JPH09243668A - Method and device for measuring instantaneous value of pulse signal - Google Patents

Abstract

(57) Abstract: To stably and accurately measure an instantaneous value of a physical quantity without being affected by the timing of a processing cycle. SOLUTION: A pulse signal oscillator 11 for generating pulse signals having different pulse intervals according to a change in a measured physical quantity,
The pulse interval measuring unit 12 for measuring the pulse interval of the pulse signal generated from the pulse signal oscillator, the instantaneous value calculating unit 13 for calculating the instantaneous value using the measured pulse interval data, and the instantaneous value It is an instantaneous value measuring device of a pulse signal provided with an indicator 14 for displaying.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for measuring an instantaneous value of a pulse signal and a measuring apparatus used in the technical field of measuring a physical quantity such as a flow rate and an electric energy. The present invention relates to a pulse signal instantaneous value measuring method for measuring a generated pulse signal and a measuring device therefor.

[0002]

2. Description of the Related Art Conventionally, there are many measuring devices as devices for measuring pulse signals having different pulse intervals which are generated due to changes in measured physical quantities such as flow rate and electric energy. Among these devices, for example, a differential pressure type flow meter using an orifice or the like is a method of measuring an instantaneous value flow rate by measuring a differential pressure across the orifice or the like with a differential pressure transmitter to measure the instantaneous value flow rate. It is possible to convert the measured instantaneous value flow rate into a current signal of 4 to 20 mA and generate it. In particular, in the differential pressure flow meter, since the instantaneous value flow rate can be directly taken out in the form of a current signal, it is easy to process when displaying or controlling the instantaneous value flow rate based on the measured value of the differential pressure flow meter.

However, the volumetric flow meter and the watt-hour meter are constructed so that the rotor is rotated in accordance with the flow velocity and the power consumption and a unit pulse proportional to the number of rotations thereof is generated. Particularly, since the volumetric flowmeter generates a measurement signal proportional to the flow velocity as a unit pulse, it is necessary to count the number of transmitted pulses. In this case, the integrated value is easily processed, but calculation is required to obtain the instantaneous value. In addition, there are cases in which the flow rate control is performed using the measured instantaneous value, demand prediction of the electric energy is performed, etc. For that purpose, it is necessary to obtain a highly accurate instantaneous value from the pulse signal transmitted.

By the way, as a method of transmitting a pulse signal as described above and measuring the pulse signal thus transmitted to obtain an instantaneous value, conventionally, a measuring method and a measuring apparatus as shown in FIG. 4 have been used. .

In this measuring method and measuring apparatus, pulse signals having different pulse intervals are transmitted from the pulse oscillator 1 in accordance with changes in flow rate, electric power, etc., and the pulse counter 2 counts the number of transmitted pulses. . Then, the count value of the pulse counter 2 is taken in by the instantaneous value calculation unit 3, the instantaneous value is calculated from this count value, and the calculated value is displayed on the indicator 4.

The instantaneous value calculation flow of the instantaneous value calculation unit 3 uses the current count value Cn and the previous count value Cn-1 of the pulse counter 2 as shown in FIG. The increase count value ΔC of is calculated (ST1).

ΔC = Cn−Cn−1 (1) Then, the instantaneous flow rate value Fn of the current processing cycle is calculated from the increased count value ΔC of the current processing cycle using the following formula (ST2).

Fn = (ΔC · 3600 · R) / Δt (2) where Fn: Instantaneous flow rate value [l / h] R of this processing cycle: pulse rate [l / pulse] Δt: Processing cycle [sec] The instantaneous flow rate value Fn thus obtained is displayed on the indicator 4 as an instantaneous flow rate value (ST3).

[0009]

However, various problems have been pointed out in the method of measuring the instantaneous value of the pulse signal and the measuring apparatus therefor as described above. (1) Even if the pulse value of the actual flow rate is constant and the pulse interval is constant, the relation of processing cycle ≠ pulse transmission interval × integer (3) As shown, there is a problem that the instantaneous value display of the indicator 4 changes rapidly once every few seconds. For example, when pulses are generated at a constant interval of 0.3 seconds and the processing cycle is 1.0 second, two of three processing cycles are:
(3 pulses · 3600 · R) [l / h], the remaining one time becomes (4 pulses · 3600 · R) [l / h], and the instantaneous value display repeatedly changes. In other words, in the case of the relationship represented by the equation (3), there is a problem that the instantaneous value display fluctuates depending on the timing of the processing cycle even if the pulse signals are transmitted at constant intervals. (2) When the pulse rate is small, the instantaneous value of the previous time is displayed during each processing cycle as shown in FIG. 7, so that the instantaneous flow rate value can be continuously displayed on the indicator 4. . However, when the pulse rate is large, for example, as shown in FIG. 8, the actual instantaneous flow rate value should be continuously displayed as indicated by the dotted line (a) in the figure, but the indicator 4 does not. There is a problem that the values are displayed intermittently and the instantaneous values seem to be zero. This is a problem that the larger the pulse rate compared to the range of the instantaneous value display, the greater the fluctuation of the instantaneous value display of the calculation result even if the actual instantaneous value is constant.

The present invention has been made in view of the above circumstances, and provides a method for measuring an instantaneous value of a pulse signal and a measuring apparatus therefor capable of measuring a stable and accurate instantaneous value for each processing cycle. It is in.

[0011]

In order to solve the above problems, the invention according to claim 1 provides a pulse interval time when a pulse signal having a different pulse interval time ΔK is generated according to a change in a physical quantity. By measuring ΔK and using this pulse interval ΔK and pulse rate R, an instantaneous value measuring method of a pulse signal for obtaining the instantaneous value Fn of the physical quantity from the arithmetic expression Fn = (3600 · R) / Δk is there.

Next, the invention according to claim 2 relates to a flow rate,
A pulse signal generating means for generating pulse signals having different pulse intervals according to changes in various measured physical quantities such as electric energy,
By using the pulse interval measuring means for measuring the pulse interval time Δt of the pulse signal generated from the pulse signal generating means and the pulse interval time Δ and the pulse rate R measured by the pulse interval measuring means (3600. R) / △
An instantaneous value measuring device for a pulse signal, which is provided with an instantaneous value calculating means for calculating an instantaneous value of the physical quantity using an arithmetic expression k.

Therefore, by taking such a measure, the pulse interval time Δt of the pulse signal is measured without adopting a configuration in which the number of pulses generated in the processing cycle is counted and the instantaneous value is obtained from the count. The above (3600
Since the instantaneous value is calculated from the calculation formula of R) / Δk, it is possible to solve the problem that the pulse count number fluctuates for each processing cycle, and it is possible to measure the instantaneous value stably and accurately over each processing cycle.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a functional block diagram illustrating a method for measuring an instantaneous value of a pulse signal and a measuring apparatus therefor according to the present invention. In the figure, reference numeral 11 is a pulse oscillator that emits pulse signals with different pulse intervals according to changes in various physical quantities. For example, in the case of a flow meter, the pulse transmitter 11 is a flow rate transmitter that transmits pulse signals having different pulse intervals according to the change in flow rate. It is a transmitter that transmits a pulse signal, and varies depending on the type of the measurement target.

The pulse oscillator 11 has a built-in timer for measuring the pulse interval of the pulse signal transmitted from the pulse oscillator 11, and a pulse measured by the pulse interval measuring unit 12. An instantaneous value calculation unit 13 that calculates an instantaneous value using the interval time is connected, and the instantaneous value calculated by this instantaneous value calculation unit 13 is displayed on the indicator 4.

Next, the operation of the measuring apparatus configured as described above will be described with reference to FIG. Now, when pulse signals with different pulse intervals are transmitted from the pulse oscillator 11 according to changes in physical quantities such as flow rate and electric power, the pulse interval measuring unit 12 uses a timer to raise the pulse signal of the pulse oscillator 11. Is used as the timing to measure the pulse interval time Δk until the rising of the next pulse signal (ST11).

Thereafter, using the pulse interval time Δk [sec] measured by the pulse interval measuring unit 12, the instantaneous value calculating unit 13 calculates the instantaneous value Fn [l / h] of the current processing cycle according to the following equation. Is calculated (ST12).

Fn = (3600 · R) / Δk (4) where R is the pulse rate [1 / pulse]. Then, the instantaneous value F of the current processing cycle obtained as described above
n is displayed on the indicator 14 (ST13).

Therefore, according to the configuration of the above-described embodiment, the instantaneous value calculation value fluctuates at the timing of the processing cycle even if the pulse signal is transmitted at a constant interval. However, the method and apparatus of the present invention. Since the instantaneous value is calculated based on the calculation formula (4), the stable and accurate instantaneous value can be measured over each processing cycle.

Incidentally, conventionally, when a pulse signal is generated at a constant interval of 0.3 seconds and the processing cycle is 1.0 second, the instantaneous value display fluctuates depending on the processing cycle. , (3600 · R) /0.3, the instantaneous value changes depending on the pulse rate, and when the pulse signal is generated at regular intervals, it is stable and accurate in every processing cycle. It can measure various instantaneous values.

Further, as shown in FIG. 3A, when a pulse signal is generated at a pulse interval time of 2 seconds, the processing cycle is 1.0 second, and the pulse rate is 10 [l / pulse]. Then, the conventional indicator 4 intermittently displays an instantaneous value of 600 [l / min] (minute substitution) as shown in FIG. 3C, but in the case of the method of the present invention, As shown in d), the instantaneous value of Fn = (60 · 10) / 2 = 300 [l / min] can be continuously displayed on the indicator 14.

Further, if the instantaneous value of the pulse signal representing the physical quantity such as the flow rate, the electric energy, the length, etc. can be accurately measured as described above, it contributes to the improvement of the safety and controllability of the control device which handles various physical quantities. can do.

[0023]

As described above, according to the invention of claim 1, the instantaneous value of the physical quantity can be accurately measured without being affected by the timing of the processing cycle. In the invention of claim 2,
For those that generate pulse signals with different pulse intervals according to changes in the measured physical quantity, this pulse interval time is measured and the instantaneous value is calculated using this pulse interval time, so it is not affected by the timing of the processing cycle. The instantaneous value of the physical quantity can be measured stably and accurately for each processing cycle, and it can be applied to a control device or the like to improve safety and controllability.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of a measuring apparatus to which an instantaneous value measuring method of a pulse signal according to the present invention is applied.

FIG. 2 is a flow chart illustrating the operation of the method and apparatus of the present invention.

FIG. 3 is a time chart for explaining the present invention and a conventional comparative example.

FIG. 4 is a configuration diagram showing an embodiment of a measuring apparatus to which a conventional pulse signal instantaneous value measuring method is applied.

FIG. 5 is a flowchart for explaining the operation of the conventional device.

FIG. 6 is a flowchart illustrating a problem of the conventional device.

FIG. 7 is a flowchart for explaining the operation of the conventional device when the pulse rate is small.

FIG. 8 is a flowchart illustrating a problem of the conventional device when the pulse rate is high.

[Explanation of symbols]

 11 ... Pulse oscillator. 12 ... Pulse interval measuring unit. 13 ... Instantaneous value calculation unit. 14 ... Indicator.

Claims (2)

[Claims] 1. An instantaneous value of a pulse signal, characterized in that the pulse intervals of pulse signals having different pulse intervals are measured according to changes in the physical quantity, and an instantaneous value of the physical quantity is obtained from the pulse interval and the pulse rate. Measuring method. 2. A pulse signal generating means for generating pulse signals having different pulse intervals according to a change in physical quantity, and a pulse interval measuring means for measuring a pulse interval time of a pulse signal generated from the pulse signal generating means, An instantaneous value measuring device for a pulse signal, comprising: an instantaneous value calculating means for calculating an instantaneous value using the pulse interval time measured by the pulse interval measuring means.