Aftershock signal elimination circuit and method

Abstract

The invention provides an aftershock signal elimination circuit and method, and the circuit comprises an aftershock signal conditioning circuit which is used for receiving an aftershock signal of an ultrasonic sensor, and converting the aftershock signal into a digital aftershock signal; the aftershock energy detection circuit is used for determining aftershock energy according to the digital aftershock signal and determining whether to send a working indication signal to the aftershock suppression signal sending circuit according to the aftershock energy; the aftershock suppression signal transmitting circuit is used for generating an aftershock suppression signal if a working indication signal is received, and transmitting the aftershock suppression signal to the ultrasonic sensor; the aftershock suppression signal is used for eliminating the aftershock signal of the ultrasonic sensor. Therefore, by adopting the elimination circuit, the elimination effect of the aftershock signal is improved, and no aftershock rebound exists; and the elimination circuit is simple in structure and lower in application cost.

Description

Technical Field

[0001] The present disclosure relates to the field of electronic technology, and in particular to a circuit and method for eliminating aftershock signals. Background Art

[0002] Ultrasonic sensors usually use piezoelectric materials to generate and detect ultrasonic waves. When an electrical signal acts on a piezoelectric material, it vibrates to generate ultrasonic waves. However, due to the physical properties of piezoelectric materials, even if the electrical signal stops, the material may continue to vibrate for a period of time, forming aftershocks. The aftershock effect may cause blind spots when measuring at close range, and the echo signal cannot be accurately detected. The aftershock signal may cause the sensor to misjudge the aftershock signal as a valid echo signal, resulting in false triggering and affecting the normal operation of the system.

[0003] In the related technology, an open-loop suppression system is generally used, which has a simple structure but low precision, poor interference suppression capability, is sensitive to changes in system parameters, and easily causes aftershock rebound, resulting in poor use effect. Summary of the invention

[0004] The present disclosure provides a circuit and method for eliminating aftershock signals to at least solve the above technical problems existing in the prior art.

[0005] In a first aspect, an embodiment of the present disclosure provides a circuit for eliminating aftershock signals, the circuit comprising:

[0006] An aftershock signal conditioning circuit, used for receiving the aftershock signal from the ultrasonic sensor, and converting the aftershock signal into a digital aftershock signal;

[0007] an aftershock energy detection circuit, used for determining the aftershock energy according to the digital aftershock signal, and determining whether to send a work indication signal to the aftershock suppression signal sending circuit according to the aftershock energy;

[0008] The aftershock suppression signal sending circuit is used to generate an aftershock suppression signal upon receiving a work indication signal, and send the aftershock suppression signal to the ultrasonic sensor; the aftershock suppression signal is used to eliminate the aftershock signal of the ultrasonic sensor.

[0009] In a second aspect, an embodiment of the present disclosure provides a method for eliminating aftershock signals, the method comprising:

[0010] The aftershock signal conditioning circuit receives the aftershock signal from the ultrasonic sensor and converts the aftershock signal to obtain a digital aftershock signal;

[0011] The aftershock energy detection circuit determines the aftershock energy according to the digital aftershock signal, and determines whether to send a work indication signal to the aftershock suppression signal sending circuit according to the aftershock energy;

[0012] If the aftershock suppression signal sending circuit receives the work instruction signal, it generates an aftershock suppression signal and sends the aftershock suppression signal to the ultrasonic sensor; the aftershock suppression signal is used to eliminate the aftershock signal of the ultrasonic sensor.

[0013] In a third aspect, an embodiment of the present disclosure provides an ultrasonic sensor chip, comprising: an ultrasonic sensor, and the above-mentioned aftershock signal elimination circuit.

[0014] The circuit and method for eliminating aftershock signals provided by the embodiments of the present disclosure include: an aftershock signal conditioning circuit, which is used to receive aftershock signals from ultrasonic sensors and convert the aftershock signals to obtain digital aftershock signals; an aftershock energy detection circuit, which is used to determine aftershock energy according to the digital aftershock signals and determine whether to send a work instruction signal to an aftershock suppression signal sending circuit according to the aftershock energy; the aftershock suppression signal sending circuit, which is used to generate an aftershock suppression signal if a work instruction signal is received and send the aftershock suppression signal to the ultrasonic sensor; the aftershock suppression signal is used to eliminate the aftershock signal of the ultrasonic sensor. In this way, the elimination circuit with the above-mentioned closed-loop structure is used to improve the elimination effect of aftershock signals without aftershock rebound; and the above-mentioned elimination circuit has a simple structure and lower application cost.

[0015] It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the present disclosure, nor is it intended to limit the scope of the present disclosure. Other features of the present disclosure will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic diagram of the structure of a circuit for eliminating aftershock signals provided in an embodiment of the present disclosure;

[0017] Figure 2 A schematic diagram of the structure of an aftershock signal conditioning circuit provided by an embodiment of the present disclosure;

[0018] Figure 3 A schematic diagram of the structure of an aftershock energy detection circuit provided by an embodiment of the present disclosure;

[0019] Figure 4 A schematic diagram of the structure of an aftershock suppression signal sending circuit provided in an embodiment of the present disclosure;

[0020] Figure 5 A schematic diagram of the structure of a circuit for eliminating aftershock signals provided in an application embodiment of the present disclosure;

[0021] Figure 6 A schematic flow chart of a method for eliminating aftershock signals provided in an embodiment of the present disclosure;

[0022] Figure 7 A schematic diagram of the structure of an ultrasonic sensor chip provided in an embodiment of the present disclosure. DETAILED DESCRIPTION

[0023] In order to make the purpose, features, and advantages of the present disclosure more obvious and easy to understand, the technical solutions in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only part of the embodiments of the present disclosure, not all of the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present disclosure.

[0024] In the following description, reference is made to “some embodiments”, which describe a subset of all possible embodiments, but it can be understood that “some embodiments” may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict.

[0025] In the following description, the terms "first\second" involved are merely used to distinguish similar objects and do not represent a specific ordering of the objects. It can be understood that "first\second" can be interchanged with a specific order or sequence where permitted, so that the embodiments of the present disclosure described herein can be implemented in an order other than that illustrated or described herein.

[0026] Unless otherwise defined, all technical and scientific terms used in this disclosure have the same meaning as those commonly understood by those skilled in the art to which this disclosure belongs. The terms used in this disclosure are only for the purpose of describing the embodiments of this disclosure and are not intended to limit this disclosure.

[0027] It should be understood that in the various embodiments of the present disclosure, the size of the serial number of each implementation process does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present disclosure.

[0028] Figure 1 A schematic diagram of a circuit for eliminating aftershock signals provided in an embodiment of the present disclosure; Figure 1 As shown, the aftershock signal elimination circuit includes:

[0029] An aftershock signal conditioning circuit, used for receiving the aftershock signal from the ultrasonic sensor, and converting the aftershock signal into a digital aftershock signal;

[0030] an aftershock energy detection circuit, used for determining the aftershock energy according to the digital aftershock signal, and determining whether to send a work indication signal to the aftershock suppression signal sending circuit according to the aftershock energy;

[0031] The aftershock suppression signal sending circuit is used to generate an aftershock suppression signal upon receiving a work indication signal, and send the aftershock suppression signal to the ultrasonic sensor; the aftershock suppression signal is used to eliminate the aftershock signal of the ultrasonic sensor.

[0032] In this way, the elimination circuit with the closed-loop structure is adopted to improve the elimination effect of aftershock signals, and the compensation effect is consistent and there is no aftershock rebound; and the elimination circuit has a simple structure and a lower application cost.

[0033] In some embodiments, the aftershock signal conditioning circuit includes: a voltage clamp circuit, an amplifier, a filter, and an analog-to-digital converter;

[0034] The voltage clamping circuit is used to clamp the voltage of the aftershock signal to a first target voltage range;

[0035] The amplifier is used to adjust the voltage amplitude of the aftershock signal in the first target voltage range to a second target voltage range;

[0036] The filter is used to filter out noise from aftershock signals within the second target voltage range;

[0037] The analog-to-digital converter is used to perform analog-to-digital conversion on the aftershock signal after noise filtering to obtain a digital aftershock signal.

[0038] Here, the voltage clamping circuit may use some components to limit the voltage range to protect the circuit from being damaged by excessively high voltage, that is, to provide overvoltage protection. For example, the voltage clamping circuit may use a diode, a voltage regulator, a voltage limiting circuit, etc. to limit the voltage of the input aftershock signal so that the voltage does not exceed a certain amplitude, for example, the first target voltage range is within 5 volts (V).

[0039] Here, the amplifier can adopt a low-noise amplifier to adjust the voltage amplitude of the aftershock signal to a second target voltage range; wherein the second target voltage range can be determined based on the analog-to-digital converter adopted, that is, the low-noise amplifier adjusts the voltage amplitude of the aftershock signal to within the voltage adaptation range of the subsequent analog-to-digital converter (that is, the second target voltage range).

[0040] Here, the filter can be a bandpass filter for filtering the aftershock signal; that is, suppressing noise other than the aftershock signal frequency in the frequency domain. In this way, the non-target frequency (noise) components in the signal are suppressed by the filter, the useful aftershock signal frequency of the ultrasonic sensor is retained, and the interference in the aftershock signal is cleared. This can not only improve the quality of the aftershock signal, but also reduce the calculation pressure of the subsequent circuit due to the reduction of the frequency components that need to be processed.

[0041] Here, the resolution of the analog-to-digital converter can be 16 bits. Since the received aftershock signal is an analog aftershock signal, for subsequent calculations, the conditioned (i.e., processed by the above-mentioned voltage clamping circuit, amplifier, and filter) analog aftershock signal is converted into a digital aftershock signal.

[0042] Here, the embodiment of the present disclosure provides a structural schematic diagram of an aftershock signal conditioning circuit, such as Figure 2 As shown, the aftershock signal conditioning circuit includes: a voltage clamping circuit 201, an amplifier 202, a filter 203, and an analog-to-digital converter 204; the input end of the voltage clamping circuit 201 is connected to the ultrasonic sensor for receiving the aftershock signal of the ultrasonic sensor, the output end of the voltage clamping circuit 201 is connected to the input end of the amplifier 202, the output end of the amplifier 202 is connected to the input end of the filter 203, the output end of the filter 203 is connected to the input end of the analog-to-digital converter 204, and the output end of the analog-to-digital converter 204 is connected to the subsequent circuit, namely, the aftershock energy detection circuit.

[0043] In some embodiments, the aftershock energy detection circuit includes: a digital mixer, an envelope extraction circuit, an envelope energy mean value calculation circuit, an envelope amplitude change calculation circuit, and an enable signal generation circuit;

[0044] The digital mixer is used to convert the oscillation frequency of the digital aftershock signal into a low frequency range;

[0045] The envelope extraction circuit is used to receive the low-frequency digital aftershock signal and extract the echo envelope signal according to the digital aftershock signal by using the absolute value calculation method;

[0046] The envelope energy mean value calculation circuit is used to receive the echo envelope signal, determine the envelope mean energy according to the echo envelope signal; and output a high level or a low level according to the envelope mean energy;

[0047] The envelope amplitude change calculation circuit is used to receive the echo envelope signal, determine the envelope difference calculation result according to the echo envelope signal; and output a high level or a low level according to the envelope difference calculation result;

[0048] The enable signal generating circuit is used to determine whether to send a work instruction signal to the aftershock suppression signal sending circuit according to the output level of the envelope energy mean value calculating circuit and the output level of the envelope amplitude change calculating circuit.

[0049] Specifically, a digital mixer is a mixer used in digital signal processing, which processes input frequency in the form of digital signals and realizes frequency conversion through mathematical operations (such as discrete Fourier transform, addition or multiplication).

[0050] The digital mixer can be configured to convert the oscillation frequency of the input digital aftershock signal to a low frequency range through a mixing process, so that the digital aftershock signal can be processed and analyzed more easily, while reducing the noise interference that may exist in the high frequency signal.

[0051] Among them, the configuration is the working parameter of the mixer, for example, it can include: input signal (such as the digital aftershock signal here), reference signal (that is, a signal with a fixed and stable frequency used to mix with the input signal), the relative relationship between the input signal and the reference signal, mixing mode (such as difference frequency mode, sum frequency mode), etc.

[0052] Here, considering that in the signal mixing process (i.e., the mixing process of the digital mixer), some unwanted high-frequency components may be generated due to the addition or subtraction of different signal frequencies, the envelope extraction circuit can first remove these high-frequency noises, and usually a filter can be used, such as a bandpass filter or a low-pass filter. Through the filter, the high-frequency noise can be effectively filtered out, and only the frequency components related to the signal itself are retained, ensuring that further signal processing is more accurate.

[0053] Specifically, the envelope extraction circuit may include: a filter and a first calculator with a fixed function (also referred to as a processor, etc., which is equivalent to a device set to perform a specific processing or calculation function). The filter is used to filter out high-frequency noise in the digital aftershock signal, and the first calculator is used to extract the echo envelope signal according to the digital aftershock signal. That is, the envelope extraction circuit is used to first filter out the high-frequency noise generated by the digital mixer during mixing, and extract the echo envelope signal according to the digital aftershock signal using an absolute value calculation method.

[0054] Specifically, the echo envelope signal refers to the envelope of the aftershock signal, which reflects or represents the curve of signal amplitude change, or the curve of energy change.

[0055] The first calculator can calculate the absolute value of the original digital aftershock signal to obtain the amplitude change of the digital aftershock signal, which is recorded as the echo envelope signal. Since the envelope of the signal reflects the amplitude of the signal and does not care about the phase or positive and negative polarity of the signal, by taking the absolute value of the signal, the phase information of the signal can be removed and the intensity change of the signal (i.e., the envelope) can be extracted.

[0056] In some embodiments, the envelope energy mean value calculation circuit is used to output a high level if the envelope average energy is higher than or equal to a first threshold value; and output a low level if the envelope average energy is lower than the first threshold value;

[0057] The envelope amplitude change calculation circuit is used to output a high level if the envelope difference calculation result is higher than or equal to a second threshold value; and to output a low level if the envelope difference calculation result is lower than the second threshold value.

[0058] Specifically, the envelope energy mean calculation circuit is specifically used to receive the echo envelope signal, determine the envelope average energy according to the echo envelope signal; compare the envelope average energy with a first threshold, and determine the output high level or low level according to the comparison result.

[0059] Here, after the envelope energy mean value calculation circuit receives the echo envelope signal output by the envelope extraction circuit, the envelope mean energy can be calculated using the root mean square.

[0060] The envelope average energy refers to the average energy of the envelope signal over a period of time. Since the square of the RMS value is exactly equal to the average value of the signal energy, the envelope average energy is equal to the square of the RMS value of the envelope signal.

[0061] The output port of the envelope energy average calculation circuit is a single-line signal, that is, the average energy of the envelope is calculated and then output to the enable signal generation circuit.

[0062] The envelope energy mean value calculation circuit may use a second calculator with a fixed function, and the second calculator has a register inside; the register stores a mean value calculation length parameter and a comparison threshold parameter (ie, a first threshold value).

[0063] The second calculator has a comparison function inside, which is used to compare the calculated envelope average energy with the first threshold. If the envelope average energy exceeds the first threshold, the second calculator outputs a high level, otherwise the second calculator outputs a low level.

[0064] Specifically, the envelope amplitude change calculation circuit is specifically used to receive the echo envelope signal, determine the envelope difference calculation result according to the echo envelope signal; compare the envelope difference calculation result with the second threshold, and determine the output high level or low level according to the comparison result.

[0065] Here, the output port of the envelope amplitude change calculation circuit is a single-line signal, that is, after the envelope difference calculation result is calculated, it is output to the enable signal generation circuit.

[0066] The envelope amplitude variation calculation circuit may use a third calculator with a fixed function, and the third calculator has a register inside; the register stores the slope calculation order and the comparison threshold parameter (ie, the second threshold).

[0067] After the third calculator obtains the slope of the echo envelope signal by calculation, it performs differential calculation on the echo envelope signal according to the slope calculation order to obtain an envelope differential calculation result.

[0068] Here, the slope of the echo envelope signal indicates the speed at which the envelope amplitude changes (ie, the inclination of the envelope curve). There are two common methods for calculating the slope: numerical difference and differentiation, which are not limited here.

[0069] The third calculator also has a comparison function, which is used to compare the envelope difference calculation result with the second threshold value. If the envelope difference calculation result exceeds the second threshold value, the third calculator outputs a high level, otherwise the third calculator outputs a low level.

[0070] It should be noted that the first threshold and the second threshold are set according to actual application requirements, and there is no limitation on their values.

[0071] In some embodiments, the enable signal generating circuit is used to determine a working indication signal to be sent to the aftershock suppression signal sending circuit if the output level of the envelope energy mean calculation circuit is a high level and the output level of the envelope amplitude change calculation circuit is a high level.

[0072] Specifically, the enable signal generating circuit receives the output level of the envelope energy mean value calculating circuit and the output level of the envelope amplitude change calculating circuit, and determines the work enable signal to be sent according to the received output levels.

[0073] The enable signal generating circuit may adopt a fourth calculator having a specific function, or a switch for determining whether to send a work enable signal.

[0074] If the output level of the envelope energy mean value calculation circuit is high and the output level of the envelope amplitude change calculation circuit is high, the low level output by the enable signal generation circuit is used as a work indication signal;

[0075] If any one of the output level of the envelope energy mean value calculation circuit and the output level of the envelope amplitude change calculation circuit is not a high level, the enable signal generation circuit outputs a high level as a work prohibition signal.

[0076] Here, the signal output by the enable signal generating circuit is a work enable signal, which is a control signal for controlling whether the aftershock suppression signal sending circuit is in a working state; if it is a low level, it indicates that the corresponding circuit is started to work, that is, it serves as a work indication signal; if it is a high level, it indicates that the corresponding circuit is prohibited from working, and it serves as a work prohibition signal. The level standards are all complementary metal oxide semiconductor (CMOS, Complementary Metal Oxide Semiconductor) levels.

[0077] In the disclosed embodiment, an aftershock energy detection circuit is used to determine whether the aftershock energy has decayed to the expected level based on the actual aftershock signal, so as to judge whether the aftershock signal needs to be suppressed, that is, to determine whether the aftershock suppression signal sending circuit is triggered to generate and send the aftershock suppression signal. In this way, the aftershock signal can be effectively suppressed accurately and in real time to reduce false operations. At the same time, the suppression mechanism is started in time in the event of interference or error to ensure the stability and reliability of the ultrasonic sensor.

[0078] Here, the embodiment of the present disclosure provides a schematic diagram of the structure of an aftershock energy detection circuit, such as Figure 3 As shown, the aftershock energy detection circuit includes: a digital mixer 301, an envelope extraction circuit 302, an envelope energy mean value calculation circuit 303, an envelope amplitude change calculation circuit 304, and an enable signal generation circuit 305; wherein, the output end of the digital mixer 301 is connected to the input end of the envelope extraction circuit 302; the output end of the envelope extraction circuit 302 is respectively connected to the input end of the envelope energy mean value calculation circuit 303 and the input end of the envelope amplitude change calculation circuit 304; the output end of the envelope energy mean value calculation circuit 303 and the output end of the envelope amplitude change calculation circuit 304 are respectively connected to the input end of the enable signal generation circuit 305; the output end of the enable signal generation circuit 305 is connected to the aftershock suppression signal sending circuit.

[0079] In some embodiments, the aftershock suppression signal sending circuit includes: an aftershock suppression signal phase generating circuit, an aftershock suppression signal energy adjusting circuit, and an aftershock suppression signal output driving circuit;

[0080] The aftershock suppression signal phase generating circuit is used to generate the aftershock suppression signal phase according to the digital aftershock signal if a work instruction signal is received;

[0081] The aftershock signal energy adjustment circuit is used to perform time-sharing interception of the aftershock suppression signal phase using a time window interception method, and output a phase signal according to the interception result;

[0082] The aftershock suppression signal output driving circuit is used to generate an aftershock suppression signal according to the phase signal, and send the aftershock suppression signal to the ultrasonic sensor.

[0083] In some embodiments, the aftershock suppression signal sending circuit further includes: a probe parameter correction circuit;

[0084] The probe parameter correction circuit is used to obtain the frequency correction code and amplitude correction code of the probe;

[0085] The aftershock suppression signal phase generating circuit is used to generate a second frequency code according to the first frequency code and the frequency correction code of the probe; and to generate an aftershock suppression signal that varies with time using a digital accumulator according to the second frequency code.

[0086] Here, the aftershock suppression signal phase generating circuit is used to generate the phase of the aftershock suppression signal in real time.

[0087] The aftershock suppression signal phase generating circuit can adopt a fifth calculator with a fixed function, which stores a frequency code (i.e., a first frequency code) that matches the probe model. The first frequency code is superimposed inside the fifth calculator with the frequency correction code output by the probe parameter correction circuit to generate a frequency code (i.e., a second frequency code) that matches the individual difference parameters of the current probe. Then, a digital accumulator is used to generate a time-varying aftershock suppression signal phase based on the second frequency code.

[0088] Among them, the probe is a device used to send or receive ultrasonic signals;

[0089] The frequency code of the probe refers to the working frequency of the probe or the frequency emitted by the probe;

[0090] Different probes may have different degrees of errors when working. For example, due to manufacturing process or environmental factors, the actual working frequency of the probe may be different from the calibrated frequency. The frequency calibration code is used to adjust and compensate for this difference to ensure that the working frequency of the probe is consistent with the design standard.

[0091] By combining the probe's frequency code with the frequency correction code, an accurate frequency value can be obtained, which represents the frequency actually emitted by the probe.

[0092] A digital accumulator is a hardware circuit used to process digital signals, usually a combination of an accumulator (adder) and a counter. The accumulator is used to continuously update and "accumulate" the phase of the signal that changes over time according to the value of the frequency code.

[0093] By superposition, a frequency code adapted to the individual difference parameters of the current probe is generated, so that a signal phase with the same frequency and opposite phase as the real aftershock signal can be generated by using the frequency and digital accumulator of the probe, that is, the aftershock suppression signal phase can be obtained, and it can be converted to obtain an aftershock suppression signal with a reverse phase.

[0094] Here, the aftershock signal energy adjustment circuit is used to time-divisionally intercept the phase signal output by the aftershock suppression signal phase generation circuit. The aftershock signal energy adjustment circuit can use a fixed-function sixth calculator, which has a register inside and stores the interception method of the adapted probe model. The interception method can be a time window interception method, that is, the sixth calculator generates a periodic time window indication signal in real time during operation. If the intercepted phase signal output by the aftershock suppression signal phase generation circuit is within the time window of the sixth calculator, the sixth calculator directly outputs the phase signal. If the intercepted phase signal output by the aftershock suppression signal phase generation circuit is not within the time window of the sixth calculator, the output of the sixth calculator becomes all 0. In this way, the timing of sending the aftershock suppression signal is accurately controlled, the output of the aftershock suppression signal is optimized, and the interference of irrelevant signals is avoided. At the same time, the output of invalid signals is effectively prevented when the signal is not needed by the mechanism of outputting all 0. The sixth calculator can also read the amplitude correction code output by the probe parameter correction circuit, and adjust the interception time length according to the amplitude correction code, and the adjustment method is to change the duration of the time window.

[0095] In some embodiments, the aftershock suppression signal output drive circuit includes: a phase amplitude converter and a current driver;

[0096] The phase amplitude converter is used to convert the phase signal into a waveform amplitude signal of an aftershock suppression signal;

[0097] The current driver is used to enhance the driving force of the waveform amplitude signal of the aftershock suppression signal and then output it to the ultrasonic sensor.

[0098] Here, the aftershock suppression signal output driving circuit integrates a phase amplitude converter and a current driver. The phase amplitude converter converts the phase signal output by the aftershock signal energy adjustment circuit into a waveform amplitude signal of the aftershock suppression signal, and outputs it after the driving force is enhanced by the current driver.

[0099] The embodiment of the present disclosure provides a structural schematic diagram of an aftershock suppression signal sending circuit, such as Figure 3As shown, the aftershock suppression signal sending circuit includes: an aftershock suppression signal phase generating circuit 401, an aftershock suppression signal energy adjusting circuit 402, an aftershock suppression signal output driving circuit 403, and a probe parameter correction circuit 404. Among them, the input end of the aftershock suppression signal phase generating circuit 401 is connected to the output end of the aftershock energy detection circuit; the output end of the aftershock suppression signal phase generating circuit 401 is connected to the input end of the aftershock suppression signal energy adjusting circuit 402, and the output end of the aftershock suppression signal energy adjusting circuit 402 is connected to the input end of the aftershock suppression signal output driving circuit 403; the output end of the aftershock suppression signal output driving circuit 403 is connected to the sender of the aftershock signal, such as an ultrasonic sensor. The output end of the probe parameter correction circuit 404 is respectively connected to the input end of the aftershock suppression signal phase generating circuit 401 and the input end of the aftershock suppression signal energy adjusting circuit 402.

[0100] In some embodiments, the circuit further includes: a memory for storing calibration parameters of the ultrasonic sensor, where the calibration parameters of the ultrasonic sensor may include: a frequency correction code and an amplitude correction code of the probe. The frequency correction code and the amplitude correction code of the probe are selected or designed based on the ultrasonic sensor, and are used to generate an aftershock suppression signal corresponding to the aftershock signal of the ultrasonic sensor, that is, the calibration parameters of the ultrasonic sensor can be used to adjust the parameter configuration of the aftershock suppression signal.

[0101] Here, the probe parameter correction circuit stores the frequency correction code and amplitude correction code of the probe. Specifically, the probe parameter correction circuit can read the frequency correction code and energy correction code of the probe from the memory of the elimination circuit and store them for reading and use by the aftershock suppression signal phase generation circuit and the aftershock suppression signal energy adjustment circuit.

[0102] Figure 5 A schematic diagram of a circuit for eliminating aftershock signals provided in an application embodiment of the present disclosure is shown in FIG. Figure 5 As shown, the aftershock signal elimination circuit includes: an aftershock signal conditioning circuit, an aftershock energy detection circuit, a sensor calibration parameter storage circuit, and an aftershock suppression signal sending circuit.

[0103] The input end of the aftershock signal conditioning circuit receives the aftershock signal from the ultrasonic sensor, amplifies and filters it, and then converts it into a digital aftershock signal through an analog-to-digital converter.

[0104] The aftershock energy detection circuit calculates the power of the digital aftershock signal output by the aftershock signal conditioning circuit, determines whether the aftershock energy has decayed to the expected level, and sends a work enable signal to the aftershock suppression signal sending circuit based on the judgment result.

[0105] The sensor calibration parameter storage circuit may adopt a memory, in which the calibration parameters of the current ultrasonic sensor are stored.

[0106] The aftershock suppression signal sending circuit is responsible for generating the aftershock suppression signal and sending the aftershock suppression signal to the ultrasonic sensor. Specifically, the aftershock signal sending circuit reads the sensor calibration parameters from the sensor calibration parameter storage circuit to adjust the parameter configuration of the aftershock suppression signal.

[0107] The aftershock signal elimination circuit provided by the embodiment of the present disclosure takes into account the problem that due to the different aftershock amplitudes of each sensor, a fixed compensation pulse amplitude cannot fully compensate all sensors, resulting in inconsistent compensation effects, and that the situation of the previous pulse of the aftershock will affect the change of the next pulse, and the fixed pulse compensation cannot predict such changes, resulting in unsatisfactory compensation effects. The elimination circuit of the above-mentioned closed-loop structure monitors and analyzes the signal of the ultrasonic sensor in real time, identifies whether there is an aftershock signal and its intensity. This precise signal detection can ensure that the suppression process is only started when suppression is really needed, avoiding over-compensation; triggering the aftershock suppression mechanism according to the energy of the aftershock signal can avoid unnecessary suppression operations and improve the accuracy of the system; the aftershock suppression signal sending circuit accurately sends out the aftershock suppression signal to counter the aftershock signal, avoiding excessive or insufficient compensation. Its high real-time and dynamic adjustment capabilities achieve rapid response and adaptability to changes, ensuring that each pulse can be effectively compensated.

[0108] Figure 6 A schematic diagram of a flow chart of a method for eliminating aftershock signals provided in an embodiment of the present disclosure is shown in FIG. Figure 6 As shown, the method for eliminating aftershock signals includes:

[0109] Step 601: the aftershock signal conditioning circuit receives the aftershock signal from the ultrasonic sensor, and converts the aftershock signal to obtain a digital aftershock signal;

[0110] Step 602: the aftershock energy detection circuit determines the aftershock energy according to the digital aftershock signal, and determines whether to send a work instruction signal to the aftershock suppression signal sending circuit according to the aftershock energy;

[0111] Step 603: If the aftershock suppression signal sending circuit receives the work instruction signal, it generates an aftershock suppression signal and sends the aftershock suppression signal to the ultrasonic sensor; the aftershock suppression signal is used to eliminate the aftershock signal of the ultrasonic sensor.

[0112] In some embodiments, the aftershock energy detection circuit includes: a digital mixer, an envelope extraction circuit, an envelope energy mean value calculation circuit, an envelope amplitude change calculation circuit, and an enable signal generation circuit;

[0113] The aftershock energy detection circuit determines the aftershock energy according to the digital aftershock signal, and determines whether to send a work instruction signal to the aftershock suppression signal sending circuit according to the aftershock energy, including:

[0114] The digital mixer converts the oscillation frequency of the digital aftershock signal into a low frequency range;

[0115] The envelope extraction circuit receives the low-frequency digital aftershock signal and extracts the echo envelope signal by using the absolute value calculation method according to the digital aftershock signal;

[0116] The envelope energy mean value calculation circuit receives the echo envelope signal, determines the envelope mean energy according to the echo envelope signal; and outputs a high level or a low level according to the envelope mean energy;

[0117] The envelope amplitude change calculation circuit receives the echo envelope signal, determines an envelope difference calculation result according to the echo envelope signal, and outputs a high level or a low level according to the envelope difference calculation result;

[0118] The enable signal generating circuit determines whether to send a working instruction signal to the aftershock suppression signal sending circuit according to the output level of the envelope energy mean value calculating circuit and the output level of the envelope amplitude change calculating circuit.

[0119] Specifically, outputting a high level or a low level according to the envelope average energy includes: if the envelope average energy is higher than or equal to a first threshold, the envelope energy mean value calculation circuit outputs a high level; if the envelope average energy is lower than the first threshold, the envelope average value calculation circuit outputs a low level;

[0120] Outputting a high level or a low level according to the envelope difference calculation result includes: if the envelope difference calculation result is higher than or equal to a second threshold, the envelope amplitude change calculation circuit outputs a high level; if the envelope difference calculation result is lower than the second threshold, the envelope amplitude change calculation circuit outputs a low level.

[0121] Determine whether to send a work instruction signal to the aftershock suppression signal sending circuit according to the output level of the envelope energy mean calculation circuit and the output level of the envelope amplitude change calculation circuit, including: if the output level of the envelope energy mean calculation circuit is a high level and the output level of the envelope amplitude change calculation circuit is a high level, send a work instruction signal to the aftershock suppression signal sending circuit.

[0122] In some embodiments, the aftershock suppression signal sending circuit includes: an aftershock suppression signal phase generating circuit, an aftershock suppression signal energy adjusting circuit, and an aftershock suppression signal output driving circuit;

[0123] If the aftershock suppression signal sending circuit receives the work instruction signal, it generates an aftershock suppression signal and sends the aftershock suppression signal to the ultrasonic sensor, including:

[0124] The aftershock suppression signal phase generation circuit generates the aftershock suppression signal phase according to the digital aftershock signal if receiving the work indication signal;

[0125] The aftershock signal energy adjustment circuit uses a time window interception method to perform time-sharing interception on the phase of the aftershock suppression signal, and outputs a phase signal according to the interception result;

[0126] The aftershock suppression signal output driving circuit generates an aftershock suppression signal according to the phase signal, and sends the aftershock suppression signal to the ultrasonic sensor.

[0127] Specifically, the aftershock suppression signal sending circuit further includes: a probe parameter correction circuit;

[0128] The probe parameter correction circuit can obtain the frequency correction code and amplitude correction code of the probe;

[0129] Generating the aftershock suppression signal phase includes: the aftershock suppression signal phase generating circuit can generate a second frequency code according to the first frequency code and frequency correction code of the probe; and generating the aftershock suppression signal phase that changes with time using a digital accumulator according to the second frequency code.

[0130] In some embodiments, the aftershock suppression signal output drive circuit includes: a phase amplitude converter and a current driver;

[0131] The aftershock suppression signal output driving circuit generates an aftershock suppression signal according to the phase signal and sends the aftershock suppression signal to the ultrasonic sensor, including:

[0132] The phase amplitude converter converts the phase signal into a waveform amplitude signal of an aftershock suppression signal;

[0133] The current driver enhances the driving force of the waveform amplitude signal of the aftershock suppression signal and outputs the enhanced driving force to the ultrasonic sensor.

[0134] In some embodiments, the circuit further comprises: a memory for storing a frequency correction code and an amplitude correction code of the probe;

[0135] The probe parameter correction circuit can obtain the frequency correction code and the amplitude correction code of the probe from the memory.

[0136] In some embodiments, the aftershock signal conditioning circuit includes: a voltage clamp circuit, an amplifier, a filter, and an analog-to-digital converter;

[0137] The aftershock signal conditioning circuit receives the aftershock signal from the ultrasonic sensor and converts the aftershock signal to obtain a digital aftershock signal, including:

[0138] The voltage clamping circuit clamps the voltage of the aftershock signal to a first target voltage range;

[0139] The amplifier adjusts the voltage amplitude of the aftershock signal in the first target voltage range to a second target voltage range;

[0140] The filter performs noise filtering on the aftershock signal within the second target voltage range;

[0141] The analog-to-digital converter performs analog-to-digital conversion on the aftershock signal after noise filtering to obtain a digital aftershock signal.

[0142] Figure 7 A schematic diagram of the structure of an ultrasonic sensor chip provided in an embodiment of the present disclosure is shown in FIG. Figure 7 As shown, the ultrasonic sensor chip includes: an ultrasonic sensor, and the above-mentioned aftershock signal elimination circuit.

[0143] Here, a circuit for eliminating aftershock signals of ultrasonic sensors integrated in CMOS process chips is provided, which adopts a closed-loop structure and is composed of an aftershock energy detection circuit, an aftershock suppression signal sending circuit, an aftershock signal conditioning circuit, etc. The circuit has the advantages of good consistency of compensation effect, no aftershock rebound, simple circuit structure, and low application cost.

[0144] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps recorded in this disclosure can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solutions disclosed in this disclosure can be achieved, and this document does not limit this.

[0145] In the above description, reference is made to “some embodiments”, which describe a subset of all possible embodiments, but it can be understood that “some embodiments” may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict.

[0146] Unless otherwise defined, all technical and scientific terms used in this disclosure have the same meaning as those commonly understood by those skilled in the art to which this disclosure belongs. The terms used in this disclosure are only for the purpose of describing the embodiments of this disclosure and are not intended to limit this disclosure.

[0147] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps recorded in this disclosure can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solutions disclosed in this disclosure can be achieved, and this document does not limit this.

[0148] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present disclosure, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0149] The above is only a specific embodiment of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any person skilled in the art who is familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present disclosure, which should be included in the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be based on the protection scope of the claims.

Claims

1. A circuit for eliminating aftershock signals, characterized in that: The circuit comprises: An aftershock signal conditioning circuit, used for receiving the aftershock signal from the ultrasonic sensor, and converting the aftershock signal into a digital aftershock signal; an aftershock energy detection circuit, used for determining the aftershock energy according to the digital aftershock signal, and determining whether to send a work indication signal to the aftershock suppression signal sending circuit according to the aftershock energy; The aftershock suppression signal sending circuit is used to generate an aftershock suppression signal upon receiving a work indication signal, and send the aftershock suppression signal to the ultrasonic sensor; the aftershock suppression signal is used to eliminate the aftershock signal of the ultrasonic sensor.

2. The circuit according to claim 1, characterized in that The aftershock energy detection circuit comprises: a digital mixer, an envelope extraction circuit, an envelope energy mean value calculation circuit, an envelope amplitude change calculation circuit, and an enable signal generation circuit; The digital mixer is used to convert the oscillation frequency of the digital aftershock signal into a low frequency range; The envelope extraction circuit is used to receive the low-frequency digital aftershock signal and extract the echo envelope signal according to the digital aftershock signal by using the absolute value calculation method; The envelope energy mean value calculation circuit is used to receive the echo envelope signal, determine the envelope mean energy according to the echo envelope signal; and output a high level or a low level according to the envelope mean energy; The envelope amplitude change calculation circuit is used to receive the echo envelope signal, determine the envelope difference calculation result according to the echo envelope signal; and output a high level or a low level according to the envelope difference calculation result; The enable signal generating circuit is used to determine whether to send a work instruction signal to the aftershock suppression signal sending circuit according to the output level of the envelope energy mean value calculating circuit and the output level of the envelope amplitude change calculating circuit.

3. The circuit according to claim 2, characterized in that The envelope energy mean value calculation circuit is used to output a high level if the envelope average energy is higher than or equal to a first threshold value; and output a low level if the envelope average energy is lower than the first threshold value; The envelope amplitude change calculation circuit is used to output a high level if the envelope difference calculation result is higher than or equal to a second threshold value; and to output a low level if the envelope difference calculation result is lower than the second threshold value.

4. The circuit according to claim 3, characterized in that The enable signal generating circuit is used to send a working instruction signal to the aftershock suppression signal sending circuit if the output level of the envelope energy mean value calculating circuit is high and the output level of the envelope amplitude change calculating circuit is high.

5. The circuit according to claim 1, characterized in that The aftershock suppression signal sending circuit comprises: an aftershock suppression signal phase generating circuit, an aftershock suppression signal energy adjusting circuit, and an aftershock suppression signal output driving circuit; The aftershock suppression signal phase generating circuit is used to generate the aftershock suppression signal phase according to the digital aftershock signal if a work instruction signal is received; The aftershock signal energy adjustment circuit is used to perform time-sharing interception of the aftershock suppression signal phase using a time window interception method, and output a phase signal according to the interception result; The aftershock suppression signal output driving circuit is used to generate an aftershock suppression signal according to the phase signal, and send the aftershock suppression signal to the ultrasonic sensor.

6. The circuit according to claim 5, characterized in that The aftershock suppression signal sending circuit further includes: a probe parameter correction circuit; The probe parameter correction circuit is used to obtain the frequency correction code and amplitude correction code of the probe; The aftershock suppression signal phase generating circuit is used to generate a second frequency code according to the first frequency code and the frequency correction code of the probe; and to generate an aftershock suppression signal phase that varies with time using a digital accumulator according to the second frequency code.

7. The circuit according to claim 5, characterized in that The aftershock suppression signal output driving circuit comprises: a phase amplitude converter and a current driver; The phase amplitude converter is used to convert the phase signal into a waveform amplitude signal of an aftershock suppression signal; The current driver is used to enhance the driving force of the waveform amplitude signal of the aftershock suppression signal and then output it to the ultrasonic sensor.

8. The circuit according to claim 6, characterized in that The circuit further comprises: a memory for storing a frequency correction code and an amplitude correction code of the probe; The probe parameter correction circuit is used to obtain the frequency correction code and amplitude correction code of the probe from the memory.

9. The circuit according to claim 1, characterized in that The aftershock signal conditioning circuit comprises: a voltage clamping circuit, an amplifier, a filter, and an analog-to-digital converter; The voltage clamping circuit is used to clamp the voltage of the aftershock signal to a first target voltage range; The amplifier is used to adjust the voltage amplitude of the aftershock signal in the first target voltage range to a second target voltage range; The filter is used to filter out noise from aftershock signals within the second target voltage range; The analog-to-digital converter is used to perform analog-to-digital conversion on the aftershock signal after noise filtering to obtain a digital aftershock signal.

10. A method for eliminating aftershock signals, characterized in that: The method comprises: The aftershock signal conditioning circuit receives the aftershock signal from the ultrasonic sensor and converts the aftershock signal to obtain a digital aftershock signal; The aftershock energy detection circuit determines the aftershock energy according to the digital aftershock signal, and determines whether to send a work indication signal to the aftershock suppression signal sending circuit according to the aftershock energy; If the aftershock suppression signal sending circuit receives the work instruction signal, it generates an aftershock suppression signal and sends the aftershock suppression signal to the ultrasonic sensor; the aftershock suppression signal is used to eliminate the aftershock signal of the ultrasonic sensor.

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