Segmented frequency parameter correction method for high-precision signal generator

Abstract

The invention discloses a segmented frequency parameter correction method for a high-precision signal generator, belongs to the technical field of signal generator correction, and solves the technical problems of low detection precision, large time delay and numerous correction data of an existing correction method. The method comprises the following steps: respectively constructing an integrated measurement platform for integrated measurement of a broadband high-precision signal generator, a voltage comparator and a meter source; constructing a K coefficient dynamic correction segmented audio model with a time dimension; independent calibration of the ppm-level amplitude and the ns-level phase shift is carried out; reproducing a calibration result and verifying the calibration result under a harmonic working condition; the method for correcting the segmented frequency parameters of the signal generator is high in accuracy, high in applicability, good in dynamics and wide in comprehensiveness.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of signal generator correction, more particularly, it relates to a high-precision signal generator segmented frequency parameter correction method. BACKGROUND

[0002] High-precision signal generators are core technologies in the industries of measurement and detection, power industry, aerospace, semiconductor manufacturing, medical equipment, etc. They are used in conjunction with power amplifiers, actuators, and various feedback and feedforward technologies to form the forefront of today's automatic control technology.

[0003] Currently, high-precision signal generators for measurement and detection have the following problems:

[0004] 1. Accuracy - unable to meet the accuracy of the range range amplitude ppm level and the time delay sub-ns level;

[0005] 2. Applicability - only meets the use of a relatively narrow frequency band and a relatively narrow range range;

[0006] 3. Dynamic - the time-consuming and labor-intensive traceability calibration steps cannot meet the needs of automatic calibration at any time;

[0007] 4. Comprehensive - harmonic parameter correction is still a major problem in the measurement industry.

[0008] Simple description of prior art method:

[0009] The prior art is a system comparison method: a system composed of power amplification and feedback loop is compared with a standard table system; this method has simple algorithm, low detection system cost, and is easy to understand as it uses the same comparison method as the standard table and the test table. However, the detection precision is low, the time delay is large, the correction data is numerous, and the harmonics are not corrected. SUMMARY

[0010] The technical problem to be solved by the present application is to overcome the above-mentioned deficiencies of the prior art. The purpose of the present application is to provide a high-precision signal generator segmented frequency parameter correction method with high accuracy, strong applicability, good dynamic performance, and wide comprehensiveness.

[0011] The technical solution of the present application is: a high-precision signal generator segmented frequency parameter correction method, characterized by comprising the following steps:

[0012] Step 11. Construct a signal generator, a voltage comparator, and a source table integrated design integrated measurement platform, respectively;

[0013] Establish an equivalent model of the signal generator and define a comprehensive K distribution coefficient related to frequency: including clock, waveform DA, amplitude DA, DC balance and gain matching operational amplifier, shielding, grounding, spatial leakage electromagnetic field, power supply, PCB device layout and wiring;

[0014] The integrated measurement platform covers more than 6 channels of 16~20 bit DA amplitude adjustment, waveform distortion 0.05%~0.01%, frequency range 45Hz~3500Hz, power frequency harmonic calculation 0~256 times, AD sampling resolution better than 0.1ppm and annual stability better than 5ppm;

[0015] Step 12. Build K coefficient dynamic correction segmented audio model with time dimension;

[0016] Segmented frequency includes: 45Hz~100Hz; 100Hz~200Hz; 200Hz~400Hz; 400Hz~800Hz; 800Hz~1800Hz; 1800Hz~3500Hz;

[0017] f represents the difference, δ represents the angle difference, ω represents the frequency, then K coefficient: KF=f / (ω^2); KT=δ / ω, that is, KF has time square dimension, KT has time first power dimension; Each channel has its own KF, KT coefficient for each segmented frequency.

[0018] As a further improvement, the following steps are also included:

[0019] Step 21. Error control, waveform DA uses 8000 points / power frequency, at which time the distortion is less than 0.005%;

[0020] Step 22. Waveform DA frequency point, initial phase finding integer point, eliminating "gap error" and increasing measurement stability;

[0021] Step 23. Set two reference channel axis symmetry symmetric load phase points of 60° and-60° for each frequency band.

[0022] Further, the following steps are also included:

[0023] Step 31. 12-step independent calibration of ppm order amplitude and ns level phase shift, set the time length of each step to 60 seconds, the first half of each step is used for switching the stable delay of the rear load, and the 10 frame statistical results of the rear half of the last step are calculated;

[0024] Step 32. After step 31 is completed, run the 12 steps in step 31 again to reproduce the measurement results;

[0025] Step 33. Verify the segmented frequency parameter correction results of the full frequency band in the harmonic state.

[0026] Further, the following steps are also included:

[0027] Step 41. After the user starts the automatic calibration, the system will automatically detect the original waveform data of the process, the process calculation result data file, and the state evaluation report compared with the factory data and load into the hard disk storage;

[0028] Step 42. The user checks the test parameter check under the hard disk record check prompt storage path;

[0029] Step 43. Key check: whether the equivalent and frequency related comprehensive K distribution coefficient produces obvious changes compared with the factory record; the changes include the channels, frequency bands and change amount producing obvious changes, the difference between the audio range "gap compensation" algorithm and the Fourier algorithm, the original test record and the harmonic verification output of 12 steps; and the changes are sent to the manufacturer for further analysis and diagnosis.

[0030] Advantages

[0031] Compared with the prior art, the present application has the advantages that:

[0032] 1. The present application can meet the 45Hz~3500Hz audio range signal generation;

[0033] 2. The present application can cover the 0~256 times signal generation of power frequency harmonics;

[0034] 3. The signal generator automatic calibration of the present application ensures the long-term stability and accuracy of the core signal source;

[0035] 4. The appropriate calibration frequency and phase point of the present application ensures low distortion and high stability in the measurement process;

[0036] 5. The present application can correct the parameters in real time and compare them with the factory data and evaluate the state;

[0037] 6. The method of the present application is advanced, simple, efficient, accurate and reliable. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 It is a segmented frequency parameter correction system schematic diagram of the signal generator;

[0039] Figure 2 It is a signal source equivalent model and error influence related principle schematic diagram;

[0040] Figure 3 It is a detection data storage path schematic diagram;

[0041] Figure 4 It is a detection data and factory data comparison schematic diagram. DETAILED DESCRIPTION

[0042] The present application will be further described below in combination with the specific embodiments in the drawings.

[0043] Explanation of special symbols used in this embodiment:

[0044] ppm—parts per million;

[0045] s — second;

[0046] ns—10E-9s;

[0047] KF—Calculation coefficient for the ratio error of frequency points;

[0048] KT—Phase error calculation coefficient at frequency point;

[0049] MC—OpenMC, an open-source, generalized measurement and control platform covering many industries, is also known as the MC platform.

[0050] GEN_MS—an integrated measurement and control platform for meters and sources, also known as the MS platform, is an important branch of the MC platform.

[0051] See Figures 1-4 A high-precision signal generator segmented frequency parameter correction method includes the following steps 11 to 12:

[0052] Step 11. Construct an integrated measurement platform that combines a signal generator, voltage comparator, and source meter, along with a software module for automatic segmented frequency parameter measurement and error correction. The software module is integrated into the integrated measurement platform, forming the system. Specifically, as follows... Figure 1 The system shown includes signal generator channel 1, signal generator channel 2, a dual-channel voltage comparator, and an integrated measurement platform. The signals from signal generator channel 1 and signal generator channel 2 are input to the dual-channel voltage comparator. The integrated measurement platform is connected to signal generator channel 1, signal generator channel 2, and the dual-channel voltage comparator. The integrated measurement platform consists of an ARM module, a GEN_MS module, and an FPGA module.

[0053] An equivalent model of the signal generator is established, and frequency-related comprehensive K-distribution coefficients are defined, including clock, waveform DA, amplitude DA, DC balanced and gain-matched op-amps, shielding, grounding, spatial leakage electromagnetic field, power supply, and PCB component layout and routing. The equivalent circuit expression is K(ω) = (1 + (KF*ω^2 + jKT*ω)), which physically means fitting the ratio error of each frequency band with a square curve and fitting the angular difference of each frequency band with a linear curve, thereby realizing wideband correction parameter measurement.

[0054] The integrated measurement platform (MS platform) covers more than 6 channels of 16-20 bit DA amplitude adjustment, waveform distortion 0.05%-0.01%, frequency range 45Hz-3500Hz, power harmonic calculation 0-256 times, AD sampling resolution better than 0.1ppm and annual stability better than 5ppm. The upper limit of the MS platform calculation channel capacity is determined by the time-consuming calculation of 6 channels, for example: the basic design of 6 channels of 16-bit AD consumes 8ms under the working condition of safe calculation time 0.1s (other threads account for about 0.1s), the maximum calculation capacity of the platform is 12*6=72 channels.

[0055] Among them, the full scale 3V of signal generator channel 1 and signal generator channel 2 is usually converted into full scale voltage or current after power amplification and gear coefficient adaptation. The following verification table 1a also represents the corresponding basic gear 100V, 1A. Figure 2 The equivalent K(ω) parameter amplitude related parameter KF is in the order of 10E-10~10E-12(s^2), and the phase shift related parameter KT is in the order of 10E-7~10E-9(s). Since the parameters are very small, the system measurement has very high requirements.

[0056] Step 12. Build a K coefficient dynamic correction segmented audio model with time dimension.

[0057] The segmented frequency includes: 45Hz-100Hz; 100Hz-200Hz; 200Hz-400Hz; 400Hz-800Hz; 800Hz-1800Hz; 1800Hz-3500Hz.

[0058] f represents the ratio difference, δ represents the angle difference, and ω represents the frequency. Then K coefficient: KF=f / (ω^2); KT=δ / ω, that is, KF has a time square dimension, and KT has a time first power dimension; Each channel has its own KF and KT coefficients for each segmented frequency.

[0059] The correction method also includes the following steps 21-23:

[0060] Step 21. Error control, waveform DA uses 8000 points / power frequency, at which time the distortion is less than 0.005%.

[0061] Step 22. Waveform DA frequency point, initial phase finding integer point, eliminating "gap error" and increasing measurement stability.

[0062] For example: 50Hz points = crystal frequency / frequency / 50 = 3906.25, the remainder of the division is the "gap", if the signal frequency is set to 50.0032 Hz, there is no remainder, at this time the signal distortion is about 1 / 3 of the remainder, the standard deviation is about 1 / 2. Because the frequency limits the number of DA points per signal period, the "gap error" caused by the signal frequency in high frequency conditions will increase by more than 10 times. Therefore, the frequency settings of the 6 frequency bands are set to: 50.0032, 122.0703, 244.1406, 488.28125, 976.5625, 1953.125 Hz.

[0063] Step 23. Set the symmetric load phase points of the two reference channels symmetric to 60° and -60° of each frequency band.

[0064] Of course, it can also be set to 72° and -72°. For example, the phase setting is affected by the crystal 100MHz, and the load phase points are set to 60°, -60°, 72°, -72°, 72°, -72°, 72°, -72°, 72°, -72°, 72°, -72°.

[0065] The correction method further includes steps 31-33:

[0066] Step 31. The amplitude of the ppm order and the phase shift of the ns order are independently calibrated in 12 steps, and the time length of each step is set to 60 seconds. The first half of each step is used to switch the stable delay of the rear load, and the statistical results of the last 10 frames of the rear half of the last step are calculated. The time interval of each frame is about 2.5 seconds, the design software time base tp = 0.2 seconds, then the time length of each step = 300*tp, the delay time length = 150*tp, and the measurement time length is less than 150*tp.

[0067] Step 32. After step 31 is completed, the 12 steps in step 31 are run again to reproduce the measurement results;

[0068] Step 33. Verify the correction results of the segmented frequency parameters of the full frequency band in the harmonic state.

[0069] Finally, the correction method further includes steps 41-43:

[0070] Step 41. After the user starts the automatic verification (i.e. in the software module according to the equivalent model, the comprehensive K distribution coefficient, the K coefficient dynamic correction of the segmented audio model, and the detection of the signal generator in steps 21-23, 31-33), the system will automatically load the original waveform data, process calculation result data file, and state evaluation report compared with the factory data into the hard disk storage.

[0071] Step 42. User checks the test parameters through the hard disk record check prompt under the path. For example: debug write record: [K_COEFF] User_Record_Time = 2025-02-02 16:29 …, and the check of the user test interface of the platform, as shown in Figure 3 、 Figure 4

[0072] Step 43. Key check: whether the equivalent and frequency related comprehensive K distribution coefficient produces obvious changes from the factory record; the changes include the channels, frequency bands that produce obvious changes, and the change amount, the difference between the audio range "gap compensation" algorithm and the Fourier algorithm, the original test record and the harmonic verification output of 12 steps; and send the changes to the manufacturer for further analysis and diagnosis.

[0073] The example test data is as follows:

[0074] Table 1a is the signal generator test analysis data

[0075]

[0076] Note: 100V, 1A in the table is the nominal value of the gear, and the actual full degree is 3V

[0077] The data in Table 1b are the standard deviation / average value of the measured data except for the phase error, sF is the frequency, sU is the voltage, and sI is the current.

[0078] Table 1b is the signal generator test stability data

[0079]

[0080] The data in Table 1 shows that the full-band accuracy is better than 10ppm.

[0081] Table 2 is the harmonic test verification audio parameter correction result

[0082]

[0083] Note: The leftmost in Table 2 is the voltage and current harmonic frequency, and the error = (measured harmonic proportion value - harmonic proportion set value) / fundamental set value

[0084] The data in Table 1 and Table 2 shows that the audio calibration data and the harmonic data are basically consistent.

[0085] Table 3 is the K coefficient user test and factory record

[0086]

[0087] ​Note: In Table 3, the KT values are all 0 as reference due to the principle of the voltage comparator method; the KF values are actually used for convenience, defined according to the angle "°" rather than the radian "rad", so there is a difference in the E-06 order of magnitude from the "E-7~E-9" order of magnitude described above.

[0088] The above embodiments of the present application are not intended to limit the protection scope of the present application, and the embodiments of the present application are not limited thereto. According to the above content of the present application, other various forms of modifications, replacements or changes to the above structure of the present application, which are made without departing from the above basic technical idea of the present application, should fall within the protection scope of the present application.

Claims

1. A method for correcting segmented frequency parameters of a high-precision signal generator, characterized in that, Includes the following steps: Step 11. Construct an integrated measurement platform that combines a signal generator, voltage comparator, and source meter; Establish an equivalent model of the signal generator and define the frequency-related comprehensive K-distribution coefficients, including clock, waveform DA, amplitude DA, DC balanced and gain-matched op-amps, shielding, grounding, spatial leakage electromagnetic field, power supply, PCB device layout and routing. The integrated measurement platform includes 16-20 bit DA amplitude adjustment with more than 6 channels, waveform distortion of 0.05%-0.01%, frequency range of 45Hz-3500Hz, power frequency harmonic calculation of 0-256th order, AD sampling resolution better than 0.1ppm, and annual stability better than 5ppm. Step 12. Construct a K-coefficient dynamic correction segmented audio model with time dimensions; The frequency segments include: 45Hz~100Hz; 100Hz~200Hz; 200Hz~400Hz; 400Hz~800Hz; 800Hz~1800Hz; 1800Hz~3500Hz; f represents the ratio difference, δ represents the angle difference, and ω represents the frequency. Then the K coefficients are: KF = f / (ω^2); KT = δ / ω, that is, KF has the dimension of time squared and KT has the dimension of time first power. Each segment frequency of each channel has its own KF and KT coefficients.

2. The high-precision signal generator segmented frequency parameter correction method according to claim 1, characterized in that, It also includes the following steps: Step 21. Error control: The waveform DA is set to 8000 points / power frequency, at which point the distortion is less than 0.005%. Step 22. Find the integer point of the waveform DA frequency and initial phase to eliminate "gap error" and increase measurement stability; Step 23. Set the axisymmetric load phase points of the two reference channels at 60° and -60° for each frequency band.

3. The high-precision signal generator segmented frequency parameter correction method according to claim 1, characterized in that, It also includes the following steps: Step 31. A total of 12 independent calibration steps are performed for the ppm-level amplitude and ns-level phase shift. The duration of each step is set to 60 seconds. The first half of each step is used for the stabilization delay after the load is switched, and the statistical results of 10 frames in the second half of the previous step are calculated. Step 32. After completing Step 31, run the 12 steps in Step 31 again to reproduce the measurement results; Step 33. Verify the segmented frequency parameter correction results across the entire frequency band under harmonic conditions.

4. A method for correcting segmented frequency parameters of a high-precision signal generator according to any one of claims 1-3, characterized in that, It also includes the following steps: Step 41. After the user initiates automatic verification, the system will load the original waveform data of the automatic detection process, the process calculation result data file, and the status evaluation report compared with the factory data into the hard disk for storage. Step 42. The user checks the test parameters in the storage path indicated by the hard drive record check prompt; Step 43. Key checks: Whether the equivalent frequency-related comprehensive K-distribution coefficient has changed significantly from the factory record; the changes include the channels, frequency bands and the amount of change, the difference between the audio range "gap compensation" algorithm and the Fourier algorithm, the original test record of 12 steps and the harmonic verification output; and send the changes to the manufacturer for further analysis and diagnosis.

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