CN109541990A - A kind of resonant electromagnetism tuning fork chopper auto gain control method - Google Patents
A kind of resonant electromagnetism tuning fork chopper auto gain control method Download PDFInfo
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- CN109541990A CN109541990A CN201811258729.3A CN201811258729A CN109541990A CN 109541990 A CN109541990 A CN 109541990A CN 201811258729 A CN201811258729 A CN 201811258729A CN 109541990 A CN109541990 A CN 109541990A
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- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
- G05B19/00—Programme-control systems
- G05B19/02—Programme-control systems electric
- G05B19/04—Programme control other than numerical control, i.e. in sequence controllers or logic controllers
- G05B19/042—Programme control other than numerical control, i.e. in sequence controllers or logic controllers using digital processors
- G05B19/0423—Input/output
Abstract
The present invention provides a kind of resonant electromagnetism tuning fork chopper auto gain control methods, by the symmetric block signal that FPGA and D/A converter output amplitude are controllable, frequency is tuning fork natural reonant frequency, it is exported after unit gain power amplification to the driving end of tuning fork chopper, the feedback signal for being able to reflect the real-time amplitude of tuning fork of tuning fork chopper induction end output is received simultaneously, and preposition amplification, bandpass filtering and peak detection are carried out to the signal；Crest voltage is sampled by converter and FPGA, FPGA is exported according to the dynamic adjustment of the difference of crest voltage and target voltage to the code value of D/A converter, control square wave signal amplitude, the frequency of square-wave signal is controlled by FPGA and is generated, it can guarantee the reliable starting of oscillation of various tuning forks and always work under natural reonant frequency, the amplitude of square-wave signal then uses auto gain control method, periodic detection tuning fork amplitude and as needed adjustment in time, it is ensured that the high amplitude stability of tuning fork chopper.
Description
Technical field
The present invention relates to technical field of photoelectric detection, and in particular to a kind of resonant electromagnetism tuning fork chopper automatic gain control
Method processed.
Background technique
It is faint usually to be carried on the back by a large amount of noise such as stray light, electronic noise to light signal in photoelectric detecting system
Scape is fallen into oblivion.In order to extract measured signal from ambient noise, the faint letter such as synchronous detection, phase sensitive detection is widely used
Number detection technique.Using chopper to the alternation for being modulated by light signal, direct current optical signal being made to become having frequecy characteristic
Signal is then the necessary means of this kind of Technique of Weak Signal Detection.Resonant electromagnetism tuning fork chopper have it is small in size, low in energy consumption,
The advantage that stability is high and anti shock and vibration ability is strong.
In resonant electromagnetism tuning fork chopper in use, stability in order to guarantee frequency and amplitude, does not use generally
The method that signal generator or open loop self-oscillation directly drive, but by analog circuit construct closed-loop control system, not by
The external world provides driving signal, and relies on tuning fork self-oscillation starting of oscillation and maintain to vibrate, adjusted later by the closed-loop control of circuit,
Stabilized amplitude.But since tuning fork parameter itself is difficult to accurately obtain in practical application, theoretical calculation go out self-exciting contion often without
Method makes tuning fork starting of oscillation, needs that circuit parameter is changed and attempted repeatedly.
The tuning fork different for natural reonant frequency needs individually to calculate and debugging or even natural reonant frequency are identical, criticizes
Secondary different tuning fork is completely the same since production technology not can guarantee its parameters, it is also difficult to the work under same group of circuit parameter
Make.This makes the driving circuit structure complex of resonant electromagnetism tuning fork chopper, debugging difficulty, research and development at high cost.Therefore,
Guarantee fork frequency and while amplitude stability, invents a kind of simple and effective, the resonant electromagnetism tuning fork of strong applicability is cut
Light device control method is those skilled in the art's urgent problem.
Summary of the invention
The embodiment of the invention provides a kind of resonant electromagnetism tuning fork chopper auto gain control methods, according to target width
It is worth the amplitude of the natural reonant frequency signal of dynamic regulation D/A converter output, realizes the automatic growth control of tuning fork.
The present invention provides a kind of resonant electromagnetism tuning fork chopper auto gain control method, which comprises
On-site programmable gate array FPGA exports the first code value and the second code value to D/A converter, will first code value with
Second code value is determined as one group of code value, and the update cycle of every group of code value is the target tuning fork natural reonant frequency period, and described first
Code value is greater than the second code value；
First code value and second code value are converted to voltage value by the D/A converter, and export required type
Square-wave signal；
Unit gain class AB complementary symmetry power amplifier is carried out to the square-wave signal, is obtained intrinsic with the tuning fork chopper
The identical tuning fork driving signal of resonant frequency exports the tuning fork driving signal to the driving end of tuning fork chopper；
Is produced from the induction end of tuning fork chopper starting of oscillation under the driving of the tuning fork driving signal, the tuning fork chopper
Raw inductive signal；
Preposition amplification and bandpass filtering are carried out to the inductive signal, the centre frequency of adjustment bandpass filtering unit is tuning fork
Natural reonant frequency obtains sine wave signal only comprising tuning fork natural reonant frequency ingredient；
The voltage peak of the sine wave signal is detected using peak detection unit, and converter is controlled by the FPGA
Voltage sample is carried out, voltage peak is obtained, the voltage peak and tuning fork amplitude are positively correlated；
Sampling is obtained voltage peak to the FPGA and target amplitude is compared, and is turned according to comparison result to the DA
Parallel operation is adjusted, to complete the automatic growth control of the tuning fork chopper.
As a kind of optional scheme, sampling is obtained voltage peak to the FPGA and target amplitude is compared, and root
The D/A converter is adjusted according to comparison result, comprising:
Sampling is obtained voltage peak to the FPGA and target amplitude is compared, when the voltage peak is less than target width
The FPGA then is adjusted according to difference when value to export to the code value of the D/A converter, increases the reduction the of the first code value and equivalent
Two code values, so that the peak-to-peak value of the square-wave signal of D/A converter output increases.
As a kind of optional scheme, sampling is obtained voltage peak to the FPGA and target amplitude is compared, and root
The D/A converter is adjusted according to comparison result, comprising:
Sampling is obtained voltage peak to the FPGA and target amplitude is compared, when the voltage peak is greater than target width
The FPGA then is adjusted according to difference when value to export to the code value of the D/A converter, increases the reduction the of the second code value and equivalent
One code value, so that the peak-to-peak value of the square-wave signal of D/A converter output reduces.
As a kind of optional scheme, sampling is obtained voltage peak to the FPGA and target amplitude is compared, and root
The D/A converter is adjusted according to comparison result, comprising:
Sampling is obtained voltage peak to the FPGA and target amplitude is compared, when voltage peak is identical with target amplitude
When keep the code value of presently described FPGA output constant.
As a kind of optional scheme, the FPGA is less than the update week of every group of code value to the sampling period of voltage peak
Phase.
As a kind of optional scheme, required type be waveform duty cycle be 50%, frequency be tuning fork natural reonant frequency,
Positive negative peak is voltage value corresponding to the first code value and the second code value and absolute value is identical.
As a kind of optional scheme, the method also includes:
It is corresponding to adjust the FPGA output first if the difference for detecting the voltage peak and the target amplitude is B1
Code value and the second code value make peak-to-peak value changing value B2, the then B2=K*B1 of D/A converter output square wave, wherein K be constant or
Variable.
As can be seen from the above technical solutions, the embodiment of the present invention has the advantage that
The present invention provides a kind of resonant electromagnetism tuning fork chopper auto gain control methods, by FPGA and D/A converter
The symmetric block signal that output amplitude is controllable, frequency is tuning fork natural reonant frequency, exported after unit gain power amplification to
The driving end of tuning fork chopper, while receiving the feedback letter for being able to reflect the real-time amplitude of tuning fork of tuning fork chopper induction end output
Number, and preposition amplification, bandpass filtering and peak detection are carried out to the signal；Crest voltage is adopted by converter and FPGA
Sample, FPGA, to the code value of D/A converter, control square-wave signal according to the dynamic adjustment output of the difference of crest voltage and target voltage
Amplitude, the frequency of square-wave signal is controlled by FPGA to be generated, it is ensured that the reliable starting of oscillation of various tuning forks simultaneously always works in intrinsic
Under resonant frequency, the amplitude of square-wave signal then uses auto gain control method, periodic detection tuning fork amplitude and as needed and
When adjust, it is ensured that the high amplitude stability of tuning fork chopper.
Detailed description of the invention
Fig. 1 is the flow chart of resonant electromagnetism tuning fork chopper auto gain control method provided by the invention；
Fig. 2 is the structural schematic diagram for the resonant electromagnetism tuning fork chopper that the present invention uses；
Fig. 3 is that D/A converter exports sound in resonant electromagnetism tuning fork chopper auto gain control method provided by the invention
Pitch the waveform diagram of driving signal；
Fig. 4 is the structural block diagram of resonant electromagnetism tuning fork chopper AGC system provided by the invention.
Specific embodiment
In order to enable those skilled in the art to better understand the solution of the present invention, below in conjunction in the embodiment of the present invention
Attached drawing, technical scheme in the embodiment of the invention is clearly and completely described, it is clear that described embodiment is only
The embodiment of a part of the invention, instead of all the embodiments.Based on the embodiments of the present invention, ordinary skill people
The model that the present invention protects all should belong in member's every other embodiment obtained without making creative work
It encloses.
Description and claims of this specification and term " first ", " second ", " third ", " in above-mentioned attached drawing
Four " etc. be to be used to distinguish similar objects, without being used to describe a particular order or precedence order.It should be understood that using in this way
Data be interchangeable under appropriate circumstances, so that the embodiments described herein can be in addition to illustrating herein or describing
Sequence other than appearance is implemented.In addition, term " includes " and " having " and their any deformation, it is intended that covering is non-exclusive
Include, for example, the process, method, system, product or equipment for containing a series of steps or units are not necessarily limited to clearly arrange
Those of out step or unit, but may include be not clearly listed or it is solid for these process, methods, product or equipment
The other step or units having.
In conjunction with shown in Fig. 1,2 and 3, the present invention provides a kind of resonant electromagnetism tuning fork chopper auto gain control method,
The described method includes:
S101, on-site programmable gate array FPGA export the first code value and the second code value to D/A converter, by described first
Code value and the second code value are determined as one group of code value, and the update cycle of every group of code value is target tuning fork natural reonant frequency period, institute
The first code value is stated greater than the second code value.
D/A converter, that is, digital analog converter, FPGA exports the first code value and the second code value to D/A converter, by described first
Code value and the second code value are defined as one group of code value, and the update cycle of every group of code value is the target tuning fork natural reonant frequency period, the
One code value is greater than the second code value.
First code value and second code value are converted to voltage value by S102, the D/A converter, and needed for output
The square-wave signal of type.
First code value and second code value are converted to voltage value by D/A converter, and are exported to power amplification unit
The square-wave signal of required type, duty ratio 50%, the frequency of square-wave signal are tuning fork natural reonant frequency, positive negative peak is first
Code value and voltage value corresponding to the second code value of code and its absolute value is identical, i.e. the first code value and the second code value of code are positive and negative right
Claim.
S103, unit gain class AB complementary symmetry power amplifier is carried out to the square-wave signal, obtained and the tuning fork chopping the light
The identical tuning fork driving signal of device natural reonant frequency exports the tuning fork driving signal to the driving end of tuning fork chopper.
Power amplification unit uses unit gain class AB complementary symmetry power amplifier circuit, carries out unit gain to square-wave signal
Class AB complementary symmetry power amplifier obtains tuning fork driving signal identical with the tuning fork chopper natural reonant frequency, by the sound
Fork driving signal is exported to the driving end of tuning fork chopper, and tuning fork chopper has driving end and induction end.
S104, tuning fork chopper starting of oscillation under the driving of the tuning fork driving signal, the tuning fork chopper lure
It leads end and generates inductive signal.
Because tuning fork driving signal is identical with tuning fork chopper natural reonant frequency, tuning fork chopper can be risen rapidly
Vibration, the starting of oscillation speed of tuning fork with start power up after the first code value A and the second code value B initial value it is related, that FPGA is exported
One code value A and the second code value B is set as the maximum code value and minimum code value of D/A converter, the initial driving that tuning fork can be made to obtain
Signal is most strong, to realize the fast start-up of tuning fork, and generates inductive signal at induction end, it should be noted that tuning fork starting of oscillation
The inductive signal of induction end output has a process from small to large, therefore even if the Voltage Peak that preceding FPGA several times is sampled afterwards
Value is less than target amplitude, if the first code value A and the second code value B have been the maximum code value and minimum code value of D/A converter,
Need to only FPGA be maintained currently to export code value.
S105, preposition amplification and bandpass filtering are carried out to the inductive signal, adjusts the centre frequency of bandpass filtering unit
For tuning fork natural reonant frequency, sine wave signal only comprising tuning fork natural reonant frequency ingredient is obtained.
Inductive signal is exported by induction end to pre-amplifier unit as feedback signal, using pre-amplifier unit to induction
Output to bandpass filtering unit, bandpass filtering unit carries out bandpass filtering, adjustment to inductive signal after signal carries out preposition amplification
The centre frequency of bandpass filtering unit is tuning fork natural reonant frequency, obtains sine only comprising tuning fork natural reonant frequency ingredient
Wave signal.
S106, the voltage peak that the sine wave signal is detected using peak detection unit, and AD is controlled by the FPGA
Converter carries out voltage sample, obtains voltage peak, and the voltage peak and tuning fork amplitude are positively correlated.
Peak detection unit can be using peak detection circuit realization, converter, that is, analog-digital converter, peak detection list
Member detects the voltage peak of sine wave signal, and converter is under the control of FPGA to the Voltage Peak of peak detection unit
Value carries out voltage sample, sampling period T, and the size and tuning fork amplitude of voltage peak are positively correlated, can directly reflect the moment
The oscillator intensity of tuning fork.
S107, sampling is obtained voltage peak to the FPGA and target amplitude is compared, and according to comparison result to institute
It states D/A converter to be adjusted, to complete the automatic growth control of the tuning fork chopper.
Sampling is obtained voltage peak to FPGA and target amplitude is compared, when the voltage peak is less than target amplitude
The FPGA then is adjusted according to difference to export to the code value of the D/A converter, increases the reduction second code of the first code value and equivalent
Value, so that the peak-to-peak value of the square-wave signal of D/A converter output increases, the then basis when the voltage peak is greater than target amplitude
Difference adjusts the FPGA and exports to the code value of the D/A converter, increases the first code value of reduction of the second code value and equivalent, makes
The peak-to-peak value for obtaining the square-wave signal of D/A converter output reduces, and keeps presently described when voltage peak is identical with target amplitude
The code value of FPGA output is constant.
FPGA dynamic adjustment is to export the variation of code value size and the first code value A and the second code value B always equivalent, often
Group code value update cycle remain unchanged, with guarantee DA output waveform be always frequency it is identical as the natural reonant frequency of tuning fork and
The square wave of Symmetrical.
In the present embodiment, FPGA should be less than the update cycle of every group of code value to the sampling period T of voltage peak V1, to guarantee
The timeliness of amplitude control.
If detecting, the difference of voltage peak V1 and target amplitude V2 are B1, corresponding adjustment FPGA export the first code value A and
Second code value B makes the peak-to-peak value changing value B2 of D/A converter output square wave, then B2=K*B1, and wherein K can be constant,
It can be the variable adjusted according to certain established rule, specific setting will be according to desired adjustment speed, degree of regulation, FPGA
Resource situation etc. is comprehensively considered.If K is constant, amplitude control is linear regulation, and, occupancy fast to adjustment speed provides
Source is few just to increase K, is reduced by K to degree of regulation height, but can accordingly reduce adjustment speed.If K is variable, there are a variety of
The control method of multiplicity, such as: when the difference of V1 and V2 is greater than V3, K=K1 is set；When the difference of V1 and V2 is greater than V4,
K=K2 is set；And so on, difference just increases greatly K value, keeps adjustment speed fast, and difference is small to be reduced by K value, and keep degree of regulation high,
By the way that multiple sections are rationally arranged, nonlinear Control is carried out to amplitude, or even some advanced control algorithms such as PID can be added, it can
To realize that the high speed to tuning fork chopper, high-precision amplitude control with a small amount of resource.Therefore, the selection of K value is varied, can
To combine with many algorithms, designer can do secondary development on this basis.
The present invention provides a kind of resonant electromagnetism tuning fork chopper auto gain control methods, by FPGA and D/A converter
The symmetric block signal that output amplitude is controllable, frequency is tuning fork natural reonant frequency, exported after unit gain power amplification to
The driving end of tuning fork chopper, while receiving the feedback letter for being able to reflect the real-time amplitude of tuning fork of tuning fork chopper induction end output
Number, and preposition amplification, bandpass filtering and peak detection are carried out to the signal；Crest voltage is adopted by converter and FPGA
Sample, FPGA, to the code value of D/A converter, control square-wave signal according to the dynamic adjustment output of the difference of crest voltage and target voltage
Amplitude, the frequency of square-wave signal is controlled by FPGA to be generated, it is ensured that the reliable starting of oscillation of various tuning forks simultaneously always works in intrinsic
Under resonant frequency, the amplitude of square-wave signal then uses auto gain control method, periodic detection tuning fork amplitude and as needed and
When adjust, it is ensured that the high amplitude stability of tuning fork chopper.
A kind of resonant electromagnetism tuning fork chopper auto gain control method is also provided in the embodiment of the present invention, including following
Step:
Step 201 is greater than the by the first code value A and the second code value B, the first code value A of FPGA alternately output D/A converter
Two code value B, and it is defined as one group of code value, the update cycle of every group of code value is the target tuning fork natural reonant frequency period, so
Step 202 is executed afterwards；
The FPGA code value exported is converted to voltage value by step 202:DA converter, so that D/A converter output waveform is to account for
Sky than 50%, frequency is tuning fork natural reonant frequency, positive negative peak is code value A and code value B corresponding to voltage value and its absolutely
It is worth identical square-wave signal A1, then executes step 203；
Step 203 carries out unit gain class AB complementary symmetry power amplifier to square-wave signal A1, obtains tuning fork driving signal
Then A2, output to the driving end of tuning fork chopper execute step 204；
Step 204, driving signal A2 are identical as tuning fork chopper natural reonant frequency, therefore tuning fork chopper can drive
The rapid starting of oscillation of meeting under the driving of signal A2, and inductive signal A3 is generated at induction end, then execute step 205；
Step 205 carries out preposition amplification and bandpass filtering to inductive signal A3, and by the centre frequency of bandpass filtering unit
It is set as tuning fork natural reonant frequency, sine wave signal A4 only comprising tuning fork natural reonant frequency ingredient is obtained, then executes
Step 206；
Step 206, the voltage peak V1 that sine wave signal A4 is detected using peak detection unit, and AD is controlled by FPGA
Converter carries out voltage sample, and the size and tuning fork amplitude of sampling period T, voltage peak V1 are positively correlated, can directly reflect
Then the oscillator intensity of the moment tuning fork executes step 207；
The voltage peak V1 that sampling obtains is compared by step 207, FPGA with target amplitude V2, if voltage peak V1 is small
The code value for being output to D/A converter is then accordingly adjusted according to difference in target amplitude V2, increases subtracting for the first code value A simultaneous equal
Small second code value B increases the peak-to-peak value of DA output square wave；It is corresponding according to difference if voltage peak V1 is greater than second voltage V2
Adjustment output code value, increases reduction the first code value A of the second code value B simultaneous equal, reduces the peak-to-peak value of DA output square wave；Directly
It is identical as target amplitude V2 to voltage peak V1, then keep current output code value constant.Circulation executes step I to VII, persistently examines
The difference of acoustic fork amplitude and target amplitude simultaneously adjusts in time, realizes the automatic growth control of tuning fork chopper.
Resonant electromagnetism tuning fork chopper auto gain control method provided by the invention, the natural resonance of tuning fork chopper
Frequency signal is generated by FPGA, it is ensured that the reliable starting of oscillation of tuning fork avoids and needs debug circuit parameter repeatedly in analog closed-loop
So that it meets the problem of tuning fork self-oscillation condition, debugging process and circuit complexity are enormously simplified.For different sounds
Fork only needs to modify in FPGA software the code value update cycle, makes the natural reonant frequency signal of its output frequency signal tuning fork i.e.
Effective driving to various tuning forks can be achieved.For because the reasons such as production technology cause different batches tuning fork natural reonant frequency with
The discrepant situation of nominal value, can be by finely tuning the FPGA code value update cycle, it is easy to make to export square wave frequency and tuning fork is solid
There is resonant frequency consistent.Component must just be replaced, debug the problem of hardware circuit, applicability again by avoiding replacement tuning fork
By force.For different tuning fork chopper target amplitudes, the target code value in FPGA software need to be only modified, FPGA can shake to tuning fork
Width carries out automatic growth control, voluntarily adjusts slit maximum width when tuning fork folding, so that effectively control reaches detector
Light signal strength is to meet a variety of detection demands.The natural reonant frequency of resonant electromagnetism tuning fork chopper generally 1kHz with
Under, frequency is very low for FPGA, it is easy to realize the accurate control and adjustment of frequency；The amplitude stability of output signal by
The performance of D/A converter determines, therefore the precision of the fork frequency and amplitude in the present invention and stability are controllable, expectable, can
To realize the long-time high stability oscillation of tuning fork chopper.
As shown in connection with fig. 4, correspondingly, the present invention provides a kind of resonant electromagnetism tuning fork chopper automatic growth control system
System, can execute previously described resonant electromagnetism tuning fork chopper auto gain control method, the system comprises scenes can
Program gate array FPGA, D/A converter, power amplification unit, converter, peak detection unit, bandpass filtering unit and preceding
Put big unit, the FPGA thinks that the D/A converter exports the first code value and the second code value, and the D/A converter is by described the
The square-wave signal of type needed for one code value and second code value are converted to voltage value and export carries out the square-wave signal single
Position gain class AB complementary symmetry power amplifier, obtains tuning fork driving signal identical with the tuning fork chopper natural reonant frequency,
The tuning fork driving signal is exported to the driving end of tuning fork chopper, the tuning fork chopper is in the tuning fork driving signal
Lower starting of oscillation is driven, the induction end of the tuning fork chopper generates inductive signal, and the pre-amplifier unit is to the inductive signal
Output to the bandpass filtering unit, the bandpass filtering unit carries out bandpass filtering to inductive signal after carrying out preposition amplification,
The centre frequency for adjusting bandpass filtering unit is tuning fork natural reonant frequency, obtains only including tuning fork natural reonant frequency ingredient
Sine wave signal is simultaneously exported to the peak detection unit, and the electricity of the sine wave signal is detected using the peak detection unit
Voltage crest value, and the converter is controlled by the FPGA, voltage sample is carried out to the peak detection unit, obtain Voltage Peak
Value, the voltage peak and tuning fork amplitude are positively correlated, and sampling is obtained voltage peak to the FPGA and target amplitude is compared,
And the D/A converter is adjusted according to comparison result, to complete the automatic growth control of the tuning fork chopper.
The FPGA is specifically used for sample obtaining voltage peak and target amplitude is compared, when the voltage peak is small
The FPGA then is adjusted according to difference when target amplitude to export to the code value of the D/A converter, increases the first code value and equivalent
The second code value of reduction so that D/A converter output square-wave signal peak-to-peak value increase, when the voltage peak be greater than target
The FPGA then is adjusted according to difference when amplitude to export to the code value of the D/A converter, increases the reduction of the second code value and equivalent
First code value is protected so that the peak-to-peak value of the square-wave signal of D/A converter output reduces when voltage peak is identical with target amplitude
The code value for holding presently described FPGA output is constant.
Required type be waveform duty cycle be 50%, frequency is tuning fork natural reonant frequency, positive negative peak is the first code value
It is identical with voltage value corresponding to the second code value and absolute value.
In infrared band detection, using the CH10-90D-500Hz type electromagnetic type tuning fork chopper pair of EOPC company, the U.S.
The optical signal being irradiated on indium gallium arsenic detector is modulated.Selected FPGA is the Virtex-2 series of Xilinx company
2V3000；Selected D/A converter is 12 D/A converter AD667 of ADI company, inputs code value 000HAnd FFFHIt respectively corresponds defeated
- 10V and+10V voltage out.Therefore, the present invention provides a kind of tool of resonant electromagnetism tuning fork chopper AGC system
Body method is as follows:
S1,000 is alternately exported by FPGAHAnd FFFHTo D/A converter, the update cycle of every group of code value is the intrinsic total of tuning fork
Vibration frequency period 2ms, then executes S2；
The FPGA code value exported is converted to voltage value by S2, D/A converter AD667, keeps working as before next group of code value updates
Preceding output makes the output duty ratio of D/A converter be 50%, the square-wave signal A1 that frequency 500Hz, peak-to-peak value are ± 10V,
Then S3 is executed；
S3, unit gain class AB complementary symmetry power amplifier is carried out to square-wave signal A1, enhances its driving capability, obtains tuning fork
Driving signal A2 exports to the driving end of tuning fork chopper, then executes S4；
The rapid starting of oscillation of meeting under the driving of A2 signal of S4, tuning fork chopper, and inductive signal A3 is generated at induction end, then
Execute S5；
S5, pre-amplifier unit and bandpass filtering unit carry out preposition amplification, bandpass filtering to inductive signal A3, by band logical
The centre frequency of filter unit is set as tuning fork natural reonant frequency, obtains sine only comprising tuning fork natural reonant frequency ingredient
Wave signal A4, then executes S6；
S6, the voltage peak V1 that sine wave signal A4 is detected using peak detection unit, and AD conversion is controlled by FPGA
Device carries out voltage sample, and the size and tuning fork amplitude of sampling period T, voltage peak V1 are positively correlated, when can directly reflect this
The oscillator intensity for carving tuning fork, then executes S7；
The voltage peak V1 that sampling obtains is compared by S7, FPGA with target amplitude V2, according to difference if V1 is less than V2
Value accordingly adjusts the code value for being output to D/A converter, increases the reduction code value B of code value A simultaneous equal, makes the peak of DA output square wave
Peak value increases；Output code value is accordingly adjusted according to difference if V1 is greater than V2, increases the reduction code value A of code value B simultaneous equal, makes
The peak-to-peak value that DA exports square wave reduces.Such as: by code value 000HAnd FFFHIt is changed to 100HAnd EFFH, then the square wave of DA output is corresponded to
Peak-to-peak value is reduced to ± 9.512V by ± 10V；Until V1 is identical as V2, then holding is current exports code value.Circulation executes S1 to S7,
It persistently detects the difference of tuning fork amplitude and target amplitude and adjusts in time, realize the automatic growth control of tuning fork chopper.
When tuning fork causes its amplitude to become smaller due to certain external interferences, induction end output signal A3 reduces, is filtered
Sine wave signal A4 reduces, the voltage peak V1 of detection reduces, becomes larger with the difference of target amplitude V2, then adjusts FPGA output code
Value makes DA output square-wave signal A1 and output to tuning fork chopper that the driving signal A2 at end be driven to become larger, to make tuning fork amplitude
Become larger, come back to default amplitude, completes automatic growth control.
In the present embodiment, FPGA is less than the update cycle of every group of code value to the sampling period of voltage peak, to guarantee amplitude
The timeliness of control.
The present invention provides a kind of resonant electromagnetism tuning fork chopper AGC systems, by FPGA and D/A converter
The symmetric block signal that output amplitude is controllable, frequency is tuning fork natural reonant frequency, exported after unit gain power amplification to
The driving end of tuning fork chopper；The feedback letter for being able to reflect the real-time amplitude of tuning fork of tuning fork chopper induction end output is received simultaneously
Number, and preposition amplification, bandpass filtering and peak detection are carried out to the signal；Crest voltage is adopted by converter and FPGA
Sample；FPGA, to the code value of D/A converter, controls square-wave signal according to the dynamic adjustment output of the difference of crest voltage and target voltage
Amplitude.The frequency of square-wave signal is controlled by FPGA and is generated, it is ensured that the reliable starting of oscillation of various tuning forks simultaneously always works in intrinsic
Under resonant frequency；The amplitude of square-wave signal then uses auto gain control method, periodic detection tuning fork amplitude and as needed and
When adjust, it is ensured that the high amplitude stability of tuning fork chopper.
It is apparent to those skilled in the art that for convenience and simplicity of description, the system of foregoing description,
The specific work process of device and unit, can refer to corresponding processes in the foregoing method embodiment, and details are not described herein.
In several embodiments provided herein, it should be understood that disclosed system, device and method can be with
It realizes by another way.For example, the apparatus embodiments described above are merely exemplary, for example, the unit
It divides, only a kind of logical function partition, there may be another division manner in actual implementation, such as multiple units or components
It can be combined or can be integrated into another system, or some features can be ignored or not executed.Another point, it is shown or
The mutual coupling, direct-coupling or communication connection discussed can be through some interfaces, the indirect coupling of device or unit
It closes or communicates to connect, can be electrical property, mechanical or other forms.
The unit as illustrated by the separation member may or may not be physically separated, aobvious as unit
The component shown may or may not be physical unit, it can and it is in one place, or may be distributed over multiple
In network unit.It can select some or all of unit therein according to the actual needs to realize the mesh of this embodiment scheme
's.
It, can also be in addition, the functional units in various embodiments of the present invention may be integrated into one processing unit
It is that each unit physically exists alone, can also be integrated in one unit with two or more units.Above-mentioned integrated list
Member both can take the form of hardware realization, can also realize in the form of software functional units.
Those of ordinary skill in the art will appreciate that all or part of the steps in the various methods of above-described embodiment is can
It is completed with instructing relevant hardware by program, which can be stored in a computer readable storage medium, storage
Medium may include: read-only memory (ROM, Read Only Memory), random access memory (RAM, Random
Access Memory), disk or CD etc..
A kind of resonant electromagnetism tuning fork chopper auto gain control method provided by the present invention has been carried out in detail above
Thin to introduce, for those of ordinary skill in the art, thought according to an embodiment of the present invention in specific embodiment and applies model
Place that there will be changes, in conclusion the contents of this specification are not to be construed as limiting the invention.
Claims (7)
1. a kind of resonant electromagnetism tuning fork chopper auto gain control method, which is characterized in that the described method includes:
On-site programmable gate array FPGA exports the first code value and the second code value to D/A converter, by first code value and second
Code value is determined as one group of code value, and the update cycle of every group of code value is target tuning fork natural reonant frequency period, first code value
Greater than the second code value；
First code value and second code value are converted to voltage value by the D/A converter, and export the square wave of required type
Signal；
Unit gain class AB complementary symmetry power amplifier is carried out to the square-wave signal, is obtained and the tuning fork chopper natural resonance
The identical tuning fork driving signal of frequency exports the tuning fork driving signal to the driving end of tuning fork chopper；
The induction end of tuning fork chopper starting of oscillation under the driving of the tuning fork driving signal, the tuning fork chopper generates sense
Induction signal；
Preposition amplification and bandpass filtering are carried out to the inductive signal, the centre frequency of adjustment bandpass filtering unit is that tuning fork is intrinsic
Resonant frequency obtains sine wave signal only comprising tuning fork natural reonant frequency ingredient；
The voltage peak of the sine wave signal is detected using peak detection unit, and is carried out by FPGA control converter
Voltage sample, obtains voltage peak, and the voltage peak and tuning fork amplitude are positively correlated；
Sampling is obtained voltage peak to the FPGA and target amplitude is compared, and according to comparison result to the D/A converter
It is adjusted, to complete the automatic growth control of the tuning fork chopper.
2. resonant electromagnetism tuning fork chopper auto gain control method according to claim 1, which is characterized in that described
Sampling is obtained voltage peak to FPGA and target amplitude is compared, and is adjusted according to comparison result to the D/A converter
It is whole, comprising:
Sampling is obtained voltage peak to the FPGA and target amplitude is compared, when the voltage peak is less than target amplitude
The FPGA then is adjusted according to difference to export to the code value of the D/A converter, increases the reduction second code of the first code value and equivalent
Value, so that the peak-to-peak value of the square-wave signal of D/A converter output increases.
3. resonant electromagnetism tuning fork chopper auto gain control method according to claim 1, which is characterized in that described
Sampling is obtained voltage peak to FPGA and target amplitude is compared, and is adjusted according to comparison result to the D/A converter
It is whole, comprising:
Sampling is obtained voltage peak to the FPGA and target amplitude is compared, when the voltage peak is greater than target amplitude
The FPGA then is adjusted according to difference to export to the code value of the D/A converter, increases first yard of reduction of the second code value and equivalent
Value, so that the peak-to-peak value of the square-wave signal of D/A converter output reduces.
4. resonant electromagnetism tuning fork chopper auto gain control method according to claim 1, which is characterized in that described
Sampling is obtained voltage peak to FPGA and target amplitude is compared, and is adjusted according to comparison result to the D/A converter
It is whole, comprising:
Sampling is obtained voltage peak to the FPGA and target amplitude is compared, and protects when voltage peak is identical with target amplitude
The code value for holding presently described FPGA output is constant.
5. resonant electromagnetism tuning fork chopper auto gain control method according to claim 1, which is characterized in that described
FPGA is less than the update cycle of every group of code value to the sampling period of voltage peak.
6. resonant electromagnetism tuning fork chopper auto gain control method according to claim 1, which is characterized in that required
Type be waveform duty cycle be 50%, frequency is tuning fork natural reonant frequency, positive negative peak is the first code value and the second code value institute
Corresponding voltage value and absolute value is identical.
7. resonant electromagnetism tuning fork chopper auto gain control method according to claim 1, which is characterized in that described
Method further include:
It is corresponding to adjust the first code value of the FPGA output if the difference for detecting the voltage peak and the target amplitude is B1
With the second code value, make the peak-to-peak value changing value B2 of D/A converter output square wave, then B2=K*B1, wherein K is constant or variable.
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Citations (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0199217A2 (en) * | 1985-04-25 | 1986-10-29 | Westinghouse Electric Corporation | Phase locked stepper motor controlled light chopper |
| EP0430661A2 (en) * | 1989-11-30 | 1991-06-05 | Hamamatsu Photonics K.K. | Apparatus for detecting a change in light intensity |
| WO1996014687A1 (en) * | 1994-11-07 | 1996-05-17 | Matsushita Electric Industrial Co., Ltd. | Piezoelectric actuator and pyroelectric infrared-ray sensor using the same |
| JP2000342354A (en) * | 1999-06-02 | 2000-12-12 | Kokuyo Co Ltd | Safety mechanism of moving rack device |
| KR20060004003A (en) * | 2004-07-06 | 2006-01-12 | 김성호 | Precision chopping device for diagnostic instrument for helicobacter pylori with photoacoustic spectroscopy |
| CN101034056A (en) * | 2007-04-02 | 2007-09-12 | 云南瑞升烟草技术（集团）有限公司 | Device of quick measuring moisture content of cigarette materials |
| CN101118181A (en) * | 2007-07-26 | 2008-02-06 | 西安劳特电子有限责任公司 | Diapason resonant vibration type episcotister |
| WO2008026183A1 (en) * | 2006-08-31 | 2008-03-06 | Koninklijke Philips Electronics N.V. | Cavity-enhanced photo acoustic trace gas detector with improved feedback loop |
| CN103107780A (en) * | 2012-12-26 | 2013-05-15 | 清华大学深圳研究生院 | Chopping amplifier |
| CN103117662A (en) * | 2013-03-08 | 2013-05-22 | 滁州学院 | PWM (pulse width modulation) chopping NC (numerical control) AC (Alternating Current) power supply |
| CN104181402A (en) * | 2014-08-18 | 2014-12-03 | 国家电网公司 | Direct-current electric field detecting device used under condition of hybrid electric field |
| CN204256263U (en) * | 2014-10-16 | 2015-04-08 | 西安毅达信息***有限公司 | A kind of intelligent precise tuning fork chopper |
| CN204359370U (en) * | 2014-12-23 | 2015-05-27 | 重庆川仪自动化股份有限公司 | Ultrasonic Wave Flowmeter receive MUT signal intensity AGC (automatic gain control) system |
| CN104709699A (en) * | 2014-11-10 | 2015-06-17 | 昆山鸿吉瑞精密机械有限公司 | Voltage regulating type vibration disc controller |
| CN107271368A (en) * | 2017-05-23 | 2017-10-20 | 哈尔滨工业大学 | A kind of interior cavity-enhanced photo acoustic spectrum-type trace-gas sensors device |
-
2018
- 2018-10-26 CN CN201811258729.3A patent/CN109541990B/en active Active
Patent Citations (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0199217A2 (en) * | 1985-04-25 | 1986-10-29 | Westinghouse Electric Corporation | Phase locked stepper motor controlled light chopper |
| EP0430661A2 (en) * | 1989-11-30 | 1991-06-05 | Hamamatsu Photonics K.K. | Apparatus for detecting a change in light intensity |
| WO1996014687A1 (en) * | 1994-11-07 | 1996-05-17 | Matsushita Electric Industrial Co., Ltd. | Piezoelectric actuator and pyroelectric infrared-ray sensor using the same |
| JP2000342354A (en) * | 1999-06-02 | 2000-12-12 | Kokuyo Co Ltd | Safety mechanism of moving rack device |
| KR20060004003A (en) * | 2004-07-06 | 2006-01-12 | 김성호 | Precision chopping device for diagnostic instrument for helicobacter pylori with photoacoustic spectroscopy |
| WO2008026183A1 (en) * | 2006-08-31 | 2008-03-06 | Koninklijke Philips Electronics N.V. | Cavity-enhanced photo acoustic trace gas detector with improved feedback loop |
| CN101034056A (en) * | 2007-04-02 | 2007-09-12 | 云南瑞升烟草技术（集团）有限公司 | Device of quick measuring moisture content of cigarette materials |
| CN101118181A (en) * | 2007-07-26 | 2008-02-06 | 西安劳特电子有限责任公司 | Diapason resonant vibration type episcotister |
| CN103107780A (en) * | 2012-12-26 | 2013-05-15 | 清华大学深圳研究生院 | Chopping amplifier |
| CN103117662A (en) * | 2013-03-08 | 2013-05-22 | 滁州学院 | PWM (pulse width modulation) chopping NC (numerical control) AC (Alternating Current) power supply |
| CN104181402A (en) * | 2014-08-18 | 2014-12-03 | 国家电网公司 | Direct-current electric field detecting device used under condition of hybrid electric field |
| CN204256263U (en) * | 2014-10-16 | 2015-04-08 | 西安毅达信息***有限公司 | A kind of intelligent precise tuning fork chopper |
| CN104709699A (en) * | 2014-11-10 | 2015-06-17 | 昆山鸿吉瑞精密机械有限公司 | Voltage regulating type vibration disc controller |
| CN204359370U (en) * | 2014-12-23 | 2015-05-27 | 重庆川仪自动化股份有限公司 | Ultrasonic Wave Flowmeter receive MUT signal intensity AGC (automatic gain control) system |
| CN107271368A (en) * | 2017-05-23 | 2017-10-20 | 哈尔滨工业大学 | A kind of interior cavity-enhanced photo acoustic spectrum-type trace-gas sensors device |
Non-Patent Citations (2)
| Title |
|---|
| 李昌晋: "基于PWM技术的新型高效率直流斩波器", 《电子技术与软件工程》 * |
| 翟保尊: "精密光学斩波控制器设计", 《仪表技术与传感器》 * |
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