CN109633251B - IF circuit integral voltage peak-to-peak value solving method and device - Google Patents

IF circuit integral voltage peak-to-peak value solving method and device Download PDF

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CN109633251B
CN109633251B CN201811379989.6A CN201811379989A CN109633251B CN 109633251 B CN109633251 B CN 109633251B CN 201811379989 A CN201811379989 A CN 201811379989A CN 109633251 B CN109633251 B CN 109633251B
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integrated voltage
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欧阳英图
彭时雨
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Hunan Aerospace Institute of Mechanical and Electrical Equipment and Special Materials
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Abstract

The invention provides a method and a device for solving peak-to-peak values of integrated voltages of an IF circuit, wherein the IF circuit is a charge balance type IF circuit, the IF circuit comprises an integrator for converting input current into integrated voltages, an AD conversion circuit for converting the integrated voltages into digital values and a pulse calculation module for calculating pulse values by using the digital values, and the method for solving the peak-to-peak values of the integrated voltages of the IF circuit comprises the following steps: (A) adding direct current excitation current to the input end of the integrator; (B) collecting the pulse value of a pulse calculation module; (C) and calculating a correction value of the peak-to-peak value of the integrated voltage. The invention can realize the rapid and accurate measurement of the integrated voltage peak value of the IF circuit accurately by one-time measurement and calculation, and reduce the debugging times and the debugging time. The invention has been successfully applied to a laser strapdown inertial unit with a certain weapon model, and can be widely applied to inertial navigation products such as various ground vehicle-mounted positioning and orienting equipment, missile-borne inertial measurement units and the like.

Description

IF circuit integral voltage peak-to-peak value solving method and device
Technical Field
The invention belongs to the technical field of inertial navigation test system IF circuit debugging application, and particularly relates to a charge balance type IF circuit integral voltage peak-to-peak value solving method and device.
Background
An accelerometer is an inertial measurement device used in an inertial navigation test system (hereinafter, inertial navigation). The information obtained from the accelerometer is usually analog and needs to be digitized by an IF circuit (current-to-frequency conversion circuit). The IF circuit converts the current signal output by the accelerometer into a pulse-frequency signal. The one-time energization stability of the accelerometer means stability of an output value thereof in the case of one-time energization when an input acceleration is 0g or 1 g. The peak value of the integral voltage is an important parameter influencing the one-time power-on stability of the charge balance type IF circuit, is an important factor influencing the one-time power-on stability of the acceleration channel in inertial navigation, and the accurate and rapid measurement of the peak value of the integral voltage influences the debugging precision and the debugging efficiency of the one-time power-on stability of the IF circuit.
As shown in fig. 1, in the existing high-precision IF circuit, on the premise of not changing the frequency scale, the voltage is sampled at the integration stage, and the uniformly output pulse is calculated according to the voltage of the sampling point and the corresponding algorithm, so as to improve the proportionality coefficient. In a high-precision IF circuit, U can be converted intoppThe peak value of the integrated voltage is evenly divided into K parts, and each part outputs 1 pulse, namely the integrated voltage UjEach change UppThe output of 1 pulse is realized, and the threshold voltage is prevented from being reachedThe phenomenon of pulse output improves the resolution capability of small current. As shown in fig. 1, in an ideal case, a difference between the highest value of the voltage at the time of completion of charging and the lowest value of the voltage at the time of completion of discharging of the integrator is the peak-to-peak value of the integrated voltage of the IF circuit.
At present, the measurement of integral voltage peak value in a charge balance type IF circuit of a domestic inertial navigation product is mainly to measure the waveform amplitude of the IF circuit in the discharging process under small current, obtain a rough integral voltage peak value and then carry out pulse acquisition, and then continuously adjust and correct the integral voltage peak value by adopting a successive approximation method to obtain an accurate integral voltage peak value.
The existing method for measuring the peak value of the integral voltage is to add a small current, measure the AD value difference value at the moment of discharge as the peak value of the integral voltage, the smaller the current value is, the longer the test time is, and the larger the current value is, the larger the error is, so the peak value of the integral voltage obtained by the method theoretically has a certain error. The one-time power-on stability of the IF circuit tested at this time is poor. In order to obtain a better one-time electrifying stability result, the existing method is to finely adjust the peak value of the measured integral voltage peak, then to test the one-time electrifying stability after adjusting, and then to correct when the test result does not reach the technical index. The measuring method needs to carry out measurement for many times, and has poor measuring precision and low efficiency. Therefore, it is necessary to provide a method for solving the peak-to-peak integrated voltage of the IF circuit.
Disclosure of Invention
The invention provides a method and a device for solving peak-to-peak values of integrated voltage of an IF circuit, aiming at the problem that the existing method for solving peak-to-peak values of integrated voltage in the IF circuit is low in efficiency.
In order to solve the technical problems, the invention adopts the technical scheme that: an integrated voltage peak-to-peak solving method of an IF circuit, the IF circuit being a charge balanced IF circuit, the IF circuit including an integrator for converting an input current into an integrated voltage, an AD conversion circuit for converting the integrated voltage into a digital value, a pulse calculation module for calculating a pulse value using the digital value, the integrated voltage peak-to-peak solving method of the IF circuit comprising the steps of:
(A) adding direct current excitation current to the input end of the integrator;
(B) collecting the pulse value of a pulse calculation module;
(C) calculating correction value U 'of peak-to-peak value of integrated voltage by using the following formula't
Figure BDA0001871638450000021
Wherein, UtFor a preset value of the integrated voltage peak-to-peak value of the IF circuit, B0The multiplying power of the module is calculated for the pulse,
Xh、Xlthe pulse value of the peak in one charging and discharging period of the IF circuit and the average value of other pulse values except the pulse value of the peak in one charging and discharging period of the IF circuit
Or the average value of the pulse values of m spikes in m charge and discharge cycles of the IF circuit and the average value of the pulse values of the other pulses except the pulse values of the m spikes in the m charge and discharge cycles of the IF circuit respectively, wherein m is more than or equal to 2.
According to the invention, by establishing the relation between the current integral voltage peak-to-peak value of the IF circuit and the pulse jump in the pulse acquisition process, relatively accurate integral voltage peak-to-peak value can be obtained through one-time test and calculation, so that the fast and accurate measurement of the integral voltage peak-to-peak value of the IF circuit is realized.
In the above technical solution, each charge-discharge cycle of the IF circuit has n frequency scale periods, and the pulse calculation module calculates a pulse value X corresponding to a sampling point of the (k + 1) th frequency scale period by using the following formulak+1
Figure BDA0001871638450000022
Wherein, Uk+1Acquired for sampling points of the (k + 1) th frequency scale periodOutput value of AD conversion circuit, UkThe output value of the AD conversion circuit collected for the sampling point of the kth frequency scale period, a is the whole pulse count, and k is 1,2, … ….
In the above technical scheme, if Uk+1>UthbIf a is-1; if U isk+1<UthaIf a is 1; if U istha<Uk+1<UthbIf a is 0;
wherein U isthb、UthaThe upper threshold and the lower threshold of the integrated voltage are respectively set.
In the above technical solution, IF no peak regularly appearing with a charge-discharge cycle of the IF circuit appears in the collected pulse value, U't＝Ut. In the invention, IF the peak which regularly appears along with the charge-discharge period of the IF circuit does not appear in the acquired pulse value, the deviation between the preset value of the peak value of the integrated voltage of the IF circuit and the real peak value of the integrated voltage is small, so that the correction is not needed.
In the above technical solution, in the step (B), the sampling frequency f is usedaSampling time T acquires the pulse value, and the sampling time T is 1/faIntegral multiple of, sampling frequency faAnd frequency scale f0Equality or frequency scale f0For sampling frequency faAn integer multiple.
In the above technical solution, the direct current excitation current I is 0.01 mA.
In the above technical solution, T is 60s, fa＝f0＝2kHz。
The invention also provides a device for solving the peak value of the integrated voltage of the IF circuit, wherein the IF circuit is a charge balance type IF circuit, and is characterized by comprising an integrator, an AD conversion circuit and a pulse calculation module, wherein the integrator is used for converting input current into integrated voltage, the AD conversion circuit is used for converting the integrated voltage into a digital value, and the pulse calculation module is used for calculating a pulse value by using the digital value; the method is characterized in that: the pulse generator further comprises a solving module, wherein the solving module is used for collecting the pulse value and calculating a correction value U 'of an integral voltage peak-to-peak value by utilizing the following formula't
Figure BDA0001871638450000031
Wherein, UtFor a preset value of the integrated voltage peak-to-peak value of the IF circuit, B0The multiplying power of the module is calculated for the pulse,
Xh、Xlthe pulse value of the peak in one charging and discharging period of the IF circuit and the average value of other pulse values except the pulse value of the peak in one charging and discharging period of the IF circuit
Or the average value of the pulse values of m spikes in m charge and discharge cycles of the IF circuit and the average value of the pulse values of the other pulses except the pulse values of the m spikes in the m charge and discharge cycles of the IF circuit respectively, wherein m is more than or equal to 2.
Furthermore, the IF circuit further comprises a comparator, a trigger, a switch circuit and a constant current source which are connected in sequence, wherein the input end of the comparator and the output end of the constant current source are respectively connected with the output end and the input end of the integrator, and the IF circuit further comprises a frequency scale generating module for providing frequency scales for the IF circuit.
Further, the device also comprises an excitation current generating module used for adding direct current excitation current to the IF circuit. By arranging the excitation current generation module, the excitation current can be added into the accelerometer.
The invention has the advantages and positive effects that: the invention provides a method for solving an integrated voltage peak-to-peak value of an IF circuit, which obtains a relatively accurate integrated voltage peak-to-peak value through one-time test and calculation so as to realize the rapid and accurate measurement of the integrated voltage peak-to-peak value of the IF circuit. The invention can realize the accurate measurement of the integrated voltage peak value of the IF circuit of the inertial navigation product through one-time pulse acquisition, does not need to repeatedly adjust the integrated voltage peak value and acquire the pulse number, and can realize the rapid measurement on the premise of reaching the higher one-time power-on stability index of the IF circuit, thereby greatly shortening the debugging time of the IF circuit of the inertial navigation product, improving the debugging efficiency and simultaneously greatly reducing the cost of the product.
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In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive labor.
Fig. 1 is a schematic diagram of charging and discharging waveforms of a conventional IF circuit.
Fig. 2 is a schematic diagram of steps of a method for solving peak-to-peak values of integrated voltages of an IF circuit according to an embodiment of the present invention.
Fig. 3 is a schematic circuit diagram of an IF circuit according to an embodiment of the present invention.
Fig. 4 is a schematic diagram of an integrated waveform of the IF circuit according to an embodiment of the present invention.
FIG. 5 is a diagram of an embodiment of the present invention employing a default value U of the peak-to-peak value of the assumed integrated voltagetAnd the sampling frequency is a curve diagram output by the pulse calculation module collected at 2 kHz.
FIG. 6 is a correction value U 'using calculated integrated voltage peak to peak values for an embodiment of the present invention'tAnd the sampling frequency is a curve diagram output by the pulse calculation module collected at 2 kHz.
In the figure, the device comprises an integrator 1, an AD conversion circuit 2, a pulse calculation module 3, a pulse calculation module 4, a solving module 5, a frequency scale generation module 6, a comparator 7, a trigger 8, a constant current source 9, a switch circuit 10, a signal processing unit 20 and an excitation current generation module.
Detailed Description
The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
As shown in fig. 2 to 6, the present invention provides an integrated voltage peak-to-peak solving method for an IF circuit, the IF circuit is a charge balance type IF circuit, the IF circuit includes an integrator 1 for converting an input current into an integrated voltage, an AD conversion circuit 2 for converting the integrated voltage into a digital value, and a pulse calculation module 3 for calculating a pulse value using the digital value, the integrated voltage peak-to-peak solving method for the IF circuit includes the following steps:
(A) adding direct current excitation current to the input end of the integrator 1;
(B) collecting a pulse value of a pulse calculation module 3;
(C) calculating correction value U 'of peak-to-peak value of integrated voltage by using the following formula't
Figure BDA0001871638450000041
Wherein, UtThe integrated peak-to-peak voltage value of the IF circuit is preset. B is0The magnification of the module 3 is calculated for the pulse. XhThe pulse value, X, of the peak in one charge-discharge cycle of the IF circuitlThe average value of other pulse values except the pulse value of the peak in one charging and discharging period of the IF circuit;
or, XhIs the average value of the pulse values of m spikes in m charge and discharge cycles of the IF circuit, XlThe average value of the pulse values except the pulse values of m spikes in m charge and discharge cycles of the IF circuit is m ≧ 2.
In the present invention, correction value U 'of integrated voltage peak-to-peak value calculated in step (C)'tAs a parameter in the pulse calculation module 3.
Each charge-discharge period of the IF circuit has n frequency scale periods, and in the pulse calculation module 3, the pulse value X corresponding to the sampling point of the (k + 1) th frequency scale period is calculated by using the following formulak+1
Figure BDA0001871638450000051
Wherein, Uk+1Output value, U, of AD conversion circuit 2 collected for sampling point of k +1 th frequency scale periodkOf AD conversion circuits 2 for sampling points of the kth frequency scale periodThe output value, a, is the full pulse count, k is 1,2, … ….
Figure BDA0001871638450000052
Wherein U isthb、UthaThe upper threshold and the lower threshold of the integrated voltage are respectively set.
IF no peak which is regularly generated along with the charging and discharging period of the IF circuit appears in the collected pulse value, U't＝Ut。
In step (B), the sampling frequency f is usedaSampling time T acquires pulse value, and the sampling time T is 1/faIntegral multiple of, sampling frequency faAnd frequency scale f0Equality or frequency scale f0For sampling frequency faAn integer multiple.
In this embodiment, the dc excitation current is I ═ 0.01mA, T ═ 60s, fa＝f 02 kHz. I, T, f can be adjusted according to actual engineering requirementsa、f0The selection is made as will be appreciated by one of ordinary skill in the art.
As shown in fig. 3, the present invention further provides an integrated voltage peak-to-peak value solving apparatus for an IF circuit, where the IF circuit is a charge balanced IF circuit, and the IF circuit includes an integrator 1 for converting an input current into an integrated voltage, an AD conversion circuit 2 for converting the integrated voltage into a digital value, and a pulse calculation module 3 for calculating a pulse value using the digital value; the pulse generator further comprises a solving module 4, wherein the solving module 4 is used for collecting pulse values and calculating a corrected value U 'of peak-to-peak values of the integrated voltage by using the following formula't
Figure BDA0001871638450000053
Wherein, UtFor a preset value of the integrated voltage peak-to-peak value of the IF circuit, B0The multiplying power of the module is calculated for the pulse,
Xh、Xlthe pulse value of the peak in one charge-discharge period of the IF circuit and one charge-discharge period of the IF circuitAverage value of other pulse values except for the pulse value of the peak
Or the average value of the pulse values of m spikes in m charge and discharge cycles of the IF circuit and the average value of the pulse values of the other pulses except the pulse values of the m spikes in the m charge and discharge cycles of the IF circuit respectively, wherein m is more than or equal to 2.
The IF circuit further comprises a comparator 6, a trigger 7, a switch circuit 9 and a constant current source 8 which are connected in sequence, wherein the input end of the comparator 6 and the output end of the constant current source 8 are respectively connected with the output end and the input end of the integrator 1, and the IF circuit further comprises a frequency scale generating module 5 for providing frequency scales for the IF circuit. The IF circuit further comprises an excitation current generating module 20 for adding a dc excitation current to the IF circuit.
In the invention, the working process of the IF conversion circuit is as follows: the current output by the accelerometer is integrated in integrator 1 to produce a voltage. When the voltage reaches a certain value, the comparator 6 is inverted and a transition signal is sent to the trigger 7. The trigger 7 sends a counting pulse to the counter, meanwhile, the trigger 7 outputs a signal to control the constant current source 8 to reversely charge the integrator 1, after the voltage on the integrator 1 is lower than the voltage on the comparator 6, the comparator 6 turns over, and the constant current source 8 stops reversely charging. The IF circuit is an analog-to-digital conversion circuit which discharges charges on an integrating capacitor by quantizing the charges and measures the current in the circuit by obtaining the number of the quantized charges in unit time. The main function of the constant current source 8 is to provide a reference current. In the present invention, the discharge time of the IF circuit is also the period of the frequency scale frequency.
The frequency scale is a time reference of the acquisition system, and plays an important role in charging the capacitor with the charge number for the quantization constant current source 8, providing gate time for the counter, and providing a trigger conversion signal for the AD conversion circuit 2. In the present invention, the frequency scale is provided by a frequency scale generating module in the signal processing unit 10. For example, the frequency scale may be obtained by frequency doubling and frequency division in the signal processing unit 10 through a crystal oscillator.
Peak-to-peak value of integrated voltage, multiplying factor B0For the expressions of frequency scale and pulse value, please refer to reference 1 and reference 2.
In the invention, the pulse value of the peak in the charge-discharge period is the pulse value at the discharge moment of the IF circuit. The average value of the pulse values except the pulse value of the peak in one charging and discharging period is the average value of the pulse values except the discharging moment in one charging and discharging period of the IF circuit.
The pulse calculation module 3 receives the output value of the AD conversion circuit 2, and calculates the sampling point pulse value of the kth frequency scale period by using the following formula 1. The frequency scale is typically tens to hundreds of kHz.
In the integrated waveform diagram of the IF circuit shown in fig. 4, IF the integrated voltage exceeds the voltage threshold, an entire pulse is recorded, IF the integrated voltage exceeds the lower limit, the count a is +1, and IF the integrated voltage exceeds the upper limit, the count a is-1. If the integrated voltage does not exceed the threshold value, a is equal to 0. The recorded pulses wait for the next calculation. The calculation formula is formula 1:
Figure BDA0001871638450000061
wherein U istTo a preset value of the peak-to-peak value of the integrated voltage, B0Multiplying power of the IF circuit is fixed value in the IF circuit, which is independent of the IF circuit, X is the pulse number of the sampling point of the current frequency scale period (i.e. the pulse value corresponding to the sampling point of the (k + 1) th frequency scale period), Uk+1Output value, U, of AD conversion circuit 2 collected for sampling point of k +1 th frequency scale periodkThe output value of the AD conversion circuit 2 collected for the sampling point of the kth frequency scale period, a, is the full pulse count, and k is 1,2, … ….
In an ideal situation, when the external excitation current of the IF circuit is small enough and the test time is long enough, the difference between the output value of the AD conversion circuit 2 at the end of discharge and the output value of the AD conversion circuit 2 at the start of discharge is the real peak-to-peak integral voltage value. During the pulse test of the IF circuit, IF the error of the peak-to-peak value of the current integral voltage is larger than the error of the peak-to-peak value of the accurate integral voltage, the pulse number collected will have a regular single-side jumping burr phenomenon, and the jumping process corresponds to the charging and discharging moment of the IF circuit (i.e. t in fig. 4)CTime tDTime of day)。
The method for solving the peak value and the peak value of the integrated voltage of the IF circuit comprises the steps of setting a preset value U of the peak value and the peak value of the integrated voltagetThen, adding a small excitation current to the IF circuit, performing pulse acquisition (namely acquiring an output value of the pulse calculation module 3), acquiring single-side pulse jump in the acquisition process, adding the single-side pulse jump into a pulse calculation model, and deriving a relatively accurate corrected value U of the peak-to-peak value of the integrated voltage of the IF circuit as shown in the formula 2tAnd the peak value of the integrated voltage is measured quickly.
As shown in FIG. 4, T0Is the frequency scale period, tATime tDThe time is a charge-discharge period tATime tCAt the moment of the charging process, tCTime tDThe moment is the discharge process. t is tBTime tCTime tDThe time is the sampling point of the frequency scale period, tBTime tCThe output values of the AD conversion circuits 2 collected at the moment are respectively UB、UC。
As shown in fig. 4, the pulse generated by the pulse calculation module 3 at the moment when the IF circuit is discharged (glitch is generated) is XhDue to the integrated voltage value exceeding the threshold value UthbWhere a is-1, the mean value of the pulse values of the pre-discharge pulse calculation module 3 is XlFormula 2 and formula 3 are derived from formula 1:
formula 2:
Figure BDA0001871638450000071
formula 3:
Figure BDA0001871638450000072
Δ' is the moment of discharge (t)CTime tDTime) of the output values of the AD conversion circuits 2 corresponding to the sampling points of the adjacent frequency scale periods. Delta is before discharge (t)ATime tCTime) of the output of the AD conversion circuit 2 corresponding to the sampling points of the adjacent frequency scale periodsMean of the difference in values. E.g. UC-UBIs a sampling point tCThe difference of the output values of the corresponding AD conversion circuits 2 is shown in fig. 4.
Equation 4 is derived by subtracting equations 2 and 3:
Figure BDA0001871638450000073
in the present invention, the excitation current generation module 20 adds 0.01mA current and sampling frequency f to the IF circuitaAt 2kHz, the pulse data of the pulse calculation block 3 is unfiltered. And taking one section of charging and discharging process, and assuming that the deviation between the preset value of the peak-to-peak value of the integral voltage and the real peak-to-peak value of the integral voltage is larger, the pulse value output by the pulse calculation module shows a pulse jump phenomenon on a smooth waveform, and the jump process corresponds to the discharging moment.
Integral voltage peak-to-peak value correction value U 'is assumed'tSetting the pulse generated by the instantaneous pulse calculation module 3 for discharging as Xh0Since the integrated voltage value exceeds the threshold value, a is-1, and the average value of the smoothed waveform data output from the pre-discharge pulse calculation block 3 is Xl0From equation 1, one can obtain:
formula 5:
Figure BDA0001871638450000081
formula 6:
Figure BDA0001871638450000082
under ideal conditions, since all the pulse values output by the pulse calculation module 3 should be varied within a range, there is X at this timeh0-Xl0When 0 is obtained, equation 5 and equation 6 are subtracted to obtain equation 7:
Δ'-Δ＝U't
equation 4 and equation 7 give equation 8:
Figure BDA0001871638450000083
in the formula: u'tFor correction of peak-to-peak value of integrated voltage of IF circuit, UtFor a preset value of the integrated voltage peak-to-peak value of the IF circuit, B0The magnification of the IF circuit. XhIs the mean value, X, of the pulse measurements at the instant of discharge of the IF circuit for k cycleslAveraging the pulse measurements of the k cycles of the IF circuit before discharge; or, XhPulse data, X, output by the pulse calculation module 3 for the moment of discharge (producing a glitch)lThe pulse data output by the pulse calculation module 3 before discharging (except for the glitch in the same period).
In the invention, firstly, a preset value U of an integrated voltage peak value of an IF circuit is sett4000 as the peak value of the current integral voltage of the pulse calculation module of the IF circuit, and setting the multiplying power B of the pulse calculation module0Add +0.01mA dc excitation current to IF circuit by multifunction calibrator at fa2kHz sampling frequency is adopted to acquire the output value of the waveform AD conversion circuit 2 in the charging and discharging process of the IF circuit and calculate the pulse number X output by the pulse calculation modulehAnd XlThe sampling time is 60s, as shown in fig. 5.
The collected and calculated pulse data is substituted into a calculation formula of an integral voltage peak value shown in formula 8, and a relatively accurate correction value U 'of the integral voltage peak value can be obtained through calculation't＝3864.28。
Calculating correction value U 'of peak-to-peak value of integrated voltage'tThe current integrated voltage peak value of the pulse calculation module of the IF circuit is used as the peak value, the output value of the pulse calculation module of the IF circuit is collected, and the pulse curve in the pulse collection process is observed, wherein the pulse curve is shown in fig. 6. As can be seen from fig. 6, when there is no pulse single-edge jump in the pulse curve output by the pulse calculation module and the primary channel stability meets the calculation index requirement, it is considered that the integrated voltage peak-to-peak value is the corrected value U'tThe voltage peak-to-peak value is accurately integrated.
Meanwhile, a correction value U 'of an integral voltage peak-to-peak value is utilized'tPerforming a primary energization stability test, verifying the accuracy of the correction value of the peak-to-peak value of the integrated voltage, and testing to obtain the primary energization stability of 3.225982 × 10-5. In the circuit, the one-time power-on stability index requirement is that sigma is less than or equal to 4.0 multiplied by 10-5. Therefore, the peak value of the integral voltage obtained by the method meets the requirement when a power-on stability test is carried out for one time.
Comparing the traditional integral voltage peak-to-peak value measuring method with the method under the same condition, adjusting the integral voltage peak-to-peak value for three times by using a successive approximation method, and testing to obtain the primary energization stability of which sigma is 3.558700 multiplied by 10-5. Obviously, compared with the traditional method of utilizing a successive approximation method to carry out three times of adjustment, the method can obtain the accurate integral voltage peak-to-peak value only through one-time test, and the one-time electrifying stability index obtained through the test is obviously superior to that of the traditional method.
According to the method, the hardware cost is not increased, and the precise peak-to-peak integral voltage value is obtained by establishing the relation between the current peak-to-peak integral voltage value of the IF circuit and the pulse jump in the pulse acquisition process, so that the precise peak-to-peak integral voltage value of the IF circuit can be obtained by one-time measurement and calculation, the rapid measurement of the peak-to-peak integral voltage value is realized, and the debugging times and the debugging time are reduced. The invention has been successfully applied to a certain laser strapdown inertial unit, and can be widely applied to various ground vehicle-mounted positioning and orienting equipment with IF circuits, inertial measurement units on a missile and other inertial navigation products.
The references of the present application are:
reference 1: journal literature published in navigation and control in 2018 and with the name of large scale coefficient and high precision I/F circuit design based on FPGA (field programmable gate array) in Chaoyuan, Suo, and the like;
reference 2: a journal literature published in scientific technology and engineering in 12 months of 2012 of Shaobanchuan et al and named as 'design of a multi-channel high-precision accelerometer data acquisition system based on FPGA'.
It should be noted that, in the present specification, the embodiments are all described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments may be referred to each other.
The embodiments of the present invention have been described in detail, but the description is only for the preferred embodiments of the present invention and should not be construed as limiting the scope of the present invention. All equivalent changes and modifications made within the scope of the present invention should be covered by the present patent. After reading this disclosure, modifications of various equivalent forms of the present invention by those skilled in the art will fall within the scope of the present application, as defined in the appended claims. The embodiments and features of the embodiments of the present invention may be combined with each other without conflict.

Claims (7)

1. An integrated voltage peak-to-peak solving method of an IF circuit, the IF circuit being a charge balanced IF circuit, the IF circuit including an integrator (1) for converting an input current into an integrated voltage, an AD conversion circuit (2) for converting the integrated voltage into a digital value, a pulse calculation module (3) for calculating a pulse value using the digital value, characterized in that: the integrated voltage peak-to-peak value solving method of the IF circuit comprises the following steps:
(A) adding direct current excitation current to the input end of the integrator (1);
(B) collecting the pulse values of a pulse calculation module (3);
(C) calculating correction value U 'of peak-to-peak value of integrated voltage by using the following formula't
Figure FDA0002886349510000011
Wherein, UtFor a preset value of the integrated voltage peak-to-peak value of the IF circuit, B0The multiplying power of the module is calculated for the pulse,
Xh、Xlthe pulse values of the spikes in one charge-discharge cycle of the IF circuit,The average value of the pulse values of the IF circuit in one charging and discharging period except the pulse value of the peak, or the average value of the pulse values of the m peaks in the m charging and discharging periods of the IF circuit and the average value of the pulse values of the IF circuit except the pulse value of the m peaks in the m charging and discharging periods respectively, wherein m is more than or equal to 2;
the IF circuit has n frequency scale periods in each charging and discharging period, and the pulse calculation module (3) calculates a pulse value X corresponding to a sampling point of the (k + 1) th frequency scale period by using the following formulak+1
Figure FDA0002886349510000012
Wherein, Uk+1Output value, U, of AD conversion circuit collected for sampling point of k +1 frequency scale periodkThe output value of the AD conversion circuit collected for the sampling point of the kth frequency scale period, where a is the whole pulse count, and k is 1,2, … …;
if U isk+1>UthbIf a is-1; if U isk+1<UthaIf a is 1; if U istha<Uk+1<UthbIf a is 0;
wherein U isthb、UthaRespectively an upper limit threshold and a lower limit threshold of the integral voltage;
IF no peak which is regularly generated along with the charging and discharging period of the IF circuit appears in the collected pulse value, U't＝Ut。
2. The integrated voltage peak-to-peak solving method of the IF circuit according to claim 1, wherein: in the step (B), the sampling frequency f is usedaSampling time T acquires the pulse value, and the sampling time T is 1/faIntegral multiple of, frequency scale f0For sampling frequency faAn integer multiple.
3. The integrated voltage peak-to-peak solving method of the IF circuit according to claim 1, wherein: the direct current excitation current I is 0.01 mA.
4. The integrated voltage peak-to-peak solving method of the IF circuit according to claim 2, wherein: t60 s, fa＝f0＝2kHz。
5. An integrated voltage peak-to-peak solving device of an IF circuit, the IF circuit is a charge balance type IF circuit, and is characterized in that the IF circuit comprises an integrator (1) for converting an input current into an integrated voltage, an AD conversion circuit (2) for converting the integrated voltage into a digital value, and a pulse calculation module (3) for calculating a pulse value by using the digital value; the method is characterized in that: the device further comprises a solving module (4), wherein the solving module (4) is used for collecting the pulse value and calculating a correction value U 'of the peak-to-peak value of the integrated voltage by using the following formula't
Figure FDA0002886349510000021
Wherein, UtFor a preset value of the integrated voltage peak-to-peak value of the IF circuit, B0The multiplying power of the module is calculated for the pulse,
Xh、Xlthe peak pulse value in one charge-discharge period of the IF circuit, the average value of other pulse values except the peak pulse value in one charge-discharge period of the IF circuit, or the average value of m peak pulse values in m charge-discharge periods of the IF circuit, the average value of other pulse values except the m peak pulse values in m charge-discharge periods of the IF circuit are respectively, and m is more than or equal to 2;
the IF circuit has n frequency scale periods in each charging and discharging period, and the pulse calculation module (3) calculates a pulse value X corresponding to a sampling point of the (k + 1) th frequency scale period by using the following formulak+1
Figure FDA0002886349510000022
Wherein, Uk+1Output value, U, of AD conversion circuit collected for sampling point of k +1 frequency scale periodkThe output value of the AD conversion circuit collected for the sampling point of the kth frequency scale period, where a is the whole pulse count, and k is 1,2, … …;
if U isk+1>UthbIf a is-1; if U isk+1<UthaIf a is 1; if U istha<Uk+1<UthbIf a is 0;
wherein U isthb、UthaRespectively an upper limit threshold and a lower limit threshold of the integral voltage;
IF no peak which is regularly generated along with the charging and discharging period of the IF circuit appears in the collected pulse value, U't＝Ut。
6. The integrated voltage peak-to-peak solving device of the IF circuit according to claim 5, wherein: the IF circuit further comprises a comparator (6), a trigger (7), a switch circuit (9) and a constant current source (8) which are sequentially connected, wherein the input end of the comparator (6) and the output end of the constant current source (8) are respectively connected with the output end and the input end of the integrator (1), and the IF circuit further comprises a frequency scale generating module (5) for providing a frequency scale for the IF circuit.
7. The integrated voltage peak-to-peak solving device of the IF circuit according to claim 5, wherein: an excitation current generating module (20) is also included for adding a direct excitation current to the IF circuit.
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