Information processing device and ultrasonic flowmeter

Abstract

To provide an information processing device which estimates a voltage value of a specific peak of a received signal in a state where a reference voltage value is set, and which can set a new reference voltage value based on the estimated voltage value, and to provide an ultrasonic flowmeter.SOLUTION: An information processing device (20) includes: a voltage value acquisition part (21) which acquires a first voltage value of a first peak of a first waveform signal and a second voltage value of a second peak including the first peak and the second peak, and which acquires a third voltage value of a third peak of a second waveform signal including the third peak and a fourth peak; a reference voltage value setting part (22) which sets a predetermined voltage value between the first voltage value and the second voltage value as a reference voltage value; and a voltage value estimation part (25) which estimates a fourth voltage value of a fourth peak based on the first voltage value, the second voltage value and the third voltage value acquired by the voltage value acquisition part. The reference voltage value setting part sets a predetermined voltage value between the third voltage value and the fourth voltage value estimated by the voltage value estimation part as a new reference voltage value, in the case where, in a state where the reference voltage value is set, the third voltage value is acquired by the voltage value acquisition part.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to an information processing device and an ultrasonic flow meter. [Background technology]

[0002] Generally, a flow measuring device is known that has a pair of ultrasonic transducers and measures the flow rate of a fluid based on the difference in propagation time between a signal output from one ultrasonic transducer and input to the other ultrasonic transducer via the fluid to be measured, and a signal output from the other ultrasonic transducer and input to the one ultrasonic transducer via the fluid to be measured.

[0003] In such a flow measurement device, a reference voltage value is set in advance, and the propagation time of a signal input to any ultrasonic transducer is calculated based on the zero-cross time of the voltage value of the signal after the signal reaches the reference voltage value (see Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2003-106882 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, there is a problem in that the relationship between the received signal and the reference voltage value may change due to factors such as changes over time after the reference voltage value is set, external mechanical forces, repeated thermal changes, and changes in the measurement environment, which may require the setting of a new reference voltage value.

[0006] The present disclosure is intended to solve the above problem, and has an object to provide an information processing device and an ultrasonic flowmeter that are capable of setting a new reference voltage value. [Means for solving the problem]

[0007] An information processing device according to the present disclosure includes a voltage value acquisition unit that acquires a first voltage value of a first peak and a second voltage value of the second peak of a first waveform signal including a first peak and a second peak, and acquires a third voltage value of a third peak of a second waveform signal including a third peak and a fourth peak; a reference voltage value setting unit that sets a predetermined voltage value between the first voltage value and the second voltage value as a reference voltage value; and a voltage value estimation unit that estimates a fourth voltage value of the fourth peak based on the first voltage value, the second voltage value, and the third voltage value acquired by the voltage value acquisition unit, wherein when the reference voltage value is set and the third voltage value is acquired by the voltage value acquisition unit, the reference voltage value setting unit sets the predetermined voltage value between the third voltage value and the fourth voltage value estimated by the voltage value estimation unit as a new reference voltage value. Effect of the Invention

[0008] According to the present disclosure, when a reference voltage value is set, it is possible to estimate the voltage value of a specific peak of a received signal, and to set a new reference voltage value based on the estimated voltage value. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram showing a configuration of a flow rate measurement system according to a first embodiment. [Diagram 2] 1 is a block diagram showing a schematic configuration of a flow rate measurement system according to a first embodiment. [Diagram 3] FIG. 2 is a diagram showing an example of a hardware configuration of a flow rate calculation unit according to the first embodiment. [Figure 4] FIG. 2 is a diagram showing an example of a hardware configuration of a flow rate calculation unit according to the first embodiment. [Diagram 5] 5 is a graph showing a first ultrasonic signal acquired by a first signal acquisition unit according to the first embodiment. [Figure 6] 5 is a flowchart showing a reference voltage value setting process performed by the flow rate calculation unit using a reference voltage value control unit according to the first embodiment. [Figure 7]5 is a flowchart showing a reference voltage value resetting process performed by the flow rate calculation unit using a reference voltage value control unit according to the first embodiment. [Figure 8] 13 is a diagram showing the concept of a method for estimating a fourth voltage value in the reference voltage value setting process performed by the flow rate calculation unit using a reference voltage value control unit according to the second embodiment. FIG. [Figure 9] 13 is a diagram showing the concept of another example of a method for estimating a fourth voltage value in the reference voltage value setting process performed by the flow rate calculation unit using a reference voltage value control unit according to the second embodiment. FIG. [Figure 10] 13 is a diagram showing voltage values ​​of each peak in a reference voltage value setting process performed by a reference voltage value control unit of a flow rate calculation unit according to the fourth embodiment. FIG. [Figure 11] 13 is a diagram showing voltage values ​​of each peak in a reference voltage value resetting process performed by a flow rate calculation unit using a reference voltage value control unit according to the fourth embodiment. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. Embodiment 1 Fig. 1 is a schematic diagram showing the configuration of a flow measurement system according to embodiment 1. As shown in Fig. 1, the flow measurement system as an ultrasonic flowmeter according to embodiment 1 includes a measurement tube 1 which is a tubular member through which a fluid to be measured flows, transducers 2 and 3 each having an ultrasonic vibrator (not shown), and a flow rate calculation unit 100 which measures the flow rate of the fluid flowing inside the measurement tube 1.

[0011] The transducer 2 is disposed on the side wall of the measurement pipe 1. The transducer 2 outputs a second ultrasonic wave, which is a pulse wave of multiple cycles, toward the inside of the measurement pipe 1, and the first ultrasonic wave output from the transducer 3 is input to the transducer 2. The transducer 3 is disposed on one side of the side wall of the measurement pipe 1, upstream or downstream, of the transducer 2. The transducer 3 outputs a first ultrasonic wave, which is a pulse wave of multiple cycles, toward the inside of the measurement pipe 1, and the second ultrasonic wave output from the transducer 2 is input to the transducer 2. In this manner, the pair of transducers 2 and 3 inputs ultrasonic waves output from one of them to the other through the fluid flowing inside the measurement pipe 1. In this manner, the transducers 2 and 3 convert the input ultrasonic waves into voltage signals and transmit them to the flow rate calculation unit 100.

[0012] Fig. 2 is a block diagram showing a schematic configuration of the flow measurement system according to the embodiment 1. The flow rate calculation unit 100 calculates the flow rate of the fluid flowing inside the measurement tube 1 based on signals from the transducers 2 and 3. As shown in Fig. 2, the flow rate calculation unit 100 includes a first signal acquisition unit 11, a second signal acquisition unit 12, a reference voltage value control unit 20, a propagation time calculation unit 30, a time difference calculation unit 40, a flow rate calculation unit 50, and a storage unit 60.

[0013] The first signal acquirer 11 acquires a first ultrasonic signal which is a pulse signal of multiple cycles based on the first ultrasonic wave input to the transducer 2. In other words, the first signal acquirer 11 acquires a first ultrasonic signal which is a pulse signal of multiple cycles based on the first ultrasonic wave input to an ultrasonic vibrator included in the transducer 2. For example, the first signal acquirer 11 acquires a first ultrasonic signal which is a signal from the transducer 2. Also, for example, the first signal acquirer 11 acquires a first ultrasonic signal which is a signal from the transducer 2 with the gain adjusted.

[0014] The second signal acquirer 12 acquires a second ultrasonic signal which is a multi-cycle pulse signal based on the second ultrasonic wave input to the transducer 3. In other words, the second signal acquirer 12 acquires a second ultrasonic signal which is a multi-cycle pulse signal based on the second ultrasonic wave input to an ultrasonic vibrator included in the transducer 3. For example, the second signal acquirer 12 acquires a second ultrasonic signal which is a signal from the transducer 3. Also, for example, the second signal acquirer 12 acquires a second ultrasonic signal which is a signal obtained by adjusting the gain of the signal from the transducer 3.

[0015] In addition, when the first signal acquisition unit 11 and the second signal acquisition unit 12 are configured to acquire signals with adjusted gains of the signals from the transducers 2 and 3, the flow rate calculation unit may be provided with a gain adjustment unit (not shown) that adjusts the gains of the signals from the transducers 2 and 3.

[0016] The reference voltage value control unit 20 as an information processing device performs processing related to setting a reference voltage value, which is a reference voltage value to be compared with the voltage values ​​of the first ultrasonic signal and the second ultrasonic signal when calculating the propagation speed of the ultrasonic wave output from the transducers 2, 3 based on the first ultrasonic signal and the second ultrasonic signal acquired by the first signal acquisition unit 11 and the second signal acquisition unit 12, and resetting the reference voltage value. For example, the reference voltage value control unit 20 sets the reference voltage value when the ultrasonic flowmeter is shipped from the production factory that produces the ultrasonic flowmeter. In addition, the reference voltage value control unit 20 resets the reference voltage value at a predetermined opportunity after the shipment from the production factory. Details of the reference voltage value control unit 20 will be described later.

[0017] The propagation time calculation unit 30 acquires output time information indicating the second output time when the second ultrasonic wave is output from the transducer 2 and the first output time when the first ultrasonic wave is output from the transducer 3, and calculates the propagation times of the first and second ultrasonic waves output from the transducers 2 and 3 based on the output time information, the first and second ultrasonic signals acquired by the first and second signal acquisition units 11 and 12, and the reference voltage value set by the reference voltage value control unit 20. For example, the propagation time calculation unit 30 calculates the propagation time of the first ultrasonic wave based on the time from the first output time to the zero cross time, which is the time when the sign of the voltage value of the first ultrasonic signal is switched after the voltage value of the first ultrasonic signal reaches the reference voltage value. Note that the process of calculating the propagation time of the second ultrasonic wave is similar to the process of calculating the propagation time of the first ultrasonic wave, so a description thereof will be omitted.

[0018] The time difference calculation section 40 calculates the difference between the propagation time of the first ultrasonic wave and the propagation time of the second ultrasonic wave acquired by the propagation time calculation section 30.

[0019] The flow rate calculation unit 50 calculates the flow rate of the fluid flowing inside the measurement tube 1 based on the calculation result by the propagation time calculation unit 30. For example, the flow rate calculation unit 50 calculates the flow rate of the fluid flowing inside the measurement tube 1 based on the following formulas (1) and (2). Note that v is the velocity of the fluid, L is the distance between transducer 2 and transducer 3 in the flow direction of the fluid, T1 is the propagation time of the first ultrasonic wave, T2 is the propagation time of the second ultrasonic wave, S is the cross-sectional area of ​​the measurement tube 1, Φ is the sensor angle (the angle between the flow direction of the fluid and the transmission direction of the ultrasonic wave from the transducer), and Q is the flow rate. v=L / 2*cosΦ*(1 / T2-1 / T1) ···(1) Q = v * S (2)

[0020] The storage unit 60 stores information used when the flow rate calculation unit 100 performs various processes and information related to the results of these various processes. For example, the storage unit 60 stores information related to the signals acquired by the first signal acquisition unit 11 and the second signal acquisition unit 12, information indicating the reference voltage value set by the reference voltage value control unit 20, information related to the measurement conditions when the flow rate calculation unit 100 measures the flow rate of the fluid, information related to the types of fluids measured in the past, etc.

[0021] Configured in this manner, the flow rate calculation unit 100 has a propagation time calculation unit 30 that calculates the propagation times of the first and second ultrasonic waves output from the transducers 2 and 3 based on the first and second ultrasonic signals acquired by the first and second signal acquisition units 11 and 12 and the reference voltage value set by the reference voltage value control unit 20, a time difference calculation unit 40 that calculates the difference between the propagation time of the first ultrasonic wave and the propagation time of the second ultrasonic wave based on the propagation time calculated by the propagation time calculation unit 30, and a flow rate calculation unit 50 that calculates the flow rate of the fluid based on the calculation result by the time difference calculation unit 40.

[0022] Next, the reference voltage value control unit 20 according to the first embodiment will be described in detail with reference to FIG. 2 and FIG. 5. FIG. 5 is a graph showing a first ultrasonic signal acquired by the first signal acquisition unit according to the first embodiment. Hereinafter, the reference voltage value control unit 20 will be described taking as an example a case in which the first signal acquisition unit 11 acquires a first ultrasonic signal having one wave including the first peak, two waves including the peak next to the first wave, three waves including the peak next to the second wave, four waves including the peak next to the third wave, and five waves including the peak next to the fourth wave and the maximum peak of the signal, as shown in FIG. 5. Note that the function of the reference voltage value control unit 20 for the first ultrasonic signal and the function of the reference voltage value control unit 20 for the second ultrasonic signal are similar, so hereinafter, the function for the first ultrasonic signal will be described, and the function for the second ultrasonic signal will not be described.

[0023] 2, the reference voltage value control unit 20 includes a voltage value acquisition unit 21, a reference voltage value setting unit 22, a judgment information acquisition unit 23, a judgment unit 24, and a voltage value estimation unit 25. The voltage value acquisition unit 21 acquires voltage values ​​at specific peaks of the first ultrasonic signal and the second ultrasonic signal. For example, the voltage value acquisition unit 21 acquires the voltage value of the peak of the second wave, the voltage value of the peak of the third wave, the voltage value of the peak of the fourth wave, and the voltage value of the peak of the fifth wave based on the first ultrasonic signal acquired by the first signal acquisition unit 11.

[0024] The reference voltage value setting unit 22 sets the reference voltage value based on the voltage value acquired by the voltage value acquisition unit 21. For example, the reference voltage value setting unit 22 sets the average value of the voltage value of the peak of the second wave and the voltage value of the peak of the third wave as the reference voltage value. When calculating the propagation time of the ultrasonic wave, the above-mentioned propagation time calculation unit 30 acquires the zero cross time, which is the time of the first zero cross point a after the timing c at which the reference voltage value is first reached, in a state where the reference voltage value is set in advance, and calculates the propagation time of the first ultrasonic wave based on the time from the first output time to the zero cross time.

[0025] It should be noted that such a reference voltage value is required to be set between specific adjacent peaks, but the relationship between the reference voltage value and the voltage value of each peak of the first ultrasonic signal is affected by various conditions. For example, the relationship between the reference voltage value and the voltage value of each peak of the first ultrasonic signal changes due to aging of the transducers 2, 3 and the flow rate calculation unit 100. In addition, the relationship between the reference voltage value and the voltage value of each peak of the first ultrasonic signal changes depending on the type of fluid. For this reason, the reference voltage value control unit 20 is configured to reset the reference voltage value when it acquires information that may affect the relationship between the reference voltage value and the voltage value of each peak of the first ultrasonic signal.

[0026] The determination information acquisition unit 23 acquires determination information for determining whether or not to reset the reference voltage value. In other words, the determination information is acquired for determining whether or not to set a new reference voltage value. For example, the determination information acquisition unit 23 acquires information on factors that change the relationship between the reference voltage value and the voltage value of each peak of the first ultrasonic signal. In other words, the determination information acquisition unit 23 acquires information that may be a factor that changes the relationship between the voltage value acquired by the voltage value acquisition unit 21 and the reference voltage value set by the reference voltage value setting unit 22. For example, the determination information acquisition unit 23 acquires determination information including any one or more of information on the elapsed time from a predetermined time, the presence or absence of acceleration applied from the outside to the transducers 2, 3 and the flow rate calculation unit 100, the temperature change of the transducers 2, 3 and the flow rate calculation unit 100, the temperature change of the fluid, the change in the type of fluid, the change in the velocity of the fluid, the change in the voltage value with respect to the voltage value of each peak acquired in the past, and the like.

[0027] The judgment unit 24 judges whether or not to reset the reference voltage value based on the judgment information acquired by the judgment information acquisition unit 23. For example, the judgment unit 24 judges whether or not the time elapsed since the reference voltage value was last set exceeds a preset time based on the information acquired by the judgment information acquisition unit 23, and if the elapsed time exceeds the preset time, decides to reset the reference voltage value. In other words, the judgment unit 24 decides to reset the reference voltage value based on the judgment information acquired by the judgment information acquisition unit 23, if the time elapsed since the first voltage value was acquired exceeds a preset time.

[0028] Also, for example, the judgment unit 24 judges whether or not the elapsed time since the flow calculation unit 100 was shipped has exceeded a preset time based on the information acquired by the judgment information acquisition unit 23, and if the elapsed time has exceeded the preset time, decides to reset the reference voltage value.

[0029] Also, for example, the determination unit 24 determines whether or not an acceleration applied from outside to any of the transducers 2, 3 and the flow rate calculation unit 100 exceeds a preset acceleration based on the information acquired by the determination information acquisition unit 23, and decides to reset the reference voltage value if the acceleration exceeds the preset acceleration. Note that, when the determination unit 24 makes a determination regarding acceleration, the flow rate calculation unit 100 may include an acceleration sensor (not shown) for measuring an acceleration applied from outside to any of the transducers 2, 3 and the flow rate calculation unit 100.

[0030] Also, for example, the judgment unit 24 judges whether or not the temperature change of any of the transducers 2, 3 and the flow rate calculation unit 100 from the temperature at which the reference voltage value was last set exceeds a preset temperature based on the information acquired by the judgment information acquisition unit 23, and decides to reset the reference voltage value if the temperature change exceeds the preset temperature. Note that when the judgment unit 24 makes a judgment regarding temperature, the flow rate calculation unit 100 may be provided with a temperature sensor (not shown) for measuring the temperature.

[0031] Also, for example, the judgment unit 24 judges whether or not the number of times that the temperature of any of the transducers 2, 3 and the flow rate calculation unit 100 has changed beyond a preset range has exceeded a preset number of times based on the information acquired by the judgment information acquisition unit 23, and if the number of times that the temperature has changed has exceeded the preset number of times, it decides to reset the reference voltage value.

[0032] Also, for example, the judgment unit 24 judges, based on the information acquired by the judgment information acquisition unit 23, whether or not the temperature change of the fluid to be measured from the temperature at which the reference voltage value was last set has exceeded a preset temperature, and if the temperature change has exceeded the preset temperature, decides to reset the reference voltage value.

[0033] Also, for example, the determination unit 24 determines whether or not the type of fluid to be measured is the same as the type of fluid when the reference voltage value was last set based on the information acquired by the determination information acquisition unit 23, and if the types of fluid are not the same, decides to reset the reference voltage value. Note that when the determination unit 24 makes a determination regarding the type of fluid, the flow rate calculation unit 100 may be configured to acquire information regarding the type of fluid based on a user's operation.

[0034] Also, for example, the judgment unit 24 judges, based on the information acquired by the judgment information acquisition unit 23, whether or not the flow rate difference between the flow rate of the fluid to be measured and the flow rate of the fluid when the reference voltage value was last set exceeds a preset flow rate, and if the flow rate difference exceeds the preset flow rate, decides to reset the reference voltage value. Also, for example, based on the information acquired by the judgment information acquisition unit 23, when the amount of change of the voltage value at a specific peak from the voltage value acquired when the previous reference voltage value was set exceeds a preset amount of change, the judgment unit 24 decides to reset the reference voltage value. Here, the specific peak may be the maximum peak, the peak of the second wave, or the peak of the third wave. In general, the maximum peak has a larger amount of change than other peaks, so by deciding to reset the reference voltage value based on the change in the maximum peak, it is possible to suppress the fluctuation in performance more than by deciding to reset the reference voltage value based on the change in the other peaks. In general, the peak of the third wave is closer to the zero crossing point than other peaks, so by deciding to reset the reference voltage value based on the change in the peak of the third wave, it is possible to reset the reference voltage with more accurate timing and higher accuracy than by deciding to reset the reference voltage value based on the change in the other peaks. The judgment unit 24 may be configured to judge whether or not to reset the reference voltage value based on any one of these multiple judgments, or may be configured to decide to reset the reference voltage value based on the judgment result based on a combination of multiple conditions.

[0035] The voltage value estimation unit 25 estimates the other voltage value based on one of the voltage values ​​of the multiple peaks of the ultrasonic signal used when setting the reference voltage value. For example, the voltage value estimation unit 25 estimates the current peak voltage value of the third wave based on the voltage values ​​of the second wave and the third wave of the first ultrasonic signal previously acquired by the voltage value acquisition unit 21 and the voltage value of the second wave of the first ultrasonic signal currently acquired by the voltage value acquisition unit 21. This enables the flow rate calculation unit 100 to reduce the time required to reset the reference voltage value, reduce the processing load when resetting the reference voltage value, and suppress current consumption.

[0036] Next, the hardware configuration of the flow rate calculation unit 100 will be described with reference to Figs. 3 and 4. Fig. 3 is a block diagram showing an example of the hardware configuration of the flow rate calculation unit 100 according to the first embodiment, and Fig. 4 is a block diagram showing an example of a hardware configuration of the flow rate calculation unit 100 according to the first embodiment, which is different from that shown in Fig. 3. For example, as shown in Fig. 3, the flow rate calculation unit 100 has a processor 100a, a memory 100b, and an I / O port 100c, and is configured so that the processor 100a reads and executes a program stored in the memory 100b. The memory 100b may be, for example, a non-volatile or volatile semiconductor memory such as a RAM, a ROM, a flash memory, an EPROM, or an EEPROM. The memory 100b may also be a magnetic disk, a flexible disk, an optical disk, a compact disk, a mini disk, a DVD, or the like. The memory 100b may also be an HDD or an SSD.

[0037] 4, the flow rate calculation unit 100 has a processing circuit 100d, which is dedicated hardware, and an I / O port 100c. The processing circuit 100d is configured, for example, by a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, a system LSI (Large-Scale Integration), an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or a combination of these. Each function of the flow rate calculation unit 100 is realized by the processor 100a or the processing circuit 100d, which is dedicated hardware, executing a program, which is software, firmware, or a combination of software and firmware.

[0038] Next, the details of the processing performed by the flow rate calculation unit 100 according to the first embodiment will be described with reference to Fig. 2 and Fig. 5 to Fig. 8. Fig. 6 is a flowchart showing the reference voltage value setting processing performed by the flow rate calculation unit 100 according to the first embodiment using the reference voltage value control unit 20. For example, the reference voltage value processing is processing for setting a reference voltage value performed when the ultrasonic flowmeter is shipped from a production factory that produces the ultrasonic flowmeter.

[0039] As shown in FIG. 6, when the process starts, the flow rate calculation unit 100 acquires a first voltage value and a second voltage value, which are the voltage values ​​at two specific peaks adjacent to each other of the first ultrasonic signal (step ST11). For example, in this process, the flow rate calculation unit 100 acquires a first voltage value, which is an initial value of the voltage value of the peak of the second wave, and a second voltage value, which is an initial value of the voltage value of the peak of the third wave, based on the first ultrasonic signal acquired by the first signal acquisition unit 11. Note that in the first embodiment, the first ultrasonic signal constitutes the first waveform signal, the peak of the second wave of the first ultrasonic signal constitutes the first peak, and the peak of the third wave of the first ultrasonic signal constitutes the second peak. Also, in the first embodiment, the first peak is not limited to the peak of the second wave, but may be the peak of the first wave, the peak of the third wave, or a peak other than the first wave to the third wave. Also, in the first embodiment, the second peak is not limited to the peak of the third wave, but may be another peak that is a peak after the first peak.

[0040] After performing the process of step ST11, the flow rate calculation unit 100 sets a predetermined voltage value between the first voltage value and the second voltage value acquired in the process of step ST11 as a reference voltage value (step ST12). In this process, the reference voltage value is set, and the flow rate calculation unit 100 is in a state where it can measure the flow rate of the fluid. After performing the process of step ST12, the flow rate calculation unit 100 stores the set reference voltage value, the first voltage value, and the second voltage value in the storage unit 60, and ends the reference voltage value setting process.

[0041] 7 is a flowchart showing a reference voltage value resetting process performed by the flow rate calculation unit 100 according to the first embodiment through the reference voltage value control unit 20. For example, the reference voltage value resetting process is a process for resetting the reference voltage value that is performed at a predetermined opportunity after the ultrasonic flowmeter is shipped from a production factory that produces the ultrasonic flowmeter. Note that the flow rate calculation unit 100 may be configured to perform the reference voltage value resetting process every time the power supply of the flow rate calculation unit 100 is turned on, or may be configured to perform the reference voltage value resetting process in response to a user operation, or may be configured to perform the reference voltage value resetting process based on another opportunity.

[0042] 7, when the process starts, the flow rate calculation unit 100 determines whether or not it has acquired judgment information (step ST21). In this process, the flow rate calculation unit 100 determines whether or not it has acquired various judgment information related to time, temperature, acceleration, type of fluid, and the like, using the judgment information acquisition unit 23, for determining whether or not to reset the reference voltage value.

[0043] In the process of step ST21, if the judgment information has not been acquired (NO in step ST21), the flow rate calculation unit 100 waits until the judgment information is acquired. In the process of step ST21, if the judgment information has been acquired (YES in step ST21), the flow rate calculation unit 100 judges whether or not the judgment information acquired in the process of step ST21 is judgment information for resetting the reference voltage value (step ST22). In this process, the flow rate calculation unit 100 judges whether or not to reset the reference voltage value by the judgment unit 24 based on the judgment information acquired in the process of step ST21.

[0044] If the judgment information acquired in step ST21 is not judgment information for resetting the reference voltage value (NO in step ST22), the flow rate calculation unit 100 returns the process to step ST21. If the judgment information acquired in step ST21 is judgment information for resetting the reference voltage value (YES in step ST22), the flow rate calculation unit 100 acquires a third voltage value, which is a voltage value of a specific peak of the first ultrasonic signal, by the voltage value acquisition unit 21 (step ST23). For example, in this process, the flow rate calculation unit 100 drives the transducer 3 to output a first ultrasonic wave, causes the first signal acquisition unit 11 to acquire the first ultrasonic signal, and causes the voltage value acquisition unit 21 to acquire a third voltage value, which is a voltage value of a peak of two waves of the first ultrasonic signal. Note that in the first embodiment, the first ultrasonic signal constitutes a second waveform signal, the peak of two waves of the first ultrasonic signal constitutes a third peak, and the peak of three waves of the first ultrasonic signal constitutes a fourth peak. In the first embodiment, the third peak is not limited to the second wave peak, but may be any wave peak corresponding to the first peak. In the first embodiment, the fourth peak is not limited to the third wave peak, but may be any wave peak corresponding to the second peak.

[0045] After performing the process of step ST23, the flow rate calculation unit 100 estimates a fourth voltage value, which is the voltage value of another peak adjacent to the peak whose voltage value is the third voltage value, by the voltage value estimation unit 25 (step ST24). In this process, the flow rate calculation unit 100 refers to the information stored in the storage unit 60, and estimates the fourth voltage value based on the first voltage value and the second voltage value acquired in the reference voltage value setting process and the third voltage value acquired in the process of step ST23.

[0046] After performing the process of step ST24, the flow rate calculation section 100 sets a predetermined voltage value between the third voltage value and the estimated value of the fourth voltage value as a new reference voltage value (step ST25).

[0047] After performing the process of step ST25, the flow rate calculation section 100 stores the new reference voltage value in the storage section 60, and ends the process.

[0048] As described above, flow rate calculation unit 100 according to the first embodiment includes voltage value acquisition unit 21 that acquires a first voltage value of a first peak and a second voltage value of the second peak of a first waveform signal including a first peak and a second peak, and acquires a third voltage value of a third peak of a second waveform signal including a third peak and a fourth peak, reference voltage value setting unit 22 that sets a predetermined voltage value between the first voltage value and the second voltage value as a reference voltage value, and voltage value estimation unit 25 that estimates a fourth voltage value of the fourth peak based on the first voltage value, the second voltage value, and the third voltage value acquired by voltage value acquisition unit 21, and reference voltage value setting unit 22 is configured to set, when the third voltage value is acquired by voltage value acquisition unit 21 with the reference voltage value set, a predetermined voltage value between the third voltage value and the fourth voltage value estimated by voltage value estimation unit 25 as a new reference voltage value.

[0049] By being configured in this manner, the flow rate calculation unit 100 does not need to obtain the fourth voltage value by measurement, which shortens the time required to reset the reference voltage value, reduces the processing burden when resetting the reference voltage value, and suppresses current consumption.

[0050] Embodiment 2 Next, a flow rate calculation unit according to the second embodiment will be described. In the first embodiment, the flow rate calculation unit 100 estimates the fourth voltage value based on the first voltage value, the second voltage value, and the third voltage value, but the flow rate calculation unit 100 may be configured to estimate the fourth voltage value based on at least the first voltage value, the second voltage value, and the third voltage value. For example, the voltage value acquisition unit 21 may be configured to acquire a fifth voltage value, which is a voltage value of a peak of another wave of the first ultrasonic signal different from the waves corresponding to the first voltage value and the second voltage value, in addition to the first voltage value and the second voltage value, in the reference voltage value setting process, and to acquire a sixth voltage value, which is a voltage value of a peak of another wave of the first ultrasonic signal different from the waves corresponding to the third voltage value and the fourth voltage value, in addition to the third voltage value, in the reference voltage value resetting process, and to estimate the fourth voltage value based on these first voltage value, second voltage value, third voltage value, fifth voltage value, and sixth voltage value. Specifically, the voltage value acquiring unit 21 may be configured to acquire a fifth voltage value, which is a voltage value of the peak of the five waves as the other waves of the first ultrasonic signal, in addition to the first voltage value and the second voltage value, in the reference voltage value setting process, and to acquire a sixth voltage value, which is a voltage value of the peak of the five waves as the other waves of the first ultrasonic signal, in addition to the third voltage value, in the reference voltage value resetting process, and to estimate the fourth voltage value based on these first voltage value, second voltage value, third voltage value, fifth voltage value, and sixth voltage value. The peak of the five waves as the other waves of the first ultrasonic signal acquired in the reference voltage value setting process constitutes the fifth peak, and the peak of the five waves as the other waves of the first ultrasonic signal acquired in the reference voltage value resetting process constitutes the sixth peak. In addition, the peak of the other waves of the first ultrasonic signal acquired in the reference voltage value setting process of the second embodiment may be a peak of a wave including a maximum peak that is a wave different from the waves corresponding to the first voltage value to the fourth voltage value, and may be a peak other than the five waves.

[0051] Specifically, the voltage value estimation unit 25 calculates a rate of change K2 from the first voltage value to the third voltage value and a rate of change Kmax from the fifth voltage value to the sixth voltage value, estimates a rate of change K3 from the second voltage value to the fourth voltage value based on the rate of change K2 and the rate of change Kmax, and estimates the fourth voltage value based on the rate of change K3 and the second voltage value. More specifically, the fourth voltage value P3_pv is calculated by linear interpolation as shown in the following formulas (4) to (7) (see FIG. 8). Note that P2_def indicates the first voltage value, P3_def indicates the second voltage value, Pmax_def indicates the fifth voltage value, P2_pv indicates the third voltage value, and Pmax_pv indicates the sixth voltage value. K2 = P2_pv / P2_def (4) Kmax=Pmax_pv / Pmax_def ···(5) K3 = Kmax / 3 + 2*K2 / 3 (6) P3_pv = P3_def * K3 (7)

[0052] Fig. 9 is a diagram showing the concept of another example of a method for estimating the fourth voltage value in the reference voltage value setting process performed by the reference voltage value control unit of the flow rate calculation unit 100 according to embodiment 2. As shown in Fig. 9, the voltage value estimation unit 25 is not limited to linear interpolation, and may be configured to estimate the fourth voltage value by, for example, known curved interpolation obtained in advance by testing or the like. In this way, when the waveform fluctuates and the rate of change (current value / initial value) of each peak is different, a more accurate estimation can be performed by finding the rate of change of the peak to be estimated using a model that is close to the fluctuation of the waveform, thereby improving the estimation accuracy. Furthermore, by estimating the fourth voltage value in this manner, it is possible to improve the estimation accuracy compared to estimating the fourth voltage value based only on the first voltage value, the second voltage value, and the third voltage value.

[0053] Embodiment 3 Next, a flow rate calculation unit according to the third embodiment will be described. For example, the flow rate calculation unit 100 may be configured to estimate the fourth voltage value based on the rate of change between the first voltage value and the third voltage value and the second voltage value. Specifically, the voltage value estimation unit 25 can calculate the fourth voltage value P3_pv, which is an estimated value, by the following formula (8). Note that P2_def indicates the first voltage value, P3_def indicates the second voltage value, P2_pv indicates the third voltage value, and K is a known constant obtained in advance by testing or the like. P3_pv=P3_def*(1+(P2_pv-P2_def) / P2_def*K) (8) By being configured in this manner, the flow rate calculation unit 100 does not need to obtain the fourth voltage value by measurement, which shortens the time required to reset the reference voltage value, reduces the processing burden when resetting the reference voltage value, and suppresses current consumption.

[0054] Embodiment 4 Next, a description will be given of a flow rate calculation unit according to embodiment 4. The flow rate calculation unit according to embodiment 4 is different from the flow rate calculation unit 100 according to embodiment 1 in the procedure in which the voltage value estimation unit 25 estimates the fourth voltage value, but other features are similar to the flow rate calculation unit 100 according to embodiment 1. Therefore, the same names or symbols are used for configurations similar to those of the flow rate calculation unit 100 according to embodiment 1, and descriptions thereof will be omitted.

[0055] Fig. 10 is a diagram showing the voltage values ​​of each peak in the reference voltage value setting process performed by the reference voltage value control unit of the flow rate calculation unit 100 according to embodiment 4, and Fig. 11 is a diagram showing the voltage values ​​of each peak in the reference voltage value resetting process performed by the reference voltage value control unit of the flow rate calculation unit 100 according to embodiment 4. The flow rate calculation unit 100 according to embodiment 4 acquires a first voltage value, a second voltage value, and a fifth voltage value in the reference voltage value setting process, acquires a third voltage value and a sixth voltage value in the reference voltage value resetting process, and estimates a fourth voltage value based on the first voltage value, the second voltage value, the third voltage value, the fifth voltage value, and the sixth voltage value.

[0056] 10 and 11, the voltage value estimation unit 25 estimates the fourth voltage value by assuming that the ratio of the difference between the second voltage value and the first voltage value to the difference between the fifth voltage value and the first voltage value is the same as the ratio of the difference between the fourth voltage value and the third voltage value to the difference between the sixth voltage value and the third voltage value. The fourth voltage value P3_pv estimated in this way can be calculated by the following formula (9). Note that P2_def indicates the first voltage value, P3_def indicates the second voltage value, Pmax_def indicates the fifth voltage value, P2_pv indicates the third voltage value, and Pmax_pv indicates the sixth voltage value. P3_pv=(Pmax_pv-P2_pv)*(P3_def-P2_def) / (Pmax_def-P2_def)+P2_pv ···(9)

[0057] By estimating the fourth voltage value in this manner, it is possible to improve the estimation accuracy compared to a case in which the fourth voltage value is estimated based only on the first voltage value, the second voltage value, and the third voltage value.

[0058] In addition, the present disclosure allows free combinations of the respective embodiments, or modifications of any of the components of the respective embodiments, or omission of any of the components of the respective embodiments. [Explanation of symbols]

[0059] 1: Measuring tube 2, 3: Transducer 11: First signal acquisition unit 12: Second signal acquisition unit 20: Reference voltage value control section 21: Voltage value acquisition unit 22: Reference voltage value setting section 23: Judgment information acquisition unit 24: Judgment section 25: Voltage value estimation unit 30: Propagation time calculation unit 40: Time difference calculation section 50: Flow rate calculation section 60: Storage section 100: Flow rate calculation section P2_def: First voltage value P3_def: Second voltage value Pmax_def: Fifth voltage value P2_pv: Third voltage value P3_pv: 4th voltage value Pmax_pv: 6th voltage value

Claims

1. a voltage value acquiring unit that acquires a first voltage value of a first peak and a second voltage value of the second peak of a first waveform signal including a first peak and a second peak, and acquires a third voltage value of the third peak of a second waveform signal including a third peak and a fourth peak; a reference voltage value setting unit that sets a predetermined voltage value between the first voltage value and the second voltage value as a reference voltage value; a voltage value estimating unit that estimates a fourth voltage value of the fourth peak based on the first voltage value, the second voltage value, and the third voltage value acquired by the voltage value acquiring unit, When the third voltage value is acquired by the voltage value acquisition unit while the reference voltage value is set, the reference voltage value setting unit sets a predetermined voltage value between the third voltage value and the fourth voltage value estimated by the voltage value estimation unit as a new reference voltage value.

23. An information processing apparatus comprising:

2. a determination information acquisition unit that acquires determination information for determining whether or not to set a new reference voltage value; The voltage value estimation unit estimates the fourth voltage value based on the information acquired by the determination information acquisition unit.

2. The information processing apparatus according to claim 1,

3. The determination information includes information regarding a temperature change when the voltage value acquisition unit acquires a voltage value.

3. The information processing apparatus according to claim 2.

4. The determination information includes information regarding an elapsed time since the first voltage value was acquired by the voltage value acquisition unit.

3. The information processing apparatus according to claim 2.

5. the first waveform signal includes a fifth peak; the second waveform signal includes a sixth peak; the voltage value acquiring unit acquires a fifth voltage value of the fifth peak of the first waveform signal and a sixth voltage value of the sixth peak of the second waveform signal; The voltage value estimation unit estimates the fourth voltage value of the fourth peak based on the first voltage value, the second voltage value, the third voltage value, the fifth voltage value, and the sixth voltage value acquired by the voltage value acquisition unit.

2. The information processing apparatus according to claim 1,

6. The first waveform signal and the second waveform signal are signals obtained based on pulse waves output from the same or identical ultrasonic transducer.

6. The information processing apparatus according to claim 1,

7. An information processing device according to any one of claims 1 to 5; a first signal acquisition unit that acquires a first ultrasonic signal based on a first ultrasonic wave output from one ultrasonic transducer and input to the other ultrasonic transducer via the fluid to be measured; a second signal acquisition unit that acquires a second ultrasonic signal based on a second ultrasonic wave output from the other ultrasonic transducer and input to the one ultrasonic transducer via the fluid; a propagation time calculation unit that calculates a propagation time of the first ultrasonic signal and the second ultrasonic signal based on a zero cross time of a voltage value of the first ultrasonic signal and the second ultrasonic signal after the voltage value reaches the reference voltage value set by the reference voltage value setting unit; a time difference calculation unit that calculates a difference between the propagation time of the first ultrasonic wave and the propagation time of the second ultrasonic wave acquired by the propagation time calculation unit; a flow rate calculation unit that calculates a flow rate of the fluid based on a calculation result by the time difference calculation unit.

1. An ultrasonic flow meter comprising:

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