CN109870231B - Automatic metering verification system and identification algorithm for vibration measuring instrument - Google Patents
Automatic metering verification system and identification algorithm for vibration measuring instrument Download PDFInfo
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Abstract
The invention relates to an automatic metering verification system of a vibration measuring instrument, which comprises a standard vibration source generation system, a measuring result identification system and a computer program control system; the standard sound source generating system includes: the system comprises a ZigBee transceiver unit, an ARM system, a program control signal source, a motor control unit and a vibrating table; the measuring result identification system comprises a display screen of a measured instrument, a camera, an image electric signal interface unit, an ARM system, a detection circuit, an AC interface, a DC interface and a ZigBee transceiver unit; the computer program control system comprises: zigBee receiving and transmitting unit, ARM system and computer host computer. The beneficial effects of the invention are as follows: the automatic metering verification system of the vibration measuring instrument is formed by combining the standard vibration source generation system, the measurement result identification system and the computer program control system, so that the automation of verification of the vibration measuring instrument is realized, and the manpower output and time cost in the verification process are greatly saved.
Description
Technical Field
The present invention relates to automated metrological verification systems, and in particular to automated metrological verification systems for vibratory measuring instruments.
Background
The vibration measuring instrument comprises vibration signal analysis and vibration level measuring instruments, and many of the instruments are used in the fields of environmental protection and the like, belong to national metrological verification equipment, are used for vibration measurement analysis such as 1/3oct analysis of vibration sound level according to national verification standards, and have the requirements of testing the bandwidth performance of the multipoint center frequency of the analysis instrument according to national standard regulation, and are required to manually and continuously set the amplitude and frequency of a measuring signal, and meanwhile, the tested indexes are manually compared, so that the workload is very large. For the measurement of vibration level (including the whole body vertical (W.B.z) weight-counting vibration level, the whole body horizontal (W.B.x-y) weight-counting vibration level and the weight-not (Lin) measurement), according to the detection rule of ISO8041 or GB/10071, the linearity and decibel values of various vibration frequency weight-counting and time weight-counting needs to be tested for manual verification and index comparison, and the workload is very large.
Disclosure of Invention
The invention aims to overcome the defects and provide a metering verification system and an identification algorithm of a vibration measurement analysis instrument, which have reasonable structure and high automation degree. In order to achieve the above purpose, the present invention adopts the following technical scheme:
the automatic metering verification system of the vibration measuring instrument comprises a standard vibration source generation system, a measuring result identification system and a computer program control system;
the standard sound source generating system includes: the system comprises a ZigBee transceiver unit, an ARM system, a program control signal source, a motor control unit and a vibrating table; the ARM system receives the signal waveform, frequency and amplitude of a standard electric signal required to be output or the size of a standard vibration level sent by the computer program control system through the Zigbee transceiver unit, one path of the signal waveform, frequency and amplitude of the standard electric signal are output through a system circuit, the other path of the signal waveform, frequency and amplitude of the signal of the vibration level are output through the control motor control unit to realize the output of the vibration level, meanwhile, the ARM system analyzes the signal frequency and amplitude of the signal of the vibration level to see whether the requirement of the standard vibration level is met, if the requirement of the signal of the vibration level is not met, the ARM system outputs the frequency of the motor control unit and the control output of a related motor are regulated, so that the motor control unit guides the impact force and the frequency of a firing pin to the vibration level until the output of the standard vibration level is achieved; the self-calibration process of the standard vibration level is realized; the program control signal source outputs corresponding signal waveform, amplitude and frequency through ARM system control AD9850 by direct digital frequency synthesis technology. When a standard vibration level signal or an electric signal is output, a signal readiness command is sent to a measurement result identification system through the ZigBee transceiver unit;
the measuring result identification system comprises a display screen of a measured instrument, a camera, an image electric signal interface unit, an ARM system, a detection circuit, an AC interface, a DC interface and a ZigBee transceiver unit; the ARM system receives a ready command sent by the standard vibration level generating system through the ZigBee receiving and transmitting unit, the ARM system realizes that a camera performs image recognition on a measurement result of a display screen of a tested instrument through an image telecommunication interface unit, and performs measurement on an AC interface and a DC interface of the tested instrument through a detection circuit; after acquiring the measurement result, the ARM system sends the measurement result to a computer program control system through the ZigBee transceiver unit;
the computer program control system comprises: the ZigBee transceiver unit, the ARM system and the computer upper computer; the ARM system obtains a measurement result of the measurement result identification system through the ZigBee transmitting and receiving unit, then sends data to an upper computer program of the program-controlled computer through a USB interface, the upper computer program sends the measurement result to an output item of a preset verification report, then sends a waveform, amplitude and frequency required by an output signal source required in the next verification procedure to the measurement result identification system through the USB interface, and the measurement result identification system sends the output signal source requirement to the standard vibration source generation system through the ZigBee transmitting and receiving unit.
An identification algorithm for a measurement result identification system of an automated metrological verification system of a vibration measuring instrument, comprising the steps of:
s1, firstly, performing digital analysis of a vibration level signal whole body vertical (W.B.z) weight-counting vibration level and a whole body horizontal (W.B.x-y) weight-counting vibration level through an AC interface, wherein the digital analysis is specifically as follows:
1/3oct analysis of 1Hz to 80Hz was first completed, according to the following steps:
1) Designing an 8-order Butterworth low-pass filter by using a design method of an analog filter;
the low-pass square function of the butterworth filter is expressed as follows:
taking 8 in the period N, and designing an 8-order low-pass filter so as to obtain a system function H (S);
2) Predistortion of the analog frequency;
in the two-line transformation method, the cut-off frequency omega of the filter is used to ensure that each boundary frequency point is a preset frequency C With the stop band side frequency ωs, the frequency predistortion must be performed as follows before determining the analog low pass filter system function:
H(s)＝H a (s/Ω c ) (5)
3) Solving a transfer function of digital filtering by using a bilinear transformation method;
the process of designing a digital filter using bilinear transformation is summarized as follows:
frequency conversion of normalized analog lowpass prototype to digital bandpass filter:
4) Inputting a sampling value, calculating an output value, and solving the root mean square of each output value;
5) The frequency band root mean square acceleration obtained through 1/3oct analysis is multiplied by the weighting factor, and then the root mean square sum is obtained to obtain the corresponding weighting acceleration of the frequency meter:
wherein: a, a i -effective acceleration value (m/s) measured in the ith frequency band in 1/3 octave spectrum 2 )；
k i -a frequency weighting factor corresponding to the i-th frequency band in the 1/3 octave spectrum;
through the calculation and 1/3oct analysis, the corresponding frequency weighting acceleration can be measured;
the weighting level can be obtained from the weighting acceleration as follows:
wherein: a, a w -effective value of weighted acceleration (m/s) 2 )；
a 0 -reference acceleration, a 0 ＝10 -6 m/s 2 ；
The corresponding weight vibration level can be obtained through the digital acquisition and calculation of the step (10);
forming a corresponding character matching module through the measurement results;
s2, through a DC interface, acquiring a corresponding unauthorized measurement result through ARM system sampling analysis, wherein the result forms an unauthorized corresponding character matching module in the optical identification measurement result;
s3, reading the ARM system through the RS232 interface by using a measuring result display screen of the measured instrument through a digital camera, and carrying out optical identification.
As preferable: the algorithm of the optical recognition in the step S3 is as follows:
the method comprises the steps of realizing graying of an image of an identification object through combining a camera with an image electric signal unit, aiming at character identification, selecting a median filtering technology to realize image smoothing, realizing binarization of the image through threshold setting, and performing character segmentation from binarization data, wherein the selected method is a template matching method, and performing character identification through skeleton feature extraction after image refinement; adopting skeleton feature extraction to reduce corresponding calculated amount, and only matching the extracted character features with the features of the character templates of the measurement results formed in the steps S1, S2 and S3; giving an image to be identified, a character skeleton image subjected to refinement treatment or a binary image without refinement and noise removal, scribing at fixed intervals in the transverse direction and the longitudinal direction, and sequentially recording the times of crossing the character image, namely the crossing times; collecting template images in advance, extracting the passing times of each template, storing the template images in a matrix form, taking the template images as a feature matrix, and taking the feature matrix as a database to store after the feature of each character is extracted; after the single character image to be recognized is obtained, the crossing times are also extracted, template data are loaded, and are sequentially compared with a crossing times matrix of the template, the correlation coefficient is calculated, and the recognition result is the largest correlation coefficient; dividing the length and the width into five parts which cannot be divided equally, taking an integer part, calculating the crossing times at each dividing position, and marking each crossing as one crossing, so that ten characteristic values are obtained; the method for calculating the difference comprises the following steps:
wherein X can represent a binary character to be identified, P is a feature matrix of a template, and the obtained difference matrix is D; d=d 11 2 +…+d 25 2 For the number of correlation measures of the two, the corresponding template with the largest number represents the recognition result.
The beneficial effects of the invention are as follows:
1) The automatic metering verification system of the vibration measuring instrument is formed by combining the standard vibration source generation system, the measurement result identification system and the computer program control system, so that the automation of verification of the vibration measuring instrument is realized, and the manpower output and time cost in the verification process are greatly saved.
2) The standard vibration source generation system is designed by combining a vibration level self-calibration technology, a program control signal source design and a wireless transmission technology, and an innovative technical means is provided for the realization of an automatic metering verification system of a vibration measuring instrument.
3) By combining a digital image recognition technology and a hardware interface circuit detection method, the accuracy and the discrimination capability of reading the measurement result are greatly improved, and an innovative technical means is provided for the realization of an automatic metering verification system of a vibration measuring instrument.
4) The computer program control system is designed by combining a wireless transmission technology, an embedded system technology and a computer programming technology. The system realizes the output instruction of the verification measurement signal required by the verification rule of the tested instrument, the acquisition of the verification result and the printing output of the verification report for the automatic metering verification system of the vibration measuring instrument.
Drawings
FIG. 1 is a system block diagram of a standard vibration source generation system;
FIG. 2 is a measurement result identification system;
FIG. 3 is a block diagram of a computer programming system;
FIG. 4 is a schematic block diagram of an automated metrological verification system for a vibratory measuring instrument;
FIG. 5 is a diagram of the overall architecture of an ARM system design;
FIG. 6 is an ARM cell circuit diagram;
FIG. 7 is a circuit diagram of a DSP unit;
FIG. 8 is a HPI bus connection diagram;
FIG. 9 is an A/D acquisition circuit diagram;
FIG. 10 is ARM flash SDRAM;
FIG. 11 is ARM FLASH;
FIG. 12 is a DSP FLASH and SDRAM FLASH expansion;
FIG. 13 is a circuit diagram of a USB interface;
FIG. 14 is a circuit diagram of an RS232 interface;
fig. 15 is an RJ45 interface circuit diagram;
FIG. 16 is a circuit diagram of a power system;
FIG. 17 is a circuit diagram of a programmable signal source;
fig. 18 is a motor control unit diagram;
fig. 19 is a schematic block diagram of image recognition.
Detailed Description
The invention is further described below with reference to examples. The following examples are presented only to aid in the understanding of the invention. It should be noted that it will be apparent to those skilled in the art that various modifications and adaptations of the invention can be made without departing from the principles of the invention and these modifications and adaptations are intended to be within the scope of the invention as defined in the following claims.
The system comprises three parts, including a standard vibration source generation system, a measurement result identification system and a computer program control system. The system design schematic block diagram is shown in fig. 4. The implementation steps are as follows:
the method comprises the steps that firstly, a computer program control system sends corresponding waveforms, frequencies and amplitudes of measurement signals or standard vibration level sizes to a standard vibration source generation system through a ZigBee transceiver unit according to each requirement in a verification procedure of a detected instrument, the standard vibration source generation system generates corresponding standard vibration level signals or electric signals to the detected instrument according to the requirements, meanwhile, an instruction sent by the standard vibration level signals or electric signals is sent to a measurement result recognition system through the ZigBee transceiver unit, after the measurement result recognition system receives the instruction, an ARM system is started to recognize the measurement result, a correct measurement result is obtained according to a method combining image recognition technology and circuit detection, then the result is sent to the computer program control system through the ZigBee transceiver unit, and after the computer program control system obtains a related verification item result, a corresponding result column of a verification certificate is written in through an upper computer program. The waveform, frequency and amplitude of the measurement signal required by the next certification protocol is then initiated to the standard vibration source generating system. Through continuous circulation, all verification projects required by verification regulations are finally realized, and a computer program control system forms a standard verification certificate according to the results and outputs the standard verification certificate from a printer. Thus, the automatic metering verification of the vibration measurement analysis instrument can be completed.
The ARM system in the system adopts the following system design overall architecture, as shown in FIG. 5. The overall architecture not only can fully exert real-time control of ARM on the system and good human-computer interface realization, but also can exert the analysis processing capacity of DSP on image and audio signals.
Wherein ARM adopts S3C2410A as a central control module. S3C2410A is a very cost effective ARM core SOC. The device has a main frequency of 203MHz, has the processing speed requirement for digital detection of audio signals, has a USB interface, can be communicated with a computer, has a plurality of serial ports, and can realize the control of the ZigBee transceiver unit. The specific circuit diagram is shown in fig. 6:
the DSP is designed by adopting a TMS320VC5502 chip, and the chip is a high-performance, low-power-consumption and fixed-point digital signal processor and completely meets the processing capacity of audio signals and image signals. The specific circuit diagram is shown in fig. 7.
The ARM unit is connected with the DSP unit by adopting an HPI bus, and the connection mode is shown in figure 8.
The acquisition of the vibration level signal is realized by adopting high-speed A/D, TMS320AIC23B is selected, and the chip adopts an advanced sigma-delta oversampling technology, so that the 16bit, 20bit, 24bit and 32bit sampling data can be provided at the sampling rate of 8kHz to 96 kHz. The output signal-to-noise ratio of the ADC and the DAC can reach 90dB and 100dB respectively. This performance is sufficient to meet the data acquisition capabilities of the audio signal. The control of the A/D by the DSP is realized through an I2C interface. The circuit is shown in figure nine.
The FLASH memory and SDRAM are expanded for DSP and ARM, and the program capacity and the storage capacity of nonvolatile data result are increased.
ARM-extended SDRAM model is K4S561632C-TC75, and the capacity is 4banks 16bit 4M, namely 256Mbit, and the capacity is converted into 32 Mbytes. In the system, two blocks of K4S561632C-TC75 are adopted as the memory of the ARM, and the circuit principle is shown in figure 10.
The S3C2410 extension NAND FLASH is a block of K9F1208U0B of Samsung company, and has a capacity of 64 Mbytes, and the circuit principle is shown in FIG. 11.
The circuit principle of the TMS320VC5502 expansion FLASH and SDRAM is shown in figure 12.
The ARM system realizes data exchange and control of the ZIGBEE wireless module and comprises three types of interfaces of RJ45, RS232 and USB, and the circuit principle of the USB interface is shown in figure 13.
The RS232 serial port controller adopted in the system is MAX3232, and the circuit principle thereof is shown in fig. 14.
The circuitry of the S3C2410A and RJ45 interfaces is relatively complex and must be connected using an IEEE 802.3 ethernet controller. The Ethernet controller uses CS8900A, which is a common Ethernet control chip, and the circuit principle is shown in FIG. 15.
Four power supplies are used in ARM systems, including 5V, 3.3V, 1.8V, and 1.26V. Since the order of supplying 3.3V and 1.26V voltages is required, 1.26V must precede 3.3V, a circuit for supplying power in order is designed here, and two power management chips of TI company, TPS75733 (3.3V) and TPS76801 (1.26V) are used.
The program-controlled signal source circuit adopts a circuit design with AD9850 as a core, and a specific circuit is shown in FIG. 17:
the program-controlled signal source unit inputs a frequency control word and a phase control word into the AD9850 by using an ARM system to realize the frequency and phase control of sine waves, and meanwhile, the amplitude precision control of 1/4096 can be achieved through the D/A amplitude control of AD7521 in twelve bits, so that the technical requirements of a program-controlled signal source in a standard sound source generating system can be well realized.
The frequency control word is calculated as follows:
let the frequency of the output signal be CLKIN and the frequency control word of AD9850 be Δphase, the relationship between the three is:
△PHASE＝(fouT×232)/CLKIN。
the phase control word is calculated as follows:
there are 5 bits in AD9850 for phase control, so the accuracy of phase control is 360. 25=11.25. With binary system being 00001, different phase control words are set according to actual needs, so that accurate phase control can be realized. Table 1 gives the correspondence between the phase shift and the phase control word.
Table 1 correspondence between phase shift and phase control word
| Phase shift (degree) | 0 | 22.5 | 45 | 67.5 |
| Phase control word | 00000 | 00010 | 00100 | 0010 |
| Phase shift (degree) | 180 | 202.5 | 225 | 247.5 |
| Phase control word | 10000 | 10010 | 10100 | 10110 |
| Phase shift (degree) | 90 | 112.5 | 135 | 157.5 |
| Phase control word | 01000 | 01010 | 01100 | 01110 |
| Phase shift (degree) | 270 | 292.5 | 315 | 337.5 |
| Phase control word | 11000 | 11010 | 111000 | 11110 |
The frequency/phase control word of the AD9850 has 40 bits in total, wherein 32 bits are frequency control words, 5 bits are phase control words, 1 bit is power sleep control, and the last 2 bits are operation mode control, and the 1-bit power sleep control and the 2-bit operation mode control are set to "000" in the application. The AD9850 loads the bit allocation table of the frequency/phase control word in parallel as shown in table 2.
Table 2 frequency/phase control words bit allocation table
| Control word | Data[7] | Data[6] | Data[5] | Data[4] |
| W0 | Phase—b4(MSB) | Phase—b3 | Phase—b2 | Phase—bl |
| Wl | Freq—b31(MSB) | Freq—b30 | Freq—b29 | Freq—b28 |
| W2 | Freq—b23 | Freq—b22 | Freq—b21 | Freq—b20 |
| W3 | Freq—b15 | Freq—b14 | Freq—b13 | Freq—b12 |
| W4 | Freq—b7 | Freq—b6 | Freq—b5 | Freq—b4 |
| Control word | Data[3] | Data[2] | Data[1] | Data[0] |
| WO | Phase—bO(LsB) | Power D0wn | Control(＝0) | Control(＝0) |
| Wl | Freq—b27 | Freq—b26 | Freq—b25 | Freq—b24 |
| W2 | Freq—b19 | Freq—b18 | Freq—b17 | Freq—b16 |
| W3 | Freq—b11 | Freq—b10 | Freq—b9 | Freq—b8 |
| W4 | Freq—b3 | Freq—b2 | Freq—bl | Freq—bo(LsB) |
In parallel loading, 40 bits of DATA are written to AD9850, WCLK and FQUD 5 consecutive times per load through the 8 bit DATA lines to determine the address and load DATA order, and the rising edge of WCLK is written to Wx (x=0, 1,2,3, 4), so on the rising edge of WCLK, DATA should be ready and remain stable, and the rising edge of FQUD writes 40 bits of DATA to the frequency/phase DATA register while the address pointer points to the first register WO. During initialization, FQUD is set to be high level, WCLK is set to be low level, and the parallel mode writing process is as follows: first, FQUD changes from high to low, and AT89C51 outputs data WO; then, the control WCLK is changed from low level to high level and then from high level to low level, AT this moment, the control word WO is written, and the AT89C51 writes W1, W2, W3 and W4 in turn according to the process of writing WO; finally, AT89C51 controls FQUD to change from low to high, completes writing of 40-bit data, and points the address pointer to W0, ready for the next writing of the frequency/phase control word.
The motor control unit adopts ARM to control a plurality of LN298N units to realize the rotation control of a plurality of motors, the impact force and the speed of a plurality of firing pins on the vibration table are controlled to realize the control of the amplitude and the speed of the vibration stage, and the circuit diagram of the single LN298N unit is shown in figure 18.
The ARM system controls the frequency of PWN waves input by L298N to control the impact frequency and amplitude control of the motor driving the firing pin, so as to realize the control of amplitude and speed of the vibration level.
The ZigBee transceiver unit adopts a CC2420 as a ZigBee transceiver unit module of a core chip. By adopting the ZigBee networking technology, wireless communication of three points is well realized. The self-searching mode of the channel, the topological structure of the star network and the full handshake (full handshake) protocol ensure the stability of data transmission. And the system and the ARM system adopt an RS232 interface to realize two-way communication.
The functions of three systems (a standard vibration source generation system, a measurement result identification system and a computer program control system) in the automatic metering verification system of the vibration measuring instrument can be well realized through the design of the unit circuit. The circuit design for three systems is specifically set forth as follows:
standard vibration source generation system: the standard vibration level signal or the specific requirement of the standard electric signal which is required to be output and sent by the computer program control system is received by controlling an RS232 interface through an ARM system (figure 5), on one hand, the corresponding signal amplitude, frequency and phase control output of the standard electric signal is realized through an ARM system control AD9850 unit (figure 17) and is sent to the standard electric signal interface, on the other hand, the amplitude and frequency of vibration impact of a plurality of firing pins on the vibration table are realized through an ARM system control motor drive circuit (figure 18), for the purpose of precisely controlling the amplitude and frequency of the control of the plurality of firing pins through motor control, the acquired signal is connected to the vibration table through a standard vibration sensor for acquisition, the acquired signal is input into a high-speed A/DTMS320AIC23B of the ARM system for digital detection analysis, whether the vibration level meets the standard requirement is analyzed, if the vibration level does not meet the standard requirement is not met, the vibration amplitude and the vibration level is realized through continuous feedback through changing the control of the ARM system control motor drive circuit. The system circuit has the following innovative design: (1) The precise program-controlled signal source realizes the design requirements of high-performance signal source generating devices such as arbitrary frequency control in various waveforms and audio frequency ranges, amplitude control reaching 1/4096 precisely and the like. (2) The standard vibration level signal is output through the vibration level self-calibration feedback technology. (3) Through ZigBee networking technology, the multipoint communication between the standard acoustic signal generation system and the computer program control system and the measuring result recognition system is realized. (4) The precise analysis of the vibration level signal is realized by a digital detection technology. The digital detection comprises the digital of the whole body vertical (W.B.z) weight-measuring vibration level and the whole body horizontal (W.B.x-y) weight-measuring vibration level and the digital index analysis of the vibration level of the alternating current signal.
The digitization process of the whole body vertical (W.B.z) weighting level and the whole body horizontal (W.B.x-y) weighting level is as follows:
1/3oct analysis of 1Hz to 80Hz was first completed, according to the following steps:
(1) Designing an 8-order Butterworth band-pass filter by using a design method of an analog filter;
(2) Predistortion of the analog frequency;
(3) Solving a transfer function of digital filtering by using a bilinear transformation method;
(4) Inputting a sampling value, calculating an output value, and solving the root mean square of each output value.
The frequency band root mean square acceleration obtained through 1/3oct analysis is multiplied by the weighting factor, and then the root mean square sum is obtained to obtain the corresponding weighting acceleration of the frequency meter:
wherein: a, a i -effective acceleration value (m/s) measured in the ith frequency band in 1/3 octave spectrum 2 )；
k i -a frequency weighting factor corresponding to the i-th frequency band in the 1/3 octave spectrum.
Through the calculation of the formula and the 1/3oct analysis, the corresponding frequency weighting acceleration can be measured.
The weighting level can be obtained from the weighting acceleration as follows:
wherein: a, a w -effective value of weighted acceleration (m/s) 2 )；
a 0 -reference acceleration, a 0 ＝10 -6 m/s 2 。
The weight vibration level can be correspondingly calculated through the digital acquisition and calculation of the formula (2).
Measurement result identification system: and the ARM system controls the RS232 interface to realize communication of the ZigBee transceiver module, and after receiving a command of signal readiness from a standard acoustic signal generation system method. The ARM system completes the following work: (1) The AC interface provided by the tested instrument is connected to the high-speed A/DTMS320AIC23B acquisition interface for digital detection analysis. (2) And D.C. analyzing the DC interface provided by the tested instrument to the built-in A/D conversion interface provided by ARM 2410. (3) The measurement result display screen of the instrument to be measured passes through I by a digital camera 2 And the C bus is used for reading the ARM system, and the analysis results of the AC interface and the DC interface are combined through an optical character recognition technology to recognize the measurement results.
The algorithm analysis in this recognition process is as follows:
s1, firstly, performing digital analysis of a vibration level signal whole body vertical (W.B.z) weight-counting vibration level and a whole body horizontal (W.B.x-y) weight-counting vibration level through an AC interface, wherein the digital analysis is specifically as follows:
1/3oct analysis of 1Hz to 80Hz was first completed, according to the following steps:
1) Designing an 8-order Butterworth low-pass filter by using a design method of an analog filter;
the low-pass square function of the butterworth filter is expressed as follows:
taking 8 for period N, designing an 8-order low-pass filter, and obtaining a system function H (S).
2) Predistortion of the analog frequency;
in the two-line transformation method, the cut-off frequency omega of the filter is used to ensure that each boundary frequency point is a preset frequency C With the stop band side frequency ωs, the frequency predistortion must be performed as follows before determining the analog low pass filter system function:
H(s)＝H a (s/Ω c ) (5)
3) Solving a transfer function of digital filtering by using a bilinear transformation method;
the process of designing a digital filter using bilinear transformation is summarized as follows:
frequency conversion of normalized analog lowpass prototype to digital bandpass filter:
4) And then inputting a sampling value, calculating an output value, and obtaining the root mean square of each output value.
5) The frequency band root mean square acceleration obtained through 1/3oct analysis is multiplied by the weighting factor, and then the root mean square sum is obtained to obtain the corresponding frequency weighting
Acceleration:
wherein: a, a i -effective acceleration value (m/s 2) measured in the ith frequency band in the 1/3 octave spectrum;
k i -a frequency weighting factor corresponding to the i-th frequency band in the 1/3 octave spectrum.
Through the calculation of the formula and the 1/3oct analysis, the corresponding frequency weighting acceleration can be measured.
The weighting level can be obtained from the weighting acceleration as follows:
wherein: a, a w -weighting the acceleration effective value (m/s 2);
a 0 -reference acceleration, a 0 ＝10 -6 m/s 2 。
The corresponding weight vibration level can be obtained through the digital acquisition and calculation of the formula (10).
And forming a corresponding character matching module through the measurement results.
S2, through a DC interface, obtaining a corresponding unauthorized measurement result through ARM system sampling analysis, wherein the result forms an unauthorized corresponding character matching module in the optical identification measurement result.
S3, reading the ARM system through the RS232 interface by using a measuring result display screen of the measured instrument through a digital camera, and carrying out optical identification, wherein the algorithm is shown in figure 19.
The image acquisition of the identification object is realized by combining a camera with an image electric signal unit, aiming at character identification, the image smoothing is realized by selecting a median filtering technology, the binarization of the image is realized by setting a threshold value, the character segmentation is carried out from the binarization data, the selected method is a template matching method, and then the character identification is carried out by adopting skeleton feature extraction after the image is thinned. The skeleton feature extraction is adopted, so that the corresponding calculated amount can be reduced, and the extracted character features are only matched with the features of the character templates of the measurement results formed in the steps S1 and S2. The image to be identified can be a character skeleton image subjected to refinement treatment or a binary image without refinement and with noise removed, wherein the horizontal and vertical lines are marked at fixed intervals, and then the times of crossing the character image, namely the crossing times, are sequentially recorded. The template images are collected in advance, the passing times of each template are extracted, the template images are stored in a matrix form to serve as a feature matrix, and the feature matrix is stored as a database after the feature of each character is extracted. After the single character image to be recognized is obtained, the crossing times are extracted, the template data are loaded, and the crossing times matrix of the template are sequentially compared, the correlation coefficient is calculated, and the recognition result is the largest correlation coefficient. In the design, the length and the width are equally divided into five parts, the parts which cannot be equally divided are taken as integer parts, the crossing times are calculated at each equal dividing position, and each crossing is recorded as one crossing, so that ten characteristic values are obtained. The method for calculating the difference comprises the following steps:
wherein X can represent a binary character to be identified, P is a feature matrix of a template, and the obtained difference matrix is D. d=d 11 2 +…+d 25 2 For the number of correlation measures of the two, the corresponding template with the largest number represents the recognition result.
In the process, the corresponding character modules are obtained by combining the measurement data obtained by the measurement of the AC interface and the DC interface to perform module matching, so that the following functions can be achieved: (1) The rapid region localization (2) of the measurement results compensates for the slow and inaccurate image recognition process. By the algorithm, rapid and accurate measurement result identification can be performed.
After the identification is performed for 30 seconds, if the image identification area is still not positioned, the fact that the interface signal provided by the AC interface or the DC interface of the instrument is wrong is indicated, a conclusion that the measurement result is wrong is sent to the computer program control system through the ZigBee module, and whether the AC interface or the DC interface is correct is also determined. If the computer program is correctly identified, the correct identification result is sent to the computer program control system through the ZigBee module.
The system circuit has the following innovative design which is embodied on the basis of combining AC and DC analysis, and can accurately and rapidly find a measurement result through an image recognition technology, so that the correctness of AC and DC interfaces provided by a tested instrument can be verified while the defect of image recognition is overcome.
Computer program control system: the ARM system controls the RS232 interface to realize the communication of the ZigBee transceiver module, realizes the reading of the measurement result identification system, reads the measurement result into the computer system through the USB interface or the RJ45 interface of the ARM system, and writes the measurement result into a corresponding database entry of the detection procedure through the computer system. And then starting the standard signal output requirement of the next detection procedure and sending the standard signal output requirement to the standard sound generation system through the ZigBee networking unit. The computer programming adopts VB language and SQL database technology to realize the functions. The innovation of the circuit is mainly characterized in that the computer program control realizes the bidirectional communication of a computer program control system to a standard sound generation system and a measurement result recognition system and the formation and output of verification certificates through a ZigBee networking technology and a computer programming technology.
Claims (2)
1. The measuring method of the automatic metrological verification system of the vibration measuring instrument is characterized in that the automatic metrological verification system of the vibration measuring instrument comprises a standard vibration source generating system, a measuring result identifying system and a computer program control system; the standard vibration source generation system comprises: the system comprises a ZigBee transceiver unit, an ARM system, a program control signal source, a motor control unit and a vibrating table; the ARM system receives the signal waveform, frequency and amplitude of a standard electric signal required to be output or the size of a standard vibration level sent by the computer program control system through the Zigbee transceiver unit, one path of the signal waveform, frequency and amplitude of the standard electric signal are output through a system circuit, the other path of the signal waveform, frequency and amplitude of the signal of the vibration level are output through the control motor control unit to realize the output of the vibration level, meanwhile, the ARM system analyzes the signal frequency and amplitude of the signal of the vibration level to see whether the requirement of the standard vibration level is met, if the requirement of the signal of the vibration level is not met, the ARM system outputs the frequency of the motor control unit and the control output of a related motor are regulated, so that the motor control unit guides the impact force and the frequency of a firing pin to the vibration level until the output of the standard vibration level is achieved; the self-calibration process of the standard vibration level is realized; the program control signal source outputs corresponding signal waveform, amplitude and frequency through ARM system control AD9850 by direct digital frequency synthesis technology; when a standard vibration level signal or an electric signal is output, a signal readiness command is sent to a measurement result identification system through the ZigBee transceiver unit; the measuring result identification system comprises a display screen of a measured instrument, a camera, an image electric signal interface unit, an ARM system, a detection circuit, an AC interface, a DC interface and a ZigBee transceiver unit; the ARM system receives a ready command sent by the standard vibration source generating system through the Zigbee receiving and transmitting unit, the ARM system realizes image recognition of a measurement result of a display screen of the instrument to be measured through the image electric signal interface unit, and measures an AC interface and a DC interface of the instrument to be measured through the detection circuit; after acquiring the measurement result, the ARM system sends the measurement result to a computer program control system through the ZigBee transceiver unit; the computer program control system comprises: the ZigBee transceiver unit, the ARM system and the program-controlled computer; the ARM system obtains a measurement result of the measurement result identification system through the ZigBee transmitting and receiving unit, then sends data to an upper computer program of the program-controlled computer through a USB interface, the upper computer program sends the measurement result to an output item of a preset verification report, then sends a waveform, amplitude and frequency required by an output signal source required in the next verification procedure to the measurement result identification system through the USB interface, and the measurement result identification system sends the output signal source requirement to the standard vibration source generation system through the ZigBee transmitting and receiving unit; the measuring method of the automatic metering verification system of the vibration measuring instrument comprises the following steps:
s1, firstly, performing digital analysis of a vibration level signal whole body vertical (W.B.z) weight-counting vibration level and a whole body horizontal (W.B.x-y) weight-counting vibration level through an AC interface, wherein the digital analysis is specifically as follows:
1/3oct analysis of 1Hz to 80Hz was first completed, according to the following steps:
1) Designing an 8-order Butterworth filter by using a design method of an analog filter;
the low-pass square function of the butterworth filter is expressed as follows:
where Ω is the frequency, Ω is the passband cut-off frequency, Ω c is the 3dB cut-off frequency, ε is defined as (Ω p/Ω c) N Ap and δp are intermediate parameters, N is the filter order, 8 is taken, and an 8-order low-pass filter is designed, so that a system function H (S) is obtained;
2) Predistortion of the analog frequency;
in the two-line transformation method, the cut-off frequency omega of the filter is used to ensure that each boundary frequency point is a preset frequency C With the stop band side frequency ωs, the frequency predistortion must be performed as follows before determining the analog low pass filter system function:
wherein H is α (s) is an analog low pass filter system function, ω C As the cut-off frequency of the filter, ωs is the stop band side frequency, and H (Z) is the Z transformation of the discrete system;
3) Solving a transfer function of digital filtering by using a bilinear transformation method;
the process of designing a digital filter using bilinear transformation is summarized as follows:
frequency conversion of normalized analog lowpass prototype to digital bandpass filter:
wherein omega 0 For the centre frequency omega u Upper sideband cutoff frequency, omega l Cut-off frequency of lower sideband, cut-off frequency of omega s analog low pass, omega su Analog low pass derives the upper sideband cut-off frequency of the bandpass;
4) Inputting a sampling value, calculating an output value, and solving the root mean square of each output value;
5) The frequency band root mean square acceleration obtained through 1/3oct analysis is multiplied by the weighting factor, and then the root mean square sum is obtained to obtain the corresponding weighting acceleration of the frequency meter:
（9）
wherein:-effective acceleration value measured in the frequency band of 1/3 octave spectrum in m/s 2 ；
-a frequency weighting factor corresponding to a frequency band in the 1/3 octave spectrum;
through the calculation and 1/3oct analysis, the corresponding frequency weighting acceleration can be measured;
the weighting level can be obtained from the weighting acceleration as follows:
（10）
wherein:-effective value of weight acceleration in m/s 2 ；
-reference acceleration, =10 -6 m/s 2 ；
The corresponding weight vibration level can be obtained through the digital acquisition and calculation of the step (10);
forming a corresponding character matching module through the measurement results;
s2, through a DC interface, acquiring a corresponding unauthorized measurement result through ARM system sampling analysis, wherein the result forms an unauthorized corresponding character matching module in the optical identification measurement result;
s3, reading the ARM system through the RS232 interface by using a measuring result display screen of the measured instrument through a digital camera, and carrying out optical identification.
2. The method of measuring a vibratory measuring instrument automated metrological verification system of claim 1, wherein: the algorithm of the optical recognition in the step S3 is as follows:
the method comprises the steps of realizing graying of an image of an identification object through a camera combined with an image electric signal interface unit, aiming at character identification, selecting a median filtering technology to realize image smoothing, realizing binarization of the image through threshold setting, and performing character segmentation from binarization data, wherein the selected method is a template matching method, and then performing character identification through skeleton feature extraction after image refinement; adopting skeleton feature extraction to reduce corresponding calculated amount, and only matching the extracted character features with the features of the character templates of the measurement results formed in the steps S1 and S2; giving an image to be identified, a character skeleton image subjected to refinement treatment or a binary image without refinement and noise removal, scribing at fixed intervals in the transverse direction and the longitudinal direction, and sequentially recording the times of crossing the character image, namely the crossing times; collecting template images in advance, extracting the passing times of each template, storing the template images in a matrix form, taking the template images as a feature matrix, and taking the feature matrix as a database to store after the feature of each character is extracted; after the single character image to be recognized is obtained, the crossing times are also extracted, template data are loaded, and are sequentially compared with a crossing times matrix of the template, the correlation coefficient is calculated, and the recognition result is the largest correlation coefficient; dividing the length and the width into five parts which cannot be divided equally, taking an integer part, calculating the crossing times at each dividing position, and marking each crossing as one crossing, so that ten characteristic values are obtained; the method for calculating the difference comprises the following steps:
wherein X can represent a binary character to be identified, P is a feature matrix of a template, and the obtained difference matrix is D; d=d 11 2 +…+d 25 2 For the number of correlation measures of the two, the corresponding template with the largest number represents the recognition result.
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Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102288278A (en) * | 2011-07-23 | 2011-12-21 | 浙江大学 | Automatic calibrating device of digital display type vibration measurer and calibrating method thereof |
| CN102506994A (en) * | 2011-11-21 | 2012-06-20 | 嘉兴中科声学科技有限公司 | Digitized acoustic detection system |
| JP2012208043A (en) * | 2011-03-30 | 2012-10-25 | Railway Technical Research Institute | Method and device for identifying vibration characteristic of railroad structure |
| CN102829941A (en) * | 2012-08-16 | 2012-12-19 | 杭州亿恒科技有限公司 | Automated method for verifying vibration system |
| CN105334460A (en) * | 2015-11-27 | 2016-02-17 | 浙江大学城市学院 | Machine running state online monitoring analysis system based on noise and vibration analysis |
| CN105606207A (en) * | 2016-01-29 | 2016-05-25 | 湖南省计量检测研究院 | Calibration apparatus and calibration method applied to vibration sensor |
| CN106404160A (en) * | 2016-06-30 | 2017-02-15 | 国网重庆市电力公司电力科学研究院 | Power transmission line monitoring device metering system and method in field environment |
| CN106645949A (en) * | 2016-09-26 | 2017-05-10 | 武汉大学 | Heterodyne sweep-frequency type spectrum analyzer based on low frequency detection |
-
2019
- 2019-03-15 CN CN201910199211.5A patent/CN109870231B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2012208043A (en) * | 2011-03-30 | 2012-10-25 | Railway Technical Research Institute | Method and device for identifying vibration characteristic of railroad structure |
| CN102288278A (en) * | 2011-07-23 | 2011-12-21 | 浙江大学 | Automatic calibrating device of digital display type vibration measurer and calibrating method thereof |
| CN102506994A (en) * | 2011-11-21 | 2012-06-20 | 嘉兴中科声学科技有限公司 | Digitized acoustic detection system |
| CN102829941A (en) * | 2012-08-16 | 2012-12-19 | 杭州亿恒科技有限公司 | Automated method for verifying vibration system |
| CN105334460A (en) * | 2015-11-27 | 2016-02-17 | 浙江大学城市学院 | Machine running state online monitoring analysis system based on noise and vibration analysis |
| CN105606207A (en) * | 2016-01-29 | 2016-05-25 | 湖南省计量检测研究院 | Calibration apparatus and calibration method applied to vibration sensor |
| CN106404160A (en) * | 2016-06-30 | 2017-02-15 | 国网重庆市电力公司电力科学研究院 | Power transmission line monitoring device metering system and method in field environment |
| CN106645949A (en) * | 2016-09-26 | 2017-05-10 | 武汉大学 | Heterodyne sweep-frequency type spectrum analyzer based on low frequency detection |
Non-Patent Citations (1)
| Title |
|---|
| 超低频振动校准自动控制系统的研究;王志鹏;何闻;于梅;沈润杰;;机电工程(第06期);第693-697页 * |
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