Multi-frequency ultrasonic liquid level instrument, liquid level determination method, medium and equipment
The frequency switching of the multi-frequency ultrasonic liquid level meter solves the problem of measurement failure of traditional ultrasonic liquid level meters in situations where the viscosity and density of liquids vary greatly, and realizes liquid level measurement with a wider range and higher accuracy.
Patent Information
- Application Number
- CN202510959436.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-11
- Publication Date
- 2025-09-30
AI Technical Summary
Traditional ultrasonic level meters can only emit fixed-frequency ultrasonic waves and cannot adapt to situations where the viscosity and density of liquids vary greatly, resulting in measurement failure or low accuracy.
A multi-frequency ultrasonic level meter is designed, which includes a disc and a ring piezoelectric chip. Each chip has multiple preset operating frequencies and can switch frequencies during the measurement process to adapt to the attenuation characteristics of the liquid, thereby improving the measurement accuracy and range.
The measurement range is widened, the measurement accuracy is improved, and it can stably measure the liquid level under different liquid conditions, reduce blind spots, and adapt to changes in viscosity and density of different liquids.
Smart Images
Figure CN120721187A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of ultrasonic liquid level meters, and in particular to a multi-frequency ultrasonic liquid level meter, a liquid level determination method, a medium, and a device. Background Art
[0002] In some industrial scenarios, such as oil storage tanks, chemical containers, pharmaceutical reactors, water treatment, and food storage tanks, ultrasonic level meters are often installed in openings above tanks and containers to measure the liquid level. Ultrasonic level meters transmit ultrasonic waves through the air toward the liquid surface below. The ultrasonic waves, traveling downward, bounce off the liquid surface, change direction, and fly upward, where they are received by the level meter. By calculating the flight time of the ultrasonic waves in the air, the liquid level information can be obtained. However, because these level meters, which transmit and receive ultrasonic waves in the air, require installation in an opening above the container, the installation process is cumbersome and prone to the introduction of impurities and contamination. They are not suitable for applications where liquids must be kept clean and hygienic, such as pharmaceutical equipment, medical devices, and food and beverage containers.
[0003] In other scenarios, the liquid level meter can be installed on the outside of the bottom of the container, and ultrasonic waves can be emitted upward through the container wall. The sound waves propagate upward in the liquid, rebound at the highest point of the liquid surface, change direction and propagate downward, and are received by the liquid level meter. By calculating the flight time of the ultrasonic wave in the liquid, the height information of the liquid level can be obtained. However, in some applications, such as protein-containing culture medium in biopharmaceutical containers, or different types of juices and syrups used to prepare drinks in juicers, the viscosity and density of these liquids often vary greatly, and the degree of attenuation of ultrasonic waves of different frequencies also varies greatly.
[0004] Traditional ultrasonic level meters, which transmit from the bottom, operate in a single mode and can only emit ultrasonic waves of a fixed frequency. If the ultrasonic transducer frequency is selected to be higher, its wavelength is shorter, its resolution is higher, and its blind spot is smaller. However, if the liquid has a high attenuation rate, high-frequency ultrasonic waves will decay quickly and cannot reach higher liquid levels, resulting in a smaller measuring range. If the ultrasonic transducer frequency is selected to be lower, its wavelength is longer, its resolution is lower, and its blind spot is larger. However, if the liquid has a high attenuation rate, low-frequency ultrasonic waves will decay more slowly, allowing them to reach higher liquid levels and extending the measuring range. If the liquid level changes, the frequency cannot be adjusted, potentially leading to measurement failure. Summary of the Invention
[0005] The technical problem to be solved by this application is: how to enable an ultrasonic liquid level meter to emit ultrasonic waves of multiple frequencies.
[0006] In response to the above technical problems, according to a first aspect of the present application, a multi-frequency ultrasonic liquid level meter is provided, wherein the multi-frequency ultrasonic liquid level meter is disposed on the outer bottom of a container containing a liquid to be measured; the multi-frequency ultrasonic liquid level meter includes at least one piezoelectric chip; the piezoelectric chip is a disk piezoelectric chip or a ring piezoelectric chip; wherein each of the piezoelectric chips has at least two corresponding preset operating frequencies; the at least two preset operating frequencies include at least one frequency corresponding to a preset radial operating mode and at least one frequency corresponding to a preset axial operating mode; The piezoelectric chip is used to send ultrasonic signals to the liquid to be measured and / or receive ultrasonic signals returned from the liquid to be measured.
[0007] According to a second aspect of the present application, a method for determining a liquid level based on a multi-frequency ultrasonic liquid level meter is provided, the method comprising: S100, obtain each preset working frequency corresponding to the multi-frequency ultrasonic level meter and sort them in descending order to obtain a preset working frequency list PL = (PL1, PL2, ..., PL i ,…,PL n ); i = 1, 2, ..., n; n is the number of preset working frequencies corresponding to the multi-frequency ultrasonic level meter; PL i The i-th preset operating frequency corresponding to the multi-frequency ultrasonic level meter after sorting in descending order; S200, according to PL, send ultrasonic signals to the liquid to be tested in sequence until PL is determined i is the target operating frequency; wherein the target operating frequency is a preset operating frequency at which, after sending an ultrasonic signal to the liquid to be tested, a returned ultrasonic signal can be received, and the amplitude of the returned ultrasonic signal is greater than a preset signal amplitude threshold; S300, sending an ultrasonic signal at a target operating frequency to the liquid to be measured at a preset time interval to obtain the liquid level of the liquid to be measured; S400: If the returned ultrasonic signal cannot be determined after the ultrasonic signal is sent, and the liquid level of the liquid to be measured decreases, then obtain the key operating frequency list GL = (PL i-1 ,…,PL a ,…,PL2,PL1);a=1,2,…,i-1; S500, according to GL, send ultrasonic signals to the liquid to be tested in sequence until PL is determined a is the updated target operating frequency, and the process jumps to step S300.
[0008] According to the third aspect of the present application, a non-transitory computer-readable storage medium is provided, in which at least one instruction or at least one program is stored, and the at least one instruction or at least one program is loaded and executed by a processor to implement the above-mentioned liquid level determination method based on a multi-frequency ultrasonic liquid level meter.
[0009] According to a fourth aspect of the present application, an electronic device is provided, comprising a processor and the above-mentioned non-transitory computer-readable storage medium.
[0010] This application has at least the following beneficial effects: The multi-frequency ultrasonic level meter provided by the present application is arranged on the outer bottom of a container containing the liquid to be measured. The multi-frequency ultrasonic level meter includes at least one piezoelectric chip; the piezoelectric chip is a disk piezoelectric chip or a ring piezoelectric chip; wherein each piezoelectric chip has at least two corresponding preset operating frequencies; the at least two preset operating frequencies include at least one frequency corresponding to a preset radial operating mode and at least one frequency corresponding to a preset axial operating mode. The multi-frequency ultrasonic level meter provided by the present application has more than one operating frequency and can adjust the operating frequency according to actual conditions during the measurement process. When the attenuation rate of the liquid is low, that is, the sound wave attenuation is also small, the system can switch to a higher ultrasonic frequency to obtain higher liquid level resolution and smaller blind spots. When the attenuation rate of the liquid is high, the high-frequency ultrasonic signal decays quickly. When the liquid level is high, the rebound signal strength is reduced, resulting in an inability to measure. At this time, the system operating mode can be switched to emit a lower frequency ultrasonic wave to increase its penetration ability, enabling it to measure higher liquid levels. This broadens the measurement range of the ultrasonic level meter and improves the measurement accuracy of the ultrasonic level meter. BRIEF DESCRIPTION OF THE DRAWINGS
[0011] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.
[0012] Figure 1 A schematic diagram of the structure of a multi-frequency ultrasonic liquid level meter provided in one embodiment of the present application; Figure 2 A schematic diagram of a piezoelectric disc wafer in a multi-frequency ultrasonic liquid level meter provided in one embodiment of the present application; Figure 3 A schematic diagram of a circular piezoelectric chip in a multi-frequency ultrasonic liquid level meter provided in one embodiment of the present application; Figure 4 A schematic diagram of the resonance points of a disc piezoelectric chip at different frequencies in a multi-frequency ultrasonic liquid level meter provided in one embodiment of the present application; Figure 5 A schematic diagram of a finite element simulation of an ultrasonic signal emitted by a circular piezoelectric chip at a 1 MHz operating frequency in a multi-frequency ultrasonic level meter provided in one embodiment of the present application; Figure 6 A schematic diagram of a finite element simulation of an ultrasonic signal emitted by a circular piezoelectric chip in a multi-frequency ultrasonic liquid level meter provided in one embodiment of the present application at an operating frequency of 200 kHz; Figure 7 A schematic structural diagram of a multi-frequency ultrasonic liquid level meter provided in another embodiment of the present application; Figure 8 A flow chart of a liquid level determination method provided in one embodiment of the present application. DETAILED DESCRIPTION
[0013] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without making creative efforts are within the scope of protection of this application.
[0014] One embodiment of the present application provides a multi-frequency ultrasonic liquid level meter, which is disposed on the outer bottom of a container containing a liquid to be measured; the multi-frequency ultrasonic liquid level meter includes at least one piezoelectric chip; the piezoelectric chip is a disk piezoelectric chip or a ring piezoelectric chip; wherein each of the piezoelectric chips has at least two corresponding preset operating frequencies; the at least two preset operating frequencies include at least one frequency corresponding to a preset radial operating mode and at least one frequency corresponding to a preset axial operating mode; The piezoelectric chip is used to send ultrasonic signals to the liquid to be measured and / or receive ultrasonic signals returned from the liquid to be measured.
[0015] The multi-frequency ultrasonic level meter provided by the present application has more than one operating frequency, and the operating frequency can be adjusted according to the actual situation during the measurement process. The attenuation rate of the liquid is low, that is, the attenuation of the sound wave is also small. The system can switch to a higher ultrasonic frequency to obtain a higher liquid level resolution and a smaller blind area; when the attenuation rate of the liquid is high, the high-frequency ultrasonic signal decays quickly. When the liquid level is high, the rebound signal intensity decreases, resulting in an inability to measure. At this time, the system working mode can be switched to increase its penetration ability by emitting lower-frequency ultrasonic waves, so that it can measure higher liquid levels. The measurement range of the ultrasonic level meter is broadened and the measurement accuracy of the ultrasonic level meter is improved.
[0016] like Figure 1As shown, a multi-frequency ultrasonic liquid level meter is provided according to an embodiment of the present application, and the multi-frequency ultrasonic liquid level meter includes a disk piezoelectric chip and a ring piezoelectric chip; wherein the thickness of the disk piezoelectric chip is the same as the thickness of the ring piezoelectric chip; the disk piezoelectric chip is nested in the ring piezoelectric chip; and there is a uniform gap between the inner wall of the ring piezoelectric chip and the outer wall of the disk piezoelectric chip; the disk piezoelectric chip has at least two corresponding preset operating frequencies; the ring piezoelectric chip has at least two corresponding preset operating frequencies; the number of the preset operating frequencies of the disk piezoelectric chip is the same as the number of the preset operating frequencies of the ring piezoelectric chip, and the disk piezoelectric chip has a preset operating frequency that is the same as any preset operating frequency of the ring piezoelectric chip; The disc piezoelectric chip is used to send ultrasonic signals to the liquid to be measured and / or receive ultrasonic signals returned from the liquid to be measured; The annular piezoelectric chip is used to send ultrasonic signals to the liquid to be tested and / or receive ultrasonic signals returned from the liquid to be tested; wherein, when one of the disc piezoelectric chip and the annular piezoelectric chip serves as an ultrasonic transmitter, the other serves as an ultrasonic receiver.
[0017] Specifically, the disc piezoelectric chip is in the shape of a round cake, such as Figure 2 As shown, it has a certain thickness, which can be used as an ultrasonic generator and an ultrasonic receiver alone. The annular piezoelectric chip is annular, as shown in FIG. Figure 3 As shown, it has a certain thickness and can also function independently as an ultrasonic generator and ultrasonic receiver. In this embodiment, when one of the disc piezoelectric wafer and the ring piezoelectric wafer functions as an ultrasonic transmitter, the other functions as an ultrasonic receiver. That is, if the disc piezoelectric wafer functions as an ultrasonic transmitter, the ring piezoelectric wafer functions as an ultrasonic receiver; conversely, if the ring piezoelectric wafer functions as an ultrasonic transmitter, the disc piezoelectric wafer functions as an ultrasonic receiver.
[0018] In one embodiment, the disc piezoelectric chip is nested in the ring piezoelectric chip, and the thickness of the disc piezoelectric chip is the same as that of the ring piezoelectric chip, that is, the two are combined together to form an ultrasonic liquid level meter, and the disc piezoelectric chip has at least two corresponding preset working frequencies, and the ring piezoelectric chip also has at least two corresponding preset working frequencies, and each preset working frequency of the ring piezoelectric chip is equal to each preset working frequency of the disc piezoelectric chip. The at least two preset working frequencies include at least one frequency corresponding to a preset radial working mode and at least one frequency corresponding to a preset axial working mode. That is, in this embodiment, the preset working frequencies of the two are exactly the same. As an example: the diameter of the disc piezoelectric chip is 12 mm and the thickness is 2 mm; the outer diameter of the ring piezoelectric chip is 25 mm, the inner diameter is 13 mm, and the thickness is 2 mm.
[0019] Furthermore, the disk piezoelectric chip has corresponding at least two preset operating frequencies, such as Figure 4 As shown in the figure, the two circles represent its resonant points at different frequencies. The resonant frequency of the disc piezoelectric chip at the first circle is approximately 200 kHz, which is the radial (diameter direction) operating mode of the disc piezoelectric chip. The resonant frequency of the second circle is approximately 1 MHz, which is the axial (thickness direction) operating mode of the disc piezoelectric chip. Using this disc piezoelectric chip to make a piezoelectric transducer can generate strong acoustic wave signals at both the 200 kHz and 1 MHz resonant frequencies and transmit them into the liquid. In other words, the disc piezoelectric chip has two preset operating frequencies, 200 kHz and 1 MHz.
[0020] Similarly, the annular piezoelectric chip has the same operating frequency as the annular piezoelectric chip. Figure 5 As shown in the figure, it is an ultrasonic signal emitted by a circular piezoelectric chip at a working frequency of 1 MHz based on finite element simulation. It can be seen that the frequency of the ultrasonic signal is higher and the wavelength is correspondingly shorter. Figure 6 The figure shows the ultrasonic signal emitted by a toroidal piezoelectric chip at a 200 kHz operating frequency based on finite element simulation. It can be seen that the ultrasonic signal has a lower frequency and a correspondingly longer wavelength. Red represents positive pressure, and blue represents negative pressure.
[0021] It should be noted that there is a uniform gap between the inner wall of the annular piezoelectric wafer and the outer wall of the disc piezoelectric wafer, and the two are not in direct contact. Because in this embodiment, one is used to transmit ultrasonic waves and the other is used to receive ultrasonic waves, the uniform gap between the two is used to isolate vibrations.
[0022] The multi-frequency ultrasonic liquid level meter in this embodiment is obtained by nesting a disc piezoelectric chip in a ring piezoelectric chip, and there is a gap between the two. When one of them serves as an ultrasonic signal transmitter, it will generate vibration to generate an ultrasonic signal and return to calm after the vibration continues for a period of time. During the vibration process, the return signal cannot be received. This is also the reason why the blind spot is large when the disc piezoelectric chip or the disc piezoelectric chip serves as an ultrasonic transmitter and ultrasonic receiver alone; in this embodiment, when one of them serves as an ultrasonic signal transmitter, the other is used as an ultrasonic receiver. Since the component serving as the receiver does not vibrate and there is a gap between it and the vibrating sender, the vibration will be isolated; therefore, using it as the receiver can further reduce the blind spot.
[0023] It's important to note that when a piezoelectric ring or disk emits an ultrasonic signal, its vibration persists for a period of time. During this time, the voltage signal generated by its vibration cannot be effectively distinguished from the voltage signal generated by the ultrasonic reflection wave. The corresponding liquid level during this period (i.e., from the bottom of the container to a certain level) cannot be measured using ultrasonic echoes. This area where the liquid level cannot be measured is called a blind zone.
[0024] In an exemplary embodiment of the present application, the area of the annular surface of the annular piezoelectric chip is larger than the area of the circular surface of the disc piezoelectric chip; then the annular piezoelectric chip serves as an ultrasonic transmitter, and the disc piezoelectric chip serves as an ultrasonic receiver.
[0025] Specifically, the area of the annular surface of the annular piezoelectric chip is larger than the area of the circular surface of the disc piezoelectric chip. Using the annular piezoelectric chip as the ultrasonic transmitter, the ultrasonic sound field generated is strong and the energy beam is more concentrated, which is conducive to the propagation of ultrasonic signals.
[0026] In an exemplary embodiment of the present application, a material of a preset material is filled in the gap between the inner wall of the annular piezoelectric chip and the outer wall of the disc piezoelectric chip; wherein the material of the preset material is used to absorb the energy of the ultrasonic signal.
[0027] Specifically, the gap between the inner wall of the annular piezoelectric wafer and the outer wall of the disc piezoelectric wafer is filled with a predetermined material. Compared to isolation by air alone, this material is more capable of absorbing the energy generated by vibrations, providing more complete isolation and further reducing blind spots.
[0028] In an exemplary embodiment of the present application, the multi-frequency ultrasonic liquid level meter includes at least two annular piezoelectric chips; and at least two annular piezoelectric chips are nested together; there is a uniform gap between any two adjacent annular piezoelectric chips; and the operating frequencies corresponding to any two annular piezoelectric chips are completely different; each of the annular piezoelectric chips is used to send ultrasonic waves emitted by itself to the liquid to be measured and receive ultrasonic waves returned from the liquid to be measured.
[0029] Specifically, in this embodiment, multiple rings are nested together, such as Figure 7 As shown, there is a uniform gap between adjacent annular piezoelectric chips; and each annular piezoelectric chip sends and receives ultrasonic signals by itself, that is, each annular piezoelectric chip can act as a piezoelectric transducer, and the working frequencies corresponding to any two annular piezoelectric chips are completely different, that is, the multi-frequency ultrasonic liquid level meter contains multiple annular piezoelectric chips with different working frequencies, so that the final combination can obtain an ultrasonic liquid level meter with a large number of working frequencies and continuously adjustable working modes within a certain range.
[0030] like Figure 8 As shown, this application provides a method for determining liquid level based on the multi-frequency ultrasonic liquid level meter, the method comprising: S100, obtain each preset working frequency corresponding to the multi-frequency ultrasonic level meter and sort them in descending order to obtain a preset working frequency list PL = (PL1, PL2, ..., PL i ,…,PL n); i = 1, 2, ..., n; n is the number of preset working frequencies corresponding to the multi-frequency ultrasonic level meter; PL i The i-th preset operating frequency corresponding to the multi-frequency ultrasonic level meter after sorting in descending order.
[0031] Specifically, each preset operating frequency corresponding to the multi-frequency ultrasonic level meter is obtained, and the frequencies are sorted from high to low.
[0032] S200, according to PL, send ultrasonic signals to the liquid to be tested in sequence until PL is determined i is the target operating frequency; wherein, the target operating frequency is a preset operating frequency at which an ultrasonic signal can be received after an ultrasonic signal is sent to the liquid to be tested, and the amplitude of the returned ultrasonic signal is greater than a preset signal amplitude threshold.
[0033] Specifically, starting from PL1, in the order of the preset working frequencies in PL, ultrasonic signals are sent to the liquid to be tested at each preset working frequency in PL in turn until PL is determined. i is the target operating frequency. For the same liquid, with the same attenuation rate, a higher operating frequency results in higher resolution and accuracy, a smaller blind spot, and faster attenuation during propagation within the liquid, resulting in a smaller measuring range. Therefore, if the current liquid level is high, the higher the operating frequency, the faster the attenuation during propagation, and the less likely it is that the returned ultrasonic signal will be received. The target operating frequency is determined by sorting each preset operating frequency corresponding to the multi-frequency ultrasonic level meter from high to low and sending ultrasonic signals to the liquid to be measured. This target operating frequency is the highest operating frequency at which the multi-frequency ultrasonic level meter can receive a returned ultrasonic signal. This target operating frequency is the highest operating frequency at which the returned ultrasonic signal can be received (i.e., the liquid level can be measured) at the current liquid level. This ensures that the liquid level can be measured while maximizing measurement accuracy.
[0034] S300 , sending an ultrasonic signal to the liquid to be measured at a target operating frequency at every preset time interval to obtain the liquid level of the liquid to be measured.
[0035] S400: If the returned ultrasonic signal cannot be determined after the ultrasonic signal is sent, and the liquid level of the liquid to be measured decreases, then obtain the key operating frequency list GL = (PL i-1 ,…,PL a ,…,PL2,PL1);a=1,2,…,i-1.
[0036] S500, according to GL, send ultrasonic signals to the liquid to be tested in sequence until PL is determined a is the updated target operating frequency, and the process jumps to step S300.
[0037] Specifically, if the returned ultrasonic signal cannot be determined after the ultrasonic signal is sent, it means that the current liquid level may be within the blind spot. At this time, the signal reflected from the liquid surface during this period is mixed with the vibration signal caused by the transmission and cannot be distinguished, so the liquid level cannot be accurately calculated. If the liquid level of the liquid to be measured decreases at this time, the operating frequency should be increased. This is because the higher the frequency, the smaller the blind spot. Therefore, in order to ensure higher measurement accuracy, this embodiment obtains a list of key operating frequencies. The key operating frequency list starts from the operating frequency adjacent to the target operating frequency and less than the target operating frequency, and is sent to the liquid to be measured in the order of the operating frequencies in the list from small to large. The updated target operating frequency determined, under the current liquid level, not only ensures that the liquid level can be measured, but also maximizes the measurement accuracy and ensures smaller attenuation.
[0038] It can be understood that the above solution can achieve continuous measurement.
[0039] In this embodiment, when the target operating frequency is initially determined, starting from PL1, ultrasonic signals are sent to the liquid to be tested at each preset operating frequency in PL in sequence until PL is determined. i is the target operating frequency. For the same liquid, that is, with the same attenuation rate, the higher the operating frequency, the higher the resolution and accuracy, and the smaller the corresponding blind spot. During propagation in the liquid, the attenuation is faster, resulting in a smaller corresponding measuring range. Therefore, if the current liquid level is high, the higher the operating frequency, the faster the attenuation during propagation, and the more likely it is that the returned ultrasonic signal will not be received. By sorting each preset operating frequency corresponding to the multi-frequency ultrasonic level meter from high to low and sending ultrasonic signals to the liquid to be measured in sequence, the target operating frequency determined is the highest operating frequency corresponding to the multi-frequency ultrasonic level meter that can receive a returned ultrasonic signal. In other words, this target operating frequency is the highest operating frequency that can receive a returned ultrasonic signal (i.e., measure the liquid level) at the current liquid level. This ensures that the liquid level can be measured while maximizing measurement accuracy. If the liquid level of the liquid to be measured decreases, the operating frequency should be increased. Starting from the operating frequency adjacent to the current target operating frequency and lower than the target operating frequency, the operating frequencies are sent in the order of the list from small to large. The updated target operating frequency is determined to be below the current liquid level, which not only ensures that the liquid level can be measured, but also maximizes the measurement accuracy.
[0040] In an exemplary embodiment of the present application, after step S300, the method further includes: S600: If no return ultrasonic signal is received after the ultrasonic signal is sent, and the liquid level of the liquid to be measured rises, then obtain the intermediate operating frequency list ZL=(PL i＋1 ,…,PLb ,…,PL n ); b=i+1,i+2,…,n.
[0041] S700, according to ZL, send ultrasonic signals to the liquid to be tested in sequence until PL is determined b is the updated target operating frequency, and the process jumps to step S300.
[0042] In this embodiment, if the ultrasonic signal sent cannot be received when the liquid level of the liquid to be measured rises and the returned ultrasonic signal is not received, it may be that the signal is attenuated too much, resulting in the inability to be received. At this time, since the lower the frequency, the smaller the attenuation, the operating frequency is lowered. At the same time, in order to ensure higher measurement accuracy, a list of intermediate operating frequencies is obtained. The intermediate operating frequency list starts from the operating frequency adjacent to the target operating frequency and greater than the target operating frequency, and is sent to the liquid to be measured in the order of the operating frequencies in the list from large to small. The determined updated target operating frequency, under the current liquid level, not only ensures that the liquid level can be measured, but also maximizes the measurement accuracy.
[0043] It can be understood that the above solution can achieve continuous measurement.
[0044] In an exemplary embodiment of the present application, after step S300, the method further includes: S800: If the returned ultrasonic signal cannot be determined after the ultrasonic signal is sent, and the liquid level of the liquid to be measured decreases, PL1 is determined as the target operating frequency, and the process jumps to step S300.
[0045] In this embodiment, if the liquid level of the liquid to be measured decreases, the operating frequency should be increased. In order to save time, the highest operating frequency is directly used as the target operating frequency.
[0046] In an exemplary embodiment of the present application, the decrease or increase in the liquid level of the liquid to be measured is determined according to the following steps: S410, obtaining the signal strength of the ultrasonic signal returned each time the ultrasonic signal is sent to the liquid to be tested before the target operating frequency receives the returned ultrasonic signal, so as to obtain a signal strength list QL = (QL1, QL2, ..., QL x ,…,QL y ); x = 1, 2, ..., y; where y is the number of ultrasonic signals received by the target operating frequency before the return ultrasonic signal is not received; QL x TQL is the signal strength of the ultrasonic signal received for the xth time before the returned ultrasonic signal is received; x+1 Later than TQL x ;TQL x QL x Corresponding signal sending time; TQLx+1 QL x+1 The corresponding signal sending time.
[0047] Specifically, if the currently determined target operating frequency cannot receive the returned ultrasonic signal, the signal strength of the ultrasonic signal returned each time the ultrasonic signal is sent to the liquid to be tested before the returned ultrasonic signal is no longer received is obtained to obtain the signal strength list QL. Here, it should be noted that for the same liquid, the higher the liquid level, the more the ultrasonic wave is attenuated, and the lower the signal strength of the returned ultrasonic signal; conversely, the lower the liquid level, the less the ultrasonic wave is attenuated, and the higher the signal strength of the returned ultrasonic signal.
[0048] S420, if QL x+1 >QL x , then determine the liquid level of the liquid to be measured is at TQL x To TQL x+1 is in a declining state during the period of time; if QL x+1 =QL x , then determine the liquid level of the liquid to be measured is at TQL x To TQL x+1 is in a stable state during the period of time; if QL x+1 <QL x , then determine the liquid level of the liquid to be measured is at TQL x To TQL x+1 is in an elevated state during the period.
[0049] Specifically, QL x It is in QL x+1 The returned ultrasonic signal received previously, if QL x+1 >QL x , it means that the signal strength of the returned ultrasonic wave has increased, which means that the liquid level has decreased. On the contrary, if QL x+1 <QL x , it means that the signal strength of the returned ultrasonic wave has become lower, which means that the liquid level has increased. x+1 =QL x , then determine the liquid level of the liquid to be measured is at TQL x To TQL x+1 The liquid level remains stable during the period of time, and the liquid level basically does not change.
[0050] This embodiment determines the rise or fall of the liquid level by acquiring the change in the intensity of the returned ultrasonic signal, which is simpler and more efficient.
[0051] In an exemplary embodiment of the present application, the decrease or increase in the liquid level of the liquid to be measured is further determined according to the following steps: S430, obtaining the signal propagation time obtained by sending an ultrasonic signal to the liquid to be tested each time before receiving the returned ultrasonic signal at the target operating frequency, so as to obtain a propagation time list SL = (SL1, SL2, ..., SL x ,…,SL y );;SL x RQL is the signal propagation time of the xth ultrasonic signal received before the return ultrasonic signal is received; x+1 Later than RQL x ;RQL x For SL x Corresponding signal sending time; RQL x+1 For SL x+1 The corresponding signal sending time.
[0052] S440, if SL x+1 >SL x , then determine the liquid level of the liquid to be measured is at TQL x To TQL x+1 In the period of time is in an increasing state; if SL x+1 =SL x , make sure the liquid level to be measured is at TQL x To TQL x+1 is in a stable state during the period of time; if SL x+1 <SL x , then determine the liquid level of the liquid to be measured is at TQL x To TQL x+1 is in a declining state during the period.
[0053] In this embodiment, it should be noted that the signal propagation duration is the time between the emission and reception of the ultrasonic signal. For the same liquid and the same frequency, a longer signal propagation duration corresponds to a higher liquid level, while a shorter signal propagation duration corresponds to a lower liquid level. Therefore, determining liquid level changes based on signal propagation duration is simpler and more efficient.
[0054] In an exemplary embodiment of the present application, after step S430, the method further includes: S450, if QL x+1 >QL x , and SL x+1 <SL x , then determine the liquid level of the liquid to be measured is at TQL x To TQL x+1 is in a declining state during the period of time; if QL x+1 =QL x , and SL x+1 =SL x, make sure the liquid level to be measured is at TQL x To TQL x+1 is in a stable state during the period of time; if QL x+1 <QL x , and SL x+1 >SL x , then determine the liquid level of the liquid to be measured is at TQL x To TQL x+1 is in an elevated state during the period.
[0055] In this embodiment, in order to improve the accuracy of the judgment of the rise and fall of the liquid level, the signal strength and the signal propagation time are simultaneously used to determine the rise and fall of the liquid level.
[0056] In an exemplary embodiment of the present application, the multi-frequency ultrasonic level meter can also be used to determine the liquid type of the liquid to be measured among several known preset liquid types. The specific steps are as follows: Sa1, obtain the ultrasonic signal attenuation rate list SL=(SL1, SL2, ..., SL i ,…,SL n ); i = 1, 2, ..., n; where n is the number of preset operating frequencies corresponding to the ultrasonic level meter; SL i is the ultrasonic signal attenuation rate obtained after the ultrasonic liquid level meter sends an ultrasonic signal to the liquid to be measured at the i-th preset operating frequency sorted in a preset order; the liquid type of the liquid to be measured is one of several preset liquid types; the viscosity coefficient and / or density of any two preset liquid types are different; the ultrasonic signal attenuation rate corresponding to the liquid to be measured is proportional to the difference in ultrasonic signal intensity.
[0057] Specifically, the ultrasonic signal attenuation rate indicates the degree of attenuation of ultrasonic waves during liquid propagation. The greater the ultrasonic signal attenuation rate, the more the ultrasonic wave attenuates during liquid propagation. Conversely, the smaller the ultrasonic signal attenuation rate, the less the ultrasonic wave attenuates during liquid propagation. The attenuation of ultrasonic waves during liquid propagation is mainly caused by the absorption of sound waves by the medium, which is related to the viscosity and density of the liquid. For two preset liquid types with the same liquid level, ultrasonic waves are sent to them at the same operating frequency. Due to their different viscosity and / or density, the attenuation rates of the returned ultrasonic waves are different. Here, the ultrasonic signal attenuation rate is proportional to the ultrasonic signal intensity difference. The ultrasonic signal intensity difference is the difference between the signal intensity of the emitted ultrasonic signal and the signal intensity of the returned ultrasonic signal.
[0058] SL i Meet the following conditions: SL i =(I 0，i -I i ) / I0，i Among them, I 0，i is the initial signal strength of the ultrasonic level meter corresponding to the i-th preset working frequency; I i is the return signal strength of the ultrasonic level meter corresponding to the i-th preset operating frequency.
[0059] Since the liquid to be measured is an unknown liquid, its viscosity coefficient and density are unknown. Therefore, in this embodiment, the ultrasonic signal attenuation rate corresponding to each preset operating frequency is obtained.
[0060] Sa2, according to SL, obtain the liquid level GD and attenuation rate change curve QX corresponding to the liquid to be tested.
[0061] Specifically, the ultrasonic level meter is used to transmit ultrasonic waves to the liquid to be measured at different preset working frequencies to obtain the liquid level GD corresponding to the liquid to be measured. The specific method for determining the liquid level is: Sa21, according to SL, get the key operating frequency list GYL=(GYL1, GYL2, ..., GYL x ,…,GYL y ); x = 1, 2, ..., y; where y is the number of key operating frequencies; GYL x is the xth key operating frequency; the key operating frequency is the preset operating frequency at which the signal strength of the returned ultrasonic signal is not 0; each key operating frequency has a corresponding liquid level height.
[0062] Sa22, determine the liquid level height corresponding to MAX (GYL) as the liquid level height GD corresponding to the liquid to be tested; wherein MAX () is a preset maximum value determination function.
[0063] In this embodiment, each preset operating frequency at which the signal strength of the returned ultrasonic signal is not 0 is obtained, wherein the signal strength of the returned ultrasonic signal is not 0, that is, the preset operating frequency can measure the liquid level height of the liquid to be measured, and since the higher the operating frequency, the higher the resolution and the higher the accuracy, the liquid level height corresponding to the maximum critical operating frequency is determined as the liquid level height GD corresponding to the liquid to be measured, which has the highest accuracy.
[0064] Furthermore, the curve obtained by connecting the attenuation rates of each ultrasonic signal in SL is smoothed to obtain the attenuation rate variation curve QX.
[0065] Sa3, according to the preset liquid level range and QX to which GD belongs, determines the target liquid type corresponding to the liquid to be tested; wherein, there are several preset liquid level ranges, and within each preset liquid level range, each preset liquid type has a corresponding preset attenuation rate change curve; the preset attenuation rate change curve is obtained by sending ultrasonic signals to the liquid of the preset liquid type in the preset order of the preset working frequency corresponding to SL according to the corresponding preset liquid type. The preset attenuation rate change curve corresponding to each preset liquid is different in different preset liquid level ranges; the target liquid type is the preset liquid type corresponding to the preset attenuation rate change curve that is most similar to QX within the preset liquid level range to which GD belongs.
[0066] Specifically, there are several preset liquid level ranges. Within each preset liquid level range, each preset liquid type has a corresponding preset attenuation rate change curve. First, the preset liquid level range to which GD belongs is obtained. Then, within this preset liquid level range, the preset attenuation rate change curve with the highest similarity to QX is determined. The preset liquid type corresponding to this most similar preset attenuation rate change curve is determined as the target liquid type. It should be noted that the method for determining the preset attenuation rate change curve with the highest similarity to QX can be any method known to those skilled in the art for determining similarity between curves and is not specifically limited here.
[0067] This embodiment obtains the ultrasonic signal attenuation rate corresponding to the liquid under test at each preset operating frequency to obtain an attenuation rate variation curve QX. Based on the preset liquid level range to which the liquid level GD corresponding to the liquid under test falls, the preset attenuation rate variation curve with the highest similarity to QX is determined. The preset liquid type corresponding to this most similar preset attenuation rate variation curve is then determined as the target liquid type. This method considers both the influence of the liquid level and the liquid type on attenuation, and uses the attenuation rate curve to determine the target liquid type from a number of preset liquid types. This allows the ultrasonic level meter to determine the type of the liquid under test even when the type of the liquid under test is unknown.
[0068] An embodiment of the present application further provides a computer program product, which includes program code. When the program product is run on an electronic device, the program code is used to enable the electronic device to execute the steps of the method according to various exemplary embodiments of the present application described above in this specification.
[0069] Furthermore, although the steps of the method of the present disclosure are described in a particular order in the accompanying drawings, this does not require or imply that the steps must be performed in this particular order, or that all steps shown must be performed to achieve the desired results. Additionally or alternatively, some steps may be omitted, multiple steps may be combined into one step, and / or one step may be decomposed into multiple steps.
[0070] Through the description of the above embodiments, it will be readily understood by those skilled in the art that the example embodiments described herein can be implemented via software or via a combination of software and necessary hardware. Therefore, the technical solutions according to the embodiments of the present disclosure can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (such as a CD-ROM, USB flash drive, or mobile hard drive) or on a network and includes several instructions for enabling a computing device (such as a personal computer, server, mobile terminal, or network device) to execute the methods according to the embodiments of the present disclosure.
[0071] In an exemplary embodiment of the present disclosure, an electronic device capable of implementing the above method is also provided.
[0072] Those skilled in the art will appreciate that various aspects of the present application can be implemented as systems, methods, or program products. Therefore, various aspects of the present application can be specifically implemented in the following forms: a complete hardware implementation, a complete software implementation (including firmware, microcode, etc.), or an implementation that combines hardware and software aspects, which may be collectively referred to herein as a "circuit," "module," or "system."
[0073] The electronic device according to this embodiment of the present application is merely an example and should not limit the functions and scope of use of the embodiments of the present application.
[0074] The electronic device is implemented as a general-purpose computing device. Components of the electronic device may include, but are not limited to, the at least one processor, the at least one memory, and a bus connecting different system components (including the memory and the processor).
[0075] The storage stores program codes, which can be executed by the processor, so that the processor executes the steps described in the above “Exemplary Method” section of this specification according to various exemplary embodiments of the present application.
[0076] The memory may include readable media in the form of volatile memory, such as random access memory (RAM) and / or cache memory, and may further include read only memory (ROM).
[0077] The storage may also include a program / utility having a set (at least one) of program modules, such program modules including but not limited to: an operating system, one or more application programs, other program modules, and program data, each of which or some combination may include an implementation of a network environment.
[0078] The bus may represent one or more of several types of bus structures, including a memory bus or memory controller, a peripheral bus, an accelerated graphics port, a processor, or a local bus using any of a variety of bus architectures.
[0079] The electronic device may also communicate with one or more external devices (e.g., a keyboard, pointing device, Bluetooth device, etc.), one or more devices that enable a user to interact with the electronic device, and / or any device that enables the electronic device to communicate with one or more other computing devices (e.g., a router, modem, etc.). This communication may occur via an input / output (I / O) interface. Furthermore, the electronic device may also communicate with one or more networks (e.g., a local area network (LAN), a wide area network (WAN), and / or a public network such as the Internet) via a network adapter. As shown in the figure, the network adapter communicates with other modules of the electronic device via a bus. It should be understood that, although not shown in the figure, other hardware and / or software modules may be used in conjunction with the electronic device, including but not limited to: microcode, device drivers, redundant processors, external disk drive arrays, RAID systems, tape drives, and data backup storage systems.
[0080] Through the description of the above embodiments, it will be readily understood by those skilled in the art that the example embodiments described herein can be implemented via software or via a combination of software and necessary hardware. Therefore, the technical solutions according to the embodiments of the present disclosure can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (such as a CD-ROM, USB flash drive, or mobile hard drive) or on a network and includes several instructions for enabling a computing device (such as a personal computer, server, terminal device, or network device) to execute the methods according to the embodiments of the present disclosure.
[0081] In exemplary embodiments of the present disclosure, a computer-readable storage medium is also provided, on which is stored a program product capable of implementing the aforementioned methods of this specification. In some possible implementations, various aspects of this application may also be implemented in the form of a program product, which includes program code. When the program product is executed on a terminal device, the program code is used to cause the terminal device to execute the steps described in the "Exemplary Methods" section of this specification according to various exemplary embodiments of the present application.
[0082] The program product may employ any combination of one or more readable media. The readable medium may be a readable signal medium or a readable storage medium. The readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device, or component, or any combination thereof. More specific examples (a non-exhaustive list) of readable storage media include: an electrical connection having one or more wires, a portable disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof.
[0083] A computer-readable signal medium may include a data signal propagated in baseband or as part of a carrier wave, which carries readable program code. Such propagated data signals may take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A readable signal medium may also be any readable medium other than a readable storage medium that can transmit, propagate, or transfer a program for use by or in conjunction with an instruction execution system, apparatus, or device.
[0084] The program code embodied on the readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing.
[0085] The program code used to perform the operations of the present application can be written in any combination of one or more programming languages, including object-oriented programming languages such as Java, C++, and conventional procedural programming languages such as "C" or similar programming languages. The program code can be executed entirely on the user computing device, partially on the user device, as a stand-alone software package, partially on the user computing device and partially on a remote computing device, or entirely on a remote computing device or server. In the case of a remote computing device, the remote computing device can be connected to the user computing device via any type of network, including a local area network (LAN) or a wide area network (WAN), or can be connected to an external computing device (e.g., via the Internet using an Internet service provider).
[0086] Furthermore, the above-mentioned figures are merely illustrative of the processes included in the methods according to exemplary embodiments of the present application and are not intended to be limiting. It is readily understood that the processes illustrated in the above-mentioned figures do not indicate or limit the temporal order of these processes. Furthermore, it is readily understood that these processes may be executed synchronously or asynchronously, for example, in multiple modules.
[0087] It should be noted that although several modules or units of the device for action execution are mentioned in the detailed description above, this division is not mandatory. In fact, according to the embodiments of the present disclosure, the features and functions of two or more modules or units described above can be concretized in one module or unit. Conversely, the features and functions of one module or unit described above can be further divided into multiple modules or units to be concretized.
[0088] The above are only specific embodiments of the present application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.
Claims
1. A multi-frequency ultrasonic level meter, characterized in that: The multi-frequency ultrasonic liquid level meter is arranged on the outer bottom of a container containing the liquid to be measured; the multi-frequency ultrasonic liquid level meter includes at least one piezoelectric chip; the piezoelectric chip is a disk piezoelectric chip or a ring piezoelectric chip; wherein each of the piezoelectric chips has at least two corresponding preset operating frequencies; the at least two preset operating frequencies include at least one frequency corresponding to a preset radial operating mode and at least one frequency corresponding to a preset axial operating mode; The piezoelectric chip is used to send ultrasonic signals to the liquid to be measured and / or receive ultrasonic signals returned from the liquid to be measured.
2. The multi-frequency ultrasonic level meter according to claim 1, characterized in that: The multi-frequency ultrasonic liquid level meter includes a disc piezoelectric chip and a ring piezoelectric chip; wherein the thickness of the disc piezoelectric chip is the same as the thickness of the ring piezoelectric chip; the disc piezoelectric chip is nested in the ring piezoelectric chip; and a uniform gap exists between the inner wall of the ring piezoelectric chip and the outer wall of the disc piezoelectric chip; the disc piezoelectric chip has at least two corresponding preset operating frequencies; the ring piezoelectric chip has at least two corresponding preset operating frequencies; the number of the preset operating frequencies of the disc piezoelectric chip is the same as the number of the preset operating frequencies of the ring piezoelectric chip, and the disc piezoelectric chip has a preset operating frequency that is the same as any preset operating frequency of the ring piezoelectric chip; The disc piezoelectric chip is used to send ultrasonic signals to the liquid to be measured and / or receive ultrasonic signals returned from the liquid to be measured; The annular piezoelectric chip is used to send ultrasonic signals to the liquid to be tested and / or receive ultrasonic signals returned from the liquid to be tested; wherein, when one of the disc piezoelectric chip and the annular piezoelectric chip serves as an ultrasonic transmitter, the other serves as an ultrasonic receiver.
3. The multi-frequency ultrasonic liquid level meter according to claim 2, characterized in that: If the area of the annular surface of the annular piezoelectric chip is larger than the area of the circular surface of the disc piezoelectric chip, the annular piezoelectric chip acts as an ultrasonic transmitter and the disc piezoelectric chip acts as an ultrasonic receiver.
4. The multi-frequency ultrasonic liquid level meter according to claim 2, characterized in that: The gap between the inner wall of the annular piezoelectric chip and the outer wall of the disc piezoelectric chip is filled with a material of a preset material; wherein the material of the preset material is used to absorb the energy of the ultrasonic signal.
5. The multi-frequency ultrasonic liquid level meter according to claim 1, characterized in that: The multi-frequency ultrasonic liquid level meter includes at least two annular piezoelectric chips; and at least two annular piezoelectric chips are nested together; there is a uniform gap between any two adjacent annular piezoelectric chips; and the operating frequencies corresponding to any two annular piezoelectric chips are completely different; each of the annular piezoelectric chips is used to send ultrasonic waves emitted by itself to the liquid to be measured and receive ultrasonic waves returned from the liquid to be measured.
6. A method for determining liquid level based on the multi-frequency ultrasonic liquid level meter according to any one of claims 1 to 5, characterized in that: The method comprises: S100, obtain each preset working frequency corresponding to the multi-frequency ultrasonic level meter and sort them in descending order to obtain a preset working frequency list PL = (PL1, PL2, ..., PL i ,…,PL n ); i = 1, 2, ..., n; n is the number of preset working frequencies corresponding to the multi-frequency ultrasonic level meter; PL i The i-th preset operating frequency corresponding to the multi-frequency ultrasonic level meter after sorting in descending order; S200, according to PL, send ultrasonic signals to the liquid to be tested in sequence until PL is determined i is the target operating frequency; wherein the target operating frequency is a preset operating frequency at which, after sending an ultrasonic signal to the liquid to be tested, a returned ultrasonic signal can be received, and the amplitude of the returned ultrasonic signal is greater than a preset signal amplitude threshold; S300, sending an ultrasonic signal at a target operating frequency to the liquid to be measured at a preset time interval to obtain the liquid level of the liquid to be measured; S400: If the returned ultrasonic signal cannot be determined after the ultrasonic signal is sent, and the liquid level of the liquid to be measured decreases, then obtain the key operating frequency list GL = (PL i-1 ,…,PL a ,…,PL2,PL1);a=1,2,…,i-1; S500, according to GL, send ultrasonic signals to the liquid to be tested in sequence until PL is determined a is the updated target operating frequency, and the process jumps to step S300.
7. The liquid level determination method according to claim 6, characterized in that: After step S300, the method further includes: S600: If no return ultrasonic signal is received after the ultrasonic signal is sent, and the liquid level of the liquid to be measured rises, then obtain the intermediate operating frequency list ZL=(PL i＋1 ,…,PL b ,…,PL n ); b=i+1,i+2,…,n; S700, according to ZL, send ultrasonic signals to the liquid to be tested in sequence until PL is determined b is the updated target operating frequency, and the process jumps to step S300.
8. The liquid level determination method according to claim 6, characterized in that: After step S300, the method further includes: S800: If the returned ultrasonic signal cannot be determined after the ultrasonic signal is sent, and the liquid level of the liquid to be measured decreases, PL1 is determined as the target operating frequency, and the process jumps to step S300.
9. A non-transitory computer-readable storage medium, wherein at least one instruction or at least one program is stored in the storage medium, characterized in that: The at least one instruction or the at least one program is loaded and executed by a processor to implement the method according to any one of claims 6 to 8.
10. An electronic device, characterized in that: The device comprises a processor and the non-transitory computer-readable storage medium as claimed in claim 9.