Gain delay compensation method based on ultrasonic signal

Abstract

The invention discloses a gain delay compensation method based on an ultrasonic signal, the method is applied to a gain delay compensation system based on the ultrasonic signal, and the method comprises the following steps: a processing module obtains a first echo signal under a basic gain, and after the gain is adjusted, an excitation module drives a signal detection module to output the echo signal, the amplification comparison module amplifies the echo signal to obtain a second echo signal; the amplification 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. According to the invention, 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 delay caused by different gains is eliminated, and the error of the calculated gas flow is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of signal processing, and in particular to a method for compensating ultrasonic signal gain delay. Background Art

[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 mechanical energy into electrical energy and vice versa. Their operating principle is as follows: Piezoelectric ceramics are the core component of the transducer, primarily composed of lead zirconium titanate (PZT). When a high-frequency alternating voltage is applied, the piezoelectric ceramics convert 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 the fluid and are received by the receiving transducer, the piezoelectric ceramics convert mechanical energy (ultrasonic vibrations) into electrical energy through the direct piezoelectric effect, 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 gain adjusted, there will indeed be a certain delay between the input signal and the output signal, and the delay will be different with different amplification gains. When calculating the gas flow, the existence of the amplification gain will cause errors in the calculated gas flow. Summary of the Invention

[0004] To solve the problems existing in the prior art, one or more embodiments of this specification describe a method for compensating for ultrasonic signal gain delay.

[0005] In the present application, a method for compensating for ultrasonic signal gain delay is provided. 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 electrically connected to the signal detection module, the amplification and comparison module, and the excitation module. The method includes: The processing module obtains a first echo signal under a basic gain, and 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 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 a magnitude relationship between the second echo signal and the first echo signal.

[0006] Preferably, when the amplitude of the second echo signal is not equal to the amplitude of the first echo signal, adjusting the distance between the excitation transducer and the receiving transducer includes: When the amplitude of the second echo signal is greater than the amplitude of the first echo signal, increasing the distance between the excitation transducer and the receiving transducer; When the amplitude of the second echo signal is smaller than the amplitude of the first echo signal, the distance between the excitation transducer and the receiving transducer is reduced.

[0007] Preferably, when the second echo signal is not equal to the first echo signal, adjusting the distance between the excitation transducer and the receiving transducer includes: An adjusted distance between the excitation transducer and the receiving transducer is calculated based on a distance between the excitation transducer and the receiving transducer corresponding to the first echo signal and a distance between the excitation transducer and the receiving transducer corresponding to the second echo signal.

[0008] 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 time chip. The signal detection module is electrically connected to the input end of the first amplification unit, the output end of the first amplification unit is electrically connected to the input end of the second amplification unit, the output end of the second amplification unit is electrically connected to the first end of the analog-to-digital converter and the input end of the signal comparator, the output end of the signal comparator is electrically connected to the first end of the time chip, and the second end of the analog-to-digital converter and the second end of the time chip are electrically connected to the processing module.

[0009] Preferably, compensating the second echo signal includes: The time chip collects the gain-adjusted upstream and downstream flight times, and calculates the gain-adjusted upstream and downstream time differences based on the gain-adjusted upstream and downstream flight times; A compensation time is calculated based on the forward and reverse flow time difference after gain adjustment and the forward and reverse flow time difference at the basic gain, and the second echo signal is compensated based on the compensation time.

[0010] 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 end of the first comparator and the first end of the first capacitor, the second input end of the first comparator is grounded, and the output end of the first comparator is electrically connected to the first chip, the second end of the first capacitor and the second amplification unit.

[0011] Preferably, a filter capacitor and a filter resistor are provided between the first amplifying unit and the second amplifying unit, the first end of the filter capacitor is electrically connected to the first amplifying unit, the first end of the filter resistor and the second amplifying unit, and the second end of the filter resistor is grounded.

[0012] 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 also 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 the set attenuation coefficient.

[0013] The beneficial effects of the present invention are: 1. The methods and systems provided in the embodiments of this specification compare echo signals at different gains with the first echo signal and compensate for the echo signals at different gains to eliminate the delay caused by the different gains, thereby reducing the error in the calculated gas flow rate. 2. The methods and systems provided in the embodiments of this specification eliminate the influence of air flow between the transducers and the ultrasonic signal by placing the signal detection module in a sealed environment, thereby improving the accuracy of the ultrasonic signal. 3. The methods and systems provided in the embodiments of this specification provide filtering circuits within the two amplifying units to isolate, shape, or purify the signal output by the first amplifying unit, thereby ensuring the quality of the signal during amplification by the second amplifying unit. 4. Compared to methods that adjust the echo signal amplitude through electronic circuits, the methods and systems provided in the embodiments of this specification adjust the echo signal amplitude by adjusting the phase difference between the transmitted wave and the reflected wave by adjusting the spacing between the two transducers using a screw. This application can be implemented in strong electromagnetic fields, high temperatures, or corrosive environments, and has strong resistance to environmental interference. 5. The methods and systems provided in the embodiments of this specification, because interference such as environmental vibration, circuit delay, and clock drift has similar effects on forward and reverse flow signals, compensate for the echo signal through the forward and reverse flow time difference to offset common mode noise and improve the signal-to-noise ratio. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] 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 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 creative work.

[0015] Figure 1 This is an architecture diagram of an ultrasonic signal gain delay compensation system in a specific implementation of this specification; Figure 2 This is a schematic diagram of a gain delay compensation system based on an ultrasonic signal in a specific implementation of this specification; Figure 3It is a schematic diagram of a first amplifying unit and a second amplifying unit based on an ultrasonic signal gain delay compensation system in a specific implementation of this specification; 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; 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; Figure 6 This is a schematic diagram of a method for compensating for ultrasonic signal gain delay in a specific implementation of this specification; Figure 7 It is a flowchart of a method for compensating ultrasonic signal gain delay in the specific implementation of this specification. DETAILED DESCRIPTION

[0016] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application.

[0017] In the following introduction, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance. The following introduction provides multiple embodiments of the present application. Different embodiments can be replaced or combined, so the present application can also be considered to include all possible combinations of the same and / or different embodiments described. Therefore, if one embodiment includes features A, B, and C, and another embodiment includes features B and D, then the present application should also be considered to include embodiments containing one or more of all other possible combinations of A, B, C, and D, even though the embodiment may not be clearly described in the following text.

[0018] 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 elements described without departing from the scope of the present application. Various examples may appropriately omit, replace, or add various processes or components. For example, the described method may be performed in an order different from the order described, and various steps may be added, omitted, or combined. In addition, features described in some examples may be combined in other examples.

[0019] See also Figure 1 , Figure 1 The following is a schematic diagram showing the architecture of an ultrasonic signal gain delay compensation system provided in an embodiment of this specification: like Figure 1As 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.

[0020] In one possible implementation, Figure 2 As shown, Figure 2 The inner ellipse is a sealed environment. The signal detection module, which includes an excitation transducer, a receiving transducer, a lead screw, and a motor, is arranged within the sealed environment. The excitation and receiving transducers are both fixed to the lead screw, and the end of the lead screw is detachably connected to the motor. By placing the signal detection module in a sealed environment, the influence of air flow between the transducers and the ultrasonic signal is eliminated, thereby improving the accuracy of the ultrasonic signal.

[0021] 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 time chip. The signal detection module is electrically connected to the input end of the first amplification unit, the output end of the first amplification unit is electrically connected to the input end of the second amplification unit, the output end of the second amplification unit is electrically connected to the first end of the analog-to-digital converter and the input end of the signal comparator, the output end of the signal comparator is electrically connected to the first end of the time chip, and the second end of the analog-to-digital converter and the second end of the time chip are electrically connected to the processing module.

[0022] Furthermore, the first amplifying unit includes a first chip U19, a first comparator IC6B, a first resistor R39, and a first capacitor C19; a first end of the first resistor R39 is electrically connected to the signal detection module, a second end of the first resistor R39 is electrically connected to the first chip U19, a first input end of the first comparator IC6B, and a first end of the first capacitor C19, a second input end of the first comparator IC6B is grounded, and an output end of the first comparator IC6B is electrically connected to the first chip U19, a second end of the first capacitor C19, and the second amplifying unit. Furthermore, the second amplifying 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 amplifying unit, the second end of the second resistor R40 is electrically connected to the second chip U30, the second input end of the second comparator IC6A and the second end of the second capacitor C18, the second input end of the second comparator IC6A is grounded, the output end 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.

[0023] Preferably, a filter capacitor C20 and a filter resistor R41 are provided in the first and second amplifying units. The first end of the filter capacitor C20 is electrically connected to the output end of the first comparator IC6B, the first end of the filter resistor R41, and the first end of the second resistor R40. The second end of the filter resistor R41 is grounded. By providing a filter circuit in the two amplifying units, the signal output by the first amplifying unit is isolated, shaped, or purified, thereby ensuring the quality of the signal during amplification in the second amplifying unit.

[0024] In one possible implementation, the excitation module includes the devices shown in the figure and the figure. The LT1945 is a dual-channel synchronous buck PWM controller, which is equipped with three ZHCS400TA (MOSFET half-bridge chips) to achieve two independent buck outputs, reducing the input voltage VIN2 to the required output voltage. The first buck circuit includes L1, C30, C33, D2, C303 and R55. L1 is an energy storage element that filters the output DC voltage in conjunction with the capacitor. C30 and C33 are used to filter out switching noise. D2 is a freewheeling diode that provides a path for the inductor current when the switch is closed. C303 is used to smooth the output voltage and reduce ripple. R55 is an enable control resistor that opens the channel when the SHDN1 pin of the LT1945 is at a high level. The second buck circuit includes L2, D3, C45, R59, R72, R 73, C47, C51 and C31, L2 are energy storage elements, which work with the capacitor to filter the output DC voltage. C31 is used to suppress switching spikes. D3 is a freewheeling diode, which provides a path for the inductor current when the switch is closed. C45 is used to smooth the output voltage and reduce ripple. R59 is an enable control resistor, which turns on the channel when the SHDN1 pin of LT1945 is at a high level. R72 and R73 are voltage divider resistors. C47 is used to stabilize the feedback loop and prevent oscillation. C51 is used to filter the small signal circuit inside the control chip. The operation process of the excitation module supplies power to VIN2, which is filtered by the input capacitor. The LT1945 controls the high-frequency switching of the ZHCS400TA (MOSFET half-bridge chip) according to the feedback signal (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 capacitor (C303, C45) are filtered to obtain a smooth DC. The voltage divider resistor (R72 / R73) samples the output voltage and feeds it back to the LT1945 to dynamically adjust the switching duty cycle and stabilize the output.

[0025] Those skilled in the art will clearly understand that the technical solutions of the embodiments of the present application can be implemented with the help of software and / or hardware. "Unit" and "module" in this specification refer to software and / or hardware that can independently perform or cooperate with other components to perform specific functions, where the hardware can be, for example, a field-programmable gate array (FPGA) or an integrated circuit (IC).

[0026] Each processing unit and / or module in the embodiments of the present application may be implemented by an analog circuit that implements the functions described in the embodiments of the present application, or may be implemented by software that executes the functions described in the embodiments of the present application.

[0027] See next Figure 2 , Figure 2 A flow chart of a method for compensating ultrasonic signal gain delay provided in an embodiment of this specification is shown.

[0028] See Figure 2 , the ultrasonic signal gain delay compensation method includes: The processing module obtains a first echo signal under a basic gain, and 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 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 a magnitude relationship between the second echo signal and the first echo signal.

[0029] In the embodiments of this specification, the processing module first obtains a first echo signal. The first echo signal is obtained by the processing module at a base gain. The base gain is defined as the initial amplification and necessary conditioning (e.g., filtering) of the raw, weak signal output by the gas flow sensor, converting it into a more robust, cleaner signal that is more suitable for subsequent precise digitization and processing, thereby laying an accurate and reliable foundation for the entire flow calculation process. After the gain is adjusted, the processing module communicates with the excitation module. The excitation module drives the signal detection module to output an echo signal. The amplification and comparison module amplifies the echo signal and then compares a second echo signal with the first echo signal. The processing module compensates the second echo signal based on the magnitude relationship between the second echo signal and the first echo signal, 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 the echo signals at different gains, the delay caused by the different gains is eliminated, thereby reducing the error in the calculated gas flow rate.

[0030] It should be noted that the echo signal is composed of the transmission wave emitted by the excitation transducer and the reflection wave emitted by the receiving transducer.

[0031] In one embodiment, when the amplitude of the second echo signal is greater than that 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 that of the first echo signal, the distance between the excitation transducer and the receiving transducer is reduced; and when the amplitude of the second echo signal is equal to that of the first echo signal, the second echo signal is compensated. Compared to adjusting the amplitude of the echo signal through an electronic circuit, the amplitude of the echo signal is adjusted by adjusting the phase difference between the transmitted wave and the reflected wave by adjusting the distance between the two transducers through a screw rod. This application can be implemented in strong electromagnetic fields, high temperatures, or corrosive environments, and has strong resistance to environmental interference.

[0032] Furthermore, assuming that under basic gain, the distance between the excitation transducer and the receiving transducer is D1, after adjusting the gain, that is, the distance between the excitation transducer and the receiving transducer corresponding to the second echo signal is D2, then the adjusted distance between the excitation transducer and the receiving transducer is D3 = D2- D1.

[0033] Specifically, the relationship between the amplitude of the echo signal and the distance between the excitation transducer and the receiving transducer is:

[0034] 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 corresponding to a distance between the excitation transducer and the receiving transducer of zero), 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. To this end, the distance between the excitation transducer and the receiving transducer corresponding to different gains can be calculated.

[0035] In one embodiment, compensating the second echo signal includes: collecting the gain-adjusted forward and reverse flight times using a time chip, where the forward and reverse flight times are the time between the excitation transducer transmitting the signal to the receiving transducer and the time between the receiving transducer transmitting the signal to the excitation transducer, subtracting the forward and reverse flight times to obtain the gain-adjusted time difference, subtracting the gain-adjusted time difference from the time difference under the basic gain to obtain the compensation time, and the processing module compensating the second echo signal based on the compensation time. Because interference such as environmental vibration, circuit delay, and clock drift have similar effects on forward and reverse signals, the echo signal is compensated using the forward and reverse time difference to offset common-mode noise and improve the signal-to-noise ratio.

[0036] The above is only an exemplary embodiment of the present disclosure and cannot be used to limit the scope of the present disclosure. That is, any equivalent changes and modifications made according to the teachings of the present disclosure are still within the scope of the present disclosure. After considering the specification and practicing the disclosure herein, those skilled in the art will easily think of the implementation scheme of the present disclosure. This application is intended to cover any variation, use or adaptation of the present disclosure, which follows the general principles of the present disclosure and includes common knowledge or customary technical means in the art that are not recorded in the present disclosure. The description and examples are to be regarded as exemplary only, and the scope and spirit of the present disclosure are defined by the claims.

Claims

1. A method for compensating ultrasonic signal gain delay, characterized in that: The method is applied to an ultrasonic signal gain delay compensation system, the system comprising a signal detection module, an amplification and comparison module, an excitation module, and a processing module, the signal detection module being electrically connected to the amplification and comparison module and the excitation module, the processing module being electrically connected to the signal detection module, the amplification and comparison module, and the excitation module, the method comprising: The processing module obtains a first echo signal under a basic gain, and 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 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 a magnitude relationship between the second echo signal and the first echo signal.

2. The method for compensating ultrasonic signal gain delay according to claim 1, characterized in that: The signal detection module includes an excitation transducer, a receiving transducer, a lead screw and a motor arranged in a sealed environment. The excitation transducer, the receiving transducer and the lead screw are connected, and the lead screw is connected to the motor.

3. The method for compensating ultrasonic signal gain delay according to claim 2, characterized in that: The compensating 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, adjusting the distance between the excitation transducer and the receiving transducer 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.

4. The method for compensating ultrasonic signal gain delay according to claim 3, characterized in that: The 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, increasing the distance between the excitation transducer and the receiving transducer; When the amplitude of the second echo signal is smaller than the amplitude of the first echo signal, the distance between the excitation transducer and the receiving transducer is reduced.

5. The method for compensating ultrasonic signal gain delay according to claim 3, characterized in that: The 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: An adjusted distance between the excitation transducer and the receiving transducer is calculated based on a distance between the excitation transducer and the receiving transducer corresponding to the first echo signal and a distance between the excitation transducer and the receiving transducer corresponding to the second echo signal.

6. The method for compensating ultrasonic signal gain delay according to claim 3, 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 time chip. The signal detection module is electrically connected to the input end of the first amplification unit, the output end of the first amplification unit is electrically connected to the input end of the second amplification unit, the output end of the second amplification unit is electrically connected to the first end of the analog-to-digital converter and the input end of the signal comparator, the output end of the signal comparator is electrically connected to the first end of the time chip, and the second end of the analog-to-digital converter and the second end of the time chip are electrically connected to the processing module.

7. The method for compensating ultrasonic signal gain delay according to claim 5, characterized in that: The compensating the second echo signal includes: The time chip collects the gain-adjusted upstream and downstream flight times, and calculates the gain-adjusted upstream and downstream time differences based on the gain-adjusted upstream and downstream flight times; A compensation time is calculated based on the forward and reverse flow time difference after gain adjustment and the forward and reverse flow time difference at the basic gain, and the second echo signal is compensated based on the compensation time.

8. The method for compensating ultrasonic signal gain delay according to claim 5, 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 end of the first comparator and the first end of the first capacitor, the second input end of the first comparator is grounded, and the output end of the first comparator is electrically connected to the first chip, the second end of the first capacitor and the second amplification unit.

9. The method for compensating ultrasonic signal gain delay according to claim 8, characterized in that: A filter capacitor and a filter resistor are provided between the first amplifying unit and the second amplifying unit. The first end of the filter capacitor is electrically connected to the first amplifying unit, the first end of the filter resistor and the second amplifying unit. The second end of the filter resistor is grounded.

10. The method for compensating ultrasonic signal gain delay according to claim 5, characterized in that: Adjusting the distance between the excitation transducer and the receiving transducer when the second echo signal is not equal to the first echo signal also 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 the set attenuation coefficient.

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