Ultrasonic flow meter with anti-vibration operating mode

Abstract

An ultrasonic flow meter (USM) includes a meter body including a pipe section for flowing fluid therethrough, the pipe section including a first ultrasonic transducer and a second ultrasonic transducer; an actuator including a housing and a PCB; a controller coupled to the ultrasonic transducers by a transmitter and / or receiver; and an accelerometer and / or acoustic sensor for sensing vibrations on the pipe section and for providing an output signal coupled to the controller. Electronics are communicatively coupled to the meter body, and the housing is mechanically coupled to the meter body. The controller analyzes the output signal to identify a vibration frequency of >1, and compares the vibration frequency to a predetermined sensitive frequency range of the USM. When the vibration frequency is determined to be within the predetermined frequency range, the controller implements an anti-vibration operating mode by increasing a measurement time and / or adding additional data processing tasks when measuring fluid flow.

Description

Technical Field

[0001] The aspects disclosed in this invention relate to ultrasonic flow meters (USM). Background Technology

[0002] In many industries involving product flow, there is a need to accurately measure the amount of flowing product at any given time. Several different types of flow meters exist. These known flow meters include mechanical flow meters (e.g., piston flow meters, screw flow meters, or jet flow meters, all of which measure fluid flow through some mechanical means), vortex flow meters (where vortices are generated by blocking a portion of the fluid path, thus producing voltage pulses whose frequency can be measured and thus the flow rate determined), magnetic flow meters (measuring the potential difference in a conductive fluid generated by an applied magnetic field and thus determining the flow rate), turbine flow meters, and rotary flow meters. Static flow meters (meaning those with no moving parts), including USMs, also exist.

[0003] Unstable flow meters (USMs) are gaining popularity in fluid flow measurement because they can measure a wide variety of flow rates, cause only minimal pressure drops, and have no moving parts, thus offering less mechanical maintenance and better reliability compared to most conventional flow meter types. A key hardware component in a USM is the ultrasonic transducer, also known as an ultrasonic sensor, which comprises at least a piezoelectric crystal or piezoelectric ceramic, typically containing lead zirconate titanate (PZT). As is known in physics, the piezoelectric effect is the ability of certain materials to generate an electric charge in response to applied mechanical stress, and vice versa. While a USM may include a single ultrasonic transducer, it typically comprises at least a pair of ultrasonic transducers that operate by converting electrical energy supplied in the form of pulsed electrically driven signals. These pulsed signals are transmitted to the ultrasonic transducers, which convert the received electrical energy into ultrasonic signals that are transmitted and directed to the fluid being measured, and vice versa when used as an ultrasonic receiver.

[0004] Such a USM may include an outer housing, within which may reside a printed circuit board (PCB) including a controller, such as a microcontroller unit (MCU) or digital signal processor, and typically other electronics. USMs are typically battery-powered and / or powered by external wiring and may include a radio frequency (RF) unit and an antenna for wireless communication, the RF unit including a transmitter and a receiver. An ultrasonic transducer pair includes a first ultrasonic transducer and a second ultrasonic transducer. In a conventional ultrasonic transducer arrangement, the first and second transducers are configured on the same side of the pipe to generate a V-shaped ultrasonic signal path using a single reflection exiting the pipe after passing through the fluid to be measured. Another known ultrasonic transducer arrangement is a direct transmission path type that does not involve any signal reflection. Several other known transducer arrangements exist, and depending on pipe diameter and cost constraints, the total number of transducers can be as high as approximately 16 or even more.

[0005] One known USM arrangement includes a device, typically described as an actuator, comprising a housing, a PCB having electronics including a processor (such as an MCU), a battery pack, and a display mechanically and electrically coupled to an instrument body, the instrument body including a conduit having a first ultrasonic transducer and at least a second ultrasonic transducer. The connection between the actuator housing and the instrument body includes wiring for communication and metal connectors for physical connection. Summary of the Invention

[0006] This summary is provided to introduce a simplified selection of disclosed concepts, which are further described below in detail with reference to the accompanying drawings. This summary is not intended to limit the scope of the claimed subject matter.

[0007] The aspects disclosed in this invention recognize that a problem with ultrasonic transducers (USMs) is their susceptibility to interference caused by external mechanical vibrations or noise at frequencies within the operating frequency range of their ultrasonic transducers. This interference effect can reduce the accuracy of USM flow measurement. In applications of USMs in this art, there are typically gas regulators and / or valves, such as ball valves, ball valves, butterfly valves, or lift valves, installed near the USM. These gas regulators can generate vibrations at frequencies typically below several hundred kilohertz (kHz), which can be picked up by the transducers of USMs that typically operate between 80 kHz and 300 kHz when located near the USM. It has been recognized that such vibrations can increase noise in the ultrasonic sensing signal, leading to reduced measurement accuracy of the USM, which can also cause problems including affecting financial transactions due to the USM providing significantly inaccurate measurements of gas volume.

[0008] One aspect of this invention includes a USM (Unstable Ultrasonic Module), comprising: an instrument body including a pipe section configured to allow fluid flow therethrough, the pipe section including a first ultrasonic transducer and a second ultrasonic transducer; and an actuator including a housing and a PCB (Printed Circuit Board), the PCB including electronics including a controller coupled to the ultrasonic transducers via a transmitter and / or receiver. The PCB also includes an accelerometer and / or an acoustic sensor for sensing vibrations on the pipe section and for providing an output signal coupled to the controller. The electronics are communicatively coupled to the instrument body and the housing, the housing being mechanically connected to the instrument body via a mechanical joint. The controller analyzes the signals from the accelerometer and / or acoustic sensor to identify at least one vibration frequency and compares the vibration frequency to a predetermined sensitive frequency range of the USM. When the vibration frequency is determined to be within the predetermined frequency range, the controller handles the vibration by increasing the measurement and processing time and / or adding additional data processing tasks during fluid flow measurement, thereby achieving a vibration-resistant operating mode.

[0009] Accelerometers are typically in the form of microelectromechanical systems (MEMS) packages with multiple leads or lead terminals to facilitate mounting on a PCB, and the acoustic sensors are typically high-frequency acoustic sensors, such as high-frequency microphones, which are usually also configured in packages designed for mounting on a PCB. The accelerometer and acoustic sensor (when both are provided) can sense external vibrations from a vibration source within a range of frequencies that may be present when the USM is located near the vibration source. The controller typically runs an algorithm in firmware that monitors and suppresses vibration noise effects by automatically switching to an anti-vibration operating mode when needed, so that the USM measurement accuracy is largely unaffected, despite the presence of vibrations in the frequency range that would otherwise affect the accuracy and repeatability of the USM. Attached Figure Description

[0010] Figure 1 A flowchart illustrating the steps of an exemplary method for operating a USM, which implements an anti-vibration operating mode in response to sensing vibrations within a predetermined sensitive frequency range of the USM.

[0011] Figure 2A A vibration source, illustrated by way of example, is depicted as a gas regulator, when the vibrator is near... Figure 2B When the USM is shown, the gas regulator causes an effect on the signals sensed by the ultrasonic transducers (T1 and T2) fixed to the instrument body of the USM. Figure 2C An exemplary graph of amplitude (in arbitrary units (au)) versus time shows the available (sensorable) signal and vibration from an external vibration source, which in turn is compared with the vibration from the external vibration source (such as...). Figure 2AThe available signal overlap is caused by the gas regulator or valve shown in the figure. Figure 2D An exemplary graph of amplitude versus time is shown, which only illustrates the situation after vibrations caused by external vibration sources have been removed or after they have been severely suppressed by the vibration-resistant operating mode disclosed in this invention. Figure 2C The available signals are shown.

[0012] Figure 3A An exemplary USM according to one exemplary aspect is shown, the exemplary USM comprising: a PCB located on top of the instrument body; and a number of exemplary components located on the PCB and including the accelerometer and acoustic sensor disclosed in this invention.

[0013] Figure 3B An exemplary component of the PCB of the actuator is shown for an exemplary USM having an actuator located on the instrument body.

[0014] Figure 4 A schematic diagram of a sensing hardware module of an exemplary vibration noise removal system according to an exemplary aspect is depicted.

[0015] Figure 5 An exemplary signal processing flowchart is depicted for an exemplary noise detection and removal method according to an exemplary aspect of a USM. Detailed Implementation

[0016] The aspects of the invention disclosed herein are described with reference to the accompanying drawings, wherein similar reference numerals are used throughout the drawings to denote similar or equivalent elements. The drawings are not drawn to scale and are provided only for illustrating certain disclosed aspects. Several disclosed aspects are described below with reference to exemplary applications for illustration. It should be understood that numerous specific details, relationships, and methods are set forth to provide a complete understanding of the disclosed aspects.

[0017] Figure 1 To illustrate the steps of exemplary method 100, this flowchart describes a method that operates a USM to achieve a vibration-resistant (or vibration-tolerant) operating mode in response to vibrations within a predetermined sensitive frequency range of the USM. The predetermined sensitive frequency range may be determined by the resonant frequency of an ultrasonic transducer. For example, the resonant frequency of the ultrasonic transducer can be determined by using at least one of the maximum phase and / or minimum impedance of an acoustic transducer. In one example, the predetermined sensitive frequency range is 80 kHz to 300 kHz.

[0018] Step 101 includes providing a USM comprising: an instrument body including a pipe section configured to allow fluid flow, the pipe section including at least a first ultrasonic transducer and a second ultrasonic transducer; and an actuator including a PCB including electronics including a controller (e.g., an MCU) having associated memory coupled to the ultrasonic transducers via at least one of a transmitter and a receiver. At least one of an accelerometer and an acoustic sensor is used to sense vibrations on the pipe section and to provide an output signal representing the vibrations coupled to an input of the controller. The PCB may also include a battery, typically comprising a battery pack such as a lithium-ion battery pack. The fluid in the pipe may contain hydrocarbon gases, such as natural gas or propane, or may also contain hydrogen.

[0019] The advantage of the method disclosed in this invention is that the length of the inlet pipe (e.g., a valve core typically installed before the USM and after the regulator) is not limited to the minimum length usually required to separate the USM from external vibration sources (such as gas regulators). A longer inlet pipe and a larger spacing result in less noise impact from the vibration source on the USM, but require more space, which is uncommon in practical installations. In most USM installations, the vibration source is typically located adjacent to the USM.

[0020] Regarding accelerometers, when installed on a vibrating structure, they proportionally convert mechanical energy into electrical energy. Accelerometers typically fall into one of two categories, producing 10 mV / g or 100 mV / g, where g is the gravitational constant and 1g = 9.81 m / s². 2 The frequency of the output voltage provided by the accelerometer will match the frequency of the vibration. The output level of the signal from the accelerometer will be proportional to the amplitude of the vibration.

[0021] The acoustic sensor may include a high-frequency microphone or an ultrasonic sensor. An acoustic sensor is known to be an electronic device that measures sound levels. The actuator may also include a display. Electronic components located on the actuator's PCB are communicatively coupled to the instrument body via wiring or a wireless connection. The actuator's housing is mechanically connected to the instrument body via mechanical joints (typically metal joints). A controller is used to implement steps 102 through 104 as described below.

[0022] Step 102 includes analyzing the output signal to identify at least one vibration frequency. Step 103 includes comparing the vibration frequency with a predetermined sensitive frequency range of the USM. Step 104 includes, when the vibration frequency is determined to be within the predetermined sensitive frequency range, implementing an anti-vibration operating mode that includes at least one of the following: increasing the measurement time when measuring fluid flow rate; and adding additional data processing tasks.

[0023] Figure 2A Depicting what is shown as proximate Figure 2B The vibration source of the gas regulator 207 of the USM 200 shown, wherein Figure 2C A graph showing amplitude versus time is displayed, illustrating the available (sensing) signal and the vibration caused by the gas regulator 207, which acts as an external vibration source. The USM 200 includes: an instrument body 220 comprising transducers T1 and T2; and an actuator 210 comprising a housing 218 located on top of the instrument body 220. The vibration generated by the gas regulator 207 in... Figure 2C As shown, the vibration affects the signal sensed by the ultrasonic transducer fixed to the instrument body of the USM by being within the frequency range of the available signal. A Fast Fourier Transform (FFT) can be used to... Figure 2C and Figure 2D The time-series signal shown is transformed into the frequency domain to obtain the signal spectrum.

[0024] As used herein, the term "adjacent" refers to a distance not exceeding three times the inner diameter (D) of the pipe section on which the USM is mounted. For example, when D = 2 inches, adjacent corresponds to an inlet distance of 6 inches from the USM. It should be noted that the greater the distance between the USM and vibration sources (such as gas regulators or valves), the smaller the vibration effect. Figure 2D An exemplary graph of amplitude versus time is shown, which only illustrates the situation after vibrations caused by external vibration sources have been removed or after they have been severely suppressed by the vibration-resistant operating mode disclosed in this invention. Figure 2C The available signals are shown. For example, for the piezoelectric element of an ultrasonic transducer operating at a center frequency of 200 kHz, the available signals may be in the frequency range of 180 kHz to 220 kHz.

[0025] Therefore, the USM disclosed in this invention may include both an accelerometer and an acoustic sensor, such as a high-frequency (HF) microphone located on the PCB of the actuator, wherein the PCB is in close physical contact with the instrument body to receive vibrations caused by external vibration sources adjacent to the USM. When the USM is mounted on the same pipe as a vibration source adjacent to it (such as a gas regulator), the vibration is transmitted through the accelerometer. Figure 2C The vibrations caused by the vibration source shown generate a noise-like signal in the ultrasonic spectrum of the available signal. This noise-like signal travels along the pipe to the instrument body of the USM and thus to the actuator, which includes the PCB of the accelerometer and / or acoustic sensor, which is typically securely attached via a metal clamp integrated into the housing.

[0026] Ultrasonic transducers and accelerometers can use built-in integrated circuits (I) 2C) Communicates with the controller via a Serial Peripheral Interface (SPI) or Universal Asynchronous Receiver / Transmitter (UART). The controller (such as including an MCU) is configured to analyze the sensed data, detect the vibration spectrum, and determine whether the USM should switch to anti-vibration mode. The anti-vibration mode disclosed in this invention is typically implemented by a firmware-based (FW) algorithm that includes program code configured to reduce noise effects by using longer measurement times and / or additional data processing tasks, as described in more detail below.

[0027] Figure 3A The exemplary USM 200 shown in Figure 2 is illustrated, with exemplary components of the PCB 340 of housing 218 shown by opening housing 218. The illustrated components include an accelerometer 310 and an acoustic sensor 320, the accelerometer potentially including a 3D accelerometer and the acoustic sensor potentially including a high-frequency microphone sensor. Both the accelerometer 310 and the acoustic sensor 320 are shown mounted on the PCB 340.

[0028] Figure 3B An exemplary USM 300 with an actuator 210' is shown, the actuator including a housing 218, wherein the actuator 210' is located on an instrument body 220, as shown, the instrument body including transducers T1 and T2 which can be located behind a front cover and are therefore not visible from the outside. The figure shows, except for Figure 3A Exemplary components of the PCB 340 of the actuator, other than the components shown. Similarly, an accelerometer 310 and an acoustic sensor 320 are shown, although not shown coupled to the controller 330, both of which are communicatively coupled to the controller 330. Figure 3B The battery 309 shown is optionally mounted on PCB 340.

[0029] The USMs disclosed in this invention (such as USM 300) are typically low-power, low-cost, and include smart USMs. As described above, controller 330 may include an MCU, memory 324 may include flash memory, and a radio frequency (RF) communication unit is shown as including a transmitter (Tx) 311 and a receiver (Rx) 312 coupled to an antenna 376, which is shown located outside a housing 218. Housing 218 typically comprises metal or a metal alloy.

[0030] The ultrasonic transducers, shown as T1 and T2, associated with the instrument body 220, comprise piezoelectric crystals or piezoelectric ceramics that are set to vibrate when a pulse voltage signal (received from Tx 311) is applied to their piezoelectric elements, thereby generating ultrasonic waves. In operation, a numerically controlled multiplexer (MUX) 315, controlled by controller 330, causes ultrasonic pulses to be alternately emitted by one piezoelectric element of the ultrasonic transducer pair and received by another piezoelectric element in the ultrasonic transducer pair required for gas flow measurement.

[0031] The memory associated with controller 330 is shown as “MEM” 324, which may store code for implementing flow measurement and for implementing the vibration-resistant mode operation disclosed in this invention. However, as is known in the art, the algorithm executed by controller 330 may be implemented in hardware or software. Regarding a hardware-based implementation, the algorithmic equations may be translated into digital logic gate patterns, such as using VHDL (Hardware Description Language), which can then be implemented using programmable devices such as Field Programmable Gate Arrays (FPGAs), Complex Programmable Logic Devices (CPLDs), or Application-Specific Integrated Circuits (ASICs) to implement the logic gate patterns. Regarding a software-based implementation, the algorithmic code is generally stored in memory, such as memory 324, which may be implemented by controller 330.

[0032] The instrument body 220 includes an inlet 221 for receiving fluid and an outlet 222 for releasing fluid after flow measurement. Although T1 and T2 are shown as a straight, face-to-face transducer arrangement, as mentioned above, the ultrasonic transducers can be configured in other ways, such as a reflection-based V-shaped arrangement. Furthermore, as mentioned above, more than two ultrasonic transducers may be present.

[0033] Figure 4 A schematic diagram 400 of the sensing hardware module of an exemplary noise removal system according to an exemplary aspect is depicted. Noise frequencies less than or equal to 20 kHz are shown, sensed by an accelerometer 310, and noise frequencies greater than or equal to 20 kHz are sensed by an acoustic sensor (which may also be an ultrasonic sensor) shown as a microphone 320'. As described above, this noise may originate from a gas regulator or valve located near the USM. The outputs of the accelerometer 310 and microphone 320' are shown coupled to a 2:1 numerically controlled multiplexer shown as 315', the output of which is coupled to a signal conditioning circuit 420, which typically includes bandpass filtering and low-noise amplification. The output of the signal conditioning circuit 420 is coupled to a high-speed analog-to-digital converter (ADC) 425, shown communicating with a controller via a serial peripheral interface (SPI), which is shown as a processing MCU 120' implementing the noise removal disclosed herein.

[0034] Figure 5 This is a signal processing flowchart for an exemplary noise detection and removal method 500 for a USM according to an exemplary aspect. Step 501 includes detecting vibrations from a vibration source (such as a gas regulator or valve adjacent to the USM) using an accelerometer and / or acoustic sensor, and generating vibration data in response. Step 502 includes transmitting the vibration data to... Figure 4 The controller shown is MCU 120'. Although not shown, both signal conditioning and ADC operation are typically performed before the vibration data is transmitted to MCU 120', such as... Figure 4 The diagram shows a signal conditioning circuit 420 for signal conditioning and an ADC 425 for performing ADC functions. The ADC 425 can operate at a sampling rate of more than 1 million samples per second (SPS).

[0035] Step 503 includes the MCU 120' performing an FFT on the processed vibration data to perform a time-domain to frequency-domain transformation function. As is known in the art, the FFT is an algorithm for computing the Discrete Fourier Transform (DFT) or its inverse Fourier Transform (IDFT) of a sequence. Fourier analysis transforms a time signal or spatial signal from its initial domain (here, amplitude versus time data, such as those described above)... Figure 2C (As shown) is converted into discrete frequency domain vibration data. Step 504 includes performing a comparison of the frequency domain vibration data with the spectrum and signal-to-noise ratio (SNR) thresholds of the known operating frequency range of the USM, wherein the known frequency range data is provided by the USM in box 507. The same known frequency range data provided by the USM box in box 507 is also provided to step 508, which includes generating an SNR threshold with a specified precision using the known frequency range data.

[0036] Data from steps 504 and 508 are provided as input data to achieve step 509, which includes determining whether vibration noise significantly affects the SNR of the USM by exceeding a threshold. Step 508 identifies the SNR, which largely determines the accuracy of the USM, and different applications may have different accuracy requirements and therefore different thresholds for comparing SNR. SNR can be expressed in decibels or a linear scale. If the SNR is determined to be too low when compared with the threshold, the low SNR may be caused by vibration noise that can be removed or suppressed by the methods disclosed in this invention, which makes the ultrasonic detection of the USM and therefore its accuracy performance more reliable, for example when using time-of-flight (ToF) detection for flow measurement.

[0037] Based on the result of step 509, the method moves to step 512, which includes a decision step involving determining whether to implement the vibration-resistant operating mode disclosed in this invention. If the result of step 509 determines that vibration noise is affecting SNR by exceeding a threshold, then step 513 is reached, which includes implementing the vibration-resistant operating mode disclosed in this invention. If the result of step 509 determines that vibration noise does not affect SNR by not exceeding a threshold, then step 514 is reached, which includes using the USM in the normal USM signal processing mode.

[0038] If the vibration-resistant operation mode disclosed in this invention is implemented (step 513), the method proceeds to steps 515 and 516, both of which include frequency domain processing. Step 515 includes signal deconvolution using the frequency domain vibration data provided by the FFT (step 503), which compares the spectrum and SNR threshold generated in step 504. The deconvolutioned signal output from step 515 is processed by the inverse FFT box (IFFT) 516. The IFFT is known to be an inverse fast algorithm that performs the inverse (or backward) Fourier transform, eliminating the process of transforming the frequency signal into a time-domain sequence as described above. Figure 2D As shown. After block 516, the method reaches step 514, which includes, as described above, the USM utilizing the normal USM signal processing mode.

[0039] The aspects disclosed in this invention are generally applicable to a variety of USMs. For example, the USMs disclosed in this invention can be applied to commercial or industrial USMs that typically operate at relatively high pressures (such as pressures above 3 bar), or residential USMs that typically operate at lower pressures.

[0040] Although various disclosed aspects have been described above, it should be understood that they are presented by way of example only and not as limitations. Many changes may be made to the subject matter disclosed herein without departing from the spirit or scope of this disclosure. Furthermore, while a particular feature may be disclosed only with respect to one of several implementations, such feature may be combined with one or more other features of other implementations as may be desired or advantageous for any given or particular application.

Claims

1. A method for noise detection and removal in an ultrasonic flow meter (USM), the method comprising: An ultrasonic flow meter USM (300) is provided, wherein the ultrasonic flow meter USM (300) comprises: An instrument body (220) comprising a pipe section configured to allow fluid flow, wherein the instrument body includes at least a first ultrasonic transducer and a second ultrasonic transducer (T1, T2); and An actuator (210') includes a housing (218) and a printed circuit board (PCB) (340), wherein the PCB includes electronic components, the electronic components including: A controller (330) having an associated memory (324) coupled to the ultrasonic transducer via at least one of a transmitter (311) and a receiver (312); and At least one of an accelerometer (310) and an acoustic sensor (320), the accelerometer and the acoustic sensor being used to sense vibrations on the pipe section to provide an output signal to the controller. The electronic device is communicatively coupled to the instrument body, and the housing is mechanically connected to the instrument body via a mechanical joint; The controller is configured to: Analyze the output signal to identify at least one vibration frequency; The vibration frequency is compared with a predetermined sensitive frequency range of the USM; and When the vibration frequency is determined to be within the predetermined sensitive frequency range, an anti-vibration operation mode is implemented. This anti-vibration operation mode includes additional data processing tasks, wherein the additional data processing tasks include: Perform a Fast Fourier Transform on the vibration output signal to generate frequency domain vibration data; and The frequency domain vibration data is deconvolved using a spectrum and signal-to-noise ratio (SNR) threshold comparison, wherein the SNR threshold comparison includes performing a spectrum and SNR threshold comparison between the frequency domain vibration data and a predetermined sensitive frequency range of the USM.

2. The method according to claim 1, wherein the USM (300) comprises both the accelerometer (310) and the acoustic sensor (320).

3. The method according to claim 1, wherein the predetermined sensitive frequency range is determined by at least one resonant frequency of the ultrasonic transducer (T1, T2), and the resonant frequency is determined by at least one of the maximum phase and the minimum impedance.

4. The method of claim 1, further comprising a gas pressure regulator along another pipe section adjacent to the pipe section.

5. An ultrasonic flow meter USM (300), the ultrasonic flow meter USM comprising: The instrument body (220) includes a pipe section for allowing fluid to flow, wherein the instrument body includes at least a first ultrasonic transducer and a second ultrasonic transducer (T1, T2). An actuator (210') comprising a housing (218) and a printed circuit board (PCB) (340), wherein the printed circuit board (PCB) includes electronic components, wherein the electronic components include: A controller (330) having an associated memory (324) coupled to the ultrasonic transducer via at least one of a transmitter (311) and a receiver (312); and At least one of an accelerometer (310) and an acoustic sensor (320), the accelerometer and the acoustic sensor being used to sense vibrations on the pipe joint and to provide an output signal coupled to the controller, the electronic device being communicatively coupled to the instrument body, and the housing being mechanically connected to the instrument body via a mechanical joint; The controller is configured to: Analyze the output signal to identify at least one vibration frequency; The vibration frequency is compared with a predetermined sensitive frequency range of the USM; and When the vibration frequency is determined to be within the predetermined sensitive frequency range, an anti-vibration operation mode is implemented. This anti-vibration operation mode includes additional data processing tasks, wherein the additional data processing tasks include: Perform a Fast Fourier Transform on the vibration output signal to generate frequency domain vibration data; and The frequency domain vibration data is deconvolved using a spectrum and signal-to-noise ratio (SNR) threshold comparison, wherein the SNR threshold comparison includes performing a spectrum and SNR threshold comparison between the frequency domain vibration data and a predetermined sensitive frequency range of the USM.

6. The USM (300) according to claim 5, wherein the USM comprises both the accelerometer (310) and the acoustic sensor (320).

7. The USM (300) of claim 5, wherein the predetermined sensitive frequency range is determined by at least one resonant frequency of the ultrasonic transducer (T1, T2), the resonant frequency being determined by using at least one of maximum phase and minimum impedance.

8. The USM (300) according to claim 5, wherein the predetermined sensitive frequency range is 80 kHz to 300 kHz.

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