JPH02268264A - Leaking-liquid detecting apparatus - Google Patents

Abstract

PURPOSE:To improve detecting accuracy by preventing erroneous detection at an input stage of measured data and a judging stage for leaking of liquid. CONSTITUTION:The electric characteristics of a sensor 1 are changed by the occurrence of the leaking of liquid. The data in the sensor are read with a data reading means 2. Of all the data of one cycle, the maximum and minimum values are removed and the average value of the remaining data is outputted from an average-data computing means 3 as the measured value. When the output data of the means 3 exceed an allowance value (a) or the changing amount per unit time exceeds the allowance value, an abnormality detection signal is outputted from an abnormality detecting means 4. When the abnormal signals are outputted continuously at least twice, a leaking-liquid judging means 5 outputs a leaking-liquid detection signal (b). Thus the highly precise detection of the leaking of liquid can be performed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a device that detects the occurrence of liquid leakage using a sensor whose electrical characteristics, such as resistance value and impedance, change upon contact with liquid leakage.

[Prior art] In a conventional liquid leakage detection device, the electrical characteristic value (resistance value, etc.) of the sensor is measured, for example, once every 5 seconds by a device body equipped with a microcomputer. The presence or absence of leakage is determined based on the data.

[Problem to be solved by the invention] However, the time required to actually read the resistance value etc. of the sensor is extremely short, about several hundred m5ec, and if noise gets mixed in during that time, measurement accuracy may drop and malfunction may occur. There was a problem that this occurred.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention, as shown in the configuration in FIG. A data reading means 2 that reads data multiple times calculates the average value of the remaining data excluding the maximum and minimum among all the data read in one cycle by the data reading means 2, and the average value is used as the measured data. and an abnormality that generates an abnormality detection signal when the data output by the average data calculation means 3 exceeds a tolerance value or when the change per unit time of the data exceeds a tolerance value. It is provided with a detection means 4 and a liquid leakage determination means 5 which determines that a liquid leakage has occurred and issues a liquid leakage detection signal when the abnormality detection signal is emitted from the abnormality detection means at least twice in succession.

[Function] In the liquid leakage detection device of the present invention, the average data calculation means 3 outputs the average value after cutting off the maximum and minimum of the measured data, so it is possible to prevent noise from entering the data, for example. Even if there is noise, the noise-containing data can be discarded, and only the noise-free data can be adopted as regular measurement data.

Further, even if the abnormality detection means issues an abnormality detection signal due to the influence of noise, for example, it will not be determined that a liquid leak has occurred unless this occurs two or more times in succession. Therefore, even if noise is picked up, there is almost no possibility of outputting an erroneous detection result.

[Example] Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 2 shows a schematic configuration of a liquid leakage detection device according to an embodiment. This device has a microcomputer 10 inside the device body.
Equipped with SA/D converter 11 and clock 12,
A signal from the sensor 1 is input to a microcomputer 10 via an A/D converter 11.

The microcomputer 10 functionally constitutes the data reading means 2, the average data calculation means 3, the abnormality detection means 4, and the leakage determination means 5 shown in FIG. The value is read to determine whether leakage has occurred, and the results are output as an alarm or other method.

In this case, as shown in Figure 3, measurement, calculation, and judgment are performed in five steps.
One second is considered as one cycle (CYCLE), and the data of the sensor 1 is read (sampled) four times at 1 second intervals during 5 seconds of one cycle. The time required for one sampling is l Q Q m5ec.

After sampling is performed four times, the maximum and minimum sampling data are discarded within the remaining time, and the average value of the remaining two data is calculated. Thereafter, data processing is performed using the average value as measurement data. The details of the processing will be explained based on FIG. 4.

Actual liquid leakage determination modes include high-speed liquid leakage, medium-speed liquid leakage, and low-speed liquid leakage. In the high-speed leakage mode, determination is made based on measurement data for each cycle, and in the medium-speed and low-speed leakage modes, leakage determination is performed based on monitoring over a longer period of time. Erroneous detection due to noise contamination occurs in the high-speed liquid leakage determination mode, so only the high-speed liquid leakage determination mode will be described here.

When the average value of the data is calculated for each cycle as described above (step 101 in Figure 4), it is determined whether there is an oven failure (disconnection), a short circuit failure, or a fault failure within that cycle based on the data. (a phenomenon in which the resistance value exceeds the allowable range for normal use due to deterioration over time)
Steps 102.103.104). In the case of a failure, after setting a flag corresponding to each failure, it is determined whether or not there has been a failure (error) of this type in the past (Step 108), and if there has been no failure, the "one-time error flag" is set. Step 109 to retain the previous data.
), this time's processing ends.

Additionally, if a similar error has occurred in the past, it will be officially recognized as an error and the error flag J will be set.
Reset the 1-time error flag (step 11)
0).

Furthermore, even if there is no open, short, or fault in the current process, if there is a determination error, the process ends (step 111).

If there is no determination error, it is determined whether or not an abnormality was detected last time (step 120); if no abnormality was detected, the previous data is read and compared with the current data to determine whether or not there is an abnormality. Perform (steps 121 and 123
．． 124). In addition, if an abnormality was detected last time, the data from the previous time is read (step 122) and compared with the current data to determine whether or not there is an abnormality (step 1).
23.124).

If it is determined in step 124 that an abnormality has been detected, it is determined whether or not an abnormality was detected last time (step 125). If no abnormality was detected last time, the "1-time abnormality flag" is set and Keep data and exit. In addition, if an abnormality was detected last time, that is, if an abnormality was detected twice in a row, it is determined that a high-speed liquid leak has occurred for the first time, and the high-speed liquid leak detection flag is set. Reset the "Yes flag" and exit.

Also, if no abnormality is detected this time in step 123,
Reset the "1-time abnormality flag" and end.

Therefore, according to the device of the embodiment, it is determined that a liquid leak has occurred only when an abnormality is detected twice in a row.

As a result, even if, for example, one data is contaminated with noise and a false detection is made, it will not be determined that a liquid leak has been detected based on that data alone. Furthermore, since the data itself that serves as the basis for determination is averaged with the maximum and minimum values discarded, noise is cut out, and the reliability of detection is improved in this respect as well.

[Effects of the Invention] As explained above, according to the liquid leakage detection device of the present invention,
Two stages: the stage of incorporating measurement data and the stage of determining leakage
Since false detection due to noise is prevented at two stages,
It becomes possible to perform Bi(l detection with high accuracy).

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of a liquid leakage detection device according to the present invention, FIG. 2 is a schematic configuration diagram of a liquid leakage detection device according to an embodiment of the present invention, and FIG. 3 is a block diagram showing the configuration of a liquid leakage detection device according to the embodiment. A timing chart showing the timing, and FIG. 4 is a flowchart showing the control procedure by the apparatus of the same embodiment. ■...Sensor, 2...Data reading means, 3...Average data calculation means, 4...
...Anomaly detection means, 5...Leakage determination means.

Claims (1)

[Claims] Data reading means for reading data multiple times in one cycle from a sensor whose electrical characteristics change due to the occurrence of liquid leakage; An average data calculation means that calculates the average value of the remaining data excluding the average value and outputs the average value as measurement data, and when the data output by the average data calculation means exceeds a permissible value, or when the data An abnormality detection means that issues an abnormality detection signal when the amount of change per unit time exceeds an allowable value; and when the abnormality detection signal is issued at least twice in succession from the abnormality detection means, it is determined that a leak has occurred and the leakage is detected. A liquid leakage detection device comprising: a liquid leakage determination means for emitting a liquid detection signal.