CN102707142B - Frequency spectrum analyzing method and device of control object - Google Patents

Abstract

The invention provides a frequency spectrum analyzing method of a control object, comprising the following steps: presetting the resistance of an inductance-capacitance-resistance (LCR) oscillating circuit, wherein the value of the resistance is more than -2 and less than 0; obtaining the input signal of the system control object, and obtaining the output signal of the system control object; inputting the input signal to the LCR oscillating circuit, obtaining the first response signal after performing the convergence treatment; inputting the output signal to the LCR oscillating circuit, obtaining the second response signal after performing the convergence treatment; comparing the first response signal with the second response signal to obtain the spectrum analysis result of the system control object. The invention further puts forward a spectrum analysis device of the control object. The anti-interference ability of the system is improved, and the reliability of the frequency spectrum analysis is improved.

Description

The frequency spectrum analysis method of control object and device

Technical field

The present invention relates to field of industrial automatic control, particularly relate to frequency spectrum analysis method and the device of control object.

Background technology

The frequency characteristic of Systematical control object is the fundamental basis of Control System Design and parameter adjustment.Points Identification for Process Frequency Response ultimate principle is: Systematical control object is under pumping signal effect, obtain system or object input signal and output signal respectively in the frequency spectrum characteristic of frequency domain by frequency spectrum discrimination method, mainly comprise: amplitude-frequency spectral property, phase spectral characteristic etc.

But the process signal of industrial process systems is generally subject to the interference of various inside and outside random noise, and the Points Identification for Process Frequency Response of noise on Process Control System constitutes very important impact.

From system response identification angle, most process object has the characteristic of similar low-pass filter, pumping signal is by after object, relative high frequency rate signal outside object low-pass cut-off frequencies will have decay by a relatively large margin, particularly under Systematical control object output terminal exists the noise of higher-strength, the jamtosignal characteristic of these relative high frequency rate signals will worsen significantly, the Points Identification for Process Frequency Response quality of Systematical control object in these relative high frequency rates be normally difficult to ensure.

Summary of the invention

The object of the invention is to the frequency spectrum analysis method proposing control object, improve the antijamming capability of system, improve the reliability of spectrum analysis.

For achieving the above object, the technical scheme of employing is:

The frequency spectrum analysis method of control object, comprises step:

Preset the resistance of LCR oscillatory circuit;

Obtain the input signal of Systematical control object;

Obtain the output signal of Systematical control object;

Described input signal is inputted described LCR oscillatory circuit, and obtains the first response signal after carrying out convergence process;

By the described LCR oscillatory circuit of described output signal input, and obtain the second response signal after carrying out convergence process;

More described first response signal and described second response signal, obtain the result of spectrum analysis of described Systematical control object.

First the inventive method arranges the resistance of LCR oscillator, and the signal amplitude through LCR oscillatory circuit exponentially strengthens in time, and the impact of such noise also just weakens gradually, thus considerably reduces the jamtosignal of output frequency signal; Then by the signal that LCR oscillatory circuit exports, be multiplied by a convergence exponent function matched, finally obtain the signal being still constant amplitude output; But the jamtosignal characteristic of signal is significantly improved, thus under stronger noise environment, significantly improves control object frequency domain characteristic identification quality, improve the antijamming capability of system, improve the reliability of spectrum analysis.

The present invention also aims to the frequency spectrum analysis method proposing control object, improve the antijamming capability of system, improve the reliability of spectrum analysis.

For achieving the above object, the technical scheme of employing is:

The arrangements for analyzing frequency of control object, comprising:

Pre-configured unit, for the resistance of default LCR oscillatory circuit;

First acquiring unit, for obtaining the input signal of Systematical control object;

Second acquisition unit, for obtaining the output signal of Systematical control object;

First signal processing unit, for described input signal is inputted described LCR oscillatory circuit, and obtains the first response signal after carrying out convergence process;

Secondary signal processing unit, for described output signal is inputted described LCR oscillatory circuit, and obtains the second response signal after carrying out convergence process;

Spectral analysis unit, for more described first response signal and described second response signal, obtains the result of spectrum analysis of described Systematical control object.

First apparatus of the present invention arrange the resistance of LCR oscillator, and the signal amplitude through LCR oscillatory circuit exponentially strengthens in time, and the impact of such noise also just weakens gradually, thus considerably reduces the jamtosignal of output frequency signal; Then by the signal that LCR oscillatory circuit exports, be multiplied by a convergence exponent function matched, finally obtain the signal being still constant amplitude output; But the jamtosignal characteristic of signal is significantly improved, thus under stronger noise environment, significantly improves control object frequency domain characteristic identification quality, improve the antijamming capability of system, improve the reliability of spectrum analysis.

Accompanying drawing explanation

Fig. 1 is an embodiment process flow diagram of the inventive method;

Fig. 2 is an embodiment schematic diagram of the inventive method;

Fig. 3 is a structural representation of apparatus of the present invention.

Embodiment

For ease of understanding, set forth below in conjunction with accompanying drawing.

The present invention proposes the frequency spectrum analysis method of control object, please refer to Fig. 1, comprises step:

The resistance of S101, default LCR oscillatory circuit;

The input signal of S102, acquisition Systematical control object, and obtain the output signal of Systematical control object;

S103, input signal is inputted LCR oscillatory circuit, and obtain the first response signal after carrying out convergence process;

S104, by output signal input LCR oscillatory circuit, and obtain the second response signal after carrying out convergence process;

S105, compare the result of spectrum analysis that the first response signal and the second response signal obtain Systematical control object.

First the inventive method arranges the resistance of LCR oscillator, and signal is after LCR oscillatory circuit, and amplitude exponentially strengthens in time, and the impact of such noise also just weakens gradually, thus considerably reduces the jamtosignal of output frequency signal; Then by the signal that LCR oscillatory circuit exports, be multiplied by a convergence exponent function matched, finally obtain the signal being still constant amplitude output; But the jamtosignal characteristic of signal is significantly improved, thus under stronger noise environment, significantly improves control object frequency domain characteristic identification quality, improve the antijamming capability of system, improve the reliability of spectrum analysis.

Fig. 2 is one embodiment of the present of invention schematic diagram, and the output signal of Systematical control object is interfered the impact of signal; Obtain the signal of input system control object to LCR oscillatory circuit, obtain the output signal of Systematical control object to LCR oscillatory circuit; After LCR oscillatory circuit, then by multiplier process, then carry out frequency spectrum processing, output spectrum result.

Wherein, LCR pierce circuit is made up of inductance L, electric capacity C, resistance R, when frequency signal holds output from resistance R, can use transport function statement relation between the two below:

$G_f\left(s\right)=\frac{Y\left(s\right)}{X\left(s\right)}=\frac{{\mathrm{RT}}_{I}s}{T_I{T}_D{s}^2+{\mathrm{RT}}_{I}s+1}---\left(1\right)$

In formula (1), R represents resistance; T _irepresent the integration constant corresponding to electric capacity; T _drepresent the derivative constant corresponding to inductance; S represents Complex frequency unit.

Without loss of generality, T is made _i=T _d=T _o, then formula (1) is converted to formula (2):

$G_f\left(s\right)=\frac{Y\left(s\right)}{X\left(s\right)}=\frac{{\mathrm{RT}}_{O}s}{{{T_O}^{2}s}^2+{\mathrm{RT}}_{O}s+1}---\left(2\right)$

Wherein, LCR oscillator center frequency ω ₀for:

${\mathrm{\ω}}_o=\frac{1}{\sqrt{T_I{T}_D}}=\frac{1}{T_O}---\left(3\right)$

Formula (2) unit-step response is formula (4):

$Y_f\left(s\right)=\frac{{\mathrm{RT}}_{O}s}{s({T_O}^2{s}^2+{\mathrm{RT}}_{O}s+1)}---\left(4\right)$

Laplace inverse transformation is carried out to formula (4) and obtains formula (5):

$Y_f\left(t\right)=\frac{R}{\sqrt{1-R^2/4}}{e}^{-0.5R{\mathrm{\ω}}_{O}t}\sin \left({\mathrm{\ω}}_{O}t\sqrt{1-R^2/4}\right)---\left(5\right)$

If in formula (5) ,-2 Ω <R<0 Ω, then the amplitude of formula (5) sine wave output signal is exponentially disperse, referred to as LCR diverging oscillation.

If but formula (5) is multiplied by a convergence exponent function then obtain formula (6):

$Y_F\left(t\right)=e^{0.5R{\mathrm{\&omega;}}_{O}t}{Y}_f\left(t\right)=\frac{R}{\sqrt{1-R^2/4}}\sin \left({\mathrm{\&omega;}}_{O}t\sqrt{1-R^2/4}\right)---\left(6\right)$

Formula (6) sine wave output signal remains constant amplitude, is simply called that LCR disperses convergence vibration.

In order to simplify problem, when R span is less, as | R| < 0.2, then formula (6) can be approximated to be formula (7), compare its former formula, the error that its amplitude and frequency produce is about ± and 0.5%, engineering can accept completely.

Y _F(t)≈Rsin(ω _Ot) (7)

Formula (7) shows, under step excitation, LCR disperses frequencies omega centered by convergence vibration output ₀constant amplitude sinusoid signal.

But in fact there is a problem, along with the increase of time, the amplitude of formula (5) sine wave output signal will be tending towards infinitely great, and physical equipment calculating may be caused to make mistakes, mainly the transfiniting of numerical range.Therefore computationally limited.

Wherein in an embodiment, before above-mentioned S102 step, preset and obtain the input signal of Systematical control object and the time (such as: at output 10 cycle Sine wave signals) of output signal; When Preset Time arrives, then stop current spectrum analysis.

Arrangement formula (2) obtains LCR oscillator closed loop form, is formula (8):

$G_f\left(s\right)=\frac{Y\left(s\right)}{X\left(s\right)}=\frac{{\mathrm{RT}}_{o}s}{{T_o}^2{s}^2+{\mathrm{RT}}_{o}s+1}=\frac{R/(T_{o}s+R)}{1+[R/(T_{o}s+R)]*[1/\left({\mathrm{RT}}_{o}s\right)]}---\left(8\right)$

Reality must pass through closed loop form, and namely formula (8) realizes LCR oscillator function.

To sum up, the present invention may be used for the data source obtaining frequency-domain analysis, and preferably, this data source is sine wave signal or the sine-wave response signal of present count frequency.

Wherein in an embodiment, above-mentioned S103 step is specially:

Input signal is inputted LCR oscillatory circuit, obtain the first diverged signal;

First diverged signal is multiplied by convergent function, obtains the first response signal;

Above-mentioned S104 step is specially:

By output signal input LCR oscillatory circuit, obtain the second diverged signal;

Second diverged signal is multiplied by convergent function, obtains the second response signal;

Wherein, convergent function is: ω ₀for the centre frequency of described LCR oscillator, R is the resistance identical with the resistance of default LCR oscillatory circuit, and t is the time.

Wherein in an embodiment, above-mentioned 105 steps comprise:

Obtain amplitude information and the phase information of the first response signal;

Obtain amplitude information and the phase information of the second response signal;

The relatively amplitude information of the first response signal and the amplitude information of the second response signal; And, compare the phase information of the first response signal and the phase information of the second response signal;

Export comparative result.

The present invention also proposes the arrangements for analyzing frequency of control object, please refer to Fig. 3, comprising:

Pre-configured list 301, for the resistance of default LCR oscillatory circuit;

First acquiring unit 302, for obtaining the input signal of Systematical control object;

Second acquisition unit 303, for obtaining the output signal of Systematical control object;

First signal processing unit 304, for input signal is inputted LCR oscillatory circuit, and obtains the first response signal after carrying out convergence process;

Secondary signal processing unit 305, for output signal is inputted LCR oscillatory circuit, and obtains the second response signal after carrying out convergence process;

Spectral analysis unit 306, for comparing the first response signal and the second response signal, obtains the result of spectrum analysis of Systematical control object.

First apparatus of the present invention arrange the resistance of LCR oscillator, and the signal amplitude through LCR oscillatory circuit exponentially strengthens in time, and the impact of such noise also just weakens gradually, thus considerably reduces the jamtosignal of output frequency signal; Then by the signal that LCR oscillatory circuit exports, be multiplied by a convergence exponent function matched, finally obtain the signal being still constant amplitude output; But the jamtosignal characteristic of signal is significantly improved, thus under stronger noise environment, significantly improves control object frequency domain characteristic identification quality, improve the antijamming capability of system, improve the reliability of spectrum analysis.

Wherein in an embodiment, pre-configured unit 301 is also for the default input signal of acquisition Systematical control object and the time of input signal;

When Preset Time arrives, then notify that spectral analysis unit stops current spectrum analysis.

Wherein in an embodiment, input signal is inputted LCR oscillatory circuit by the first signal processing unit 304, and when obtaining the first response signal after carrying out convergence process, input signal is inputted LCR oscillatory circuit, obtains the first diverged signal; First diverged signal is multiplied by convergent function, obtains the first response signal;

Secondary signal processing unit 305 by output signal input LCR oscillatory circuit, and when obtaining the second response signal after carrying out convergence process, by output signal input LCR oscillatory circuit, obtains the second diverged signal; Second diverged signal is multiplied by convergent function, obtains the second response signal;

Wherein, convergent function is: ω ₀for the centre frequency of described LCR oscillator, R is the resistance identical with the resistance of default LCR oscillatory circuit, and t is the time.

Wherein in an embodiment, spectral analysis unit 306 compares the first response signal and the second response signal when obtaining the result of spectrum analysis of Systematical control object,

Obtain amplitude information and the phase information of the first response signal;

Obtain amplitude information and the phase information of the second response signal;

The relatively amplitude information of the first response signal and the amplitude information of the second response signal; And, compare the phase information of the first response signal and the phase information of the second response signal;

Export comparative result.

The above embodiment only have expressed several embodiment of the present invention, and it describes comparatively concrete and detailed, but therefore can not be interpreted as the restriction to the scope of the claims of the present invention.It should be pointed out that for the person of ordinary skill of the art, without departing from the inventive concept of the premise, can also make some distortion and improvement, these all belong to protection scope of the present invention.Therefore, the protection domain of patent of the present invention should be as the criterion with claims.

Claims (8)

1. the frequency spectrum analysis method of control object, is characterized in that, comprises step:

Preset the resistance of LCR oscillatory circuit; Wherein, the span of described resistance is: be greater than-2 Ω and be less than 0 Ω;

Obtain the input signal of Systematical control object;

Obtain the output signal of Systematical control object;

Described input signal is inputted described LCR oscillatory circuit, and obtains the first response signal after carrying out convergence process;

By the described LCR oscillatory circuit of described output signal input, and obtain the second response signal after carrying out convergence process;

More described first response signal and described second response signal, obtain the result of spectrum analysis of described Systematical control object.

2. the frequency spectrum analysis method of control object according to claim 1, is characterized in that,

Before the step of the input signal of described acquisition Systematical control object, preset and obtain the input signal of Systematical control object and the time of output signal; When Preset Time arrives, then stop current spectrum analysis.

3. the frequency spectrum analysis method of control object according to claim 1, is characterized in that,

Describedly input signal is inputted described LCR oscillatory circuit, and the step obtaining the first response signal after carrying out convergence process is specially:

Described input signal is inputted described LCR oscillatory circuit, obtains the first diverged signal;

Described first diverged signal is multiplied by convergent function, obtains described first response signal;

Described by the described LCR oscillatory circuit of output signal input, and the step obtaining the second response signal after carrying out convergence process is specially:

By the described LCR oscillatory circuit of described output signal input, obtain the second diverged signal;

Described second diverged signal is multiplied by convergent function, obtains described second response signal;

Wherein, described convergent function is: ω ₀for the centre frequency of described LCR oscillator, R is the resistance identical with the resistance of described default LCR oscillatory circuit, and t is the time.

4. the frequency spectrum analysis method of the control object according to any one of claims 1 to 3, is characterized in that,

Describedly compare the step that the first response signal and described second response signal obtain the result of spectrum analysis of described Systematical control object and comprise:

Obtain amplitude information and the phase information of described first response signal;

Obtain amplitude information and the phase information of described second response signal;

The amplitude information of more described first response signal and the amplitude information of described second response signal; And, the phase information of more described first response signal and the phase information of described second response signal;

Export comparative result.

5. the arrangements for analyzing frequency of control object, is characterized in that, comprising:

Pre-configured unit, for the resistance of default LCR oscillatory circuit; Wherein, the span of described resistance is: be greater than-2 Ω and be less than 0 Ω;

First acquiring unit, for obtaining the input signal of Systematical control object;

Second acquisition unit, for obtaining the output signal of Systematical control object;

First signal processing unit, for described input signal is inputted described LCR oscillatory circuit, and obtains the first response signal after carrying out convergence process;

Secondary signal processing unit, for described output signal is inputted described LCR oscillatory circuit, and obtains the second response signal after carrying out convergence process;

Spectral analysis unit, obtains the result of spectrum analysis of described Systematical control object for more described first response signal and described second response signal.

6. the arrangements for analyzing frequency of control object according to claim 5, is characterized in that,

Described pre-configured unit is also for the default input signal of acquisition Systematical control object and the time of output signal;

When Preset Time arrives, then notify that described spectral analysis unit stops current spectrum analysis.

7. the arrangements for analyzing frequency of control object according to claim 5, is characterized in that,

Input signal is inputted described LCR oscillatory circuit by described first signal processing unit, and when obtaining the first response signal after carrying out convergence process, described input signal is inputted described LCR oscillatory circuit, obtains the first diverged signal; Described first diverged signal is multiplied by convergent function, obtains described first response signal;

Described secondary signal processing unit by the described LCR oscillatory circuit of output signal input, and when obtaining the second response signal after carrying out convergence process, by the described LCR oscillatory circuit of described output signal input, obtains the second diverged signal; Described second diverged signal is multiplied by convergent function, obtains described second response signal;

Wherein, described convergent function is: ω ₀for the centre frequency of described LCR oscillator, R is the resistance identical with the resistance of described default LCR oscillatory circuit, and t is the time.

8. the arrangements for analyzing frequency of the control object according to any one of claim 5 to 7, is characterized in that,

Described spectral analysis unit compares the first response signal and described second response signal when obtaining the result of spectrum analysis of described Systematical control object,

Obtain amplitude information and the phase information of described first response signal;

Obtain amplitude information and the phase information of described second response signal;

The amplitude information of more described first response signal and the amplitude information of described second response signal; And, the phase information of more described first response signal and the phase information of described second response signal;

Export comparative result.