Frequency searching method and device of ultrasonic transducer, ultrasonic instrument and storage medium

Abstract

The invention provides a frequency searching method and device of an ultrasonic transducer, an ultrasonic instrument and a computer readable storage medium, and the frequency searching method of the ultrasonic transducer comprises the steps: controlling a power supply to output the alternating current of the current output frequency to the ultrasonic transducer, and collecting the current voltage and current of the ultrasonic transducer; calculating a target phase change rate of the phase relative to the frequency according to the current module value and the current phase angle; and determining a frequency adjustment step length according to the target phase change rate, and determining a next output frequency according to the frequency adjustment step length, the frequency adjustment step length being negatively correlated with the target phase change rate.

Description

Technical Field

[0001] The present application belongs to the field of ultrasound, and in particular, relates to a frequency search method and device for an ultrasonic transducer, an ultrasonic instrument, and a computer-readable storage medium. Background Art

[0002] Ultrasonic devices use the ultrasonic transducer in them to emit a certain dose of ultrasonic energy to achieve treatment or diagnosis of the target. As the core component of ultrasonic devices, the ultrasonic transducer uses the inverse piezoelectric effect of piezoelectric ceramics to convert periodic electrical signals into mechanical vibrations, thereby generating ultrasonic waves.

[0003] When the frequency of the electrical signal input to the ultrasonic transducer is the resonant frequency of the ultrasonic transducer, the energy of the electrical signal can be converted into mechanical energy to the greatest extent, and the ultrasonic instrument can work stably. However, the resonant frequencies of different ultrasonic transducers are inconsistent, and the load will affect the resonant frequency of the ultrasonic transducer, so that the resonant frequency often changes with working time and load. Therefore, it is necessary to search the frequency of the ultrasonic transducer to find the resonant frequency or the approximate resonant frequency.

[0004] The equivalent impedance of the ultrasonic transducer changes nonlinearly with frequency. At the resonant frequency, the modulus of the equivalent impedance of the ultrasonic transducer is the smallest and the phase is zero, that is, it behaves as a pure resistor. Near the resonant frequency, the modulus and phase of the impedance change very drastically. Therefore, if a fixed step size is used for frequency search, most of the time it is far away from the resonant frequency, and the search efficiency is low; if the step size is increased to reduce the search time, the resonant frequency is easily missed, which increases the difficulty of the search and makes it difficult to achieve fast and accurate frequency search. Summary of the invention

[0005] The embodiments of the present application provide a method and device for searching the frequency of an ultrasonic transducer, an ultrasonic instrument, and a computer-readable storage medium, which can solve the problem in the related art that it is difficult to quickly and accurately search the frequency of an ultrasonic transducer.

[0006] In the first aspect, an embodiment of the present application provides a frequency search method for an ultrasonic transducer, comprising: controlling a power supply to output alternating current of a current output frequency to the ultrasonic transducer, and collecting a current voltage and a current current of the ultrasonic transducer; calculating a current modulus and a current phase angle of the ultrasonic transducer impedance based on the current voltage and the current current; calculating a target phase change rate of phase relative to frequency based on the current modulus and the current phase angle; determining a frequency adjustment step based on the target phase change rate, and determining a next output frequency based on the frequency adjustment step, wherein the frequency adjustment step is negatively correlated with the target phase change rate.

[0007] In a possible implementation of the first aspect, calculating the target phase change rate of the phase with respect to the frequency based on the current modulus value and the current phase angle includes: selecting one of a first phase change rate and a second phase change rate as the target phase change rate according to a preset rule.

[0008] In a possible implementation of the first aspect, before selecting one of a first phase change rate and a second phase change rate as the target phase change rate according to a preset rule, it further includes: calculating the first phase change rate according to the current phase angle; and / or calculating the first modulus change rate of the modulus value with respect to the frequency according to the current modulus value; calculating the second phase angle change rate according to the first modulus change rate, the current modulus value, and the current phase angle.

[0009] In a possible implementation of the first aspect, calculating the second phase angle change rate according to the first modulus change rate, the current modulus value, and the current phase angle includes: converting the first modulus change rate into the second phase angle change rate according to the mapping relationship between the current modulus value and the current phase angle.

[0010] In a possible implementation of the first aspect, the first modulus change rate is the ratio of a first modulus difference value to a first frequency difference value, the first modulus difference value is the difference between the current modulus value and a first historical modulus value, the first historical modulus value is the modulus value of the ultrasonic transducer impedance collected and calculated at a first historical output frequency, the first frequency difference value is the difference between the current output frequency and the first historical output frequency, the first phase angle change rate is the ratio of a first phase angle difference value to the first frequency difference value, the first phase angle difference value is the difference between the current phase angle and a first historical phase angle, and the first historical phase angle is the phase angle of the ultrasonic transducer impedance collected and calculated at the first historical output frequency.

[0011] In a possible implementation of the first aspect, the first historical output frequency is the previous output frequency of the current output frequency, or the frequency corresponding to the minimum modulus value that has been searched.

[0012] In a possible implementation of the first aspect, the preset rule includes: when the absolute value of the current phase angle is less than a first threshold value, selecting the first phase change rate as the target phase change rate; when the absolute value of the current phase angle is greater than or equal to the first threshold value, selecting the second phase change rate as the target phase change rate.

[0013] In a possible implementation of the first aspect, the preset rule includes: selecting the maximum value of the first phase change rate and the second phase change rate as the target phase change rate.

[0014] In a possible implementation of the first aspect, it further includes: determining a range of change rate values according to the current modulus value and the current phase angle; when the target phase change rate is greater than the upper limit of the range of change rate values, updating the target phase change rate to the upper limit of the range of change rate values, and when the target phase change rate is less than the lower limit of the range of change rate values, updating the target phase change rate to the lower limit of the range of change rate values.

[0015] In a possible implementation of the first aspect, after calculating the current modulus value and the current phase angle of the ultrasonic transducer impedance based on the current voltage and the current current, it further includes: determining whether the search is abnormal according to the current modulus value and / or the current phase angle, and when the search is abnormal, using the minimum modulus frequency as the next output frequency and adjusting the frequency search parameters, where the minimum modulus frequency is the frequency corresponding to the minimum modulus value that has been searched.

[0016] In a possible implementation of the first aspect, determining whether the search is abnormal according to the current modulus value and / or the current phase angle includes: determining that the search is abnormal when the first modulus difference is greater than the first set value and / or the positive and negative signs of the current phase angle and the phase angle corresponding to the minimum modulus value are different.

[0017] In a possible implementation of the first aspect, adjusting the frequency search parameters includes: reducing the step coefficient, where the step coefficient is used to determine the frequency adjustment step size in combination with the target phase change rate, and the frequency adjustment step size is positively correlated with the step coefficient.

[0018] In a possible implementation of the first aspect, adjusting the frequency search parameters includes: increasing the current current.

[0019] In a possible implementation of the first aspect, when the current modulus value is less than the minimum modulus value, updating the minimum modulus value to the current modulus value and updating the minimum modulus frequency to the current output frequency.

[0020] In a possible implementation of the first aspect, the current current is the maximum allowable current.

[0021] In a possible implementation of the first aspect, after calculating the current modulus value and the current phase angle of the ultrasonic transducer impedance based on the current voltage and the current current, it further includes: ending the frequency search when the absolute value of the current phase angle is less than the second threshold.

[0022] In the second aspect, an embodiment of the present application provides a frequency search device for an ultrasonic transducer, including: an acquisition module, used to control the power supply to output alternating current of the current output frequency to the ultrasonic transducer, and to collect the current voltage and current current of the ultrasonic transducer; a first calculation module, used to calculate the current modulus and current phase angle of the ultrasonic transducer impedance based on the current voltage and the current current; a second calculation module, used to calculate the target phase change rate of the phase relative to the frequency based on the current modulus and the current phase angle; a determination module, used to determine the frequency adjustment step according to the target phase change rate, and determine the next output frequency according to the frequency adjustment step, wherein the frequency adjustment step is negatively correlated with the target phase change rate.

[0023] In a third aspect, an embodiment of the present application provides an ultrasonic instrument, comprising: a power supply, an ultrasonic transducer, a sensor, a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the frequency search method for the ultrasonic transducer described in any one of the first aspects is implemented.

[0024] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the frequency search method for an ultrasonic transducer described in any one of the first aspects above.

[0025] In a fifth aspect, an embodiment of the present application provides a computer program product. When the computer program product is run on an ultrasonic instrument, the ultrasonic instrument executes the frequency search method of the ultrasonic transducer described in any one of the first aspects above.

[0026] Compared with the prior art, the embodiments of the present application have the following beneficial effects: by controlling the power supply to output the alternating current of the current output frequency to the ultrasonic transducer, the current voltage and current current of the ultrasonic transducer are collected; the current modulus and current phase angle of the ultrasonic transducer impedance are calculated according to the current voltage and current current; the first modulus change rate of the modulus relative to the frequency is calculated according to the current modulus and / or the first phase change rate of the phase relative to the frequency is calculated according to the current phase angle; the frequency adjustment step is determined according to the first modulus change rate or the first phase change rate, and the next output frequency is determined according to the frequency adjustment step, wherein the frequency adjustment step is negatively correlated with the first phase change rate. Since the target phase change rate of the phase angle relative to the frequency increases as it approaches the resonant frequency, a smaller target phase change rate means that it is far from the resonant frequency, and a faster search is performed with a larger frequency step; an increase in the target phase change rate means that it is close to the resonant frequency, and the frequency step becomes smaller accordingly for a more precise search, thereby improving the efficiency and accuracy of the frequency search of the ultrasonic transducer. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] To more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the accompanying drawings required for the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other accompanying drawings can be obtained based on these drawings without creative efforts.

[0028] Figure 1 is a schematic diagram of the system of an ultrasonic instrument provided by an embodiment of the present application;

[0029] Figure 2 is a schematic diagram of the equivalent circuit of an ultrasonic transducer provided by an embodiment of the present application;

[0030] Figure 3 is a schematic diagram showing the variation of the amplitude and phase of the equivalent impedance of an ultrasonic transducer with frequency provided by an embodiment of the present application;

[0031] Figure 4 is a schematic flowchart of a frequency search method for an ultrasonic transducer provided by an embodiment of the present application;

[0032] Figure 5 is a schematic flowchart of a frequency search method for an ultrasonic transducer provided by another embodiment of the present application;

[0033] Figure 6 is a schematic flowchart of a frequency search method for an ultrasonic transducer provided by yet another embodiment of the present application;

[0034] Figure 7 is a schematic diagram of the structure of a frequency search device for an ultrasonic transducer provided by an embodiment of the present application. Detailed implementation manners

[0035] In the following description, specific details such as specific system structures and technologies are presented for the purpose of illustration rather than limitation, so as to thoroughly understand the embodiments of the present application. However, those skilled in the art should clearly understand that the present application can also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to avoid unnecessary details from interfering with the description of the present application.

[0036] It should be understood that when used in the specification of the present application and the appended claims, the term "comprising" indicates the presence of the described features, wholes, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components, and / or their combinations.

[0037] It should also be understood that the term "and / or" as used in the specification and appended claims of this application refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0038] As used in the specification and appended claims of this application, the term "if" can be interpreted as "when", "once", "in response to determining", or "in response to detecting" depending on the context. Similarly, the phrase "if determined" or "if [the described condition or event] is detected" can be interpreted as meaning "once determined", "in response to determining", "once [the described condition or event] is detected", or "in response to detecting [the described condition or event]" depending on the context.

[0039] In addition, in the description of the specification and appended claims of this application, the terms "first", "second", "third", etc. are only used for distinguishing descriptions and cannot be understood as indicating or implying relative importance.

[0040] Reference to "one embodiment" or "some embodiments" or the like described in the specification of this application means that a specific feature, structure, or characteristic described in connection with that embodiment is included in one or more embodiments of this application. Thus, statements such as "in one embodiment", "in some embodiments", "in other some embodiments", "in still other embodiments", etc. that appear in different places in this specification do not necessarily all refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "comprising", "including", "having", and their variants all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0041] Figure 1 Shown is a block diagram of a part of the structure of an ultrasonic instrument provided by an embodiment of this application. Refer to Figure 1 , the ultrasonic instrument includes: a processor 10, a memory 20, a power supply 30, a sensor 40, and an ultrasonic transducer 50. The processor 10 is connected to the memory 20 and the sensor 40, the power supply 30 is respectively connected to the processor 10, the memory 20, and the ultrasonic transducer 50, and the sensor 40 can be electrically connected to the ultrasonic transducer 50. In addition, the ultrasonic instrument may further include other elements not shown in the figure, such as elements for conducting ultrasonic waves coupled to the ultrasonic transducer 50, protection elements, etc. Those skilled in the art can understand that Figure 1 the structure of the ultrasonic instrument shown in

[0042] An ultrasonic instrument can include an ultrasonic cutting instrument, also known as a harmonic scalpel. According to the cutting object, it can be classified into soft tissue ultrasonic cutting instruments, bone tissue ultrasonic cutting instruments, etc.

[0043] The following will specifically introduce each component of the ultrasonic instrument in conjunction with Figure 1 :

[0044] The processor 10 is the control center of the ultrasonic instrument and can execute various functions and process data by running the programs stored in the memory 20. The processor 10 can be a Central Processing Unit (CPU), or it can also be other general-purpose processors, Digital Signal Processors (DSPs), Application Specific Integrated Circuits (ASICs), Field-Programmable Gate Arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or any conventional processor, etc.

[0045] The memory 20 is used to store the operating system, application programs, BootLoader, data, and other programs, such as the program code of computer programs. The memory 20 can also be used to temporarily store the data required for executing the programs and the generated data. The memory 20 can include high-speed random access memory and can also include non-volatile memory, such as flash memory, hard disks, multimedia cards, card-type memories, etc. The memory 20 can include storage units provided inside the ultrasonic instrument, such as the hard disk of the ultrasonic instrument, and / or removable external storage units, such as external hard disks, USB flash drives, Smart Media Cards (SMCs), Secure Digital (SD) cards, etc.

[0046] The power supply 30 provides electrical energy for the processor 10, the memory 20, and the ultrasonic transducer 50. The processor 10 and the memory 20 are electronic components that require low-voltage direct current for operation, while the ultrasonic transducer 50 requires alternating current with a frequency exceeding the acoustic wave range according to its working principle, and for frequency searching, it is required that the frequency of the alternating current is controllable. Therefore, the power supply 30 can include two parts to provide the required power for the electronic components and the ultrasonic transducer 50 respectively.

[0047] The sensor 40 is used to collect the working current and working voltage of the ultrasonic transducer 50 and feed them back to the processor 10 to monitor the working state of the ultrasonic transducer 50.

[0048] The ultrasonic transducer 50 is the core component of the ultrasonic instrument. Its principle is to utilize the inverse piezoelectric effect of piezoelectric ceramics to convert the alternating current signal into mechanical vibration, thereby generating ultrasonic waves.

[0049] The equivalent circuit of the ultrasonic transducer 50 is as Figure 2 shown, where C0 is the static capacitance of the ultrasonic transducer 50 and can be obtained through pre-measurement; C1 is the equivalent dynamic capacitance of the ultrasonic transducer 50, and its sources mainly include the elastic vibration of the ultrasonic transducer 50; R1 is the equivalent resistance of the ultrasonic transducer 50, and its sources mainly include mechanical loss and load loss; L1 is the equivalent dynamic inductance of the ultrasonic transducer 50, which is mainly related to mass. The branch where C0 is located is the static branch, and the branch where C1, R1, and L1 are located is the dynamic branch, also known as the series branch.

[0050] When the frequency of the alternating current provided by the power supply 30 to the ultrasonic transducer 50 (hereinafter referred to as the frequency) is the resonant frequency of the ultrasonic transducer 50, most of the electrical energy is converted into the mechanical energy of ultrasonic waves, and the ultrasonic instrument can work stably. The resonant frequency here can include the series resonant frequency, which is the alternating current frequency when the series branch resonates. In the equivalent circuit of the ultrasonic transducer 50, the dynamic branch reflects the dynamic mechanical and electrical properties of the ultrasonic transducer 50 and will change with the working time and the load of the ultrasonic transducer 50 (such as the coupled components, tissues in direct or indirect contact, etc.), resulting in a change in the resonant frequency of the ultrasonic transducer 50. Therefore, in actual use, it is often necessary to perform a frequency search on the ultrasonic transducer 50, that is, to search for the resonant frequency or approximate resonant frequency of the ultrasonic transducer 50.

[0051] For the series branch, or the dynamic branch, in the equivalent circuit of the ultrasonic transducer 50, the series-connected C1, R1, and L1 can be equivalent to an impedance, which is used to represent the hindering effect of this branch on the alternating current. The impedance is commonly represented by Z and is a complex number. The real part is called the resistance, and the imaginary part is called the reactance. Among them, the hindering effect of the capacitor on the alternating current in the circuit is called capacitive reactance, and the hindering effect of the inductor on the alternating current in the circuit is called inductive reactance. The total hindering effect of the capacitor and the inductor on the alternating current in the circuit is collectively called reactance. The impedance can be rewritten from the real part and the imaginary part into the form of modulus and argument. The modulus of the impedance can also be called the modulus value, which is specifically the ratio of the amplitude or effective value of the detected working voltage and working current of the series branch. The argument of the impedance can also be called the impedance angle, phase angle, or phase, which is specifically the phase difference between the detected working voltage and working current of the series branch.

[0052] As Figure 3As shown, the impedance and phase of the series branch vary non-linearly with frequency. When the frequency reaches the resonance point, that is, when the frequency is the resonance frequency, the dynamic branch generates resonance. Reflected in the impedance, it is manifested as the minimum modulus value and the phase angle being zero. The closer to the resonance point, the smaller the modulus change rate of the modulus value with respect to frequency, and the larger the phase change rate of the phase with respect to frequency. In theory, both the modulus value and the phase angle can be used to determine whether the resonance point is reached during the frequency search process. However, due to changes in the working time and load of the ultrasonic device during the actual working process, the impedance of the series branch will change, making it difficult to quickly determine whether the current search direction is correct during the frequency search. Therefore, in practical applications, it is generally based on the phase angle to determine whether the resonance point is reached, that is, using zero phase as the sign of the resonance point.

[0053] Figure 4 The flowchart of the frequency search method for the ultrasonic transducer provided by an embodiment of the present application is shown. By way of example and not limitation, this method can be applied to the above-mentioned ultrasonic device.

[0054] S1: Control the power supply to output alternating current with the current output frequency to the ultrasonic transducer, and collect the current voltage and current of the ultrasonic transducer.

[0055] The current voltage and current of the ultrasonic transducer can be collected by sensors. The current voltage is the working voltage of the collected ultrasonic transducer under the action of alternating current with the current output frequency, and the current current is the working current of the collected ultrasonic transducer under the action of alternating current with the current output frequency. Since the dynamic branch and the static branch in the equivalent circuit are in parallel, the currents passing through them may be different, and the total current of the ultrasonic transducer is the sum of the currents of the dynamic branch and the static branch. The working current here can include at least one of the current of the dynamic branch and the total current.

[0056] S2: Calculate the current modulus value and current phase angle of the impedance of the ultrasonic transducer according to the current voltage and current.

[0057] In this embodiment, the search for the series resonance frequency is selected, so the impedance of the ultrasonic transducer to be calculated is the impedance of the dynamic branch in the equivalent circuit. Taking the working current as the total current as an example, dividing the current voltage by the current current can obtain the total impedance of the equivalent circuit. According to the known static capacitance, the static capacitive reactance can be calculated. Combining the parallel impedance calculation formula, the current impedance of the dynamic branch can be calculated. If the working current is the current of the dynamic branch, then dividing the current voltage by the current current can directly obtain the current impedance. The modulus value of the current impedance is the current modulus value, and the phase angle of the current impedance is the current phase angle.

[0058] S3: Calculate the target phase change rate of the phase with respect to frequency according to the current modulus value and current phase angle.

[0059] Optionally, one of the first phase change rate and the second phase change rate can be selected as the target phase change rate according to a preset rule, and then the adjustment step size is determined according to the target phase change rate.

[0060] The first phase change rate is directly calculated using the current phase angle. The second phase change rate is calculated according to the first modulus change rate, the current modulus and the current phase angle. The first modulus change rate is obtained by directly calculating the change rate of the modulus with respect to the frequency using the current modulus.

[0061] Specifically, the first modulus change rate is the ratio of the first modulus difference to the first frequency difference. The first modulus difference is the difference between the current modulus and the first historical modulus. The first historical modulus is the modulus of the ultrasonic transducer impedance collected and calculated at the first historical output frequency. The first frequency difference is the difference between the current output frequency and the first historical output frequency. It is expressed by the formula where K zf is the first modulus change rate, is the first modulus difference, is the first frequency difference, Z1 is the current modulus, Z0 is the first historical modulus, f1 is the current output frequency, and f0 is the first historical output frequency.

[0062] The first phase angle change rate is the ratio of the first phase angle difference to the first frequency difference. The first phase angle difference is the difference between the current phase angle and the first historical phase angle. The first historical phase angle is the phase angle of the ultrasonic transducer impedance collected and calculated at the first historical output frequency. It is expressed by the formula where is the first modulus change rate, is the first modulus difference, is the current modulus, is the first historical modulus.

[0063] The first historical output frequency f0 can include at least one of the previous output frequency of the current output frequency f1 and the frequency corresponding to the minimum modulus found.

[0064] Specifically, the first modulus change rate can be converted into the second phase angle change rate according to the mapping relationship between the current modulus and the current phase angle. For example, the calculation formula of the second phase angle change rate can be or where is the second phase angle change rate.

[0065] An optional method is to select according to the current phase angle. The specific preset rules may include: when the absolute value of the current phase angle is less than the first threshold, select the first phase change rate as the target phase change rate; when the absolute value of the current phase angle is greater than or equal to the first threshold, select the second phase change rate as the target phase change rate. The first threshold is greater than the second threshold. In this way, after calculating the current phase angle, the target phase change rate used for calculating the frequency adjustment step size in this round can be determined, and then only the target phase change rate can be calculated without calculating the other unselected phase change rate; alternatively, the first phase change rate and the second phase change rate can be calculated first, and then selected according to the current phase angle.

[0066] Refer to Figure 3 It can be known that although both the phase-frequency (i.e., phase-frequency curve) and the modulus-frequency (i.e., modulus-frequency curve) are non-linearly changing, near the resonance point, the slope of the phase-frequency is significantly greater than that of the modulus-frequency, meaning that the change rate of the phase angle is larger; correspondingly, in the region far from the resonance point, the slope of the phase-frequency is significantly less than that of the modulus-frequency, meaning that the change rate of the modulus value is larger. When the change rate of the phase angle is smaller, it means that the first phase angle difference is smaller, and the first phase change rate directly calculated from the first phase angle difference is more susceptible to measurement errors and has lower accuracy, and vice versa. Since it is judged whether the resonance point is reached based on the current phase angle, the comparison result of the absolute value of the current phase angle with the first threshold is used here to indicate whether to enter the vicinity of the resonance point, so as to select the first phase change rate near the resonance point and select the second phase change rate calculated from the first modulus change rate in the region far from the resonance point, which can effectively reduce the influence that may be caused by measurement errors, thereby improving the accuracy of the frequency adjustment step size. The specific value of the first threshold can be obtained through experimental measurement, experience summary, theoretical calculation, etc.

[0067] Another optional method is to select according to the values of the two phase change rates. The specific preset rules may include: select the maximum value of the first phase change rate and the second phase change rate as the target phase change rate. A larger phase change rate is less susceptible to measurement errors. Selecting the maximum value of the first phase change rate and the second phase change rate as the target phase change rate can effectively reduce the influence that may be caused by measurement errors, thereby improving the accuracy of the frequency adjustment step size.

[0068] In addition to the above two methods, other methods can also be used to select the target phase angle change rate, such as random selection.

[0069] Optionally, the value range of the change rate is determined according to the current modulus value and the current phase angle. The specific calculation methods for the upper and lower limits of the value range of the change rate can be determined according to actual requirements. When the target phase change rate is greater than the upper limit of the value range of the change rate, the target phase change rate is updated to the upper limit of the value range of the change rate. When the target phase change rate is less than the lower limit of the value range of the change rate, the target phase change rate is updated to the lower limit of the value range of the change rate, so as to limit the target phase change rate within the value range of the change rate, thereby restricting the value of the frequency adjustment step size.

[0070] S4: Determine the frequency adjustment step size according to the target phase change rate, and determine the next output frequency according to the frequency adjustment step size.

[0071] The frequency adjustment step size is negatively correlated with the target phase change rate, that is, the greater the target phase change rate, the smaller the frequency adjustment step size. Generally, the next output frequency is the sum or difference of the current output frequency and the frequency adjustment step size. Specifically, whether it is the sum or the difference is generally determined by the frequency search direction. If the frequency search direction is increasing, then the next output frequency is the sum of the current output frequency and the frequency adjustment step size. If the frequency search direction is decreasing, then the next output frequency is the difference between the current output frequency and the frequency adjustment step size.

[0072] What is described in this embodiment is the processing process of the current output frequency during the entire frequency search process. After determining the next output frequency, the current output frequency can be updated with the next output frequency, and then the above process is repeated until the stop search condition is met. The stop search condition may include that the absolute value of the current phase angle is less than the second threshold. Theoretically, the phase angle is 0° when reaching the resonance point. Due to the influence of factors such as measurement accuracy, measurement error, and calculation accuracy, in practical applications, the second threshold is generally set to be slightly greater than 0°, such as 5°. Specifically, after calculating the current phase angle, it can be determined whether the absolute value of the current phase angle is less than the second threshold. If it is less, the current output frequency is used as the resonance frequency and the frequency search ends. The execution order between this judgment process and S3 is not limited and can be arbitrarily swapped or executed in parallel.

[0073] Calculate the reciprocal of the target phase change rate to obtain the frequency change amount Δf. The frequency adjustment step size step can be a monotonically increasing function of the frequency change amount Δf. For example, step = Δf a , a>0, and a common value is a = 1. In addition, a step coefficient can be introduced to determine the frequency adjustment step size in combination with the target phase change rate. The frequency adjustment step size is positively correlated with the step coefficient. For example, step = Δf a *k b , a>0, b>0, and a common value is a = b = 1.

[0074] Ideally, the process of frequency search is to iteratively update the current output frequency along the set search direction until the resonance point is found. However, in practical applications, search anomalies may occur. Search anomaly means that the resonance point is between the current output frequency and the initial point where the search starts. This phenomenon can also be referred to as passing over the resonance point. If a search anomaly occurs, it is impossible to find the resonance point by continuing to search along the set direction. The absolute value of the modulus will increase, while it normally decreases.

[0075] The data of a single-round frequency search can be used to determine whether a search anomaly occurs; or, to reduce misjudgment caused by measurement errors, the data of continuous multi-round frequency searches can be used for determination. Using the data of multi-round frequency searches for determination can be to obtain the judgment results of each round and then combine these judgment results for the final result. Hereinafter, taking the use of the data of a single-round frequency search for determination, that is, using only the current modulus and / or the current phase angle for determination as an example for illustration.

[0076] Specifically, after calculating the current modulus and the current phase angle, it can be determined whether the search is anomalous based on the current modulus and / or the current phase angle. When the search is anomalous, the frequency corresponding to the minimum modulus is used as the next output frequency, and the frequency search parameters are adjusted. The frequency corresponding to the minimum modulus is the frequency corresponding to the minimum modulus that has been searched. There is no limit to the execution order between this judgment process and the process of S3 and determining whether to end the frequency search, and they can be arbitrarily swapped or executed in parallel.

[0077] To correctly maintain the minimum modulus and the frequency corresponding to the minimum modulus, after calculating the current modulus, it can be determined whether the current modulus is less than the minimum modulus. In the case where the current modulus is less than the minimum modulus, the minimum modulus is updated to the current modulus, and the frequency corresponding to the minimum modulus is updated to the current output frequency. There is no limit to the execution order between this judgment process and the process of S3 and determining whether to end the frequency search, and they can be arbitrarily swapped or executed in parallel. Since the conditions for search anomaly and updating the minimum modulus are generally mutually exclusive, it is possible to choose to first determine whether one of the conditions is met. If it is met, the judgment of the other condition can be omitted. Of course, it is also possible to judge whether the conditions for search anomaly and updating the minimum modulus are met successively or in parallel.

[0078] The specific judgment criteria for search anomaly can include: the first modulus difference is greater than the first set value and / or the positive and negative signs of the current phase angle and the phase angle corresponding to the minimum modulus are different.

[0079] The first modulus difference here can be the same as or different from the first modulus difference used in calculating the first modulus change rate described above. For example, the first modulus change rate can be calculated based on the modulus at the previous output frequency of the current output frequency, and the first modulus difference used to determine whether the search is abnormal can be calculated based on the modulus at the minimum modulus frequency. The first set value is generally greater than 0 and close to 0, rather than being directly set to 0, to avoid frequent occurrences of meeting the search abnormality due to factors such as measurement errors.

[0080] Reference Figure 3 It can be seen that the phase angle is a monotonically increasing function with respect to the frequency. When the output frequency is less than the resonance frequency, the phase angle is less than 0, and when the output frequency is greater than the resonance frequency, the phase angle is greater than 0. It can be observed that if there is no phenomenon of crossing the resonance point, the positive and negative signs of the phase angle will not change. Therefore, it can be determined that the search is abnormal when it is detected that the positive and negative signs of the current phase angle are different from those of the phase angle corresponding to the minimum modulus.

[0081] Adjusting the frequency search parameters can include reducing the step coefficient. After reducing the step coefficient, the frequency adjustment step size will decrease accordingly.

[0082] Adjusting the frequency search parameters can include increasing the current current. A lower drive current may increase the difficulty of searching for the resonance point, and increasing the operating current helps in searching for the resonance point.

[0083] Optionally, when the frequency adjustment step size is less than the allowable minimum step size, which is common in scenarios where the search abnormality occurs multiple times, resulting in the step coefficient being repeatedly reduced, the frequency adjustment step size can be updated to the allowable minimum step size.

[0084] Optionally, the current current is the allowable maximum current. In this case, the current current will not be increased anymore to prevent system failures. The current current can be set to a smaller value at the start of the search, and then increased each time the search abnormality is met until the allowable maximum current is reached. Or, the current current can be directly set to the allowable maximum current at the start of the search, and the current current will not be adjusted in subsequent cases where the search abnormality is met, so as to reduce the influence of the power supply current on the frequency search.

[0085] After determining that the next output frequency is the frequency with the minimum modulus value, the foregoing steps can be repeatedly executed to determine the frequency adjustment step again. Optionally, together with the minimum modulus value and the minimum modulus value frequency, the frequency change amount corresponding to the minimum modulus value can be maintained. In this case, when determining the frequency adjustment step again, it is not necessary to calculate the frequency change amount again, but directly substitute the frequency change amount corresponding to the minimum modulus value and the updated step coefficient into the calculation formula of the frequency adjustment step to obtain the frequency adjustment step. Alternatively, together with the minimum modulus value and the minimum modulus value frequency, the first historical output frequency, the first historical modulus value, and the first historical phase angle corresponding to the minimum modulus value frequency can be maintained. In this case, the frequency change amount can be recalculated according to the description of the foregoing steps, and then the frequency adjustment step can be determined based on the frequency change amount.

[0086] Through the implementation of this embodiment, the control power supply outputs alternating current with the current output frequency to the ultrasonic transducer, and the current voltage and current of the ultrasonic transducer are collected; the current modulus value and the current phase angle of the impedance of the ultrasonic transducer are calculated based on the current voltage and current; the first modulus change rate of the modulus value with respect to the frequency is calculated based on the current modulus value and / or the first phase change rate of the phase with respect to the frequency is calculated based on the current phase angle; the frequency adjustment step is determined according to the first modulus change rate or the first phase change rate, and the next output frequency is determined according to the frequency adjustment step, where the frequency adjustment step is negatively correlated with the first phase change rate. Since the target phase change rate of the phase angle with respect to the frequency increases as it approaches the resonant frequency, a smaller target phase change rate means a greater distance from the resonant frequency, and at this time, a larger frequency step is used for rapid search; the increase of the target phase change rate means approaching the resonant frequency, and the frequency step becomes smaller for more refined search, thereby improving the efficiency and accuracy of the frequency search of the ultrasonic transducer.

[0087] The following takes the attached drawings as an example to illustrate the specific process of the frequency search method of the ultrasonic transducer, where the specific numerical values and formulas are only for illustration. Most of the specific content can refer to the description of the foregoing embodiment and will not be repeated here.

[0088] As Figure 5 shown, the frequency search method of the ultrasonic transducer provided by another embodiment of the present application includes the following parts.

[0089] S11: Start frequency search according to the initial search parameters.

[0090] The initial search parameters include: the initial output frequency and its matching search direction, the initial frequency adjustment step, the initial value of the step coefficient, etc.

[0091] The current impedance and current phase angle calculated at the initial output frequency are generally only temporarily stored for subsequent output frequency calculations and cannot be used to calculate the frequency adjustment step at the initial output frequency. Instead, the initial frequency adjustment step is directly used to determine the next output frequency, and the calculated next output frequency is used to update the current frequency, and then the subsequent steps are executed.

[0092] S12: Control the power supply to output alternating current at the current output frequency to the ultrasonic transducer, and collect the current voltage and current of the ultrasonic transducer.

[0093] S13: Calculate the current modulus value and current phase angle of the impedance of the ultrasonic transducer based on the current voltage and current.

[0094] S14: Determine whether the absolute value of the current phase angle is less than the first threshold.

[0095] If so, jump to S15; otherwise, jump to S17.

[0096] S15: Calculate the first phase angle change rate.

[0097] Obtain the temporarily stored first historical output frequency and first historical phase angle, calculate the difference between the current output frequency and the first historical output frequency to obtain the first frequency difference, calculate the difference between the current phase angle and the first historical phase angle to obtain the first phase angle difference, and calculate the ratio of the first phase angle difference to the first frequency difference to obtain the first phase angle change rate.

[0098] S16: Calculate the reciprocal of the first phase angle change rate as the frequency change amount.

[0099] Jump to S19.

[0100] S17: Calculate the second phase angle change rate.

[0101] Obtain the temporarily stored first historical output frequency and first historical modulus value, calculate the difference between the current output frequency and the first historical output frequency to obtain the first frequency difference, calculate the difference between the current modulus value and the first historical modulus value to obtain the first modulus difference, and calculate the ratio of the first modulus difference to the first frequency difference to obtain the first modulus change rate.

[0102] Use the formula Calculate to obtain the second phase angle change rate.

[0103] S18: Calculate the reciprocal of the second phase angle change rate as the frequency change amount.

[0104] S19: Determine whether the absolute value of the current phase angle is less than the second threshold.

[0105] If so, it means that the stop search condition is satisfied, and jump to S25; otherwise, jump to S20.

[0106] S20: Determine whether the difference between the current modulus value and the minimum modulus value is greater than a first set value.

[0107] If so, it means that an abnormality occurs in the search, and jump to S24; otherwise, jump to S21.

[0108] S21: Determine whether the current modulus value is less than the minimum modulus value.

[0109] If so, jump to S22; otherwise, jump to S23.

[0110] S22: Update the minimum modulus value to the current modulus value, and update the minimum modulus value frequency to the current output frequency.

[0111] S23: Calculate the product of the frequency change amount and the step coefficient as the frequency adjustment step, determine the next output frequency according to the frequency adjustment step and the current output frequency, and perform relevant updates.

[0112] The relevant updates may specifically include updating the first historical frequency with the current frequency, updating the first historical modulus value with the current modulus value, updating the first historical phase angle with the current phase angle; and then updating the current frequency with the next output frequency.

[0113] Jump to S12.

[0114] S24: Use the minimum modulus value frequency as the next output frequency, perform relevant updates, and adjust the frequency search parameters.

[0115] The relevant updates may specifically include updating the first historical frequency with the first historical frequency corresponding to the minimum modulus value frequency, updating the first historical modulus value with the first historical modulus value corresponding to the minimum modulus value frequency, updating the first historical phase angle with the first historical phase angle corresponding to the minimum modulus value frequency, and updating the current frequency with the next output frequency.

[0116] Jump to S12.

[0117] S25: Use the current output frequency as the frequency search result and end the frequency search.

[0118] Among them, S19, S20 and S24, S21 - S22 only need to be after S13, and there is no limitation on the execution order between each other, and between S14 - S18 and S23.

[0119] As Figure 6 shown, the frequency search method of the ultrasonic transducer provided by another embodiment of the present application includes the following parts.

[0120] S31: Start frequency search according to the initial search parameters.

[0121] The initial search parameters include: the initial output frequency, the matching search direction, the initial frequency adjustment step size, the initial value of the step coefficient, etc.

[0122] The current impedance and the current phase angle calculated at the initial output frequency are generally only temporarily stored for use in subsequent output frequency calculations, and cannot be used to calculate the frequency adjustment step size at the initial output frequency. Instead, the initial frequency adjustment step size is directly used to determine the next output frequency, and the calculated next output frequency is used to update the current frequency, and then the subsequent steps are executed.

[0123] S32: Control the power supply to output alternating current at the current output frequency to the ultrasonic transducer, and collect the current voltage and current of the ultrasonic transducer.

[0124] S33: Calculate the current modulus value and the current phase angle of the impedance of the ultrasonic transducer based on the current voltage and current.

[0125] S34: Determine whether the absolute value of the current phase angle is less than the second threshold.

[0126] If so, it means that the stop search condition is satisfied, and jump to S42; otherwise, jump to S35.

[0127] S35: Determine whether the difference between the current modulus value and the minimum modulus value is greater than the first set value.

[0128] If so, it means that the search is abnormal, and jump to S41; otherwise, jump to S36.

[0129] S36: Calculate the first phase angle change rate and the second phase angle change rate.

[0130] Obtain the temporarily stored first historical output frequency and the first historical phase angle, calculate the difference between the current output frequency and the first historical output frequency to obtain the first frequency difference, calculate the difference between the current phase angle and the first historical phase angle to obtain the first phase angle difference, and calculate the ratio of the first phase angle difference to the first frequency difference to obtain the first phase angle change rate.

[0131] Obtain the temporarily stored first historical output frequency and the first historical modulus value, calculate the difference between the current output frequency and the first historical output frequency to obtain the first frequency difference, calculate the difference between the current modulus value and the first historical modulus value to obtain the first modulus difference, and calculate the ratio of the first modulus difference to the first frequency difference to obtain the first modulus change rate.

[0132] Use the formula to calculate the second phase angle change rate.

[0133] S37: Calculate the reciprocal of the maximum value of the first phase angle change rate and the second phase angle change rate as the frequency change amount.

[0134] S38: Determine whether the current modulus value is less than the minimum modulus value.

[0135] If so, jump to S39; otherwise, jump to S40.

[0136] S39: Update the minimum modulus value to the current modulus value, and update the minimum modulus value frequency to the current output frequency.

[0137] S40: Calculate the product of the frequency change amount and the step coefficient as the frequency adjustment step size, determine the next output frequency according to the frequency adjustment step size and the current output frequency, and perform relevant updates.

[0138] The relevant updates may specifically include updating the first historical frequency with the current frequency, updating the first historical modulus value with the current modulus value, updating the first historical phase angle with the current phase angle; and then updating the current frequency with the next output frequency.

[0139] Jump to S32.

[0140] S41: Use the minimum modulus value frequency as the next output frequency, perform relevant updates, and adjust the frequency search parameters.

[0141] The relevant updates may specifically include updating the first historical frequency with the first historical frequency corresponding to the minimum modulus value frequency, updating the first historical modulus value with the first historical modulus value corresponding to the minimum modulus value frequency, updating the first historical phase angle with the first historical phase angle corresponding to the minimum modulus value frequency, and updating the current frequency with the next output frequency.

[0142] Jump to S32.

[0143] S42: Use the current output frequency as the frequency search result, and end the frequency search.

[0144] Among them, S34, S35, S38 - S39 only need to be after S33, and there is no restriction on the execution order among them, as well as between them and S36 - S37 and S40.

[0145] Figure 7 The structural schematic diagram of the frequency search device of the ultrasonic transducer provided by an embodiment of the present application is shown. The frequency search device of the ultrasonic transducer includes an acquisition module 101, a first calculation module 102, a second calculation module 103, and a determination module 104.

[0146] The acquisition module 101 is configured to control the power supply to output alternating current with the current output frequency to the ultrasonic transducer, and acquire the current voltage and current of the ultrasonic transducer.

[0147] The first calculation module 102 is configured to calculate the current modulus value and the current phase angle of the ultrasonic transducer impedance based on the current voltage and the current current.

[0148] The second calculation module 103 is configured to calculate the target phase change rate of the phase with respect to the frequency based on the current modulus value and the current phase angle.

[0149] The determination module 104 is configured to determine the frequency adjustment step based on the target phase change rate, and determine the next output frequency based on the frequency adjustment step, where the frequency adjustment step is negatively correlated with the target phase change rate.

[0150] Optionally, the determination module 104 is configured to select one of a first phase change rate and a second phase change rate as the target phase change rate according to a preset rule.

[0151] Optionally, the determination module 104 is configured to calculate a first phase change rate based on the current phase angle; and / or calculate a first modulus change rate of the modulus with respect to the frequency based on the current modulus value; calculate a second phase angle change rate based on the first modulus change rate, the current modulus value, and the current phase angle.

[0152] Optionally, the determination module 104 is configured to convert the first modulus change rate into a second phase angle change rate according to the mapping relationship between the current modulus value and the current phase angle.

[0153] Optionally, the first modulus change rate is the ratio of a first modulus difference to a first frequency difference, the first modulus difference is the difference between the current modulus value and a first historical modulus value, the first historical modulus value is the modulus value of the ultrasonic transducer impedance collected and calculated at a first historical output frequency, the first frequency difference is the difference between the current output frequency and the first historical output frequency, the first phase change rate is the ratio of a first phase angle difference to the first frequency difference, the first phase angle difference is the difference between the current phase angle and a first historical phase angle, and the first historical phase angle is the phase angle of the ultrasonic transducer impedance collected and calculated at the first historical output frequency.

[0154] Optionally, the first historical output frequency includes the previous output frequency of the current output frequency, and / or the frequency corresponding to the minimum modulus value that has been searched.

[0155] Optionally, the preset rule includes: when the absolute value of the current phase angle is less than a first threshold, select the first phase change rate as the target phase change rate; when the absolute value of the current phase angle is greater than or equal to the first threshold, select the second phase change rate as the target phase change rate.

[0156] Optionally, the preset rule includes: selecting the maximum value of the first phase change rate and the second phase change rate as the target phase change rate.

[0157] Optionally, the determination module 104 further includes a range unit (not shown in the figure) for determining the change rate value range according to the current modulus value and the current phase angle; when the target phase change rate is greater than the upper limit of the change rate value range, the target phase change rate is updated to the upper limit of the change rate value range, and when the target phase change rate is less than the lower limit of the change rate value range, the target phase change rate is updated to the lower limit of the change rate value range.

[0158] Optionally, the frequency search device of the ultrasonic transducer further includes an abnormality determination module (not shown in the figure) for determining whether the search is abnormal according to the current modulus value and / or the current phase angle. When the search is abnormal, the minimum modulus frequency is used as the next output frequency, and the frequency search parameters are adjusted, where the minimum modulus frequency is the frequency corresponding to the minimum modulus value that has been searched.

[0159] Optionally, determining whether the search is abnormal according to the current modulus value and / or the current phase angle includes: when the first modulus difference is greater than the first set value and / or the positive and negative signs of the current phase angle and the phase angle corresponding to the minimum modulus value are different, it is determined that the search is abnormal.

[0160] Optionally, the growth module is used to reduce the step coefficient, and the step coefficient is used to determine the frequency adjustment step length together with the target phase change rate, and the frequency adjustment step length is positively correlated with the step coefficient.

[0161] Optionally, the growth module is used to increase the current current.

[0162] Optionally, the frequency search device of the ultrasonic transducer further includes a maintenance module (not shown in the figure) for updating the minimum modulus value to the current modulus value and updating the minimum modulus frequency to the current output frequency when the current modulus value is less than the minimum modulus value.

[0163] Optionally, the current current is the maximum allowable current.

[0164] Optionally, the frequency search device of the ultrasonic transducer further includes an end module (not shown in the figure) for ending the frequency search when the absolute value of the current phase angle is less than the second threshold.

[0165] It should be noted that for the information interaction, execution process, etc. between the above-mentioned devices / modules / units, since they are based on the same concept as the method embodiment of the present application, their specific functions and the technical effects brought about can be specifically referred to in the method embodiment part, and will not be elaborated here.

[0166] It should be understood that the magnitudes of the sequence numbers of the steps in the above embodiments do not mean the order of execution. The execution order of each process should be determined according to its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.

[0167] Those skilled in the art can clearly understand that, for the convenience and conciseness of description, only the above-mentioned division of each functional unit and module is used as an example. In practical applications, the above-mentioned functions can be allocated to different functional units and modules according to needs, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. Each functional unit and module in the embodiments can be integrated into a processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of a software functional unit. In addition, the specific names of each functional unit and module are only for the convenience of mutual distinction and do not limit the protection scope of this application. The specific working processes of the units and modules in the above system can refer to the corresponding processes in the foregoing method embodiments and will not be elaborated herein.

[0168] The frequency search method of the ultrasonic transducer provided by the embodiments of this application can be implemented as a computer software program. For example, an embodiment of this application provides a computer program product, which includes a computer program carried on a computer-readable medium, and the computer program contains program codes for executing the method shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed from the network and / or installed from a removable external storage unit. When the computer program is executed by a processor, various functions defined in the frequency search method of the ultrasonic transducer provided by the embodiments of this application are realized.

[0169] If the above-mentioned integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on such an understanding, to implement all or part of the processes in the above-mentioned method embodiments of this application, it can be completed by instructing relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium. When the computer program is executed by a processor, the steps of the above-mentioned method embodiments can be realized. Among them, the computer program includes computer program codes, and the computer program codes can be in the form of source code, object code, executable files or some intermediate forms, etc. The computer-readable medium can at least include: any entity or device that can carry the computer program codes to the photographing device / electronic device, recording medium, computer memory, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), electrical carrier signals, telecommunication signals, and software distribution media. For example, USB flash drives, mobile hard disks, magnetic disks or optical discs, etc. In some jurisdictions, according to legislation and patent practice, computer-readable media may not be electrical carrier signals and telecommunication signals.

[0170] In the above embodiments, the descriptions of the various embodiments each have their own emphasis. For parts not detailed or recorded in a certain embodiment, reference may be made to the relevant descriptions of other embodiments.

[0171] Those of ordinary skill in the art can realize that the units and algorithm steps of the examples described in combination with the embodiments disclosed herein can be implemented by electronic hardware, or by a combination of computer software and electronic hardware. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods for each specific application to implement the described functions, but such implementation should not be considered to exceed the scope of this application.

[0172] In the embodiments provided in this application, it should be understood that the disclosed apparatus / network device and method can be implemented in other ways. For example, the apparatus / network device embodiments described above are merely illustrative. For example, the division of the modules or units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the couplings or direct couplings or communication connections shown or discussed with each other can be through some interfaces, and the indirect couplings or communication connections of the devices or units can be in electrical, mechanical or other forms.

[0173] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they can be located in one place, or distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0174] The above embodiments are only used to illustrate the technical solutions of this application, rather than to limit them; although this application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included in the protection scope of this application.

Claims

1. A frequency search method for an ultrasonic transducer, characterized in that, The method includes: Controlling the power supply to output alternating current with the current output frequency to the ultrasonic transducer, and collecting the current voltage and current of the ultrasonic transducer; Calculating the current modulus value and current phase angle of the impedance of the ultrasonic transducer based on the current voltage and the current; Calculating the target phase change rate of the phase relative to the frequency based on the current modulus value and the current phase angle; Determining the frequency adjustment step according to the target phase change rate, and determining the next output frequency according to the frequency adjustment step, where the frequency adjustment step is negatively correlated with the target phase change rate.

2. The method according to claim 1, wherein The calculating the target phase change rate of the phase relative to the frequency based on the current modulus value and the current phase angle includes: Selecting one of a first phase change rate and a second phase change rate as the target phase change rate according to a preset rule.

3. The method according to claim 2, wherein Before the selecting one of a first phase change rate and a second phase change rate as the target phase change rate according to a preset rule, further includes: Calculating a first phase change rate according to the current phase angle; and / or Calculating a first modulus change rate of the modulus relative to the frequency according to the current modulus value; calculating a second phase angle change rate according to the first modulus change rate, the current modulus value and the current phase angle.

4. The method according to claim 2, wherein The preset rule includes: When the absolute value of the current phase angle is less than a first threshold, selecting the first phase change rate as the target phase change rate; When the absolute value of the current phase angle is greater than or equal to the first threshold, selecting the second phase change rate as the target phase change rate.

5. The method according to claim 2, wherein The preset rule includes: Selecting the maximum value of the first phase change rate and the second phase change rate as the target phase change rate.

6. The method according to any one of claims 1-5, wherein After calculating the current modulus value and current phase angle of the impedance of the ultrasonic transducer based on the current voltage and the current, further includes: Judging whether the search is abnormal according to the current modulus value and / or the current phase angle. When the search is abnormal, taking the minimum modulus frequency as the next output frequency, and adjusting the frequency search parameters, where the minimum modulus frequency is the frequency corresponding to the minimum modulus value that has been searched.

7. The method according to claim 6, wherein The judging whether the search is abnormal according to the current modulus value and / or the current phase angle includes: When the first modulus difference is greater than a first set value and / or the positive and negative signs of the current phase angle and the phase angle corresponding to the minimum modulus value are different, determining that the search is abnormal.

8. The method according to claim 6, wherein The method further includes: When the current modulus value is less than the minimum modulus value, updating the minimum modulus value to the current modulus value, and updating the minimum modulus frequency to the current output frequency.

9. The method according to claim 6, wherein The method further includes: The adjusting the frequency search parameters includes: Reduce the step coefficient, which is used to determine the frequency adjustment step together with the target phase change rate, and the frequency adjustment step is positively correlated with the step coefficient.

10. The method according to claim 6, wherein the adjusting frequency search parameter includes: Increase the current current.

11. The method according to any one of claims 1-5, wherein the current current is the maximum allowable current.

12. A frequency search device for an ultrasonic transducer, characterized in that, The device includes: An acquisition module, configured to control the power supply to output alternating current with a current output frequency to the ultrasonic transducer, and acquire the current voltage and current current of the ultrasonic transducer; A first calculation module, configured to calculate the current modulus value and the current phase angle of the impedance of the ultrasonic transducer according to the current voltage and the current current; A second calculation module, configured to calculate a first modulus change rate of the modulus with respect to frequency based on the current modulus value and / or calculate a first phase change rate of the phase with respect to frequency based on the current phase angle; A determination module, configured to determine a frequency adjustment step according to the first modulus change rate or the first phase change rate, and determine a next output frequency according to the frequency adjustment step, wherein the frequency adjustment step is negatively correlated with the first phase change rate.

13. An ultrasonic device, comprising a power supply, an ultrasonic transducer, a sensor, a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, the method according to any one of claims 1 to 11 is implemented.

14. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, the method according to any one of claims 1 to 11 is implemented.

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