CN102710221B - Self-adaptive amplifying and filtering system for laser energy measurement of back reverse calorimeter - Google Patents

Abstract

The invention relates to a self-adaptive amplifying and filtering system for laser energy measurement of a back calorimeter, which comprises a calorimetric detector, an impedance matching device, a front programmable gain amplifier, a programmable switch capacitance low-pass filter, a post programmable gain amplifier, a signal acquisition and control module and a gain and bandwidth control module, wherein the signal acquisition and control module analyzes and processes an acquired signal by adopting a self-adaptive frequency spectrum analysis method and transmits processing results to the gain and bandwidth control module; and the gain and bandwidth control module downloads the processing results to the front programmable gain amplifier, the post programmable gain amplifier and the programmable switch capacitance low-pass filter. The self-adaptive amplifying and filtering system has the benefits that the gain of all amplifiers and the bandwidth of the filter are realized through online adjustment, the use is convenient, and the signal to noise ratio of an output signal is improved while the environmental noise is effectively restrained.

Description

Carrying on the back the self adaptation of anti-calorimeter measurement of laser energy amplifies and filtering system

Technical field

The present invention relates to carry on the back self adaptation amplification and the filtering system of anti-calorimeter measurement of laser energy.

Background technology

At present, the amplification and the filter that are applied to the anti-calorimeter measurement of laser energy of the back of the body are to be made up of fix level gain amplifier and fixed-bandwidth filter, and the bandwidth adjustment of filter and the gain adjustment of amplifier need manual configuration switch before use to realize.In order to adapt to the frequency change of interference source and the change of input signal energy, need to adjust the bandwidth of filter and the gain of amplifier, prior art is in course of adjustment and has following deficiency.

First, while adjusting the bandwidth of filter and the gain of amplifier, need to realize by manual configuration switch, operation and use are very inconvenient; Secondly, for adapting to the frequency change of interference source and the change of input signal energy, need to repeatedly adjust the bandwidth of filter and the gain of amplifier, and each adjustment all needs detaching equipment, not only to equipment, application causes difficulty for this, has caused difficulty also to the reliability and maintainability of equipment; The 3rd, on existing filter construction, exist can bandwidth progression for the election less, can not realize the continuous setup of filter bandwidht, complicated circuit structure has also been introduced more noise simultaneously, has reduced the noise inhibiting ability of circuit.

Summary of the invention

The problems referred to above that exist for prior art, the technical problem that the present invention solves is: realizes online amplifier gain and the bandwidth filter bandwidth adjusted, increased adjustable progression simultaneously, easy to operate.

Solve this technical problem, the present invention is achieved in that self adaptation amplification and the filtering system of the anti-calorimeter measurement of laser energy of the back of the body, comprises calorimetric detector, impedance matching, preposition programmable gain amplifier, Programmable Switched Filters, rearmounted programmable gain amplifier, signals collecting and control module and gain and bandwidth control module; Described calorimetric detector, impedance matching, preposition programmable gain amplifier, Programmable Switched Filters are connected successively with rearmounted programmable gain amplifier; The output of described rearmounted programmable gain amplifier is connected with the acquisition channel of signals collecting and control module, and the output of described signals collecting and control module is connected with the input of gain and bandwidth control module; The output of described gain and bandwidth control module is connected with the control end of the control end of preposition programmable gain amplifier, rearmounted programmable gain amplifier and the isolation of the control end of Programmable Switched Filters respectively; Described signals collecting and control module adopt adaptive spectrum analysis method that the signal gathering is analyzed and processed, and result is transferred to gain and bandwidth control module, this result is downloaded to preposition programmable gain amplifier and rearmounted programmable gain amplifier and Programmable Switched Filters by described gain and bandwidth control module.

With respect to prior art, tool of the present invention has the following advantages:

1, the control end of preposition programmable gain amplifier and the control end of rearmounted programmable gain amplifier in the present invention, and the control end of Programmable Switched Filters is connected with the output isolation of gain and bandwidth control module respectively, the signal that gain and bandwidth control module are published books according to signals collecting and control module is adjusted the gain of preposition programmable gain amplifier and rearmounted programmable gain amplifier and the cut-off frequency of Programmable Switched Filters, thereby do not need disassembling system, easy to use.

2, because the present invention does not need disassembling system, and can realize the online gain of programmable gain amplifier and the cut-off frequency of Programmable Switched Filters adjusted in real time, when effectively having suppressed ambient noise, improve the signal to noise ratio of output signal.

3, due in system of the present invention, the logical self-adaptive control module of gain and band is adjusted the cut-off frequency of Programmable Switched Filters and the gain of two programmable gain amplifiers according to the signal of signals collecting and control module output, middle technical staff's manual operation has increased variable progression compared to existing technology, and it is higher to adjust accuracy.

Brief description of the drawings

Fig. 1-schematic block circuit diagram of the present invention.

Fig. 2-adaptive spectrum analysis Method And Principle figure.

The circuit theory diagrams of Fig. 3-embodiment of the present invention.

In figure, the preposition programmable gain amplifier of 1001-, 1002-Programmable Switched Filters, the rearmounted programmable gain amplifier of 1003-, 1004-gain and bandwidth control module, 1005-signals collecting and control module, 1006-calorimetric detector, 1007-impedance matching, 2005-control and connect photoelectric isolation module, 2007-communication interface photoelectric isolation module.

Embodiment

Below the present invention is described in further detail.

Isolation connection in the present invention refers to and between two links, is connected with photoelectrical coupler or electromagnetic coupler, two links are not directly linked together.

In the present invention, carry on the back anti-calorimeter measurement of laser energy and refer to and first adopt calorimetric detector to carry out measurement of time integration to scattered energy, afterwards detector output signal is amplified to a kind of metering system of processing and calculating scattered energy.

Referring to Fig. 1, from scheming, can find out, carry on the back the self adaptation of anti-calorimeter measurement of laser energy and amplify and filtering system, calorimetric detector 1006, impedance matching 1007, preposition programmable gain amplifier 1001, Programmable Switched Filters 1002 are connected successively with rearmounted programmable gain amplifier 1003; The output of rearmounted programmable gain amplifier 1003 is connected with the acquisition channel of signals collecting and control module 1005, and the output of described signals collecting and control module 1005 is connected with the input of gain and bandwidth control module 1004; The output of described gain and bandwidth control module 1004 is connected with control end, the control end of rearmounted programmable gain amplifier 1003 and the isolation of the control end of Programmable Switched Filters 1002 of preposition programmable gain amplifier 1001 respectively; Described signals collecting and control module 1005 adopt adaptive spectrum analysis method that the signal gathering is analyzed and processed, and result is transferred to gain and bandwidth control module 1004, this result is downloaded to preposition programmable gain amplifier 1001 and rearmounted programmable gain amplifier 1003 and Programmable Switched Filters 1002 by described gain and bandwidth control module 1004.

Referring to Fig. 2, analysis to collection signal of signals collecting and control module 1005 and to process the adaptive spectrum analysis method adopting specific as follows:

The 1st step, reads preposition programmable gain amplifier 1001 and rearmounted programmable gain amplifier 1003 configuration files;

The 2nd step, judges whether to adjust parameter, if desired adjusts and carries out the 3rd step, otherwise carry out the 4th step.

The 3rd step, can be divided into following several stages:

1) initialization, establishes amplifier gain and is , , wherein, , amplifier gain can choose arbitrarily.G is amplifier gain collection, , Programmable Switched Filters 1002 cut-off frequencies elect maximum as; Amplifier gain herein refer to: global gain, the i.e. combined amplifier of preposition programmable gain amplifier 1001 and rearmounted programmable gain amplifier 1003 gain.

2) establishing current amplifier gain is , collect observation data by signals collecting and control module 1005 , calculate observation signal according to formula (1) peak-to-peak value:

（1）

Calculate amplifier gain according to formula (2) again renewal :

（2）

Wherein, , with represent that respectively preposition programmable gain amplifier 1001 and rearmounted programmable gain amplifier 1003 allow the maximum voltage of output, iteration said process, when time stop iteration, carry out next step;

3) according to observation signal draw observation signal power spectral density function , then calculate observation signal according to formula (3) power :

（3）

Definition according to bandwidth is known, observation signal the Frequency point that power declines 50% time is half-power point, and the frequency interval between half-power point is usually said-three dB bandwidth, therefore, and according to the angular frequency of the half-power point of formula (4) Programmable Switched Filters 1002

（4）

According to the cut-off frequency of (5) formula calculating Programmable Switched Filters 1002 be again:

（5）

The 4th step, the cut-off frequency of the amplifier gain calculating and Programmable Switched Filters 1002 is delivered to gain and bandwidth control module 1004 by signals collecting and control module 1005, by gaining and bandwidth control module 1004 downloads to preposition programmable gain amplifier 1001 and rearmounted programmable gain amplifier 1003 and Programmable Switched Filters 1002.

Adopt the combining structure of the low-pass filtering of preposition programmable gain amplifier 1001 and the program control amplification of 1003 two-stage of rearmounted programmable gain amplifier and Programmable Switched Filters 1002, can meet on the one hand the requirement of plus and blowup and high s/n ratio in faint light energy measurement, can also adapt on the other hand the change of noise characteristic in the variation of large-scale faint light energy value and measurement environment, thereby ensure that circuit has higher signal to noise ratio.

Self adaptation amplification and filtering system that the present invention carries on the back anti-calorimeter measurement of laser energy are divided into two stages in use, first stage is to adopt correction signal input, under the control of signals collecting and control module 1005, rearmounted programmable gain amplifier 1003 output signals are gathered, and adopt the method for adaptive spectrum analysis to analyze, obtain output signal and proofread and correct parameter used; Second stage is to adopt the signal of calorimetric detector 1006 as input, and signals collecting and control module 1005 gather and store rearmounted programmable gain amplifier 1003 output signals, and provide output signal to proofread and correct needed parameter.

embodiment:as shown in Figure 3, according to the output impedance of calorimetric detector 1006, the build-out resistor in impedance matching 1007 is set, preposition programmable gain amplifier 1001 and rearmounted programmable gain amplifier 1003 are selected instrument amplifier PGA204, can select 1 by programming pin, 10, 100 and 1000 gains of totally four gears, Programmable Switched Filters 1002 is selected 8 rank programmable switch electric capacity Low-pass Elliptic Filter MAX7400, adjust the cut-off frequency of low pass filter by adjusting incoming frequency, control interface photoelectric isolation module 2005 and communication interface photoelectric isolation module 2007 select HCPL2630 and TPL521-4 to form, all communication and control signal are isolated completely, according to analysis and the result of signals collecting and control module 1005, by gain and online preposition programmable gain amplifier 1001 and the gain of rearmounted programmable gain amplifier 1003 and the cut-off frequency of Programmable Switched Filters 1002 adjusted of bandwidth control module 1004, with the variation of adaptive capacity hot type detector 1006 output signal features and noise source frequency band.

Finally explanation is, above embodiment is only unrestricted in order to technical scheme of the present invention to be described, although the present invention is had been described in detail with reference to preferred embodiment, those of ordinary skill in the art is to be understood that, can modify or be equal to replacement technical scheme of the present invention, and not departing from aim and the scope of technical solution of the present invention, it all should be encompassed in the middle of claim scope of the present invention.

Claims (1)

1. the self adaptation of the anti-calorimeter measurement of laser energy of the back of the body is amplified and filtering system, it is characterized in that: comprise calorimetric detector (1006), impedance matching (1007), preposition programmable gain amplifier (1001), Programmable Switched Filters (1002), rearmounted programmable gain amplifier (1003), signals collecting and control module (1005) and gain and bandwidth control module (1004);

Described calorimetric detector (1006), impedance matching (1007), preposition programmable gain amplifier (1001), Programmable Switched Filters (1002) are connected successively with rearmounted programmable gain amplifier (1003);

The output of described rearmounted programmable gain amplifier (1003) is connected with the acquisition channel of signals collecting and control module (1005), and the output of described signals collecting and control module (1005) is connected with the input of gain and bandwidth control module (1004); The output of described gain and bandwidth control module (1004) is connected with the control end of the control end of preposition programmable gain amplifier (1001), rearmounted programmable gain amplifier (1003) and the isolation of the control end of Programmable Switched Filters (1002) respectively;

Described signals collecting and control module (1005) adopt adaptive spectrum analysis method that the signal gathering is analyzed and processed, and result is transferred to gain and bandwidth control module (1004), this result is downloaded to preposition programmable gain amplifier (1001), rearmounted programmable gain amplifier (1003) and Programmable Switched Filters (1002) by described gain and bandwidth control module (1004);

Wherein, analysis to collection signal of signals collecting and control module (1005) and to process the adaptive spectrum analysis method adopting specific as follows:

The 1st step, reads preposition programmable gain amplifier (1001) and rearmounted programmable gain amplifier (1003) configuration file;

The 2nd step, judges whether to adjust parameter, if desired adjusts and carries out the 3rd step, otherwise carry out the 4th step;

The 3rd step, is divided into following several stages:

1) initialization, establishing amplifier gain is g _i, i=1,2 ..., M-1, wherein, g _i<g _i+1, amplifier gain gi can choose arbitrarily; G is amplifier gain collection, G={g ₁, g ₂..., g _m, Programmable Switched Filters (1002) cut-off frequency F _celect maximum as; Amplifier gain g herein _irefer to: global gain, the i.e. combined amplifier of preposition programmable gain amplifier (1001) and rearmounted programmable gain amplifier (1003) gain;

2) establishing current amplifier gain is g _i, collect observation data X (t) by signals collecting and control module (1005), t=1,2 ..., N, calculates the peak-to-peak value of observation signal X (t) according to formula (1):

V _pp＝max(X(t))-min(X(t)) (1)

Calculate amplifier gain g according to formula (2) again _irenewal g _next:

$g_{\mathrm{Next}}=\left\{\begin{array}{c}{g}_{i-1},V_{\mathrm{pp}}>0.9\&CenterDot;V_{\mathrm{MAX}}\\ g_i,V_{\mathrm{pp}}\&Element;\left(\mathrm{0.1,0.9}\right)\&CenterDot;V_{\mathrm{MAX}}\\ g_{i+1},V_{\mathrm{pp}}<0.1\&CenterDot;V_{\mathrm{MAX}}\end{array}\right.---\left(2\right)$

Wherein, V _mAX={ v ₁, v ₂, v ₁and v ₂represent that respectively preposition programmable gain amplifier (1001) and rearmounted programmable gain amplifier (1003) allow the maximum voltage of output, iteration said process, works as g _next=g _itime stop iteration, carry out next step;

3) draw the power spectral density function S of observation signal X (t) according to observation signal X (t) _x(ω), then calculate the power P of observation signal X (t) according to formula (3) _x:

$P_x=\frac{1}{2\mathrm{\&pi;}}{\&Integral;}_{-\&infin;}^{\&infin;}{S}_x\left(\mathrm{\&omega;}\right)\mathrm{d\&omega;}---\left(3\right)$

Definition according to bandwidth is known, the Frequency point that observation signal X (t) power declines 50% time is half-power point, frequency interval between half-power point is-three dB bandwidth, therefore, according to the angular frequency of the half-power point of formula (4) Programmable Switched Filters (1002) _c

$\frac{1}{2\mathrm{\&pi;}}{\&Integral;}_{{\mathrm{\&omega;}}_c}^{{\mathrm{\&omega;}}_c}{S}_x\left(\mathrm{\&omega;}\right)\mathrm{d\&omega;}=\frac{1}{2}{P}_x---\left(4\right)$

According to the cut-off frequency of (5) formula calculating Programmable Switched Filters 1002 be again:

$F_c=\frac{{\mathrm{\&omega;}}_c}{2\mathrm{\&pi;}}---\left(5\right)$

The 4th step, the cut-off frequency of the amplifier gain calculating and Programmable Switched Filters 1002 is delivered to gain and bandwidth control module (1004) by signals collecting and control module (1005), by gaining and bandwidth control module (1004) downloads to preposition programmable gain amplifier (1001) and rearmounted programmable gain amplifier (1003) and Programmable Switched Filters (1002).