An ultrasonic signal gain delay compensation method

Abstract

The application discloses a method for compensating gain and time delay based on an ultrasonic signal, which is applied to a system for compensating gain and time delay based on an ultrasonic signal, and comprises the following steps: a processing module acquires a first echo signal under basic gain; after gain adjustment, an excitation module drives a signal detection module to output the echo signal; and an amplification and comparison module amplifies the echo signal to obtain a second echo signal; the amplification and comparison module compares the second echo signal with the first echo signal; and the processing module compensates the second echo signal based on the size relationship between the second echo signal and the first echo signal. In the application, the echo signals under different gains are compared with the first echo signal, and the echo signals under different gains are compensated, so that the time delay caused by different gains is eliminated, and the error of calculated gas flow is reduced.

Description

Technical Field

[0001] This invention relates to the field of signal processing technology, and in particular to a method for gain delay compensation based on ultrasonic signals. Background Technology

[0002] Ultrasonic signals are primarily generated by transducers, which consist of piezoelectric ceramics, an acoustic matching layer, and a damping layer. When two transducers are placed face-to-face, they can convert between mechanical energy and electrical energy. Their working principle is as follows: The piezoelectric ceramic is the core component of the transducer, and its main component is lead zirconium titanate (PZT). When a high-frequency alternating voltage is applied, the piezoelectric ceramic converts electrical energy into mechanical energy through the inverse piezoelectric effect, generating high-frequency vibrations and thus emitting ultrasonic waves. When the ultrasonic waves propagate through a fluid and are received by the receiving transducer, the piezoelectric ceramic converts the mechanical energy (ultrasonic vibration) back into electrical energy through the direct piezoelectric effect, thereby generating an ultrasonic signal.

[0003] The ultrasonic signal received by the transducer is usually weak and needs to be amplified. After the ultrasonic signal is adjusted for gain, there will indeed be a certain delay between the input signal and the output signal. The delay will also vary depending on the amplification gain. When calculating gas flow rate, the presence of amplification gain will cause errors in the calculated gas flow rate. Summary of the Invention

[0004] To address the problems existing in the prior art, this specification describes a method for ultrasonic signal gain delay compensation through one or more embodiments.

[0005] This application provides a method for ultrasonic signal gain delay compensation, applied to an ultrasonic signal gain delay compensation system. The system includes a signal detection module, an amplification and comparison module, an excitation module, and a processing module. The signal detection module is electrically connected to the amplification and comparison module and the excitation module. The processing module is electrically connected to the signal detection module, the amplification and comparison module, and the excitation module. The method includes:

[0006] The processing module acquires the first echo signal at the base gain. After gain adjustment, the excitation module drives the signal detection module to output the echo signal. The amplification and comparison module amplifies the echo signal to obtain the second echo signal.

[0007] The amplification and comparison module compares the second echo signal with the first echo signal, and the processing module compensates the second echo signal based on the magnitude relationship between the second echo signal and the first echo signal.

[0008] Preferably, adjusting the distance between the excitation transducer and the receiving transducer when the amplitude of the second echo signal is not equal to the amplitude of the first echo signal includes:

[0009] When the amplitude of the second echo signal is greater than the amplitude of the first echo signal, the distance between the excitation transducer and the receiving transducer is increased;

[0010] When the amplitude of the second echo signal is less than the amplitude of the first echo signal, the distance between the excitation transducer and the receiving transducer is reduced.

[0011] Preferably, adjusting the distance between the excitation transducer and the receiving transducer when the second echo signal is not equal to the first echo signal includes:

[0012] The adjustment distance between the excitation transducer and the receiving transducer is calculated based on the distance between the excitation transducer and the receiving transducer corresponding to the first echo signal and the distance between the excitation transducer and the receiving transducer corresponding to the second echo signal.

[0013] Preferably, the amplification and comparison module includes a first amplification unit, a second amplification unit, a signal comparator, an analog-to-digital converter, and a timing chip. The signal detection module is electrically connected to the input terminal of the first amplification unit, the output terminal of the first amplification unit is electrically connected to the input terminal of the second amplification unit, the output terminal of the second amplification unit is electrically connected to the first terminal of the analog-to-digital converter and the input terminal of the signal comparator, the output terminal of the signal comparator is electrically connected to the first terminal of the timing chip, and the second terminal of the analog-to-digital converter and the second terminal of the timing chip are electrically connected to the processing module.

[0014] Preferably, the compensation of the second echo signal includes:

[0015] The time chip acquires the gain-adjusted forward and reverse flight time, and calculates the gain-adjusted forward and reverse time difference based on the gain-adjusted forward and reverse flight time.

[0016] The compensation time is calculated based on the time difference between forward and reverse currents after gain adjustment and the time difference between forward and reverse currents under the base gain, and the second echo signal is compensated based on the compensation time.

[0017] Preferably, the first amplification unit includes a first chip, a first comparator, a first resistor, and a first capacitor; the first end of the first resistor is electrically connected to the signal detection module, the second end of the first resistor is electrically connected to the first chip, the first input terminal of the first comparator, and the first end of the first capacitor, the second input terminal of the first comparator is grounded, and the output terminal of the first comparator is electrically connected to the second end of the first chip, the first capacitor, and the second amplification unit.

[0018] Preferably, a filter capacitor and a filter resistor are provided between the first amplification unit and the second amplification unit. The first end of the filter capacitor is electrically connected to the first amplification unit, the first end of the filter resistor, and the second amplification unit, and the second end of the filter resistor is grounded.

[0019] Preferably, adjusting the distance between the excitation transducer and the receiving transducer when the second echo signal is not equal to the first echo signal further includes: calculating the distance between the excitation transducer and the receiving transducer corresponding to the second echo signal based on the amplitude of the first echo signal, the amplitude of the second echo signal, and a set attenuation coefficient.

[0020] The beneficial effects of this invention are as follows:

[0021] 1. The method and system provided in the embodiments of this specification compare the echo signal under different gains with the first echo signal and compensate for the echo signal under different gains to eliminate the delay caused by different gains, thereby reducing the error in the calculated gas flow rate;

[0022] 2. The methods and systems provided in the embodiments of this specification improve the accuracy of ultrasonic signals by arranging the signal detection module in a sealed environment to eliminate the influence of airflow between transducers and ultrasonic signals.

[0023] 3. The methods and systems provided in the embodiments of this specification isolate, shape, or purify the signal output from the first amplification unit by setting filter circuits in the two amplification units, thereby ensuring the quality of the signal during the amplification process in the second amplification unit;

[0024] 4. The method and system provided in the embodiments of this specification, compared with the method of adjusting the amplitude of the echo signal through electronic circuits, adjusts the phase difference between the transmitted wave and the reflected wave by adjusting the distance between the two transducers by a lead screw, and adjusts the amplitude of the echo signal. This application can be implemented in strong electromagnetic fields, high temperature or corrosive environments, and has a strong resistance to environmental interference.

[0025] 5. The methods and systems provided in the embodiments of this specification have similar effects on forward and reverse current signals due to environmental vibration, circuit delay, clock drift, and other interference. Therefore, the echo signal is compensated by the time difference between forward and reverse current to cancel common-mode noise and improve the signal-to-noise ratio. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is an architecture diagram of an ultrasonic signal gain delay compensation system implemented in this specification.

[0028] Figure 2 This is a schematic diagram of an ultrasonic signal gain delay compensation system implemented in this specification.

[0029] Figure 3 This is a schematic diagram of the first and second amplification units of an ultrasonic signal gain delay compensation system in a specific implementation of this specification.

[0030] Figure 4 This is a first schematic diagram of an excitation module based on an ultrasonic signal gain delay compensation system in a specific implementation of this specification;

[0031] Figure 5 This is a second schematic diagram of an excitation module based on an ultrasonic signal gain delay compensation system in a specific implementation of this specification;

[0032] Figure 6 This is a schematic diagram of a method for compensating for the gain delay of ultrasonic signals in a specific implementation of this specification;

[0033] Figure 7 This is a flowchart illustrating a specific implementation of an ultrasonic signal gain delay compensation method in this specification. Detailed Implementation

[0034] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings.

[0035] In the following description, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The following description provides multiple embodiments of this application, which can be substituted or combined with each other. Therefore, this application can also be considered to include all possible combinations of the same and / or different embodiments described. Thus, if one embodiment includes features A, B, and C, and another embodiment includes features B and D, then this application should also be considered to include embodiments containing one or more other possible combinations of A, B, C, and D, even if such embodiments are not explicitly described in the following text.

[0036] The following description provides examples and does not limit the scope, applicability, or examples set forth in the claims. Changes may be made to the function and arrangement of the described elements without departing from the scope of this application. Various processes or components may be appropriately omitted, substituted, or added to the examples. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Furthermore, features described with respect to some examples may be combined into other examples.

[0037] Please see Figure 1 , Figure 1 This specification illustrates a schematic diagram of the architecture of an ultrasonic signal gain delay compensation system provided in an embodiment:

[0038] like Figure 1 As shown, the ultrasonic signal gain delay compensation system includes a signal detection module, an amplification and comparison module, an excitation module, and a processing module. The signal detection module is electrically connected to the amplification module and the excitation module, and the processing module is electrically connected to the signal detection module, the amplification and comparison module, and the excitation module.

[0039] In one possible implementation, such as Figure 2 As shown, Figure 2 The inner ellipse contains a sealed environment. The signal detection module includes an excitation transducer, a receiving transducer, a lead screw, and a motor. These components are arranged within the sealed environment. Both the excitation and receiving transducers are fixed to the lead screw, and the end of the lead screw is detachably connected to the motor. By placing the signal detection module within a sealed environment, the influence of airflow between transducers and the ultrasonic signal is eliminated, thus improving the accuracy of the ultrasonic signal.

[0040] In one possible implementation, the amplification and comparison module includes a first amplification unit, a second amplification unit, a signal comparator, an analog-to-digital converter, and a timing chip. The signal detection module is electrically connected to the input terminal of the first amplification unit, the output terminal of the first amplification unit is electrically connected to the input terminal of the second amplification unit, the output terminal of the second amplification unit is electrically connected to the first terminal of the analog-to-digital converter and the input terminal of the signal comparator, the output terminal of the signal comparator is electrically connected to the first terminal of the timing chip, and the second terminal of the analog-to-digital converter and the second terminal of the timing chip are electrically connected to the processing module.

[0041] Furthermore, the first amplification unit includes a first chip U19, a first comparator IC6B, a first resistor R39, and a first capacitor C19; the first end of the first resistor R39 is electrically connected to the signal detection module, the second end of the first resistor R39 is electrically connected to the first chip U19, the first input terminal of the first comparator IC6B, and the first end of the first capacitor C19, the second input terminal of the first comparator IC6B is grounded, and the output terminal of the first comparator IC6B is electrically connected to the second end of the first chip U19, the first capacitor C19, and the second amplification unit.

[0042] Furthermore, the second amplification unit includes a second chip U30, a second comparator IC6A, a second resistor R40, and a second capacitor C18; the first end of the second resistor R40 is electrically connected to the first amplification unit, the second end of the second resistor R40 is electrically connected to the second chip U30, the second input terminal of the second comparator IC6A, and the second end of the second capacitor C18, the second input terminal of the second comparator IC6A is grounded, the output terminal of the second comparator IC6A is electrically connected to the second chip U30, the second end of the second capacitor C18, and the signal comparator, and the second chip U30 is electrically connected to the first chip U19.

[0043] Preferably, a filter capacitor C20 and a filter resistor R41 are provided in the first amplification unit and the second amplification unit. The first terminal of the filter capacitor C20 is electrically connected to the output terminal of the first comparator IC6B, the first terminal of the filter resistor R41, and the first terminal of the second resistor R40. The second terminal of the filter resistor R41 is grounded. By providing filter circuits in the two amplification units, the signal output from the first amplification unit is isolated, shaped, or purified, ensuring the signal quality during the amplification process in the second amplification unit.

[0044] In one possible implementation, the excitation module includes the devices shown in Figures 1 and 2. The LT1945 is a dual-channel synchronous buck PWM controller, paired with three ZHCS400TA (MOSFET half-bridge chips) to achieve two independent buck outputs, reducing the input voltage VIN2 to the desired output voltage. The first buck circuit includes L1, C30, C33, D2, C303, and R55. L1 is an energy storage element, working with the capacitor to filter the output DC voltage. C30 and C33 are used to filter switching noise. D2 is a freewheeling diode, providing a path for the inductor current when the switch is off. C303 is used to smooth the output voltage and reduce ripple. R55 is an enable control resistor, enabling the channel when the SHDN1 pin of the LT1945 is high. The second buck circuit includes L2, D3, C45, R59, R72, and R55. 73, C47, C51, and C31; L2 is an energy storage element that works with the capacitor to filter the output DC voltage; C31 is used to suppress switching spikes; D3 is a freewheeling diode that provides a path for inductor current when the switch is off; C45 is used to smooth the output voltage and reduce ripple; R59 is an enable control resistor that enables the channel when the SHDN1 pin of the LT1945 is high; R72 and R73 are voltage divider resistors; C47 is used to stabilize the feedback loop and prevent oscillation; and C51 is used for filtering the small signal circuit inside the control chip. The excitation module operates by supplying power to VIN2. Through input capacitor filtering, the LT1945 controls the high-frequency switching of the ZHCS400TA (MOSFET half-bridge chip) based on feedback signals (FB1 / FB2). The switching pulse drives the inductor to store / release energy, converting the high-voltage input into a low-voltage output. The inductor and output capacitors (C303, C45) filter to obtain smooth DC. The voltage divider resistors (R72 / R73) sample the output voltage and feed it back to the LT1945 to dynamically adjust the switching duty cycle and stabilize the output.

[0045] Those skilled in the art will clearly understand that the technical solutions of the embodiments of this application can be implemented by means of software and / or hardware. In this specification, "unit" and "module" refer to software and / or hardware that can independently complete or cooperate with other components to complete a specific function, wherein the hardware may be, for example, a field-programmable gate array (FPGA), an integrated circuit (IC), etc.

[0046] Each processing unit and / or module in the embodiments of this application can be implemented by an analog circuit that implements the functions described in the embodiments of this application, or by software that executes the functions described in the embodiments of this application.

[0047] Please refer to the following. Figure 2 , Figure 2A flowchart illustrating an ultrasonic signal gain delay compensation method provided in an embodiment of this specification is shown.

[0048] See Figure 2 Methods based on ultrasonic signal gain delay compensation include:

[0049] The processing module acquires the first echo signal at the base gain. After gain adjustment, the excitation module drives the signal detection module to output the echo signal. The amplification and comparison module amplifies the echo signal to obtain the second echo signal.

[0050] The amplification and comparison module compares the second echo signal with the first echo signal, and the processing module compensates the second echo signal based on the magnitude relationship between the second echo signal and the first echo signal.

[0051] In the embodiments described in this specification, the processing module first acquires a first echo signal, which is obtained by the processing module at a base gain. The base gain means that the original, weak signal output by the gas flow sensor is initially amplified and properly conditioned (e.g., filtered), converting it into a more robust, cleaner signal form that is more suitable for subsequent precise digitization and processing, thus laying an accurate and reliable foundation for the entire flow calculation process. After gain adjustment, the processing module communicates with the excitation module, which drives the signal detection module to output an echo signal. The amplification and comparison module amplifies the echo signal and compares it with the first echo signal. The processing module compensates for the second echo signal based on the magnitude relationship between the two signals, thereby calculating the gas flow rate of the gas meter. In this application, by comparing the echo signals at different gains with the first echo signal and compensating for the echo signals at different gains, the delay caused by different gains is eliminated, thereby reducing the error in the calculated gas flow rate.

[0052] It should be noted that the echo signal consists of the transmitted wave emitted by the excitation transducer and the reflected wave emitted by the receiving transducer.

[0053] In one possible implementation, when the amplitude of the second echo signal is greater than the amplitude of the first echo signal, the distance between the excitation transducer and the receiving transducer is increased; when the amplitude of the second echo signal is less than the amplitude of the first echo signal, the distance between the excitation transducer and the receiving transducer is decreased; and when the amplitude of the second echo signal is equal to the amplitude of the first echo signal, compensation is performed on the second echo signal. Compared to adjusting the echo signal amplitude through electronic circuitry, adjusting the phase difference between the transmitted and reflected waves by adjusting the distance between the two transducers using a lead screw, and thus adjusting the echo signal amplitude, allows this application to be implemented in strong electromagnetic fields, high-temperature environments, or corrosive environments, exhibiting stronger resistance to environmental interference.

[0054] Furthermore, assuming that the distance between the excitation transducer and the receiving transducer is D1 under the base gain, and the distance between the excitation transducer and the receiving transducer corresponding to the second echo signal is D2 after the gain is adjusted, then the distance adjusted between the excitation transducer and the receiving transducer is D3 = D2 - D1.

[0055] Specifically, the relationship between the amplitude of the echo signal and the distance between the excitation transducer and the receiving transducer is as follows:

[0056]

[0057] Where is the amplitude of the echo signal corresponding to a certain gain, is the initial peak value (i.e., the amplitude of the echo signal when the distance between the excitation transducer and the receiving transducer is 0), is the attenuation coefficient, which is related to the frequency of the ultrasound and the characteristics of the medium and can be obtained experimentally, and d is the distance between the excitation transducer and the receiving transducer. As can be seen from the above, the initial peak value is a fixed value, and the attenuation coefficient can be obtained experimentally. Therefore, the relationship between the amplitude of the echo signal corresponding to a certain gain and the distance between the excitation transducer and the receiving transducer can be obtained. Thus, the distance between the excitation transducer and the receiving transducer corresponding to different gains can be calculated.

[0058] In one possible implementation, compensating for the second echo signal includes: a time chip acquiring the gain-adjusted forward and reverse flow flight times, which are the time it takes for the excitation transducer to transmit the signal to the receiving transducer and the time it takes for the receiving transducer to transmit the signal to the excitation transducer; subtracting the forward and reverse flow flight times to obtain the gain-adjusted time difference; subtracting the gain-adjusted time difference from the time difference under the base gain to obtain the compensation time; and a processing module compensating for the second echo signal based on the compensation time. Since environmental vibrations, circuit delays, clock drift, and other interferences have similar effects on the forward and reverse flow signals, compensation for the echo signal using the forward and reverse flow time difference is used to offset common-mode noise and improve the signal-to-noise ratio.

[0059] The foregoing description is merely an exemplary embodiment of this disclosure and should not be construed as limiting the scope of this disclosure. Any equivalent changes and modifications made in accordance with the teachings of this disclosure shall still fall within the scope of this disclosure. Those skilled in the art will readily conceive of embodiments of this disclosure upon considering the specification and practicing the disclosure herein. This application is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not described herein. The specification and embodiments are to be considered exemplary only, and the scope and spirit of this disclosure are defined by the claims.

Claims

1. A method for compensating for gain delay of ultrasonic signals, characterized in that, The method is applied to an ultrasonic signal gain delay compensation system. The system includes a signal detection module, an amplification and comparison module, an excitation module, and a processing module. The signal detection module is electrically connected to the amplification and comparison module and the excitation module. The processing module is also electrically connected to the signal detection module, the amplification and comparison module, and the excitation module. The signal detection module includes an excitation transducer, a receiving transducer, a lead screw, and a motor, all arranged in a sealed environment. The excitation transducer, the receiving transducer, and the lead screw are connected to the lead screw, which is connected to the motor. The method includes: The processing module acquires the first echo signal at the base gain. After gain adjustment, the excitation module drives the signal detection module to output the echo signal, and the amplification and comparison module amplifies the echo signal to obtain the second echo signal. The amplification and comparison module compares the second echo signal with the first echo signal, and the processing module compensates the second echo signal based on the magnitude relationship between the second echo signal and the first echo signal. The compensation of the second echo signal based on the magnitude relationship between the second echo signal and the first echo signal includes: When the amplitude of the second echo signal is not equal to the amplitude of the first echo signal, the distance between the excitation transducer and the receiving transducer is adjusted so that the second echo signal is equal to the first echo signal. The second echo signal is compensated when the amplitude of the second echo signal is equal to the amplitude of the first echo signal.

2. The method for compensating for gain delay of ultrasonic signals according to claim 1, characterized in that, The step of adjusting the distance between the excitation transducer and the receiving transducer when the amplitude of the second echo signal is not equal to the amplitude of the first echo signal includes: When the amplitude of the second echo signal is greater than the amplitude of the first echo signal, the distance between the excitation transducer and the receiving transducer is increased; When the amplitude of the second echo signal is less than the amplitude of the first echo signal, the distance between the excitation transducer and the receiving transducer is reduced.

3. The method for compensating for gain delay of ultrasonic signals according to claim 1, characterized in that, The step of adjusting the distance between the excitation transducer and the receiving transducer when the second echo signal is not equal to the first echo signal includes: The adjustment distance between the excitation transducer and the receiving transducer is calculated based on the distance between the excitation transducer and the receiving transducer corresponding to the first echo signal and the distance between the excitation transducer and the receiving transducer corresponding to the second echo signal.

4. The method for compensating for gain delay of ultrasonic signals according to claim 1, characterized in that, The amplification and comparison module includes a first amplification unit, a second amplification unit, a signal comparator, an analog-to-digital converter, and a timing chip. The signal detection module is electrically connected to the input terminal of the first amplification unit, the output terminal of the first amplification unit is electrically connected to the input terminal of the second amplification unit, the output terminal of the second amplification unit is electrically connected to the first terminal of the analog-to-digital converter and the input terminal of the signal comparator, the output terminal of the signal comparator is electrically connected to the first terminal of the timing chip, and the second terminal of the analog-to-digital converter and the second terminal of the timing chip are electrically connected to the processing module.

5. The method for compensating for gain delay of ultrasonic signals according to claim 4, characterized in that, The compensation of the second echo signal includes: The time chip acquires the gain-adjusted forward and reverse flight time, and calculates the gain-adjusted forward and reverse time difference based on the gain-adjusted forward and reverse flight time. The compensation time is calculated based on the time difference between forward and reverse currents after gain adjustment and the time difference between forward and reverse currents under the base gain, and the second echo signal is compensated based on the compensation time.

6. The method for compensating for gain delay of ultrasonic signals according to claim 4, characterized in that, The first amplification unit includes a first chip, a first comparator, a first resistor, and a first capacitor; the first end of the first resistor is electrically connected to the signal detection module, the second end of the first resistor is electrically connected to the first chip, the first input terminal of the first comparator, and the first end of the first capacitor, the second input terminal of the first comparator is grounded, and the output terminal of the first comparator is electrically connected to the second end of the first chip, the first capacitor, and the second amplification unit.

7. The method for compensating for gain delay of ultrasonic signals according to claim 6, characterized in that, A filter capacitor and a filter resistor are provided between the first amplification unit and the second amplification unit. The first end of the filter capacitor is electrically connected to the first amplification unit, and the second end of the filter capacitor is electrically connected to the first end of the filter resistor and the second amplification unit. The second end of the filter resistor is grounded.

8. The method for compensating for gain delay of ultrasonic signals according to claim 3, characterized in that, The step of adjusting the distance between the excitation transducer and the receiving transducer when the second echo signal is not equal to the first echo signal further includes: calculating the distance between the excitation transducer and the receiving transducer corresponding to the second echo signal based on the amplitude of the first echo signal, the amplitude of the second echo signal, and a set attenuation coefficient.

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