JP2967676B2 - Ventilation automatic control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic ventilation control device for automatically controlling a ventilator so that a pollution concentration in a road tunnel does not exceed an allowable value, and more particularly to an input processing device for a VI (smoke permeability) meter. .

[0002]

2. Description of the Prior Art FIG. 4 is a block diagram of a conventional automatic ventilation control system in a road tunnel. The prediction unit 1 includes a VI meter (smoke transmittance, good visibility) 2 which is a sensor installed inside and outside the tunnel, a CO meter (carbon monoxide concentration) 3, and WS
The current measured values are fetched from a meter (wind anemometer) 4 and a TC meter (traffic counter, traffic meter) 5 and the like, and the NJF (current ventilator operation amount) is fetched, and the smoke transmission rate predicted value VIf and one A predicted carbon oxide concentration COf is obtained.

[0003] The control output determining unit 6 calculates an increase or decrease in the operation amount of the ventilator from the predicted value derived by the predicting unit 1,
Get control output.

With this automatic ventilation control device, the concentration of pollutants due to exhaust gas, soot and the like in the road tunnel is reduced.

[0005] Here, the VI meter is required to obtain a true value, a representative value, or an average value of the contamination state in the tunnel. However, the behavior of the VI meter is affected by the variation of the approach pattern of the vehicle into the tunnel and the local effect of the exhaust gas of the large vehicle passing through the installation position of the VI meter, and as shown in FIG. With significant fluctuations.

[0006] This fluctuation is caused by the fact that the contamination characteristics (the time required for the contamination state to stabilize) in the tunnel are generally 10-15.
Has a fluctuation period of 3 to 4 minutes,
It is considered to be a variation around the average value and a disturbance rather than a true pollution state in the tunnel.

Hitherto, as a method of removing the fluctuation of the measured value of the VI meter, a method of taking a moving average or inserting a first-order lag filter has been used.

[0008]

In the conventional method for removing the fluctuation of the VI value in the automatic ventilation control device, the interposition of a filter for sufficiently attenuating the fluctuation having a period of several minutes requires the measurement response itself of the VI meter. The delay is so great that it is not desirable for control.

It is an object of the present invention to provide an automatic ventilation control apparatus which obtains measurement data of soot transmittance from which disturbance has been eliminated while improving responsiveness and performs appropriate ventilation control.

[0010]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention predicts a soot transmission rate or the like from each measured value of a road tunnel obtained from a soot transmission meter or the like and a current operation amount of a ventilator, In a ventilation automatic control device that controls increase and decrease of the operation amount of the ventilator according to the predicted value, a storage unit that stores and updates a measurement signal from the smoke permeability meter as time-series data,
FFT analysis means for periodically analyzing the frequency components of the time-series data stored in the storage means; and a plurality of peak areas of the frequency components, a peak area due to a higher frequency disturbance and an average peak of a lower frequency. a corner frequency determining section for determining the corner frequency f ₁ for separating region, said frequency f ₁ is set as the cutoff frequency, and cuts the high-frequency and soot transmittance measurement of the measuring signal from the soot permeameter And a filter serving as a signal.

In the present invention, the turning point frequency f ₁ is calculated by searching for a frequency f ₂ at a point where the frequency component becomes higher than a set level G from a high frequency range to a low frequency, and ₂ locate the frequency f ₃ becomes substantially zero at and the initial frequency higher than is obtained as the frequency of the integrated value of the frequency components in the frequency decreasing direction from the frequency f ₃ becomes 1 / N of the integrated value of the to zero frequency It is characterized by the following.

[0012]

The frequency characteristics of the soot transmittance meter are analyzed by the FFT analysis means, and from this frequency characteristic, the break frequency determining unit determines the frequency range of the fluctuation of the measured value due to the disturbance by the cutoff frequency f.
_It is determined as ₁ and this frequency range is removed from the measured smoke transmittance.

The frequency range due to disturbance is obtained as a ratio N between the integral value of the frequency component and the total integral value.

FIG. 1 shows an example of an analysis result of a frequency component of a measured value of soot transmittance by the FFT analysis unit. As seen from this frequency characteristic, the peak of the frequency component of the VI meter is
The peak at the low frequency indicates the average change of the pollution in the tunnel, and the peaks higher than the peak are disturbance components affected by the approach pattern of the vehicle. it is conceivable that.

[0015] For the extraction and separation of these peak areas, the corner frequency determining unit searches the points g ₁ frequency components g (f) is greater than the set level G to a peak detection reference from a high frequency range.

[0016] The determined frequency f ₃ as the highest frequency in the region of the peaks with the point g _1, integrates the frequency components of the regions from the frequency f ₃ to zero frequency, the frequency f ₃ following N of the total integral value By obtaining the frequency f ₁ that becomes 1/1, the peak area having the g ₁ and the average area of the contamination in the tunnel are separated and extracted. By removing the frequency component in the distinguished peak region, frequency fluctuation due to disturbance or the like is eliminated.

[0017]

FIG. 2 is a block diagram of a soot transmittance measuring process according to an embodiment of the present invention. The measurement signal from the VI meter is
The data is converted into a time-series digital value by an A / D converter 11 and sequentially stored and updated in a memory 12 as storage means.

The FFT analysis unit 13 takes in the stored data of the memory 12 periodically (period T) or at an appropriate time,
Perform frequency analysis to find the frequency component of the measured value.

The turning point frequency determination unit 14 includes an FFT analysis unit 1
From the frequency component data obtained from _{No. 3} , a frequency range to be removed as a disturbance is determined as a break point f ₁ of the soft filter 15.

The soft filter 15 to which the break point f ₁ is set obtains a measured value obtained by cutting the soot transmittance measurement value from the A / D converter 11 and cutting the high frequency range using the break point f ₁ as a cutoff frequency. .

Since the frequency characteristic of the VI meter changes depending on the pattern of the vehicle entering the tunnel, the FFT analyzer 1
3 and the determination of the break point by the break frequency determination unit 14 are corrected each time in a relatively short time such as at regular intervals.
It is possible to cope with a change in fluctuation characteristics due to a vehicle's approach pattern.

FIG. 3 shows a flowchart for calculating the break point f ₁ by the break frequency determining section 14. Reading analysis data of the FFT analyzer 13 (step S1), and thereafter, it sets the initial set frequency f at a sufficiently high frequency f ₀ (step S2), and the frequency components of each frequency f g (f)
Is compared with the set level G for peak area extraction (step S3), and the frequency f is decreased by Δf until g (f) becomes larger than the set level G (step S3).
4).

[0023] obtained as the frequency f ₂ becomes high peak area frequency f when g of (f) is greater than the set level G (step S5). Setting to increase by frequency Δf from frequency f at which this frequency f ₂ is reached (step S
6), the frequency component g (f) at that time, and the minimum set value δ
Repeat the determination to determine the frequency f ₃ becomes zero by comparison between (step S7), and determines the frequency f ₃ (step S8).

[0024] Next, the integral of the frequency f ₃ to zero frequency for the frequency component g (f) (step S9), and
This integrated value W ₀ is stored. Thereafter, the set integer n is initialized to 1 (step S10), and the frequency component g
(F) from frequency f ₃ to frequency (f ₃ −n × Δf)
Until subjected to integration (step S11), and the integral value W _f at this time a determination is made as to whether or greater than 1 or not the N-th of the total integral value W ₀ (step S12), the time small n = n + 1
(Step S13), and the integration and comparison are repeated again.

[0025] When the integrated value W _f is greater than W ₀ / N, it determines the frequency (f ₃ -n × Δf) at this time as a break point frequency f ₁ (step S14).

[0026] As described above, in this embodiment, the corner frequency determining section 14 searches a point g ₁ frequency components g (f) is greater than the set level G to a peak detection reference from a high frequency range, obtains a frequency f ₃ as the highest frequency in the region of the peaks with the point g _1, integrates the frequency components of the regions from the frequency f ₃ to zero frequency, one N in the frequency f ₃ or less of the total integral value By obtaining the frequency f ₁ , a peak region having the g ₁ and an average region of contamination in the tunnel are separated and extracted. The frequency component due to disturbance or the like is eliminated by removing the frequency component of the distinguished peak region by the soft filter 15.

[0027]

As described above, according to the present invention, the frequency component of the measurement signal from the smoke transmittance meter is analyzed, and the peak region due to the higher frequency disturbance from the plurality of peak regions of the frequency component is analyzed. seeking corner frequency f ₁ for separating the average peak area of the low frequency and a high-frequency soot transmittance measurement signal to cut the measurement signal of the frequency f ₁ from the soot permeameter as a cut-off frequency With this configuration, it is possible to obtain only an average frequency component obtained by removing a disturbance component included in the measurement signal of the smoke transmittance meter, and appropriate ventilation control can be performed without lowering responsiveness.

The frequency analysis and the breakpoint frequency calculation are performed periodically so that an appropriate variation can be removed following a change in the approach pattern of the vehicle.

[Brief description of the drawings]

FIG. 1 is a frequency characteristic diagram of a VI meter for explaining the present invention in principle.

FIG. 2 is a block diagram showing one embodiment of the present invention.

FIG. 3 is a flowchart for calculating a corner frequency in the embodiment.

FIG. 4 is a block diagram of a ventilation control device.

FIG. 5 shows actual measurement data of a VI meter and the like.

[Explanation of symbols]

 Reference Signs List 11 A / D converter 12 Memory part 13 FFT analysis part 14 Breakpoint frequency determination part 15 Soft filter

Claims (2)

(57) [Claims] 1. A ventilation automatic control for predicting a smoke transmission rate or the like from each measurement value of a road tunnel obtained from a smoke transmission meter or the like and a current operation amount of a ventilator, and increasing or decreasing the operation amount of the ventilator according to the predicted value. In the apparatus, storage means for storing and updating the measurement signal from the smoke permeability meter as time-series data, FFT analysis means for periodically analyzing frequency components of the time-series data stored in the storage means, and the frequency component a plurality of the corner frequency determining section for determining the corner frequency f ₁ for separating the average peak area of peak regions and the low frequency due to a disturbance of higher frequency from peak areas, said frequency f ₁ is the cut-off frequency with the And a filter that cuts a high range of a measurement signal from the smoke transmittance meter to obtain a smoke transmittance measurement signal. 2. The method according to claim 1, wherein the turning point frequency f ₁ is calculated based on a frequency f _{2 at a} point where the frequency component becomes larger than a set level G.
Find toward lower frequencies from a high frequency range, locate the frequency f ₃ becomes substantially zero at and the initial frequency higher than the frequency f _2, the integral value of the frequency components in the frequency decreasing direction from the frequency f ₃ is 1 / N of integral value up to zero frequency
2. The automatic ventilation control device according to claim 1, wherein the frequency is determined as the following frequency.