阅读说明：本技术 一种用于摇匀仪测量的复合测量系统及测量方法 (Composite measurement system and measurement method for shake-up meter measurement ) 是由 廖旭辉 杨润东 任志颖 黄成刚 王尧君 于 2021-05-27 设计创作，主要内容包括：本发明公开了一种用于摇匀仪测量的复合测量系统及测量方法,包括主设备和无线子设备；主设备包括主控单元及与均与其连接的程控激励源、调理单元、数据处理单元、无线通信单元和电源；主设备包括依次连接的振动传感器、滤波器、调理单元、模数转换单元；程控激励源连接振动传感器；无线子设备包括无线主控单元和用于测量摇匀仪运行转速、温度、磁场强度和加速度的传感器组；无线子设备还包括与无线主控连接的电源和无线通信单元；主设备中的无线通信单元与子设备的无线通信单元连接,实现主设备和无线子设备的数据传输；本发明测量范围广泛、使用方便,具有更好的测量精度。(The invention discloses a composite measuring system and a measuring method for measuring a shake-up device, which comprise a main device and a wireless sub-device; the main equipment comprises a main control unit, and a program-controlled excitation source, a conditioning unit, a data processing unit, a wireless communication unit and a power supply which are all connected with the main control unit; the main equipment comprises a vibration sensor, a filter, a conditioning unit and an analog-to-digital conversion unit which are connected in sequence; the program-controlled excitation source is connected with the vibration sensor; the wireless sub-equipment comprises a wireless main control unit and a sensor group for measuring the running rotating speed, the temperature, the magnetic field intensity and the acceleration of the shaking instrument; the wireless sub-equipment also comprises a power supply and a wireless communication unit which are connected with the wireless master control; the wireless communication unit in the main equipment is connected with the wireless communication unit of the sub-equipment to realize data transmission of the main equipment and the wireless sub-equipment; the invention has wide measuring range, convenient use and better measuring precision.)

1. A composite measuring system for measuring a shake-up device is characterized by comprising a main device and a wireless sub-device; the main equipment comprises a main control unit, and a program-controlled excitation source, a conditioning unit, a data processing unit, a wireless communication unit and a power supply which are all connected with the main control unit; the main equipment comprises a vibration sensor, a filter, a conditioning unit and an analog-to-digital conversion unit which are connected in sequence; the program-controlled excitation source is connected with the vibration sensor; the wireless sub-equipment comprises a wireless main control unit and a sensor group for measuring the running rotating speed, the temperature, the magnetic field intensity and the acceleration of the shaking instrument; the wireless sub-equipment also comprises a power supply and a wireless communication unit which are connected with the wireless master control; the wireless communication unit in the main equipment is connected with the wireless communication unit of the sub-equipment, so that data transmission of the main equipment and the wireless sub-equipment is realized.

2. A composite measuring system for a shake-up table measurement according to claim 1, characterised in that the wireless sub-device is arranged on a cradle of the shake-up table; the magnetic field intensity is measured by a magnetometer; the running speed of the shaking-up instrument is measured by a three-axis gyroscope; the acceleration of the shaking-up instrument is measured by a three-axis accelerometer; the temperature of the shaking-up instrument is measured by a temperature sensor.

3. A method of measurement using the composite measuring system for shake-up measurement according to claim 2, comprising the steps of:

step 1: the method comprises the steps that a vibration sensor measuring signal is obtained and sequentially passes through a filter, a conditioning unit, an analog-to-digital conversion unit and a data processing unit, and the data processing unit processes and obtains the frequency spectrum characteristic of a current signal;

step 2: judging whether the frequency spectrum of the noise exceeds or equals to the noise amplitude or not and whether the frequency spectrum of the noise exceeds or equals to the non-noise frequency point or not according to the pre-stored frequency spectrum characteristics of the noise under different excitations and the frequency spectrum characteristics obtained in the step 1;

and step 3: if not, discarding, and if yes, obtaining a suspected frequency point set N;

and 4, step 4: obtaining the magnetic field intensity change of the shaking up instrument in working according to the measurement of the magnetometer; amplitude comparison is carried out to obtain suspected frequency B and corresponding measured signal-to-noise value S_b；

And 5: according to the angular velocity measured by the gyroscope, calculating to obtain a suspected frequency C and a corresponding measured signal-to-noise value S_c；

Step 6: calculating the difference value between the suspected frequency point in the suspected frequency point set N and the suspected frequency point B and the suspected frequency point C, if the difference value is less than a set error value, outputting the result as the suspected frequency A and the corresponding measured signal-to-noise value S_a(ii) a If not, adjusting the output size of the program control excitation source, the signal amplification gain of the conditioning unit, the sampling rate of the analog-to-digital converter and the block length of the data processing unit for re-measurement;

and 7: weighting and summing the suspected frequency A, the suspected frequency B and the suspected frequency C to obtain a frequency f_nAccording to frequency f_nThe required measuring rotating speed n can be obtained.

4. The composite measurement method for the shake-up machine measurement according to claim 3, wherein the step 5 is specifically calculated as follows:

in the formula: f is the calculated rotation frequency, and omega is the angular velocity measured by the gyroscope;

according to the suspected frequency C, checking a frequency C-measurement signal-noise value table to obtain a corresponding measurement signal-noise value S_c。

5. A combined measurement method for a shake-up meter measurement according to claim 3, characterized in that in step 4 the suspected frequency B and the measured signal-to-noise value S are_bCalculated according to the following method:

the data processing unit calculates the spectral characteristics of the magnetic field change by adopting an FFT algorithm according to the magnetic field intensity change of the shaking-up instrument in the work process measured by the magnetometer, compares the amplitudes to obtain a non-0 frequency point with the maximum amplitude as a suspected frequency point, and the frequency corresponding to the frequency point is a suspected frequency B; the non-zero frequency point with the amplitude lower than the suspected frequency point and higher than other frequency points is a noise frequency point, and the suspected frequency point and the noise frequency pointThe amplitude ratio of the acoustic frequency points is a measured signal-to-noise value S corresponding to the suspected frequency B_b。

6. A composite measurement method for a shake-up meter measurement according to claim 3, characterized in that the noise spectrum characteristics under different excitation pre-stored in step 2 are generated as follows:

s11: setting initial excitation current of a program-controlled excitation source, initial amplification gain of a conditioning unit and an initial value of sampling frequency of an analog-to-digital converter;

s12: denoising after setting the vibration frequency of the shaking-up instrument to be 0; the program-controlled excitation source is configured to be minimum excitation, the data processing unit obtains corresponding spectrum characteristics by adopting an FFT algorithm according to the collected signals, and the spectrum characteristics comprise noise frequency points and noise amplitude ranges;

s13: the programmed control excitation source is excited and increased by one step, and the step S12 is repeated;

s14: and repeating the step S13 until the excitation setting range reaches the upper limit set by the program control excitation source, so that the noise spectrum characteristics under different levels of excitation can be obtained.

7. The composite measuring method for the shake-up table measurement according to claim 3, wherein the vibration sensor in step 1 is fixed on the shake-up table side shell through a magnetic base; the shaking-up instrument is started by setting the vibration rotating speed to be measured, and the program-controlled excitation source drives the vibration sensor to acquire a vibration signal; the vibration signal is filtered by a filter and enters a conditioning unit to amplify the signal and adjust direct current bias; then, the analog signals are converted into digital signals by a digital-to-analog conversion unit; the output digital signal enters a data processing unit, and the frequency spectrum characteristic is obtained through an FFT algorithm; the frequency spectrum characteristic is compared with the noise frequency spectrum characteristic with the same excitation magnitude in the 0-rotation-speed noise measurement, and a frequency point with the amplitude lower than the noise range and a frequency point with the same amplitude as the noise frequency point are filtered to obtain a suspected frequency point set N.

8. A composite measuring method for a shake-up meter measurement according to claim 3, whichCharacterized in that f in step 7_yThe calculation method is as follows:

f_y＝x_AA+x_BB+x_CC

wherein f is_yFor the calculated frequency, A, B, C is the corresponding suspected frequency, x_A、x_B、x_CWeight coefficients corresponding to the frequencies respectively;

the weight coefficient generation process is as follows: generating a difference coordinate according to the measured signal-to-noise value; and determining the coefficient according to the difference coordinate-coefficient table.

Technical Field

The invention relates to the field of shake-up meter measurement, in particular to a composite measurement system and a measurement method for shake-up meter measurement.

Background

The shake-up apparatus is a mechanical device that utilizes mechanical vibration to thoroughly mix the mixture. The shaking-up instrument is widely applied to the fields of medical treatment and health, scientific research, industry and the like at present. In order to ensure the normal work of the shaking apparatus, the shaking apparatus needs to be calibrated to work under appropriate parameters, the vibration frequency of the shaking apparatus needs to be accurately measured in order to calibrate the shaking apparatus, and the accurate measurement of the vibration frequency of the shaking apparatus is essential.

The vibration frequency measuring equipment of the existing shaking-up instrument partially adopts a photoelectric detection technology to realize the measurement of the vibration frequency of the shaking-up instrument, and partially adopts a vibration sensor to measure the vibration frequency. The existing measurement method of the photoelectric shaking instrument needs to add a reflective strip on the shaking instrument and accurately align the reflective strip by using a sensor, so that the alignment operation is time-consuming and labor-consuming and is difficult to be compatible with shaking instrument equipment with different sizes and shapes. And the photoelectric shaking-up instrument measuring method is difficult to measure the point-moving shaking-up instrument, so the method has great limitation. The existing measuring method of the vibration sensor shaking-up instrument is limited by the response frequency of the vibration sensor when measuring low vibration frequency, and the measuring precision is lower under the low range of the shaking-up instrument.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides a composite measuring system and a measuring method for measuring a shaking-up instrument, which have high measuring precision and simple measuring method.

The technical scheme adopted by the invention is as follows:

a composite measuring system for measuring a shake-up device comprises a main device and a wireless sub-device; the main equipment comprises a main control unit, and a program-controlled excitation source, a conditioning unit, a data processing unit, a wireless communication unit and a power supply which are all connected with the main control unit; the main equipment comprises a vibration sensor, a filter, a conditioning unit and an analog-to-digital conversion unit which are connected in sequence; the program-controlled excitation source is connected with the vibration sensor; the wireless sub-equipment comprises a wireless main control unit and a sensor group for measuring the running rotating speed, the temperature, the magnetic field intensity and the acceleration of the shaking instrument; the wireless sub-equipment also comprises a power supply and a wireless communication unit which are connected with the wireless master control; the wireless communication unit in the main equipment is connected with the wireless communication unit of the sub-equipment, so that data transmission of the main equipment and the wireless sub-equipment is realized.

Further, the wireless sub-equipment is arranged on a bracket of the shaking instrument; the magnetic field intensity is measured by a magnetometer; the rotation angular speed of the shaking-up instrument is measured by a three-axis gyroscope; the acceleration of the shaking-up instrument is measured by a three-axis accelerometer; the temperature of the shaking-up instrument is measured by a temperature sensor.

A composite measuring method for shake-up gauge measurement comprises the following steps:

step 1: the method comprises the steps that a vibration sensor measuring signal is obtained and sequentially passes through a filter, a conditioning unit, an analog-to-digital conversion unit and a data processing unit, and the data processing unit processes and obtains the frequency spectrum characteristic of a current signal;

step 2: judging whether the frequency spectrum of the noise exceeds or equals to the noise amplitude or not and whether the frequency spectrum of the noise exceeds or equals to the non-noise frequency point or not according to the pre-stored frequency spectrum characteristics of the noise under different excitations and the frequency spectrum characteristics obtained in the step 1;

and step 3: if not, discarding, and if yes, obtaining a suspected frequency point set N;

and 4, step 4: obtaining the magnetic field intensity change of the shaking up instrument in working according to the measurement of the magnetometer; amplitude comparison is carried out to obtain suspected frequency B and corresponding measured signal-to-noise value S_b；

And 5: according to the angular velocity measured by the gyroscope, calculating to obtain a suspected frequency C and a corresponding measured signal-to-noise value S_c；

Step 6: calculating the difference value between the suspected frequency point in the suspected frequency point set N and the suspected frequency point B and the suspected frequency point C, if the difference value is less than a set error value, outputting the result as the suspected frequency A and the corresponding measured signal-to-noise value S_a(ii) a If not, adjusting the output size of the program control excitation source, the signal amplification gain of the conditioning unit, the sampling rate of the analog-to-digital converter and the block length of the data processing unit for re-measurement;

and 7: weighting and summing the suspected frequency A, the suspected frequency B and the suspected frequency C to obtain a frequency f_nAccording to frequency f_nCan obtainThe required measurement speed n.

Further, the specific calculation process in the step 5 is as follows:

in the formula: f is the calculated rotation frequency, and omega is the angular velocity measured by the gyroscope;

according to the suspected frequency C, checking a frequency C-measurement signal-noise value table to obtain a corresponding measurement signal-noise value S_c。

Further, the suspected frequency B and the measured signal-to-noise value S in the step 4_bCalculated according to the following method:

the data processing unit calculates the spectral characteristics of the magnetic field change by adopting an FFT algorithm according to the magnetic field intensity change of the shaking-up instrument in the work process measured by the magnetometer, compares the amplitudes to obtain a non-0 frequency point with the maximum amplitude as a suspected frequency point, and the frequency corresponding to the frequency point is a suspected frequency B; the non-zero frequency point with the amplitude lower than the suspected frequency point and higher than other frequency points is a noise frequency point, and the amplitude ratio of the suspected frequency point to the noise frequency point is a measured signal-to-noise value S corresponding to the suspected frequency B_b。

Further, the noise spectrum characteristics under different excitation pre-stored in step 2 are generated as follows:

s11: setting initial excitation current of a program-controlled excitation source, initial amplification gain of a conditioning unit and an initial value of sampling frequency of an analog-to-digital converter;

s12: denoising after setting the vibration frequency of the shaking-up instrument to be 0; the program-controlled excitation source is configured to be minimum excitation, the data processing unit obtains corresponding spectrum characteristics by adopting an FFT algorithm according to the collected signals, and the spectrum characteristics comprise noise frequency points and noise amplitude ranges;

s13: the programmed control excitation source is excited and increased by one step, and the step S12 is repeated;

s14: and repeating the step S13 until the excitation setting range reaches the upper limit set by the program control excitation source, so that the noise spectrum characteristics under different levels of excitation can be obtained.

Further, the vibration sensor in the step 1 is fixed on a shell on the side surface of the shaking-up instrument through a magnetic type base; the shaking-up instrument is started by setting the vibration rotating speed to be measured, and the program-controlled excitation source drives the vibration sensor to acquire a vibration signal; the vibration signal is filtered by a filter and enters a conditioning unit to amplify the signal and adjust direct current bias; then, the analog signals are converted into digital signals by a digital-to-analog conversion unit; the output digital signal enters a data processing unit, and the frequency spectrum characteristic is obtained through an FFT algorithm; the frequency spectrum characteristic is compared with the noise frequency spectrum characteristic with the same excitation magnitude in the 0-rotation-speed noise measurement, and a frequency point with the amplitude lower than the noise range and a frequency point with the same amplitude as the noise frequency point are filtered to obtain a suspected frequency point set N.

Further, f in step 7_yThe calculation method is as follows:

f_y＝x_AA+x_BB+x_CC

wherein f is_yFor the calculated frequency, A, B, C is the corresponding suspected frequency, x_A、x_B、x_CWeight coefficients corresponding to the frequencies respectively;

the weight coefficient generation process is as follows: generating a difference coordinate according to the measured signal-to-noise value; and determining the coefficient according to the difference coordinate-coefficient table.

The invention has the beneficial effects that:

(1) the invention can measure the electrodynamic type shaking-up instrument and the rotary type shaking-up instrument, and has wide measuring range;

(2) compared with the traditional photoelectric vibration frequency measuring system of the shaking uniform instrument, the invention does not need the process of pasting and aligning the reflective strips, and only needs to put the wireless sub-equipment into the rotating shaft bracket and the vibration sensor for magnetic attraction and attachment, thereby simplifying the use process and facilitating the use;

(3) compared with the existing measuring method of the vibration sensor shaking-up instrument, the measuring method has better measuring precision by improving the measuring method and combining the combination of a plurality of sensors.

Drawings

FIG. 1 is a schematic view of a measurement system according to the present invention.

FIG. 2 is a schematic flow chart of the measurement method of the present invention.

Detailed Description

The invention is further described with reference to the following figures and specific embodiments.

As shown in fig. 1, a composite measuring system for a shake-up meter measurement includes a main device and a wireless sub-device; the main equipment comprises a main control unit, and a program-controlled excitation source, a conditioning unit, a data processing unit, a wireless communication unit and a power supply which are all connected with the main control unit; the main equipment comprises a vibration sensor, a filter, a conditioning unit and an analog-to-digital conversion unit which are connected in sequence; the program-controlled excitation source is connected with the vibration sensor; the wireless sub-equipment comprises a wireless main control unit and a sensor group for measuring the running rotating speed, the temperature, the magnetic field intensity and the acceleration of the shaking instrument; the wireless sub-equipment also comprises a power supply and a wireless communication unit which are connected with the wireless master control; the wireless communication unit in the main equipment is connected with the wireless communication unit of the sub-equipment, so that data transmission of the main equipment and the wireless sub-equipment is realized.

The wireless sub-equipment is arranged on a bracket of the shaking instrument and rotates along with the rotation of the rotating shaft of the shaking instrument; the magnetic field intensity is measured by a magnetometer; the running speed of the shaking-up instrument is measured by a three-axis gyroscope; the acceleration of the shaking-up instrument is measured by a three-axis accelerometer; the temperature of the shaking-up instrument is measured by a temperature sensor. The vibration sensor of the main equipment is adsorbed on the shaking-up instrument through the strong magnetic base to measure the running speed of the shaking-up instrument.

In the main equipment, a vibration sensor is used for collecting mechanical vibration generated in the running process of the shaking-up instrument and can work only by exciting by a program-controlled excitation source. A common vibration sensor is excited to a constant current when it is of a current-driven type, and to a constant voltage when it is of a voltage-driven type. If the vibration sensor is of a current-driven type, the programmable excitation source is a programmable low-noise constant current source. The main control program-controlled excitation source outputs a constant current with a specified magnitude as the excitation of the vibration sensor. The conditioning unit comprises a low-noise operational amplifier, a DAC (digital-to-analog converter) and a program-controlled operational amplifier and is used for realizing voltage conversion and signal amplification, so that signals meet the input requirements of the next-stage analog-to-digital conversion unit. The analog-to-digital conversion unit comprises an ADC driving circuit and an ADC, and is used for converting an input analog signal into a digital signal. The data processing unit comprises an FPGA or a DSP which executes an FFT algorithm to process data. The power supply comprises a battery and a power management chip for supplying power to the equipment. The wireless communication unit comprises a wireless communication chip and an antenna and is used for data wireless transmission with the sub-equipment and the user computer terminal. The main control is a processor and is used for realizing the driving and control of other components. In the wireless sub-device, the wireless master control is the master control of the wireless sub-device. For implementing drive control of other components within the sub-device. The sensor group comprises an accelerometer, a magnetometer, a gyroscope and a temperature sensor, and is used for measuring acceleration, magnetic field change, angular velocity and temperature inside the instrument. The wireless communication unit of the wireless device comprises a wireless communication module and an antenna, and is used for communicating with the main device to carry out data transmission.

The accelerometer is a sensor for measuring acceleration, and the accelerometer is arranged on the shaking instrument bracket along with the wireless sub-equipment and rotates along with the rotation shaft of the shaking instrument. The imbalance of the rotating shaft can generate vibration to generate acceleration, and the acceleration measured by the vibration is the acceleration of the shaking instrument. The temperature sensor is used for measuring the working temperature of the instrument, and the acceleration, the temperature and the rotating speed are measured results.

As shown in fig. 2, a measuring method of a composite measuring system for a shake-up table measurement includes the steps of:

step 1: the method comprises the steps that a vibration sensor measuring signal is obtained and sequentially passes through a filter, a conditioning unit, an analog-to-digital conversion unit and a data processing unit, and the data processing unit processes and obtains the frequency spectrum characteristic of a current signal;

the vibration sensor is fixed on the shell on the side surface of the shaking-up instrument through the magnetic type base, and vibration is conducted to the vibration sensor from the shell. The vibration sensor is a sensor for measuring vibration, and the unbalance of the rotating shaft of the shaking instrument causes the shaking instrument to generate periodic vibration in work. The frequency of the vibration has correlation with the rotating speed, so that the vibration frequency can be calculated by measuring the vibration signal to obtain the rotating speed of the shaking instrument. The shaking instrument is set with the rotating speed to be measured and started, the shaking instrument generates vibration when working, and the master control controls the excitation source to output excitation with a certain size. A program-controlled excitation source of the system drives the vibration sensor to acquire a vibration signal. And the signal after filtering processing by the filter enters a next stage of conditioning unit. The main control conditioning unit of the system amplifies signals with a certain gain and adjusts direct current bias to enable signal parameters to meet the input requirements of the next-stage analog-to-digital converter. The master control controls the analog-to-digital converter to sample the input analog signal at a certain sampling rate and convert the analog signal into a digital signal. The obtained digital signal enters a data processing unit to carry out FFT algorithm to obtain the spectrum characteristic.

Judging whether the amplitude of the frequency spectrum of the step 1 exceeds the noise amplitude of the same frequency point on the noise frequency spectrum by a certain magnitude according to the pre-stored noise frequency spectrum characteristics under different excitations and the frequency spectrum characteristics obtained in the step 1;

the pre-stored noise spectrum characteristics under different excitations are generated as follows:

the vibration sensor is attached to the side shell of the shaking-up instrument through the magnetic type base, and the wireless sub-equipment is installed on a rotating shaft support of the tested equipment. After the system is powered on, initialization parameters are loaded for configuration, the initialization parameters comprise an excitation setting range (namely a voltage and current range) of the vibration sensor and a vibration frequency measurement range, and an excitation source initial excitation current, a conditioning unit initial amplification gain and an analog-to-digital converter sampling frequency initial value are set according to a parameter table.

Electrifying the shaking-up instrument, setting the vibration frequency to be 0, and then starting the system denoising setting; the programmable excitation source is configured to be the minimum excitation within the set range of the excitation source; the system acquires the current signal to obtain the noise spectrum characteristics including the noise frequency point and the noise amplitude range and stores the characteristics. The system acquisition flow is shown in fig. 2. After the measuring step is finished, further increasing the excitation, if the excitation does not exceed the excitation set range, outputting the excitation and repeating the measuring step; and obtaining and storing the noise spectral characteristics at the level until the set range of the excitation source is exceeded, and storing the noise spectral characteristics at different levels of excitation.

And step 3: if not, discarding, and if yes, obtaining a suspected frequency point set N;

the specific comparison process is as follows:

and (3) comparing with the noise spectrum characteristics of the same excitation magnitude, comparing the amplitudes of the frequency points on the frequency spectrum in the step (1) with the amplitudes of the same frequency points on the noise spectrum, wherein suspected frequency points are obtained if the amplitudes exceed a certain magnitude, otherwise, the suspected frequency points are discarded, and thus a suspected frequency point set N is obtained.

And 4, step 4: obtaining the magnetic field intensity change of the shaking up instrument in working according to the measurement of the magnetometer; amplitude comparison is carried out to obtain suspected frequency B and corresponding measured signal-to-noise value S_b；

The magnetometer is the sensor of measuring magnetic field intensity size, and the strong magnetism that adsorbs on the shell is inhaled the permanent magnet homoenergetic of formula base and motor and is produced a high-intensity magnetic field in certain distance. The magnetometer is arranged on the shaking instrument bracket along with the wireless sub-equipment and periodically approaches to and departs from the strong magnetic field along with the rotation of the shaking instrument rotating shaft. A periodically varying magnetic field strength value is sensed by its rotary magnetometer. The spectrum characteristic of the magnetic field intensity value obtained by the FFT algorithm is executed by the data processing unit, the non-zero frequency point with the highest amplitude is a suspected frequency point, the corresponding value of the frequency point is a suspected frequency B, the non-zero frequency point with the amplitude lower than the suspected frequency point and higher than other frequency points is a noise frequency point, and the ratio of the amplitudes of the suspected frequency point and the noise frequency point is a measured signal-to-noise value S corresponding to the suspected frequency B_b。

And 5: according to the angular velocity measured by the gyroscope, calculating to obtain a suspected frequency C and a corresponding measured signal-to-noise value S_c；

The gyroscope is a sensor for measuring angular velocity, the gyroscope is arranged on a shaking instrument bracket along with the wireless sub-equipment and rotates along with a rotation shaft of the shaking instrument, therefore, the measured angular velocity is the rotation angular velocity of the shaking instrument, and the rotation frequency, namely the suspected frequency C, can be calculated through a conversion formula of the angular velocity and the rotation frequency.

The calculation process is as follows:

in the formula: f is the calculated rotation frequency, and omega is the angular velocity measured by the gyroscope.

According to the suspected frequency C, the frequency C-measurement signal-noise value table is searched to obtain the measurement signal-noise value S in the corresponding range_c. The frequency C-measured signal to noise table contains measured signal to noise values S corresponding to different frequency ranges_cThe instrument is pre-set with a watch.

Step 6: calculating the difference value between the suspected frequency point in the suspected frequency point set N and the suspected frequency point B and the suspected frequency point C, if the difference value is less than a set error value, outputting the result as the suspected frequency A and the corresponding measured signal-to-noise value S_a(ii) a If not, adjusting the output size of the program control excitation source, the signal amplification gain of the conditioning unit, the sampling rate of the analog-to-digital converter and the block length of the data processing unit for re-measurement;

the mode of gyroscope measuring rotation speed is suitable for measuring at low rotation speed, the magnetometer is suitable for measuring at medium and low rotation speed, and the vibration sensor is suitable for measuring at high rotation speed. And a composite measurement mode is adopted to combine the advantages of the three modes to realize a better measurement result. The measurement of the magnetometer (suspected frequency B), the gyroscope (suspected frequency C) and the results of the vibration sensor measurement process (suspected frequency bin set N) are compared. And taking the frequency point closest to the suspected frequency B and the suspected frequency C as the suspected frequency point N2. If the difference value between the suspected frequency point N2 and the suspected frequency B and the suspected frequency C is smaller than the error value V in the corresponding range (the error value is set according to different ranges), the suspected frequency point is output, that is, the suspected frequency a. The ratio of the amplitude of the suspected frequency point to the amplitude of the same frequency point on the noise spectrum is the measured signal-to-noise value S of the suspected frequency A_a. And if the difference value between the suspected frequency point N2 and the suspected frequency B and the suspected frequency C is larger than the error value V under the corresponding measuring range, adjusting the output excitation size of the excitation source, the signal amplification gain of the conditioning unit, the sampling rate of the analog-to-digital converter and the block length (FFT point number) of the data processing unit for measuring again. The above determination process is repeated.

And 7: weighting and summing the suspected frequency A, the suspected frequency B and the suspected frequency C to obtain a frequency f_yAccording to frequency f_yThe required measuring rotating speed n can be obtained.

The gyroscope has the highest accuracy under low vibration frequency, the magnetometer has better accuracy under medium and low rotating speed measuring range, and the vibration sensor has the highest accuracy under high rotating speed measuring range. Therefore, the superposition of the measurement results of the three types of sensors at different measuring ranges needs to be considered.

Therefore, the measurement results of the three types of sensors are superposed by adopting a weighting calculation mode shown in the following formula, and the corresponding weight coefficient is selected according to the measuring range corresponding to the suspected frequency. And substituting the numerical values of the suspected frequency A, the suspected frequency B and the suspected frequency C to obtain a rotating speed measurement result.

f_y＝x_AA+x_BB+x_CC

Wherein f is_yFor the calculated frequency, A, B, C is the corresponding suspected frequency, x_A、x_B、x_CRespectively, the weighting coefficients corresponding to the frequencies.

The weight coefficient is generated by the measured signal-to-noise value corresponding to the suspected frequency, and the step of generating the weight coefficient is as follows: generating a difference coordinate according to the measured signal-to-noise value, and checking a difference coordinate-coefficient table according to the difference coordinate to determine a coefficient; the difference coordinate look-up difference coordinate-coefficient table contains weight coefficients corresponding to different difference coordinates and is a preset table for the instrument.

The final speed n calculation is as follows:

n＝60f_y

n is the calculated rotational speed (rpm).

Compared with the traditional vibration frequency measuring system of the photoelectric shaking-up instrument, the invention can measure both the inching type shaking-up instrument and the rotating type shaking-up instrument, and has wide measuring range. Compared with the traditional photoelectric vibration frequency measuring system of the shaking uniform instrument, the method does not need the process of pasting and aligning the reflective strips, only needs to put the wireless sub-equipment into the rotary shaft bracket and the vibration sensor for magnetic attraction attachment, simplifies the use flow and is convenient and easy to use. Compared with the existing measuring method of the vibration sensor shaking-up instrument, the existing measuring method is limited by the limitation of the response frequency of the vibration sensor when measuring low vibration frequency, and the measuring precision is low under the low measuring range of the shaking-up instrument. The method of the invention combines a plurality of sensors, which has better measurement accuracy.