude of the first ultrasonic signal at two or more points along a first traversal path of the first ultrasonic signal; determine one or more characteristics of the medium by fitting an attenuation model to first data points, each of the first data points being defined by: the amplitude of the first ultrasonic signal at a given point of the two or more points along the first traversal path, the total distance the first ultrasonic signal has traversed the medium to the given point of the two or more points, and the frequency of the one or more first excitation frequencies used to excite the first transducer; and classify the medium type at least in part based on a comparison between the one or more characteristics of the medium and one or more baseline characteristics.

[0245] 22. The system according to any of the preceding clauses, wherein the two or more points along the first traversal path of the first ultrasonic signal include a first point located at the first transducer and a second point located at the second transducer.

[0246] 23. The system according to any of the preceding clauses, wherein: the first traversal path includes at least a first segment spanning between the first transducer and the second transducer and a second segment spanning between the second transducer and the first transducer, wherein when the first transducer is excited, the first ultrasonic signal traverses from the first transducer to the second transducer along the first segment, at least echoes from the second transducer, and traverses from the second transducer to the first transducer along the second segment, and wherein the two or more points along the first traversal path of the first ultrasonic signal include a first point located at the first transducer and corresponding to the first segment of the first traversal path, a second point located at the second transducer and corresponding to a transition point between the first segment and the second segment of the first traversal path, and a third point located at the first transducer and corresponding to the second segment of the first traversal path.

[0247] 24. The system according to any of the preceding clauses, wherein the one or more processors are further configured to: excite the second transducer at one or more second excitation frequencies such that the second transducer guides a second ultrasonic signal through the medium to the first transducer; and at one or more of the one or more second excitation frequencies, determine the amplitude of the second ultrasonic signal at two or more points along a second crossing path of the second ultrasonic signal, and wherein, in determining the one or more characteristics of the medium, the one or more processors are configured to fit the attenuation model to second data points other than the first data points, each second data point being defined by: the amplitude of the second ultrasonic signal at a given point among the two or more points along the second crossing path, the total distance the second ultrasonic signal has traveled through the medium to the given point among the two or more points along the second crossing path, and the frequency among the one or more second excitation frequencies that excite the second transducer.

[0248] 25. The system according to any of the preceding clauses, wherein: the second crossing path includes at least a first segment spanning between the second transducer and the first transducer and a second segment spanning between the first transducer and the second transducer, wherein when the second transducer is excited, the second ultrasonic signal crosses from the second transducer to the first transducer along the first segment, echoes at least from the first transducer, and crosses from the first transducer to the second transducer along the second segment, and wherein the two or more points along the second crossing path of the second ultrasonic signal include a first point located at the second transducer and corresponding to the first segment of the second crossing path, a second point located at the first transducer and corresponding to a transition point between the first segment and the second segment of the second crossing path, and a third point located at the second transducer and corresponding to the second segment of the second crossing path.

[0249] 26. The system according to any of the preceding clauses, wherein the synthesis function of the attenuation model fitted to the first data point is related to one or more characteristics of the medium.

[0250] 27. The system according to any of the preceding clauses, wherein when classifying the medium type based at least in part on a comparison between the medium and one or more features of the medium and the one or more baseline features, the one or more processors are configured to compare the synthesis function with a plurality of baseline functions, each of the baseline functions corresponding to a predetermined medium type.

[0251] 28. A system according to any of the preceding clauses, wherein the predetermined medium type associated with the baseline function that most closely matches the synthesis function among the plurality of baseline functions is classified as the medium type of the medium flowing through the conduit.

[0252] 29. The system according to any of the preceding clauses, wherein the one or more processors are further configured to: for each of the one or more first excitation frequencies, determine the amplitude of the first ultrasonic signal at two or more points along a first traversal path of the first ultrasonic signal, and wherein when determining the one or more characteristics of the medium by fitting the attenuation model to the first data points, the one or more processors are configured to: fit the attenuation model to the first data points associated with each of the one or more first excitation frequencies to give a synthesis function associated with each of the one or more first excitation frequencies; and determine a collective synthesis function based at least in part on each of the synthesis functions, and wherein when classifying the medium type based at least in part on a comparison between the one or more characteristics of the medium and the one or more baseline characteristics, the one or more processors are configured to compare the collective synthesis function with a plurality of baseline functions.

[0253] 30. A method comprising: exciting a first transducer at one or more first excitation frequencies such that the first transducer guides a first ultrasonic signal through a medium flowing through a conduit to a second transducer spaced apart from the first transducer; determining, at one or more frequencies of the one or more first excitation frequencies, the amplitude of the first ultrasonic signal at two or more points along a first traversal path of the first ultrasonic signal; determining one or more characteristics of the medium by fitting an attenuation model to first data points, each of the first data points being defined by: the amplitude of the first ultrasonic signal at a given point of the two or more points along the first traversal path, the total distance the first ultrasonic signal has traversed the medium to the given point of the two or more points, and the frequency of the one or more first excitation frequencies exciting the first transducer; and classifying the medium type based at least in part on a comparison between the one or more characteristics of the medium and one or more baseline characteristics.

[0254] 31. The method according to any of the preceding clauses, wherein the two or more points along the first traversal path of the first ultrasonic signal include a first point located at the first transducer and a second point located at the second transducer.

[0255] 32. The method according to any of the preceding clauses, wherein: the first crossing path includes at least a first segment spanning between the first transducer and the second transducer and a second segment spanning between the second transducer and the first transducer, wherein when the first transducer is excited, the first ultrasonic signal crosses from the first transducer to the second transducer along the first segment, echoes from the second transducer, and crosses from the second transducer to the first transducer along the second segment, and wherein the two or more points along the first crossing path of the first ultrasonic signal include a first point located at the first transducer and corresponding to the first segment of the first crossing path, a second point located at the second transducer and corresponding to a transition point between the first segment and the second segment of the first crossing path, and a third point located at the first transducer and corresponding to the second segment of the first crossing path.

[0256] 33. The method according to any of the preceding clauses, further comprising: exciting the second transducer at one or more second excitation frequencies such that the second transducer guides a second ultrasonic signal through the medium to the first transducer; and determining, at one or more of the one or more of the one or more second excitation frequencies, the amplitude of the second ultrasonic signal at two or more points along a second crossing path of the second ultrasonic signal, and wherein, when determining the one or more characteristics of the medium, the one or more processors are configured to fit the attenuation model to second data points other than the first data points, each second data point being defined by: the amplitude of the second ultrasonic signal at a given point among the two or more points along the second crossing path, the total distance the second ultrasonic signal has traveled through the medium to the given point among the two or more points along the second crossing path, and the frequency among the one or more second excitation frequencies that excited the second transducer.

[0257] 34. The method according to any of the preceding clauses, wherein: the second crossing path includes at least a first segment spanning between the second transducer and the first transducer and a second segment spanning between the first transducer and the second transducer, wherein when the second transducer is excited, the second ultrasonic signal crosses from the second transducer to the first transducer along the first segment, echoes from the first transducer, and crosses from the first transducer to the second transducer along the second segment, and wherein the two or more points along the second crossing path of the second ultrasonic signal include a first point located at the second transducer and corresponding to the first segment of the second crossing path, a second point located at the first transducer and corresponding to a transition point between the first segment and the second segment of the second crossing path, and a third point located at the second transducer and corresponding to the second segment of the second crossing path.

[0258] 35. The method according to any of the preceding clauses, wherein the synthesis function of the attenuation model fitted to the first data point is related to one or more characteristics of the medium.

[0259] 36. The method according to any of the preceding clauses, wherein classifying the medium type of the medium based at least in part on a comparison between the one or more features of the medium and the one or more baseline features comprises: comparing the synthesis function with a plurality of baseline functions, each baseline function corresponding to a predetermined medium type.

[0260] 37. The method according to any of the preceding clauses, wherein the predetermined medium type associated with the baseline function that most closely matches the synthetic function among the plurality of baseline functions is classified as the medium type of the medium flowing through the conduit.

[0261] 38. The method according to any one of the preceding clauses, further comprising: for each of the one or more first excitation frequencies, determining the amplitude of the first ultrasonic signal at two or more points along a first traversal path of the first ultrasonic signal, and wherein determining the one or more characteristics of the medium by fitting the attenuation model to the first data points comprises: fitting the attenuation model to the first data points associated with each of the one or more first excitation frequencies to give a synthesis function associated with each of the one or more first excitation frequencies; and determining a collective synthesis function based at least in part on each of the synthesis functions, and wherein when classifying the medium type based at least in part on a comparison between the one or more characteristics of the medium and the one or more baseline characteristics, the one or more processors are configured to compare the collective synthesis function with a plurality of baseline functions.

[0262] 39. A non-transitory computer-readable medium comprising computer-executable instructions, which, when executed by one or more processors of a fuel flow measurement system, cause the one or more processors to: excite a first transducer of the fuel flow measurement system at one or more first excitation frequencies such that the first transducer directs a first ultrasonic signal through a medium flowing through a duct to a second transducer of the fuel flow measurement system; determine, at one or more frequencies of the one or more first excitation frequencies, the amplitude of the first ultrasonic signal at two or more points along a first traversal path of the first ultrasonic signal; determine one or more characteristics of the medium by fitting an attenuation model to first data points, each of the first data points being defined by: the amplitude of the first ultrasonic signal at a given point of the two or more points along the first traversal path, the total distance the first ultrasonic signal has traversed the medium to the given point of the two or more points, and the frequency of the one or more first excitation frequencies that excite the first transducer; and classify the medium type at least in part based on a comparison between the one or more characteristics of the medium and one or more baseline characteristics.

[0263] 40. A non-transitory computer-readable medium according to any of the preceding clauses, wherein one or more characteristics of the medium determined by fitting the attenuation model to the first data point are related to the attenuation rate of the medium.

[0264] 41. A system comprising: a first transducer; a second transducer spaced apart from the first transducer; and one or more processors configured to: cause the first transducer to emit an ultrasonic signal toward the second transducer through a medium flowing through a conduit; determine a time of flight of the ultrasonic signal, the time of flight indicating the time taken for the ultrasonic signal to travel through the medium and return to the first transducer; compare the time of flight of the ultrasonic signal with a baseline time of flight; and determine the presence of a contaminant based at least in part on the comparison between the time of flight of the ultrasonic signal and the baseline time of flight.

[0265] 42. The system according to any of the preceding clauses, wherein the medium is hydrogen.

[0266] 43. The system according to any of the preceding clauses, wherein the medium is injectable fuel.

[0267] 44. The system according to any of the preceding clauses, wherein the contaminant is the boiling of the medium.

[0268] 45. The system according to any of the preceding clauses, wherein the one or more processors are further configured to: trigger a response when the contaminant is detected, thereby regulating the state or phase of the medium flowing through the conduit by one or more upstream and / or downstream systems.

[0269] 46. ​​The system according to any of the preceding clauses, wherein the one or more upstream systems and / or downstream systems include one or more heat exchangers, one or more pumps, one or more fluid compression devices and / or one or more radiators and / or heat sources.

[0270] 47. The system according to any of the preceding clauses, wherein the one or more processors are further configured to: trigger a response upon detection of the contaminant, causing one or more upstream and / or downstream systems to maintain their current operation.

[0271] 48. A method comprising: causing a first transducer of an ultrasonic flow sensor to emit an ultrasonic signal through a medium flowing through a conduit to a second transducer of the ultrasonic flow sensor; determining a time-of-flight of the ultrasonic signal, the time-of-flight of the ultrasonic signal indicating the time taken for the ultrasonic signal to travel through the medium and return to the first transducer; comparing the time-of-flight of the ultrasonic signal to a baseline time-of-flight; and determining the presence of a contaminant based at least in part on the comparison between the time-of-flight of the ultrasonic signal and the baseline time-of-flight.

[0272] 49. A non-transitory computer-readable medium comprising computer-executable instructions, which, when executed by one or more processors of a flow measurement system, cause the one or more processors to: cause a first transducer of an ultrasonic flow sensor to emit an ultrasonic signal through a medium flowing through a duct to a second transducer of the ultrasonic flow sensor; determine a time-of-flight of the ultrasonic signal, the time-of-flight of the ultrasonic signal indicating the time taken for the ultrasonic signal to travel through the medium and return to the first transducer; compare the time-of-flight of the ultrasonic signal with a baseline time-of-flight; and determine, at least in part, the presence of a contaminant based on the comparison between the time-of-flight of the ultrasonic signal and the baseline time-of-flight.

[0273] 50. A system comprising: a first transducer arranged to guide an ultrasonic signal through a conduit; a second transducer spaced apart from the first transducer and arranged to guide an ultrasonic signal through the conduit; and one or more processors configured to: excite the first transducer at a first excitation frequency and a second excitation frequency, the first excitation frequency and the second excitation frequency being different from each other; determine a frequency range within a predetermined range of peak resonant frequencies associated with the first transducer, at least in part based on fitting a model to a first dataset, the first dataset indicating i) impedance when excited at the first excitation frequency and impedance at the first transducer when excited at the second excitation frequency, and ii) a phase difference between voltage and current at the first transducer when excited at the first excitation frequency and a phase difference between said voltage and said current at the first transducer when excited at the second excitation frequency; and set one or more characteristics of one or more second excitation signals guided to the second transducer, at least in part based on the frequency range associated with the first transducer.

[0274] 51. A method comprising: exciting a first transducer of a fuel flow sensor assembly at one or more first excitation frequencies such that the first transducer directs one or more first ultrasonic signals through a medium flowing through a conduit; determining, at one or more of the one or more first excitation frequencies, the amplitude of the one or more first ultrasonic signals received at a second transducer of the fuel flow sensor assembly and / or the amplitude of the one or more first ultrasonic signals echoing back to and received by the first transducer; and determining one or both of the following: i) determining a first amplitude response transfer function associated with the fuel flow sensor assembly based at least in part on the amplitude of the one or more first ultrasonic signals received at the second transducer; and ii) determining a third amplitude response transfer function associated with the fuel flow sensor assembly based at least in part on the amplitude of the one or more first ultrasonic signals echoing back to and received by the first transducer.

[0275] 52. The method according to any of the preceding clauses, wherein the first transducer is located upstream of the second transducer.

[0276] 53. The method according to any of the preceding clauses, wherein the second transducer is located upstream of the first transducer.

[0277] 54. The method according to any of the preceding clauses further comprises: selecting an excitation frequency for the first transducer based at least in part on the first amplitude response transfer function and / or the third amplitude response transfer function.

[0278] 55. The method according to any of the preceding clauses further comprises: tracking the excitation frequency selected at two or more different sampling times; and monitoring the health status of the fuel flow sensor assembly based at least in part on the tracked excitation frequency.

[0279] 56. The method according to any of the preceding clauses, wherein the health status of the fuel flow sensor assembly is determined by determining the difference between an excitation frequency sampled at one of the two or more different sampling times and another excitation frequency sampled at another of the two or more different sampling times.

[0280] 57. The method according to any of the preceding clauses, wherein the excitation frequency is selected to maximize the signal-to-noise ratio of the fuel flow sensor assembly.

[0281] 58. The method according to any of the preceding clauses, wherein the excitation frequency is selected to correspond to the frequency at which the fuel flow sensor assembly operates at a minimum power level but still provides a predetermined level of measurement accuracy.

[0282] 59. The method according to any of the preceding clauses, wherein the first amplitude response transfer function models the amplitude response of the one or more first ultrasonic signals at a first circuit and a second circuit of the fuel flow sensor assembly, the first circuit including a plurality of electrically connected first components including a first transducer, a first signal generator, a first driver, and a first input / output circuit of an electronics box, and the second circuit including a plurality of electrically connected second components including a second transducer, a second signal generator, a second driver, and a second input / output circuit of the electronics box.

[0283] 60. The method according to any of the preceding clauses, wherein the third amplitude response transfer function models the amplitude response of the one or more first ultrasonic signals at a first circuit, but not a second circuit, of the fuel flow sensor assembly, the first circuit comprising a plurality of electrically connected first components, including a first transducer, a first signal generator, a first driver, and a first input / output circuit of an electronics box, and the second circuit comprising a plurality of electrically connected second components, including a second transducer, a second signal generator, a second driver, and a second input / output circuit of the electronics box.

[0284] 61. The method according to any one of the preceding clauses further comprises: combining the first amplitude response transfer function and the third amplitude response transfer function into a combined amplitude response transfer function.

[0285] 62. The method according to any of the preceding clauses, further comprising: exciting a second transducer at one or more second excitation frequencies such that the second transducer directs one or more second ultrasonic signals through the medium flowing through the conduit; determining, at one or more of the one or more second excitation frequencies, the amplitude of the one or more second ultrasonic signals received at the first transducer and / or the amplitude of the one or more second ultrasonic signals echoing back to and received by the second transducer; and determining one or both of the following: i) determining a second amplitude response transfer function associated with the fuel flow sensor assembly based at least in part on the amplitude of the one or more second ultrasonic signals received at the first transducer; and ii) determining a fourth amplitude response transfer function associated with the fuel flow sensor assembly based at least in part on the amplitude of the one or more second ultrasonic signals echoing back to and received by the second transducer.

[0286] 63. The method according to any of the preceding clauses, wherein the second amplitude response transfer function models the amplitude response of the one or more second ultrasonic signals at a first circuit and a second circuit of the fuel flow sensor assembly, the first circuit comprising a plurality of electrically connected first components including a first transducer, a first signal generator, a first driver, and a first input / output circuit of an electronics box, and the second circuit comprising a plurality of electrically connected second components including a second transducer, a second signal generator, a second driver, and a second input / output circuit of the electronics box.

[0287] 64. The method according to any of the preceding clauses, wherein the fourth amplitude response transfer function models the amplitude response of the one or more second ultrasonic signals at a first circuit, but not a second circuit, of the fuel flow sensor assembly, the first circuit comprising a plurality of electrically connected first components, including a first transducer, a first signal generator, a first driver, and a first input / output circuit of an electronics box, and the second circuit comprising a plurality of electrically connected second components, including a second transducer, a second signal generator, a second driver, and a second input / output circuit of the electronics box.

[0288] 65. The method according to any one of the preceding clauses further comprises: combining the second amplitude response transfer function and the fourth amplitude response transfer function into a combined amplitude response transfer function.

[0289] 66. The method according to any one of the preceding clauses further comprises: combining the third amplitude response transfer function and the fourth amplitude response transfer function into a combined amplitude response transfer function.

[0290] 67. The method according to any one of the preceding clauses further comprises: combining the first amplitude response transfer function and the second amplitude response transfer function into a combined amplitude response transfer function.

[0291] 68. The method according to any one of the preceding clauses further comprises: combining at least one of the first amplitude response transfer function, the second amplitude response transfer function, and the third amplitude response transfer function and the fourth amplitude response transfer function into a combined amplitude response transfer function.

[0292] 69. A fuel flow sensor assembly comprising: a first transducer; a second transducer spaced apart from the first transducer; and one or more processors configured to: excite the first transducer at one or more first excitation frequencies such that the first transducer guides one or more first ultrasonic signals through a medium flowing through a conduit; at one or more of the one or more first excitation frequencies, determine the amplitude of the one or more first ultrasonic signals received at the second transducer and / or the amplitude of the one or more first ultrasonic signals echoing back to and received by the first transducer; and determine one or both of the following: i) determining a first amplitude response transfer function associated with the fuel flow sensor assembly based at least in part on the amplitude of the one or more first ultrasonic signals received at the second transducer; and ii) determining a third amplitude response transfer function associated with the fuel flow sensor assembly based at least in part on the amplitude of the one or more first ultrasonic signals echoing back to and received by the first transducer.

[0293] 70. A non-transitory computer-readable medium comprising computer-executable instructions, which, when executed by one or more processors of a fuel flow sensor assembly, cause the one or more processors to: excite a first transducer of the fuel flow sensor assembly at one or more first excitation frequencies such that the first transducer directs one or more first ultrasonic signals through a medium flowing through a conduit; determine, at one or more of the one or more first excitation frequencies, the amplitude of the one or more first ultrasonic signals received at a second transducer and / or the amplitude of the one or more first ultrasonic signals echoing back to and received by the first transducer; and determine one or both of the following: i) determining a first amplitude response transfer function associated with the fuel flow sensor assembly based at least in part on the amplitude of the one or more first ultrasonic signals received at the second transducer; and ii) determining a third amplitude response transfer function associated with the fuel flow sensor assembly based at least in part on the amplitude of the one or more first ultrasonic signals echoing back to and received by the first transducer.

Claims

1. A system, characterized in that, include: A first transducer is arranged to guide an ultrasonic signal through a medium flowing through a conduit to a second transducer. A second transducer, spaced apart from the first transducer, is arranged to guide an ultrasonic signal through the medium flowing through the conduit to the first transducer. and One or more processors, said one or more processors being configured to: The first transducer is excited at a first excitation frequency and a second excitation frequency, wherein the first excitation frequency and the second excitation frequency are different from each other; Based at least in part on fitting the model to a first dataset, a complex impedance spectrum associated with the first transducer is determined, the first dataset indicating i) the voltage-to-current ratio at the first transducer when excited at the first excitation frequency and the voltage-to-current ratio at the first transducer when excited at the second excitation frequency, and ii) the phase difference between the voltage and current at the first transducer when excited at the first excitation frequency and the phase difference between the voltage and current at the first transducer when excited at the second excitation frequency; and Based at least in part on the complex impedance spectrum associated with the first transducer, one or more characteristics of one or more second excitation signals directed to the second transducer are set. The one or more features are set in real time, at least in part, based on the complex impedance spectrum.

2. The system according to claim 1, characterized in that, The first transducer is excited one at a time by a first excitation signal at the first excitation frequency and a second excitation signal at the second excitation frequency.

3. The system according to claim 1, characterized in that, The first transducer is simultaneously excited by a first excitation signal at the first excitation frequency and a second excitation signal at the second excitation frequency, wherein the first excitation signal has a first phase and the second excitation signal has a second phase.

4. The system according to claim 1, characterized in that, The model mentioned is the Butterworth van Dyke model.

5. The system according to claim 1, characterized in that, The one or more processors are further configured to: The second transducer is excited at a first excitation frequency and a second excitation frequency, wherein the first excitation frequency and the second excitation frequency associated with the second transducer are different from each other; Based at least in part on fitting the model to a second dataset, a complex impedance spectrum associated with the second transducer is determined, the second dataset indicating i) the voltage-to-current ratio at the second transducer when excited at the first excitation frequency and the voltage-to-current ratio at the second transducer when excited at the second excitation frequency, and ii) the phase difference between the voltage and current at the second transducer when excited at the first excitation frequency and the phase difference between the voltage and current at the second transducer when excited at the second excitation frequency; and One or more characteristics of one or more first excitation signals directed to the first transducer are set, at least in part, based on the complex impedance spectrum associated with the second transducer.

6. The system according to claim 5, characterized in that, The one or more processors are further configured to: The second transducer is excited by the one or more second excitation signals, causing the second transducer to guide the ultrasonic signal to the first transducer; and The first transducer is excited by one or more first excitation signals, causing the first transducer to guide the ultrasonic signal to the second transducer.

7. The system according to claim 6, characterized in that, in: i) The one or more second excitation signals directed to the second transducer cause the second transducer to be excited at a plurality of excitation frequencies, wherein each of the plurality of excitation frequencies at which the second transducer is excited is within a predetermined range of a peak resonant frequency associated with the first transducer in a previous time step; and ii) The one or more first excitation signals directed to the first transducer cause the first transducer to be excited at a plurality of excitation frequencies, wherein the plurality of excitation frequencies at which the first transducer is excited are each within a predetermined range of the peak resonant frequency associated with the second transducer at the previous time step.

8. The system according to claim 1, characterized in that, Wherein, when determining the complex impedance spectrum associated with the first transducer based at least in part on fitting the model to the first dataset, the one or more processors are configured to: Determine the peak resonant frequency associated with the first transducer, the peak resonant frequency corresponding to the minimum impedance determined by fitting the model to the first dataset; and Determine the excitation frequency range within a predetermined range of the peak resonant frequency, and The excitation frequency range within the predetermined range of the peak resonant frequency is related to the complex impedance spectrum associated with the first transducer.

9. The system according to claim 8, characterized in that, The lower and upper limits of the predetermined range are set at least in part based on a receiving threshold, which is set as a preselected impedance value.

10. The system according to claim 1, characterized in that, Wherein, when determining the complex impedance spectrum associated with the first transducer based at least in part on fitting the model to the first dataset, the one or more processors are configured to: A first data point is generated, defined by the complex impedance and the first excitation frequency, and the complex impedance associated with the first data point is determined at least in part based on the ratio of the voltage to the current at the first transducer when excited at the first excitation frequency. A second data point is generated, defined by the complex impedance and the second excitation frequency, and the complex impedance associated with the second data point is determined at least in part based on the ratio of the voltage to the current at the first transducer when excited at the second excitation frequency. and The model is fitted to at least the first data point and the second data point.

11. The system according to claim 1, characterized in that, The one or more features mentioned therein include at least the excitation frequency and amplitude of the excitation signal guided to the second transducer.

12. The system according to claim 1, characterized in that, The characteristics of one or more first excitation signals guided to the first transducer are set in real time based at least in part on the complex impedance spectrum associated with the second transducer.

13. The system according to claim 1, characterized in that, The catheter defines an axial direction, and the system further includes: The third transducer is arranged flush with the first transducer along the axial direction; A fourth transducer is arranged flush with the second transducer along the axial direction; and The first transducer and the second transducer have the same design resonant frequency, and the third transducer and the fourth transducer have the same design resonant frequency, but the design resonant frequencies of the first transducer and the second transducer are different from the design resonant frequencies of the third transducer and the fourth transducer.

14. The system according to claim 1, characterized in that, Also includes: Third transducer; and A fourth transducer, offset from the second transducer, such that the signal path length between the third and fourth transducers is greater than the signal path length between the first and second transducers, and The first transducer and the second transducer have the same design resonant frequency, and the third transducer and the fourth transducer have the same design resonant frequency, but the design resonant frequencies of the first transducer and the second transducer are different from the design resonant frequencies of the third transducer and the fourth transducer.

15. A method, characterized in that, include: The first transducer is excited with multiple different excitation frequencies, so that the first transducer guides one or more ultrasonic signals through the medium flowing through the conduit to a second transducer spaced apart from the first transducer. Based at least in part on fitting the model to a first dataset, a complex impedance spectrum associated with the first transducer is determined, wherein for at least two of the plurality of different excitation frequencies, the first dataset indicates i) the ratio of voltage to current at the first transducer, and ii) the phase difference between the voltage and current at the first transducer when excited at a given excitation frequency of the plurality of different excitation frequencies; One or more features of one or more second excitation signals directed to the second transducer are set at least in part based on the complex impedance spectrum associated with the first transducer, wherein the one or more features are set in real time at least in part based on the complex impedance spectrum; and The second transducer is excited by one or more second excitation signals having the one or more of the aforementioned features, such that the second transducer guides one or more ultrasonic signals through the medium flowing through the conduit to the first transducer.

16. The method according to claim 15, characterized in that, Also includes: The second transducer is excited with multiple different second excitation frequencies, such that the second transducer guides one or more ultrasonic signals through the conduit to the first transducer; Based at least in part on fitting the model to a second dataset, a complex impedance spectrum associated with the second transducer is determined, wherein for at least two of the plurality of different second excitation frequencies, the second dataset indicates i) the ratio of voltage to current at the second transducer, and ii) the phase difference between the voltage and current at the second transducer when excited at a given second excitation frequency of the plurality of different second excitation frequencies; One or more characteristics of one or more first excitation signals directed to the first transducer are set, at least in part, based on the complex impedance spectrum associated with the second transducer. and The first transducer is excited by one or more first excitation signals having one or more of the aforementioned features, such that the first transducer guides one or more ultrasonic signals through the conduit to the second transducer.

17. The method according to claim 15, characterized in that, The determination of the complex impedance spectrum associated with the first transducer, based at least in part on fitting the model to the first dataset, includes: A first data point is generated, defined by the complex impedance and a first excitation frequency among the plurality of different excitation frequencies, and the complex impedance associated with the first data point is determined based at least in part on the ratio of the voltage to the current at the first transducer when excited at the first excitation frequency. A second data point is generated, defined by the complex impedance and a second excitation frequency among the plurality of different excitation frequencies, and the complex impedance associated with the second data point is determined, at least in part, based on the ratio of the voltage to the current at the first transducer when excited at the second excitation frequency; and The model is fitted to at least the first data point and the second data point.

18. The method according to claim 15, characterized in that, The determination of the complex impedance spectrum associated with the first transducer, based at least in part on fitting the model to the first dataset, includes: Determine the peak resonant frequency associated with the first transducer, the peak resonant frequency corresponding to the minimum impedance determined by fitting the model to the first dataset; and Determine the excitation frequency range within a predetermined range of the peak resonant frequency, and The excitation frequency range within the predetermined range of the peak resonant frequency is related to the complex impedance spectrum associated with the first transducer.

19. A non-transitory computer-readable medium comprising computer-executable instructions, characterized in that, When the computer-executable instructions are executed by one or more processors of the fuel flow measurement system, the one or more processors: The first transducer of the fuel flow sensor is excited at a first excitation frequency and a second excitation frequency, such that the first transducer guides one or more ultrasonic signals through the medium flowing through the duct to the second transducer of the fuel flow sensor, the second transducer being spaced apart from the first transducer, and the first excitation frequency and the second excitation frequency being different from each other. Based at least in part on fitting the model to a first dataset, a complex impedance spectrum associated with the first transducer is determined, the first dataset indicating i) the voltage-to-current ratio at the first transducer when excited at the first excitation frequency and the voltage-to-current ratio at the first transducer when excited at the second excitation frequency, and ii) the phase difference between the voltage and current at the first transducer when excited at the first excitation frequency and the phase difference between the voltage and current at the first transducer when excited at the second excitation frequency; and Based at least in part on the complex impedance spectrum associated with the first transducer, one or more characteristics of one or more second excitation signals directed to a second transducer spaced apart from the first transducer are configured. The one or more features are set in real time, at least in part, based on the complex impedance spectrum.

20. The non-transitory computer-readable medium according to claim 19, characterized in that, Wherein, when the computer-executable instructions are executed by the one or more processors of the fuel flow measurement system, the one or more processors further cause the following: The second transducer is excited at a first excitation frequency and a second excitation frequency, such that the second transducer guides one or more ultrasonic signals through the conduit to the first transducer, wherein the first excitation frequency and the second excitation frequency at which the second transducer is excited are different from each other. The complex impedance spectrum associated with the second transducer is determined, at least in part, by fitting the model to a second dataset, the second dataset indicating i) the voltage-to-current ratio at the second transducer when excited at the first excitation frequency and the voltage-to-current ratio at the second transducer when excited at the second excitation frequency, and ii) the phase difference between the voltage and current at the second transducer when excited at the first excitation frequency and the phase difference between the voltage and current at the second transducer when excited at the second excitation frequency; and One or more characteristics of one or more first excitation signals directed to the first transducer are set, at least in part, based on the complex impedance spectrum associated with the second transducer.

21. A system, characterized in that, include: First transducer; A second transducer, which is spaced apart from the first transducer; and One or more processors, said one or more processors being configured to: The first transducer is excited at one or more first excitation frequencies, such that the first transducer guides a first ultrasonic signal through the medium flowing through the conduit to the second transducer; One or more features of one or more excitation frequencies directed to the first or second transducer are set, at least in part, based on the complex impedance spectrum associated with the second or first transducer, respectively, wherein the one or more features are set in real time at least in part based on the complex impedance spectrum. At one or more of the one or more first excitation frequencies, determine the amplitude of the first ultrasonic signal at two or more points along the first crossing path of the first ultrasonic signal; By fitting an attenuation model to first data points, one or more characteristics of the medium are determined, each of the first data points being defined by: the amplitude of the first ultrasonic signal at a given point among two or more points along the first traversal path; the total distance the first ultrasonic signal has traveled through the medium to the given point among the two or more points; and the frequency among one or more first excitation frequencies that excite the first transducer; and The medium type is classified based at least in part on a comparison between one or more features of the medium and one or more baseline features.

22. The system according to claim 21, characterized in that, The two or more points along the first traversal path of the first ultrasonic signal include a first point located at the first transducer and a second point located at the second transducer.

23. The system according to claim 21, characterized in that, in: The first traversal path includes at least a first segment spanning between the first transducer and the second transducer, and a second segment spanning between the second transducer and the first transducer, wherein when the first transducer is excited, the first ultrasonic signal travels along the first segment from the first transducer to the second transducer, at least echoes from the second transducer, and travels along the second segment from the second transducer to the first transducer. The two or more points along the first crossing path of the first ultrasonic signal include a first point located at the first transducer and corresponding to the first segment of the first crossing path, a second point located at the second transducer and corresponding to the transition point between the first segment and the second segment of the first crossing path, and a third point located at the first transducer and corresponding to the second segment of the first crossing path.

24. The system according to claim 21, characterized in that, The one or more processors are further configured to: The second transducer is excited at one or more second excitation frequencies, such that the second transducer guides a second ultrasonic signal through the medium to the first transducer; and At one or more of the one or more second excitation frequencies, determine the amplitude of the second ultrasonic signal at two or more points along the second crossing path of the second ultrasonic signal, and When determining the one or more characteristics of the medium, the one or more processors are configured to fit the attenuation model to a second data point in addition to the first data point, each second data point being defined by: the amplitude of the second ultrasonic signal at a given point among the two or more points along the second crossing path, the total distance the second ultrasonic signal has traveled through the medium to the given point among the two or more points along the second crossing path, and the frequency among the one or more second excitation frequencies that excite the second transducer.

25. The system according to claim 24, characterized in that, in: The second crossing path includes at least a first segment spanning between the second transducer and the first transducer, and a second segment spanning between the first transducer and the second transducer, wherein when the second transducer is excited, the second ultrasonic signal travels along the first segment from the second transducer to the first transducer, at least echoes from the first transducer, and travels along the second segment from the first transducer to the second transducer. The two or more points along the second crossing path of the second ultrasonic signal include a first point located at the second transducer and corresponding to the first segment of the second crossing path, a second point located at the first transducer and corresponding to the transition point between the first and second segments of the second crossing path, and a third point located at the second transducer and corresponding to the second segment of the second crossing path.

26. The system according to claim 21, characterized in that, The synthesis function of the attenuation model fitted to the first data point is related to one or more characteristics of the medium.

27. The system according to claim 26, characterized in that, When classifying the medium type based at least in part on a comparison between one or more features of the medium and one or more baseline features, the one or more processors are configured to compare the synthesis function with a plurality of baseline functions, each of the baseline functions corresponding to a predetermined medium type.

28. The system according to claim 27, characterized in that, The predetermined medium type associated with the baseline function that most closely matches the synthetic function among the plurality of baseline functions is classified as the medium type of the medium flowing through the conduit.

29. The system according to claim 21, characterized in that, The one or more processors are further configured to: For each of the one or more first excitation frequencies, determine the amplitude of the first ultrasonic signal at two or more points along the first traversal path of the first ultrasonic signal, and When determining one or more characteristics of the medium by fitting the attenuation model to the first data point, the one or more processors are configured to: The attenuation model is fitted to the first data points associated with each of the one or more first excitation frequencies to provide a synthesis function associated with each of the one or more first excitation frequencies; and The collective composition function is determined, at least in part, based on each of the aforementioned composition functions, and When classifying the medium type based at least in part on a comparison between the medium's one or more features and the one or more baseline features, the one or more processors are configured to compare the collective synthesis function with a plurality of baseline functions.

30. A method, characterized in that, include: A first transducer is excited at one or more first excitation frequencies, such that the first transducer guides a first ultrasonic signal through a medium flowing through a conduit to a second transducer spaced apart from the first transducer. At one or more of the one or more first excitation frequencies, determine the amplitude of the first ultrasonic signal at two or more points along the first crossing path of the first ultrasonic signal; By fitting an attenuation model to first data points, one or more characteristics of the medium are determined, each of the first data points being defined by: the amplitude of the first ultrasonic signal at a given point among the two or more points along the first traversal path, the total distance the first ultrasonic signal has traversed the medium to the given point among the two or more points, and the frequency among the one or more first excitation frequencies that excite the first transducer. and The medium type is classified based at least in part on a comparison between one or more features of the medium and one or more baseline features.

31. The method according to claim 30, characterized in that, The two or more points along the first traversal path of the first ultrasonic signal include a first point located at the first transducer and a second point located at the second transducer.

32. The method according to claim 30, characterized in that, in: The first traversal path includes at least a first segment spanning between the first transducer and the second transducer, and a second segment spanning between the second transducer and the first transducer. When the first transducer is excited, the first ultrasonic signal travels along the first segment from the first transducer to the second transducer, echoes from the second transducer, and travels along the second segment from the second transducer to the first transducer. The two or more points along the first crossing path of the first ultrasonic signal include a first point located at the first transducer and corresponding to the first segment of the first crossing path, a second point located at the second transducer and corresponding to the transition point between the first segment and the second segment of the first crossing path, and a third point located at the first transducer and corresponding to the second segment of the first crossing path.

33. The method according to claim 30, characterized in that, Also includes: The second transducer is excited at one or more second excitation frequencies, such that the second transducer guides a second ultrasonic signal through the medium to the first transducer; and At one or more of the one or more second excitation frequencies, determine the amplitude of the second ultrasonic signal at two or more points along the second crossing path of the second ultrasonic signal, and When determining the one or more characteristics of the medium, the one or more processors are configured to fit the attenuation model to a second data point in addition to the first data point, each second data point being defined by: the amplitude of the second ultrasonic signal at a given point among the two or more points along the second crossing path, the total distance the second ultrasonic signal has traveled through the medium to the given point among the two or more points along the second crossing path, and the frequency among the one or more second excitation frequencies that excite the second transducer.

34. The method according to claim 33, characterized in that, in: The second crossing path includes at least a first segment spanning between the second transducer and the first transducer, and a second segment spanning between the first transducer and the second transducer, wherein when the second transducer is excited, the second ultrasonic signal travels along the first segment from the second transducer to the first transducer, echoes from the first transducer, and travels along the second segment from the first transducer to the second transducer. The two or more points along the second crossing path of the second ultrasonic signal include a first point located at the second transducer and corresponding to the first segment of the second crossing path, a second point located at the first transducer and corresponding to the transition point between the first and second segments of the second crossing path, and a third point located at the second transducer and corresponding to the second segment of the second crossing path.

35. The method according to claim 30, characterized in that, The synthesis function of the attenuation model fitted to the first data point is related to one or more features of the medium.

36. The method according to claim 35, characterized in that, The classification of the medium type, based at least in part on a comparison between one or more features of the medium and one or more baseline features, includes: The synthesized function is compared with a plurality of baseline functions, each baseline function corresponding to a predetermined media type.

37. The method according to claim 36, characterized in that, The predetermined medium type associated with the baseline function that most closely matches the synthetic function among the plurality of baseline functions is classified as the medium type of the medium flowing through the conduit.

38. The method according to claim 30, characterized in that, Also includes: For each of the one or more first excitation frequencies, determine the amplitude of the first ultrasonic signal at two or more points along the first traversal path of the first ultrasonic signal, and Determining one or more characteristics of the medium by fitting the attenuation model to the first data point includes: The attenuation model is fitted to the first data points associated with each of the one or more first excitation frequencies to provide a synthesis function associated with each of the one or more first excitation frequencies; and The collective composition function is determined, at least in part, based on each of the aforementioned composition functions, and When classifying the medium type based at least in part on a comparison between the medium's one or more features and the one or more baseline features, the one or more processors are configured to compare the collective synthesis function with a plurality of baseline functions.

39. A non-transitory computer-readable medium comprising computer-executable instructions, characterized in that, When the computer-executable instructions are executed by one or more processors of the fuel flow measurement system, the one or more processors: The first transducer of the fuel flow measurement system is excited at one or more first excitation frequencies, such that the first transducer guides a first ultrasonic signal through the medium flowing through the duct to the second transducer of the fuel flow measurement system. At one or more of the one or more first excitation frequencies, determine the amplitude of the first ultrasonic signal at two or more points along the first crossing path of the first ultrasonic signal; One or more features of one or more excitation signals directed to the first or second transducer are set at least in part based on the complex impedance spectrum associated with the second or first transducer, respectively, wherein the one or more features are set in real time at least in part based on the complex impedance spectrum. By fitting an attenuation model to first data points, one or more characteristics of the medium are determined, each of the first data points being defined by: the amplitude of the first ultrasonic signal at a given point among two or more points along the first traversal path; the total distance the first ultrasonic signal has traveled through the medium to the given point among the two or more points; and the frequency among one or more first excitation frequencies that excite the first transducer; and The medium type is classified based at least in part on a comparison between one or more features of the medium and one or more baseline features.

40. The non-transitory computer-readable medium according to claim 39, characterized in that, The one or more characteristics of the medium determined by fitting the attenuation model to the first data point are related to the attenuation rate of the medium.

41. A system, characterized in that, include: First transducer; A second transducer, which is spaced apart from the first transducer; and One or more processors, said one or more processors being configured to: The first transducer emits ultrasonic signals toward the second transducer through the medium flowing through the conduit; One or more features of the ultrasonic signal guided to the first or second transducer are set at least in part based on the complex impedance spectrum associated with the second or first transducer, respectively, wherein the one or more features are set in real time at least in part based on the complex impedance spectrum. Determine the time of flight of the ultrasonic signal, the time of flight indicating the time it takes for the ultrasonic signal to travel through the medium and return to the first transducer; The flight time of the ultrasonic signal is compared with a baseline flight time; and The presence of contaminants is determined, at least in part, based on a comparison between the flight time of the ultrasonic signal and the baseline flight time.

42. The system according to claim 41, characterized in that, The medium mentioned is hydrogen gas.

43. The system according to claim 41, characterized in that, The medium is jet fuel.

44. The system according to claim 41, characterized in that, The contaminant is the boiling of the medium.

45. The system according to claim 41, characterized in that, The one or more processors are further configured to: When the contaminant is detected, a response is triggered, thereby regulating one or more upstream and / or downstream systems to control the state or phase of the medium flowing through the conduit.

46. ​​The system according to claim 45, characterized in that, The one or more upstream and / or downstream systems mentioned above include one or more heat exchangers, one or more pumps, one or more fluid compression devices and / or one or more radiators and / or heat sources.

47. The system according to claim 41, characterized in that, The one or more processors are further configured to: When the contaminant is detected, a response is triggered, causing one or more upstream and / or downstream systems to maintain their current operation.

48. A method, characterized in that, include: The first transducer of the ultrasonic flow sensor transmits an ultrasonic signal to the second transducer of the ultrasonic flow sensor through the medium flowing through the duct. One or more features of the ultrasonic signal guided to the first or second transducer are set at least in part based on the complex impedance spectrum associated with the second or first transducer, respectively, wherein the one or more features are set in real time at least in part based on the complex impedance spectrum. Determine the time of flight of the ultrasonic signal, the time of flight of the ultrasonic signal indicating the time it takes for the ultrasonic signal to travel through the medium and return to the first transducer; The flight time of the ultrasonic signal is compared with a baseline flight time; and The presence of contaminants is determined, at least in part, based on a comparison between the flight time of the ultrasonic signal and the baseline flight time.

49. A non-transitory computer-readable medium comprising computer-executable instructions, characterized in that, When the computer-executable instructions are executed by one or more processors of the flow measurement system, the one or more processors: The first transducer of the ultrasonic flow sensor transmits an ultrasonic signal to the second transducer of the ultrasonic flow sensor through the medium flowing through the duct. One or more features of the ultrasonic signal guided to the first or second transducer are set at least in part based on the complex impedance spectrum associated with the second or first transducer, respectively, wherein the one or more features are set in real time at least in part based on the complex impedance spectrum. Determine the time of flight of the ultrasonic signal, the time of flight of the ultrasonic signal indicating the time it takes for the ultrasonic signal to travel through the medium and return to the first transducer; The flight time of the ultrasonic signal is compared with a baseline flight time; and The presence of contaminants is determined, at least in part, based on a comparison between the flight time of the ultrasonic signal and the baseline flight time.

50. A system, characterized in that, include: A first transducer is arranged to guide an ultrasonic signal through a medium flowing through a conduit to a second transducer. A second transducer, spaced apart from the first transducer, is arranged to guide an ultrasonic signal through the medium flowing through the conduit to the first transducer; and One or more processors, said one or more processors being configured to: The first transducer is excited at a first excitation frequency and a second excitation frequency, wherein the first excitation frequency and the second excitation frequency are different from each other; One or more features of the excitation frequency directed to the first or second transducer are set, at least in part, based on the complex impedance spectrum associated with the second or first transducer, respectively, wherein the one or more features are set in real time, at least in part, based on the complex impedance spectrum. At least in part, based on fitting a model to a first dataset, a frequency range within a predetermined range of peak resonant frequencies associated with the first transducer is determined, the first dataset indicating i) the impedance when excited at the first excitation frequency and the impedance at the first transducer when excited at the second excitation frequency, and ii) the phase difference between the voltage and current at the first transducer when excited at the first excitation frequency and the phase difference between the voltage and current at the first transducer when excited at the second excitation frequency; and One or more characteristics of one or more second excitation signals directed to the second transducer are set, at least in part, based on the frequency range associated with the first transducer.

51. A method, characterized in that, include: A first transducer of a fuel flow sensor assembly is excited at one or more first excitation frequencies, such that the first transducer directs one or more first ultrasonic signals through a medium flowing through a duct to a second transducer; One or more features of the excitation frequency directed to the first or second transducer are set, at least in part, based on the complex impedance spectrum associated with the second or first transducer, respectively, wherein the one or more features are set in real time, at least in part, based on the complex impedance spectrum. At one or more of the one or more first excitation frequencies, determine the amplitude of the one or more first ultrasonic signals received at the second transducer of the fuel flow sensor assembly and / or the amplitude of the one or more first ultrasonic signals echoing back to and received by the first transducer; and Determine one or both of the following: i) Determine a first amplitude response transfer function associated with the fuel flow sensor assembly, based at least in part on the amplitude of the one or more first ultrasonic signals received at the second transducer; and ii) Determine a third amplitude response transfer function associated with the fuel flow sensor assembly, based at least in part on the amplitude of the one or more first ultrasonic signals that echo back to and are received by the first transducer.

52. The method according to claim 51, characterized in that, in, The first transducer is located upstream of the second transducer.

53. The method according to claim 51, characterized in that, in, The second transducer is located upstream of the first transducer.

54. The method according to claim 51, characterized in that, Also includes: The excitation frequency for the first transducer is selected based at least in part on the first amplitude response transfer function and / or the third amplitude response transfer function.

55. The method according to claim 54, characterized in that, Also includes: Track the excitation frequency selected at two or more different sampling times; and The health status of the fuel flow sensor assembly is monitored, at least in part, based on the frequency of the tracked excitation.

56. The method according to claim 55, characterized in that, The health status of the fuel flow sensor assembly is determined by determining the difference between an excitation frequency sampled at one of the two or more different sampling times and another excitation frequency sampled at another of the two or more different sampling times.

57. The method according to claim 54, characterized in that, The excitation frequency is selected to maximize the signal-to-noise ratio of the fuel flow sensor assembly.

58. The method according to claim 54, characterized in that, The excitation frequency is selected to correspond to the frequency at which the fuel flow sensor assembly operates at a minimum power level but still provides a predetermined level of measurement accuracy.

59. The method according to claim 51, characterized in that, The first amplitude response transfer function models the amplitude response of one or more first ultrasonic signals at the first and second circuits of the fuel flow sensor assembly. The first circuit includes multiple electrically connected first components, including a first transducer, a first signal generator, a first driver, and a first input / output circuit of an electronic box. The second circuit includes multiple electrically connected second components, including a second transducer, a second signal generator, a second driver, and a second input / output circuit of the electronic box.

60. The method according to claim 51, characterized in that, The third amplitude response transfer function models the amplitude response of one or more first ultrasonic signals at a first circuit (but not a second circuit) of the fuel flow sensor assembly. The first circuit includes a plurality of electrically connected first components, including a first transducer, a first signal generator, a first driver, and a first input / output circuit of an electronics box. The second circuit includes a plurality of electrically connected second components, including a second transducer, a second signal generator, a second driver, and a second input / output circuit of the electronics box.

61. The method according to claim 51, characterized in that, Also includes: The first amplitude response transfer function and the third amplitude response transfer function are combined into a combined amplitude response transfer function.

62. The method according to claim 51, characterized in that, Also includes: A second transducer is excited at one or more second excitation frequencies, such that the second transducer guides one or more second ultrasonic signals through the medium flowing through the conduit; At one or more of the one or more second excitation frequencies, determine the amplitude of the one or more second ultrasonic signals received at the first transducer and / or the amplitude of the one or more second ultrasonic signals that echo back to the second transducer and are received by the second transducer. and Determine one or both of the following: i) Determine a second amplitude response transfer function associated with the fuel flow sensor assembly based at least in part on the amplitude of the one or more second ultrasonic signals received at the first transducer; and ii) Determine a fourth amplitude response transfer function associated with the fuel flow sensor assembly, based at least in part on the amplitude of the one or more second ultrasonic signals that echo back to and are received by the second transducer.

63. The method according to claim 62, characterized in that, The second amplitude response transfer function models the amplitude response of one or more second ultrasonic signals at the first and second circuits of the fuel flow sensor assembly. The first circuit includes multiple electrically connected first components, including a first transducer, a first signal generator, a first driver, and a first input / output circuit of an electronic box. The second circuit includes multiple electrically connected second components, including a second transducer, a second signal generator, a second driver, and a second input / output circuit of the electronic box.

64. The method according to claim 62, characterized in that, The fourth amplitude response transfer function models the amplitude response of the one or more second ultrasonic signals at the first circuit, but not the second circuit, of the fuel flow sensor assembly. The first circuit includes a plurality of electrically connected first components, including a first transducer, a first signal generator, a first driver, and a first input / output circuit of an electronics box. The second circuit includes a plurality of electrically connected second components, including a second transducer, a second signal generator, a second driver, and a second input / output circuit of the electronics box.

65. The method according to claim 62, characterized in that, Also includes: The second amplitude response transfer function and the fourth amplitude response transfer function are combined into a combined amplitude response transfer function.

66. The method according to claim 62, characterized in that, Also includes: The third amplitude response transfer function and the fourth amplitude response transfer function are combined into a combined amplitude response transfer function.

67. The method according to claim 62, characterized in that, Also includes: The first amplitude response transfer function and the second amplitude response transfer function are combined into a combined amplitude response transfer function.

68. The method according to claim 62, characterized in that, Also includes: The first amplitude response transfer function, the second amplitude response transfer function, and at least one of the third amplitude response transfer function and the fourth amplitude response transfer function are combined to form a combined amplitude response transfer function.

69. A fuel flow sensor assembly, characterized in that, include: First transducer; A second transducer, which is spaced apart from the first transducer; and One or more processors, said one or more processors being configured to: The first transducer is excited at one or more first excitation frequencies, such that the first transducer guides one or more first ultrasonic signals through the medium flowing through the conduit to the second transducer; One or more features of one or more excitation frequencies directed to the first or second transducer are set, at least in part, based on the complex impedance spectrum associated with the second or first transducer, respectively, wherein the one or more features are set in real time at least in part based on the complex impedance spectrum. At one or more of the one or more first excitation frequencies, determine the amplitude of the one or more first ultrasonic signals received at the second transducer and / or the amplitude of the one or more first ultrasonic signals echoing back to the first transducer and received by the first transducer; and Determine one or both of the following: i) Determine a first amplitude response transfer function associated with the fuel flow sensor assembly, based at least in part on the amplitude of the one or more first ultrasonic signals received at the second transducer; and ii) Determine a third amplitude response transfer function associated with the fuel flow sensor assembly, based at least in part on the amplitude of the one or more first ultrasonic signals that echo back to and are received by the first transducer.

70. A non-transitory computer-readable medium comprising computer-executable instructions, characterized in that, When the computer-executable instructions are executed by one or more processors of the fuel flow sensor assembly, the one or more processors cause the following: The first transducer of the fuel flow sensor assembly is excited at one or more first excitation frequencies, such that the first transducer guides one or more first ultrasonic signals through the medium flowing through the duct to the second transducer. One or more features of one or more excitation frequencies directed to the first or second transducer are set, at least in part, based on the complex impedance spectrum associated with the second or first transducer, respectively, wherein the one or more features are set in real time at least in part based on the complex impedance spectrum. At one or more of the one or more first excitation frequencies, determine the amplitude of the one or more first ultrasonic signals received at the second transducer and / or the amplitude of the one or more first ultrasonic signals echoing back to and received by the first transducer; and Determine one or both of the following: i) Determine a first amplitude response transfer function associated with the fuel flow sensor assembly, based at least in part on the amplitude of the one or more first ultrasonic signals received at the second transducer; and ii) Determine a third amplitude response transfer function associated with the fuel flow sensor assembly, based at least in part on the amplitude of the one or more first ultrasonic signals that echo back to and are received by the first transducer.

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