Constant voltage control protection method and device for ultrasonic generator

Abstract

The application discloses a constant voltage control protection method and device of an ultrasonic generator, comprising the following steps: step one, establishing a linear relationship between the output waveform amplitude of the ultrasonic generator and the control frequency; the linear relationship is extracted from the change condition of test data and described by a linear frequency interval and a linear frequency change amount; step two, monitoring the output waveform amplitude of the ultrasonic generator and adjusting the control frequency according to the linear relationship, so that the output voltage is kept constant and the output of the ultrasonic generator is stopped when the no-load condition is met. The linear relationship between the control frequency and the output voltage of the ultrasonic generator established based on the test data makes the output voltage of the ultrasonic generator stable within the set error voltage, improves the stability and consistency of the output power of the ultrasonic generator, and establishes the no-load condition based on the linear relationship and the control strategy to protect the ultrasonic transducer in the no-load condition, which has the characteristics of real-time control, fast response speed, strong robustness and convenient debugging.

Description

Technical Field

[0001] This invention relates to the field of ultrasonic equipment control, and in particular to a constant pressure control and protection method and device for an ultrasonic generator. Background Technology

[0002] In the field of high-frequency medical ultrasound equipment application technology, the input terminal of its core component, the ultrasonic piezoelectric ceramic transducer, is generally connected to the output terminal of a power amplifier. The ultrasonic output is controlled by the output voltage of the power amplifier; that is, the amplitude of the ultrasonic output waveform is proportional to the output voltage of the power amplifier, which is also the operating voltage of the ultrasonic piezoelectric ceramic transducer. However, in practical applications, the linear frequency range available for constant output voltage control is very small. With the introduction of power and impedance matching circuits, this linear frequency range becomes even smaller and more difficult to extract, increasing the difficulty of controlling and debugging medical ultrasound equipment. Achieving stable ultrasonic power output is a key technology in the control of high-frequency medical ultrasound equipment. On the other hand, if the medical ultrasound equipment is in an atypical application or poor contact operating state, the ultrasonic energy will not be completely absorbed and will be reflected back into the ultrasonic piezoelectric ceramic transducer. This will cause a significant increase in the internal temperature of the ultrasonic piezoelectric ceramic transducer, changing its parameters and reducing its service life. It will also cause local temperature rise at the patient contact surface. Detecting the no-load condition or poor contact condition of the medical ultrasound equipment to achieve no-load protection of the ultrasonic transducer is another key technology in the control of high-frequency medical ultrasound equipment.

[0003] While existing ultrasonic equipment control schemes exist, such as the optimal resonant frequency mode control scheme based on maximum output current detection, and schemes using sampling conditioning circuits and dedicated contact detection circuits for detection and control, these schemes still have many problems. For example, the optimal resonant frequency mode control scheme based on maximum output current detection cannot achieve complete impedance and power matching, resulting in poor precision frequency control and consistency of ultrasonic output. Furthermore, setting up dedicated sampling conditioning circuits and contact detection circuits significantly increases structural costs. Moreover, with the addition of extra cable connections and contact detection modules, these cables are routed in parallel with the ultrasonic output cables, making the confidence level of the detection results susceptible to various interference factors, which hinders implementation in applications with high protection requirements. Summary of the Invention

[0004] In order to overcome the technical problems of high difficulty in controlling medical ultrasound equipment and poor no-load protection, the present invention provides a constant voltage control protection method and device for ultrasound generators that can stably control ultrasound generators and provide no-load protection.

[0005] To achieve the above-mentioned technical objectives, the technical solution of the present invention is as follows:

[0006] A constant voltage control and protection method for an ultrasonic generator includes the following steps:

[0007] Step 1: Establish a linear relationship between the output voltage of the ultrasonic generator and the control frequency. The output voltage is the operating voltage of the ultrasonic generating component in the ultrasonic generator. The linear relationship is extracted from the variation of the test data and described by the linear frequency range and the linear frequency change.

[0008] Step two: Monitor the output voltage of the ultrasonic generator in real time, and adjust the control frequency according to the linear relationship in step one, so as to keep the output voltage constant.

[0009] In the method described above, step one involves extracting a linear relationship from the changes in test data. This is achieved by dividing the preset control frequency range [Freq_min, Freq_max] into multiple frequency points at equal intervals, measuring the effective waveform value of the ultrasonic generator output voltage at each frequency point, and then calculating the corresponding output voltage using the following formula:

[0010] Vout_n = 1.414 * Vout_rms_n

[0011] This yields a graph showing the relationship between the control frequency and the output voltage.

[0012] Where Freq_min is the preset minimum control frequency and Freq_max is the preset maximum control frequency. Vout_rms_n is the effective waveform value of the ultrasonic generator output voltage at the nth frequency point Freq_n, and Vout_n is the output voltage corresponding to Vout_rms_n.

[0013] In the method described above, step one, the linear relationship described by the linear frequency range and the linear frequency change is:

[0014] Find the maximum continuous frequency range [FreqMin, FreqMax] in the relationship graph between control frequency and output voltage, and obtain the linear relationship between output voltage and control frequency Freq = Kf * Vout + Bf by performing inverse linear fitting within the maximum frequency range using the least squares method. Then determine the linear frequency change FreqDelta = Kf * VoutDelta that satisfies the output voltage control accuracy VoutDelta.

[0015] Where FreqMin represents the minimum control frequency within the maximum continuous frequency range, and FreqMax represents the maximum control frequency within the maximum continuous frequency range. Freq represents the control frequency value, Kf represents the linear frequency voltage coefficient, Bf represents the frequency bias, and Vout represents the output voltage value.

[0016] For the described method of finding the maximum continuous frequency interval, it is to find the interval with the most number of cases satisfying the condition Vout_n - Vout_n_1 > 0, where Vout_n_1 represents the output voltage corresponding to the (n - 1)-th frequency point Freq_n_1.

[0017] For the described method, in step two, adjusting the control frequency includes:

[0018] When the output voltage Vout is greater than the set voltage VoutSet by VoutDelta, the control frequency Freq = Freq - FreqDelta. When the output voltage Vout is less than the set voltage VoutSet by VoutDelta, the control frequency Freq = Freq + FreqDelta. If Freq < FreqMin, then Freq = FreqMin. If Freq > FreqMax, then Freq = FreqMax.

[0019] For the described method, the set voltage VoutSet is the output voltage value corresponding to the center frequency (FreqMin + FreqMax) / 2 of the maximum frequency interval [FreqMin, FreqMax].

[0020] The described method further includes step three of performing no-load protection on the ultrasonic generator:

[0021] Stop the output of the ultrasonic generator when the no-load condition is met, where the no-load condition is: when at the minimum control frequency FreqMin, the output voltage of the ultrasonic generator is less than the set voltage VoutSet.

[0022] An electronic device includes:

[0023] One or more processors.

[0024] A storage device for storing one or more programs,

[0025] When the one or more programs are executed by the one or more processors, the one or more processors implement the前述 method.

[0026] A computer-readable medium having a computer program stored thereon, and when the program is executed by a processor, it implements the前述 method.

[0027] The technical advantages of this invention lie in that, through experimental search analysis, the linear relationship not only considers the linear frequency coefficient but also accurately defines the linear interval and objectively applies it to the control program. This ensures stability during the control process, preventing significant overshoot or undershoot; it also helps ensure batch consistency. The constant voltage control method based on the Bang-Bang strategy is established on the linear relationship between ultrasonic output voltage and control frequency, enabling rapid and stable ultrasonic output. The program is easy to handle through simple comparisons and addition / subtraction operations, avoiding overflow anomalies caused by large control frequency values; it features real-time control, fast response speed, and strong robustness. The no-load condition is based on the contradictory relationship between output voltage and control frequency, eliminating the need for additional hardware or structural costs, and easily achieving reliable and highly adaptable no-load protection control. The sampling process of this invention can be completed with just an oscilloscope in actual operation; the established linear relationship is simple and intuitive, making equipment debugging convenient and complete. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the method principle of the present invention;

[0029] Figure 2 This is a schematic diagram of the constant pressure control process of the present invention;

[0030] Figure 3 This is a schematic diagram illustrating the linear relationship between the control frequency and the output voltage of the present invention;

[0031] Figure 4 This is a schematic diagram of the output voltage adjustment process of the ultrasonic generator of the present invention. Implementation

[0032] See Figures 1-4 The constant pressure control and protection method given in this embodiment includes the following steps:

[0033] Step 1: Establish a linear relationship between the output voltage and control frequency of the ultrasonic generator using experimental test data. This linear relationship is described by the linear frequency range and the linear frequency variation. The linear relationship is extracted by searching and analyzing the changes in the experimental test data. The obtained linear frequency range and linear frequency coefficient are then applied to the equipment control program.

[0034] Step 2: Perform constant voltage control. Periodically detect the output voltage of the ultrasonic generator. Based on the linear frequency range and linear frequency coefficient, adopt the Bang-Bang control strategy to synchronously modify the control frequency and achieve constant output voltage control.

[0035] Step 3: Perform no-load protection control. When the no-load condition is met, the output will be shut off. The no-load condition is expressed as the ultrasonic generator output voltage at the minimum frequency being less than the set voltage.

[0036] Specifically, in this embodiment, step one involves establishing a linear relationship between the ultrasonic generator's output voltage and the control frequency using experimental test data. This linear relationship is described by a linear frequency range and a linear frequency change. The linear relationship is extracted by searching and analyzing the changes in the experimental test data. The extracted linear frequency range and linear frequency change are then incorporated into the control program.

[0037] Establishing a linear relationship between the ultrasonic generator's output voltage and control frequency through experimental test data involves using an oscilloscope to measure the effective value Vout_rms_n of the output voltage waveform at equally spaced frequency points Freq_n (n=1,2,3,...) within a large frequency range [Freq_min,Freq_max]. The output voltage Vout_n = 1.414 * Vout_rms_n is then plotted as the control frequency-output voltage relationship. Since the ultrasonic transducer's actuating element is piezoelectric ceramic, and the ultrasonic output waveform amplitude is proportional to the power amplifier's output voltage, the acquired power amplifier output voltage actually reflects the ultrasonic output waveform amplitude. Of course, the power amplifier output voltage is also the operating voltage of the piezoelectric ceramic component that generates the ultrasonic wave.

[0038] The linear relationship is extracted through continuous search analysis of experimental test data changes and described by a linear frequency range and a linear frequency change. Specifically, it involves continuously searching the maximum frequency range [FreqMin, FreqMax] in the control frequency-output voltage relationship graph to satisfy the condition Vout_n - Vout_n_1 > 0, and then performing inverse linear fitting within this maximum frequency range using the least squares method to obtain the linear relationship Freq = Kf * Vout + Bf. This leads to the determination of the linear frequency change FreqDelta = Kf * VoutDelta corresponding to the output voltage control accuracy VoutDelta (e.g., 0.1V). Here, Kf represents the linear frequency voltage coefficient (Coefficient of frequency), and Bf represents the frequency bias (Bias of frequency).

[0039] The linear relationship is solidified into the control program, which means that FreqMin, FreqMax, FreqDelta, and VoutDelta, which were extracted through experimental analysis, are written into the control program.

[0040] Step 2: Perform constant voltage control. Periodically detect the output voltage of the ultrasonic generator. Based on the linear frequency range and linear frequency coefficient, adopt the Bang-Bang control strategy to synchronously modify the control frequency and achieve constant output voltage control.

[0041] Among them, for the Bang-Bang control strategy, when the output voltage Vout is greater than the set voltage VoutSet by VoutDelta, the control frequency Freq = Freq - FreqDelta. When the output voltage Vout is less than the set voltage VoutSet by VoutDelta, the control frequency Freq = Freq + FreqDelta. If Freq < FreqMin, then Freq = FreqMin. If Freq > FreqMax, then Freq = FreqMax. The set voltage VoutSet is usually located at the center of the linear frequency range.

[0042] Step 3: Perform no-load protection control. When the no-load condition is met, the output is turned off. The no-load condition is expressed as the voltage value at the minimum frequency being less than the set voltage.

[0043] Among them, for the no-load protection control, when the ultrasonic transducer has no contact or poor contact with the typical application surface (human skin), most of the ultrasonic output energy is reflected back into the ultrasonic transducer, resulting in high temperatures and even damage to the ultrasonic transducer. The no-load protection control is used to solve the above abnormal conditions.

[0044] The no-load condition is expressed as the voltage value at the minimum frequency being less than the voltage set value. When the frequency control value is the minimum frequency, the output voltage is at the maximum voltage value. If the detected voltage value is smaller than the set voltage VoutSet, it will be much smaller than the voltage at the minimum frequency, and thus it can be determined as no-load. That is, when Freq <= FreqMin and Vout < VoutSet, it is determined as no-load. At this time, the output should be turned off.

[0045] Since the no-load condition is based on the contradictory relationship between the output voltage and the control frequency, when it is lightly loaded or no-load, the output voltage drops. At this time, to keep the output voltage constant at the set voltage, the control frequency will decrease. When the control frequency drops to the lower limit of the linear frequency range, the output voltage will be at the maximum value. If the output voltage is still very small, it means that it is in a lightly loaded or no-load state.

[0046] That is, the output voltage can be expressed by the formula Vout = Vin ·(1 + (2 πf · R · C )) f , C , R , R ) represents. Among them Vin represents the input voltage, f represents the control frequency, R represents the load impedance, C represents the sum of the static capacitance of the transducer and the matching capacitance. Here R actually determines the value of the output voltage.

[0047] The method of implementing this scheme was verified using a 1000KHz ultrasound physiotherapy device, wherein the resonant frequency of the ultrasound transducer is approximately 1085KHz, the load impedance of the typical application is approximately 25 ohms, and the unload impedance is approximately 8 ohms.

[0048] Implementation Step 1 Figure 3 The data represents the experimental data of control frequency and output voltage. The blue line Vout(Vrms) represents the original test data, the red line VoutLine represents the searched linear interval, and the dashed line VoutModel represents the linear relationship between output voltage and control frequency, with a coefficient of determination better than 0.95. Based on the foregoing description, the following parameters are fixed:

[0049] FreqMin=1065KHz, FreqMax=1095KHz, FreqDelta=-1.402KHz, VoutDelta=0.1V, VoutSet=35V.

[0050] Step two involves setting the initial frequency to the minimum voltage frequency FreqMax. Figure 4 This describes the adjustment process of the output voltage (after passing through the output voltage amplitude detection circuit), which is related to... Figure 3 The linear relationship is extremely strong, thanks to the complete combination of the Bang-Bang control strategy and the linear relationship.

[0051] Step three involves placing the ultrasonic transducer in an atypical application (such as air). The output voltage will be about 50% lower than in a typical application. In the linear frequency range, no matter how the frequency is modified, it cannot compensate for this large voltage drop. Therefore, the no-load condition will be met, thereby triggering the no-load protection control program.

[0052] According to embodiments of the present invention, the present invention also provides an electronic device and a computer-readable medium.

[0053] Electronic devices include:

[0054] One or more processors;

[0055] Storage device for storing one or more programs.

[0056] When the one or more programs are executed by the one or more processors, the one or more processors implement the aforementioned method.

[0057] In practical use, users can interact with servers, which are also electronic devices, via a network to receive or send messages. Terminal devices are generally various electronic devices equipped with a display and used through a human-computer interface, including but not limited to smartphones, tablets, laptops, and desktop computers. Various specific application software can be installed on these terminal devices as needed, including but not limited to web browsers, instant messaging software, social media platforms, and shopping apps.

[0058] A server is a network service provider that offers various services, such as a backend server that provides corresponding calculation services for test data transmitted from terminal devices. This allows for linear relationship calculations on the received test data and the final control method to be returned to the terminal device.

[0059] The sales forecasting method provided in this embodiment is generally executed by the server. In practical applications, under necessary conditions, the terminal device can also directly execute constant voltage control and protection.

[0060] Similarly, the computer-readable medium of the present invention stores a computer program thereon, which, when executed by a processor, implements a constant pressure control and protection method for an ultrasonic generator according to an embodiment of the present invention.

Claims

1. A constant voltage control protection method of an ultrasonic generator, characterized by, The method comprises the following steps: Step one, establishing a linear relationship between the output voltage of the ultrasonic generator and the control frequency; wherein the output voltage is the working voltage of the ultrasonic generating component in the ultrasonic generator; the linear relationship is extracted by the following steps: In the preset control frequency range [Freq_min, Freq_max], the frequency range is equally spaced into multiple frequency points; The waveform effective value Vout_rms_n of the output voltage of the ultrasonic generator at each frequency point is measured, and the output voltage Vout_n is calculated by the formula Vout_n=1.414*Vout_rms_n; The relationship diagram of the control frequency and the output voltage is drawn; And the maximum continuous frequency interval [FreqMin, FreqMax] is found in the relationship diagram of the control frequency and the output voltage to fit the linear relationship; Wherein Freq_min is the preset minimum control frequency, Freq_max is the preset maximum control frequency; Vout_rms_n is the waveform effective value of the output voltage of the ultrasonic generator corresponding to the nth frequency point Freq_n, Vout_n is the output voltage corresponding to Vout_rms_n, FreqMin represents the minimum value of the control frequency in the maximum continuous frequency interval, and FreqMax represents the maximum value of the control frequency in the maximum continuous frequency interval; Step two, real-time monitoring the output voltage of the ultrasonic generator, and adjusting the control frequency according to the linear relationship in step one, so as to keep the output voltage constant.

2. The method of claim 1, wherein, In step one, the linear relationship between the output voltage and the control frequency is obtained by inverse linear fitting in the maximum frequency interval by the least square method, that is, Freq= Kf * Vout +Bf, and then the linear frequency variation FreqDelta=Kf*VoutDelta corresponding to the output voltage control precision VoutDelta is determined; Freq represents the value of the control frequency, Kf represents the linear frequency voltage coefficient, Bf represents the frequency offset, and Vout represents the value of the output voltage.

3. The method of claim 2, wherein, Finding the maximum continuous frequency interval is to find the interval with the most Vout_n-Vout_n_1>0 conditions, wherein Vout_n_1 represents the output voltage corresponding to the nth-1 frequency point Freq_n_1.

4. The method of claim 2, wherein, In step two, adjusting the control frequency includes: adopting the Bang-Bang control strategy and operating in the frequency interval [FreqMin, FreqMax]; specifically, When the output voltage Vout is greater than the set voltage VoutSet by VoutDelta, the control frequency Freq=Freq-FreqDelta; when the output voltage Vout is less than the set voltage VoutSet by VoutDelta, the control frequency Freq=Freq+FreqDelta; if Freq<FreqMin, then Freq=FreqMin; if Freq>FreqMax, then Freq=FreqMax.

5. The method of claim 4, wherein, The set voltage VoutSet is the output voltage value corresponding to the center frequency (FreqMin+FreqMax) / 2 of the maximum frequency range [FreqMin, FreqMax].

6. The method of claim 4, wherein, Further comprising a step three, performing no-load protection on the ultrasonic generator: stopping the output of the ultrasonic generator when a no-load condition is met, wherein the no-load condition is that the output voltage of the ultrasonic generator is less than the set voltage VoutSet when the minimum control frequency FreqMin is met; The no-load condition is determined by the contradictory relationship between the output voltage and the control frequency at the minimum frequency point.

7. An electronic device, comprising: Comprise: one or more processors; a memory device for storing one or more programs, which when executed by the one or more processors, cause the one or more processors to implement the method of any one of claims 1-6.

8. A computer readable medium having stored thereon a computer program, characterized in that, The program is executed by the processor to implement the method of any one of claims 1-6.

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