Vibration frequency measurement method and system
By configuring multiple accelerometers to measure high vibration frequency, the problems of cost, power consumption and noise in the prior art are solved, and high-precision vibration frequency measurement under the premise of low cost and low power consumption are achieved.
Patent Information
- Application Number
- CN202311146302.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-09-06
- Publication Date
- 2025-03-07
AI Technical Summary
When measuring high vibration frequency, existing accelerometers have high cost, power consumption and measurement noise, making it difficult to achieve a balance between cost and power consumption.
By configuring multiple accelerometers, the acceleration value of the vibrating object is measured in sequence at a set bandwidth and time interval, and the vibration frequency of the object is determined by continuous measurement, ensuring that the sum of the bandwidths of the multiple accelerometers is greater than or equal to the expected vibration frequency.
When measuring high vibration frequency, the cost and power consumption of the accelerometer are reduced while reducing measurement noise, achieving a balance between cost and power consumption and measurement noise.
Smart Images
Figure CN119573867A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to vibration frequency measurement using an accelerometer, and in particular to a vibration frequency measurement method and system. Background Art
[0002] Accelerometers have been widely used in vibration frequency measurement, especially MEMS accelerometers, which usually have the advantages of low cost, low power consumption and small size, and are therefore widely used in vibration frequency detection. However, if higher vibration frequencies need to be detected, such as vibration frequencies above 10kHz, a MEMS accelerometer with a higher bandwidth is required, and the cost and power consumption of such a MEMS accelerometer will increase, and the measurement noise will also increase. In addition to using MEMS accelerometers, common accelerometers for detecting higher vibration frequencies include mechanical and laser types, but these two types of accelerometers also have their own disadvantages. Mechanical accelerometers usually have a relatively low measurable vibration frequency range, low measurement sensitivity, and large measurement noise. Laser accelerometers usually involve high cost, high power consumption, and large size.
[0003] Therefore, there is a need for a method and system utilizing an accelerometer that is particularly suitable for measuring high vibration frequencies and that balances cost, power consumption, and measurement noise. Summary of the invention
[0004] In order to achieve the above objectives, the present invention proposes a vibration frequency measurement method and system. The vibration frequency measurement method according to the present invention comprises:
[0005] Step S1: configuring a plurality of accelerometers to sequentially measure acceleration values of an object in vibration motion at a set bandwidth and a set time interval;
[0006] Step S2: Continuously execute step S1 for multiple times, and determine the change period of the acceleration value of the object as the vibration frequency of the object.
[0007] Wherein a sum of bandwidths of the plurality of accelerometers is greater than or equal to an expected vibration frequency of the object.
[0008] The vibration frequency measurement system according to the present invention comprises a controller, a timer and a plurality of accelerometers, wherein:
[0009] The controller is configured to execute step S1: setting a timer to enable a plurality of accelerometers to sequentially measure acceleration values of an object in vibration motion at a set bandwidth and a set time interval; and
[0010] The controller is configured to further perform step S2: continuously perform step S1 for multiple times, and determine the change period of the acceleration value of the object as the vibration frequency of the object,
[0011] Wherein a sum of bandwidths of the plurality of accelerometers is greater than or equal to an expected vibration frequency of the object.
[0012] The present invention further provides a machine-readable storage medium storing executable instructions, which implement the method according to the present invention when executed by a processor. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The present invention will now be described in more detail with reference to the accompanying drawings, in which:
[0014] Figure 1 A diagram schematically showing the variation of the amplitude of an object in vibratory motion over time;
[0015] Figure 2 A block diagram of a vibration frequency measurement system according to the present invention is schematically shown. DETAILED DESCRIPTION
[0016] Before introducing the vibration frequency measurement method and system according to the present invention, several concepts of accelerometer are first introduced:
[0017] Sampling rate SR: usually refers to the output data rate ODR of the accelerometer, that is, the rate at which the accelerometer outputs the measurement results of the vibrating object being measured.
[0018] Bandwidth BW: The highest frequency signal that the accelerometer can sample without aliasing at the specified output data rate ODR, which corresponds to the highest vibration frequency of the vibrating object that the accelerometer can measure. For the accelerometer, its actual bandwidth BW is adjustable. The larger the BW, the higher the vibration frequency that the accelerometer can measure, but the measurement noise will also increase accordingly.
[0019] Fn: The highest vibration frequency of the vibrating object.
[0020] Generally, BW=1 / 2*SR. In order to measure the highest vibration frequency of the vibrating object without aliasing, SR≥2*Fn, that is, BW≥Fn. Preferably, SR≥5*Fn, that is, BW≥2.5*Fn.
[0021] The vibration frequency measurement method according to the present invention comprises:
[0022] Step S1: configuring a plurality of accelerometers to sequentially measure acceleration values of an object in vibration motion at a set bandwidth and a set time interval;
[0023] Step S2: Continuously execute step S1 for multiple times, and determine the change period of the acceleration value of the object as the vibration frequency of the object.
[0024] Wherein a sum of bandwidths of the plurality of accelerometers is greater than or equal to an expected vibration frequency of the object.
[0025] In step S1, it is preferred that each of the plurality of accelerometers is set to the same bandwidth and sequentially measures the acceleration value of the object in vibration motion at the same time interval, thereby simplifying the measurement of the vibration frequency of the object. In addition, in order to accurately measure the vibration frequency of the object, the plurality of accelerometers may be arranged to be in direct contact with the object.
[0026] The purpose of continuously performing step S1 multiple times in step S2 is to more accurately determine the change period of the acceleration value of the object, thereby more accurately determining the vibration frequency of the object. Specifically, when each accelerometer measures the acceleration value of the object once, the measured acceleration value may have a certain deviation compared with the actual acceleration value of the object due to factors such as the accelerometer's own accuracy or external interference. Therefore, continuously performing step S1 multiple times can average the acceleration value of the object to reduce the measurement error, thereby more accurately determining the vibration frequency of the object.
[0027] Usually, there is a preliminary expectation of the vibration frequency of the object to be measured before measurement. In order to accurately measure the vibration frequency of the object, the sum of the bandwidths BW of multiple accelerometers should be greater than or equal to the expected vibration frequency of the object. As mentioned above, in order to avoid aliasing, it is preferred that the total sampling rate SR of multiple accelerometers is greater than or equal to 5 times the highest vibration frequency Fn of the object. In other words, in order to avoid aliasing, it is preferred that the total bandwidth BW of multiple accelerometers is greater than or equal to 2.5 times the highest vibration frequency Fn of the object. Among them, the total bandwidth BW of multiple accelerometers is the sum of the bandwidths of each accelerometer.
[0028] It should be noted that the vibration frequency measurement method according to the present invention is particularly suitable for measuring a vibration object with a relatively high vibration frequency.
[0029] If a single accelerometer is used to measure a vibrating object with a high vibration frequency, the accelerometer is required to have a large bandwidth, which results in high cost and power consumption. In addition, the bandwidth of an accelerometer is generally proportional to its measurement noise, so the noise measured by such a single accelerometer will also be large.
[0030] The method according to the present invention uses multiple accelerometers, and the total bandwidth BW of the multiple accelerometers only needs to be greater than or equal to the highest vibration frequency of the object to meet the measurement of the vibration frequency of the object, so accelerometers with relatively low cost and power consumption can be used, and because the required bandwidth of each accelerometer is small, the measurement noise will also be small. Therefore, using the vibration frequency measurement method according to the present invention, a balance between cost and power consumption and measurement noise can be achieved.
[0031] The multiple accelerometers used in the vibration frequency measurement method according to the present invention can be MEMS accelerometers, which have the advantages of small size and low power consumption. Integrating multiple MEMS accelerometers together to measure the vibration frequency can generate lower measurement noise than a single MEMS accelerometer with larger measurement noise under the premise of minimizing the size and power consumption.
[0032] In addition, by integrating multiple accelerometers together, the number of accelerometers actually required for measurement can be adjusted accordingly according to different measurement requirements. For example, when a very high vibration frequency needs to be measured, all or most of the accelerometers can be triggered for measurement, and when the vibration frequency to be measured is not so high, only a part of the accelerometers can be triggered for measurement, thereby reducing power consumption as much as possible. Therefore, the vibration frequency measurement method using multiple accelerometers can achieve improved measurement flexibility, meet the accurate measurement of a wider range of vibration frequencies, and obtain a balance between cost and power consumption and measurement noise.
[0033] As mentioned above, the sum of the bandwidths of multiple accelerometers needs to be greater than or equal to the expected vibration frequency of the object in order to accurately measure the vibration frequency of the object. However, the actual vibration frequency of the object may have a certain deviation from its expected vibration frequency. Therefore, in order to achieve accurate measurement of the vibration frequency of the object, the method steps of the present invention may need to be adjusted accordingly.
[0034] If the vibration frequency of the object determined in step S2 is greater than the expected vibration frequency of the object and the difference between the two exceeds a set threshold, the method according to the present invention further comprises:
[0035] Step S3: modifying the configuration of the plurality of accelerometers to increase the number of accelerometers measuring the acceleration value of the object and / or to increase the set bandwidth of each accelerometer and / or to reduce the set time interval, and measuring the acceleration value of the object in vibrating motion with the modified configuration;
[0036] Step S4: Execute step S3 for multiple times continuously, and determine the variation period of the acceleration value of the object as the vibration frequency of the object.
[0037] Specifically, if the vibration frequency of the object determined in step S2 is greater than the expected vibration frequency of the object and the difference between the two exceeds a set threshold (for example, 20%, 30%, etc.), it means that the vibration frequency of the object may be significantly higher than the expected vibration frequency of the object before measurement. Since the number of accelerometers used in step S1, the set bandwidth of each accelerometer, and the set time interval are all set for the expected vibration frequency of the object, in order to more accurately measure the vibration frequency of the object, it is necessary to make corresponding adjustments to the above configurations, and the adjustments include increasing the number of accelerometers that measure the acceleration value of the object and / or increasing the set bandwidth of each accelerometer and / or reducing the set time interval.
[0038] Depending on actual needs, one or more of the above adjustments may be made. For example, if you want to reduce power consumption as much as possible, you may not increase the number of accelerometers used, but increase the set bandwidth of each accelerometer and / or reduce the set time interval. If you want to reduce measurement noise as much as possible, you may not increase the set bandwidth of each accelerometer, but increase the number of accelerometers used and / or reduce the set time interval. If you want to simplify the calculation of the vibration frequency of the object as much as possible, you may not reduce the set time interval, but increase the number of accelerometers used and / or increase the set bandwidth of each accelerometer.
[0039] On the contrary, if the vibration frequency of the object determined in step S2 is less than the expected vibration frequency of the object and the difference between the two exceeds a set threshold, the method according to the present invention further comprises:
[0040] Step S5: modifying the configuration of the plurality of accelerometers to reduce the number of accelerometers measuring the acceleration value of the object and / or reduce the set bandwidth of each accelerometer and / or increase the set time interval, and measuring the acceleration value of the object in vibrating motion with the modified configuration;
[0041] Step S6: Execute step S5 multiple times continuously, and determine the variation period of the acceleration value of the object as the vibration frequency of the object.
[0042] Specifically, if the vibration frequency of the object determined in step S2 is less than the expected vibration frequency of the object and the difference between the two exceeds a set threshold (for example, 20%, 30%, etc.), it means that the vibration frequency of the object may be significantly lower than the expected vibration frequency of the object before measurement. Since the number of accelerometers used in step S1, the set bandwidth of each accelerometer, and the set time interval are all set for the expected vibration frequency of the object, in order to reduce power consumption and measurement noise as much as possible on the basis of accurately measuring the vibration frequency of the object, the above configurations can be adjusted accordingly, and the adjustment includes reducing the number of accelerometers that measure the acceleration value of the object and / or reducing the set bandwidth of each accelerometer and / or increasing the set time interval.
[0043] Depending on actual needs, one or more of the above adjustments may be made. For example, if you want to reduce power consumption as much as possible, you can reduce the number of accelerometers used without reducing the set bandwidth of each accelerometer and / or increasing the set time interval. If you want to reduce measurement noise as much as possible, you can reduce the set bandwidth of each accelerometer without reducing the number of accelerometers used and / or increasing the set time interval. If you want to simplify the calculation of the vibration frequency of the object as much as possible, you can increase the set time interval without reducing the number of accelerometers used and / or reducing the set bandwidth of each accelerometer.
[0044] The vibration frequency measurement method according to the present invention is described below by taking the measurement of the vibration frequency of an object in sinusoidal vibration as an example.
[0045] First, in this example, the sampling rate SR or output data rate ODR of each accelerometer is 1000Hz, and the maximum bandwidth BW is 500Hz. That is, each accelerometer can sample the vibration once every 1ms.
[0046] In this example, 10 accelerometers are triggered to measure the acceleration value of the object in vibration motion in sequence at a time interval of 0.1ms. Therefore, in general, 10 samples can be taken within 1ms, that is, the total sampling rate SR or output data rate ODR of the whole composed of 10 accelerometers is 10kHz, and the total maximum bandwidth BW is 5kHz. In other words, the total sampling rate SR or output data rate ODR of the whole is 10 times the sampling rate SR or output data rate ODR of a single accelerometer, and the total maximum bandwidth BW of the whole is 10 times the maximum bandwidth BW of a single accelerometer.
[0047] Therefore, in this example, the first step S1 is to set the bandwidth of 10 accelerometers to 500 Hz and measure the acceleration value of the object in vibration motion in sequence at a time interval of 0.1 ms.
[0048] Next, step S2 is executed to continuously execute step S1 for multiple times, and determine the change period of the acceleration value of the object as the vibration frequency of the object. Specifically, 10 accelerometers can be continuously triggered at a time interval of 0.1 ms within a time period of, for example, 10 ms, 20 ms, etc. to sequentially measure the acceleration value of the object in vibration motion, so as to minimize the measurement error and obtain an accurate change period of the acceleration value as the vibration frequency of the object.
[0049] Figure 1 The schematic diagram of the change of the amplitude of the object in vibration motion over time in this example is shown. The horizontal axis represents time T, and the vertical axis represents the amplitude A of the object. The amplitude A corresponding to a certain time point can be converted based on the acceleration value of the object at that time point. Therefore, based on Figure 1 It can be seen intuitively that the object is vibrating sinusoidally. For example, if Figure 1 It is found that the amplitude variation period (i.e. the period corresponding to the acceleration variation) of the object's sinusoidal vibration is 1ms, and its vibration frequency is 1kHz.
[0050] In this example, the number of accelerometers used, the bandwidth set for each accelerometer, and the sampling time interval are determined based on the expected vibration frequency of the object before measurement. As mentioned above, after the vibration frequency of the object is measured, the number of accelerometers used and / or the bandwidth set for each accelerometer and / or the sampling time interval can be adjusted accordingly for the purpose of reducing power consumption, reducing measurement noise, and simplifying calculation.
[0051] The invention also provides a vibration frequency measurement system. Figure 2 The block diagram of the vibration frequency measurement system 100 according to the present invention is schematically shown. The system 100 includes a controller 110, a timer 120, and a plurality of accelerometers 130. The controller 110 is connected in communication with the timer 120 and the plurality of accelerometers 130, and the timer 120 is connected in communication with the plurality of accelerometers 130. The plurality of accelerometers 130 can be integrated together into an integral module, and the module can be in direct contact with the object 140 to be measured to measure the vibration frequency of the object 140.
[0052] The controller 110 is configured to execute the vibration frequency measurement method according to the present invention. Specifically, the controller 110 is configured to execute step S1: setting the timer 120 to enable the plurality of accelerometers 130 to sequentially measure the acceleration value of the object 140 in vibration motion at a set bandwidth and a set time interval; and
[0053] The controller 110 is configured to further perform step S2: continuously perform step S1 for multiple times, and determine the change period of the acceleration value of the object 140 as the vibration frequency of the object 140,
[0054] The sum of bandwidths of the plurality of accelerometers 130 is greater than or equal to an expected vibration frequency of the object 140 .
[0055] As mentioned above, there may be a certain deviation between the actual vibration frequency of the object 140 and its expected vibration frequency. Therefore, in order to achieve accurate measurement of the vibration frequency of the object 140, it may be necessary to make corresponding adjustments to the measurement process.
[0056] Specifically, if the vibration frequency of the object 140 determined in step S2 is greater than the expected vibration frequency of the object 140 and the difference between the two exceeds a set threshold (e.g., 20%, 30%, etc.), the controller 110 is configured to further perform the following steps:
[0057] Step S3: modifying the configuration of the plurality of accelerometers 130 to increase the number of accelerometers 130 measuring the acceleration value of the object 140 and / or to increase the set bandwidth of each accelerometer and / or to reduce the set time interval, and measuring the acceleration value of the object 140 with the modified configuration;
[0058] Step S4 : Continuously perform step S3 for multiple times, and determine the variation period of the acceleration value of the object 140 as the vibration frequency of the object 140 .
[0059] On the contrary, if the vibration frequency of the object 140 determined in step S2 is less than the expected vibration frequency of the object 140 and the difference between the two exceeds a set threshold (e.g., 20%, 30%, etc.), the controller 110 is configured to further perform the following steps:
[0060] Step S5: modifying the configuration of the plurality of accelerometers 130 to reduce the number of accelerometers 130 measuring the acceleration value of the object 140 and / or reduce the set bandwidth of each accelerometer and / or increase the set time interval, and measuring the acceleration value of the object 140 with the modified configuration;
[0061] Step S6 : Continuously perform step S5 for multiple times, and determine the variation period of the acceleration value of the object 140 as the vibration frequency of the object 140 .
[0062] For the purpose of reducing power consumption, reducing measurement noise and simplifying calculation, the number of accelerometers 130 used and / or the set bandwidth and / or sampling time interval of each accelerometer 130 may be adjusted accordingly, which will not be elaborated here.
[0063] The vibration frequency measurement system according to the present invention is particularly suitable for measuring high vibration frequencies, and it can balance cost, power consumption and measurement noise. In addition, the vibration frequency measurement system according to the present invention can be applied in a wide range of fields where vibration frequencies are measured using accelerometers, such as household appliances, smart devices such as smart phones and hearable or wearable devices, MEMS IMU systems, etc.
[0064] The present invention further provides a machine-readable storage medium storing executable instructions, which implement the vibration frequency measurement method according to the present invention when executed by a processor.
[0065] The above describes in detail a feasible but non-limiting implementation of the vibration frequency measurement method and system according to the present invention with the aid of the accompanying drawings. For those of ordinary skill in the art, without departing from the scope and essence of the present disclosure as set forth in the following claims, modifications and supplements to the technology and structure and the re-combination of the features in each embodiment should be deemed to be included in the scope of the present invention. Therefore, these modifications and supplements that can be conceived under the teachings of the present invention should be regarded as part of the present disclosure. The scope of the present disclosure is defined by the claims attached below, and includes equivalent technologies known at the filing date of the present disclosure and equivalent technologies that have not yet been foreseen.
Claims
1. Vibration frequency measurement method, including: Step (S1): configuring a plurality of accelerometers to sequentially measure acceleration values of an object in vibrating motion at a set bandwidth and a set time interval; Step (S2): Continuously executing step (S1) for multiple times, and determining the change period of the acceleration value of the object as the vibration frequency of the object, Wherein, the sum of bandwidths of the plurality of accelerometers is greater than or equal to an expected vibration frequency of the object. 2 . The vibration frequency measurement method according to claim 1 , wherein in the step ( S1 ), the plurality of accelerometers are configured to sequentially measure acceleration values of the object at the same time intervals.
3. The method of claim 1, wherein the sum of the bandwidths of the plurality of accelerometers is at least 2.5 times the expected vibration frequency of the object.
4. The method according to claim 1, wherein when performing the step (S1), the plurality of accelerometers are in direct contact with the object.
5. The method according to any one of claims 1 to 4, wherein: If the vibration frequency of the object determined in step (S2) is greater than the expected vibration frequency of the object and the difference between the two exceeds a set threshold, the method further comprises: Step (S3): modifying the configuration of the plurality of accelerometers to increase the number of accelerometers measuring the acceleration value of the object and / or increase the set bandwidth of each accelerometer and / or reduce the set time interval, and measuring the acceleration value of the object with the modified configuration; Step (S4): Continuously executing step (S3) for multiple times, and determining the variation period of the acceleration value of the object as the vibration frequency of the object.
6. The method according to any one of claims 1 to 4, wherein: If the vibration frequency of the object determined in step (S2) is less than the expected vibration frequency of the object and the difference between the two exceeds a set threshold, the method further comprises: Step (S5): modifying the configuration of the plurality of accelerometers to reduce the number of accelerometers measuring the acceleration value of the object and / or reducing the set bandwidth of each accelerometer and / or increasing the set time interval, and measuring the acceleration value of the object with the modified configuration; Step (S6): Continuously executing step (S5) for multiple times, and determining the variation period of the acceleration value of the object as the vibration frequency of the object.
7. A vibration frequency measurement system (100), comprising a controller (110), a timer (120) and a plurality of accelerometers (130), wherein: The controller (110) is configured to execute step (S1): setting the timer (120) so that the plurality of accelerometers (130) sequentially measure acceleration values of an object (140) in a vibrating motion at a set bandwidth and a set time interval; and The controller (110) is configured to further perform step (S2): continuously perform step (S1) for multiple times, and determine the change period of the acceleration value of the object (140) as the vibration frequency of the object (140), Wherein, the sum of the bandwidths of the plurality of accelerometers (130) is greater than or equal to an expected vibration frequency of the object (140).
8. The system (100) according to claim 7, wherein if the vibration frequency of the object (140) determined in the step (S2) is greater than the expected vibration frequency of the object (140) and the difference between the two exceeds a set threshold, the controller (110) is configured to further perform the following steps: Step (S3): modifying the configuration of the plurality of accelerometers (130) to increase the number of accelerometers (130) measuring the acceleration value of the object (140) and / or increase the set bandwidth of each accelerometer and / or reduce the set time interval, and measuring the acceleration value of the object (140) with the modified configuration; Step (S4): Continuously executing step (S3) for multiple times, and determining the change period of the acceleration value of the object (140) as the vibration frequency of the object (140).
9. The system (100) according to claim 7, wherein if the vibration frequency of the object (140) determined in the step (S2) is less than the expected vibration frequency of the object (140) and the difference between the two exceeds a set threshold, the controller (110) is configured to further perform the following steps: Step (S5): modifying the configuration of the plurality of accelerometers (130) to reduce the number of accelerometers (130) measuring the acceleration value of the object (140) and / or reduce the set bandwidth of each accelerometer and / or increase the set time interval, and measuring the acceleration value of the object (140) with the modified configuration; Step (S6): Continuously executing step (S5) for multiple times, and determining the change period of the acceleration value of the object (140) as the vibration frequency of the object (140).
10. A machine-readable storage medium storing executable instructions, which, when executed by a processor, implement the method according to any one of claims 1 to 6.