JP2022149893A - Abnormality detection device using battery-type sensor - Google Patents

Abstract

To provide an abnormality detection device using a battery-type sensor capable of accurately detecting abnormality that occurs in a state quantity of a fluid while suppressing battery consumption.SOLUTION: An abnormality detection device 1 includes a time zone setting section 11, a detection frequency varying section 12, and an abnormality detection section 13 in order to detect a state quantity of a fluid by using a battery-type sensor 2. The time zone setting section 11 sets, in time zones of one day, a first time zone where it is predicted that a change of the state quantity of the fluid due to a disturbance is suppressed within an assumed change range, and a second time zone where it is predicted that a change of the state quantity of the fluid due to a disturbance has a possibility of deviating from the assumed change range. The detection frequency varying section 12 sets a detection frequency in the first time zone to be higher than the detection frequency in the second time zone. The abnormality detection section 13 sets the range of a first permission value of abnormality detection in the first time zone to be narrower than the range of a second permission value of abnormality detection in the second time zone.SELECTED DRAWING: Figure 1

Description

The present invention relates to an abnormality detection device using a battery-powered sensor.

For example, in various factories, piping through which air, steam, cooling water, and other various fluids flow while being pressurized to a predetermined pressure is used. Moreover, various fluids are used after being heated or cooled to a predetermined temperature. State quantities such as fluid pressure and temperature are measured by sensors (measuring instruments) provided in various facilities or pipes.

For example, in the air leak detection method of Patent Document 1, a pressure gauge is used to monitor the pressure of compressed air used in an air jet loom to detect whether or not compressed air leaks. It is

JP 2013-83016 A

By the way, in various facilities or pipes, it is not always necessary to monitor abnormalities occurring in various state quantities of fluids, but there are cases where it is desired to temporarily monitor them as necessary. In addition, when using a wire-powered sensor that receives power from a commercial power supply, power supply construction is required in equipment or piping to supply commercial power to the wire-powered sensor, and this work is time-consuming. . In some cases, power supply construction may not be possible.

In such a case, it is conceivable to use a battery-powered sensor, which receives power from a battery, instead of a wired-powered sensor. Note that Patent Document 1 does not describe the use of a battery-powered sensor for the pressure gauge.

When a battery-powered sensor is used to detect abnormalities occurring in various state quantities of fluids, it is necessary to replace the battery every predetermined usage time depending on the capacity of the battery. In other words, if the state quantity is detected frequently, the battery will be exhausted quickly, and it will be necessary to replace the battery frequently.

In addition, the state quantity of the fluid may fluctuate greatly as a disturbance factor due to the use of the fluid, for example, when various facilities in the factory are in operation. In the air leakage detection method of Patent Document 1, no device is made to solve the problem of battery exhaustion and the influence of disturbance factors. Therefore, in order to detect an abnormality occurring in the state quantity of the fluid while reducing the influence of disturbance factors and suppressing battery consumption, further ingenuity is required.

SUMMARY OF THE INVENTION The present invention has been made in view of such problems, and an object thereof is to provide an anomaly detection device using a battery-powered sensor capable of suppressing battery consumption and accurately detecting an anomaly occurring in a fluid state quantity. It is something to do.

One aspect of the present invention is
An abnormality detection device that uses a battery-powered sensor that operates by receiving power from a battery to detect a state quantity of a fluid flowing through a detection target device or a pipe, and detects an abnormality that occurs in the state quantity,
A first time period in which the increase/decrease amount, increase/decrease speed, and increase/decrease frequency of the state quantity due to a disturbance are predicted to fall within a predetermined assumed fluctuation range, and the increase/decrease amount, increase/decrease of the state quantity due to the disturbance, in a time period of one day. a time period setting unit configured to set a second time period during which the speed or increase/decrease frequency is likely to deviate from the assumed fluctuation range;
a detection frequency variable unit that increases the frequency with which the battery-powered sensor detects the state quantity in the first time period compared to the frequency with which the battery-powered sensor detects the state quantity in the second time period;
When the state quantity detected by the battery-powered sensor is out of the range of a predetermined first allowable value in the first time period, an abnormality occurring in the state quantity is detected and the second time period is detected. an anomaly detection unit that detects an anomaly occurring in the state quantity when the state quantity detected by the battery-powered sensor falls outside a range of a second allowable value that is wider than the range of the first allowable value; and an anomaly detection device using a battery-powered sensor.

In the anomaly detection device using the battery-powered sensor of the one aspect, by including the time period setting unit, the detection frequency variable unit, and the anomaly detection unit, the The state quantity of the fluid is detected. Specifically, in the time period setting unit, the first time period in which disturbance factors that affect the state quantity of the fluid are expected to be few, and the time period that affects the state quantity of the fluid A second time period in which many disturbance factors are expected is set. The disturbance factor appears as an increase/decrease amount, an increase/decrease speed, or an increase/decrease frequency of the state quantity of the fluid.

In the detection frequency varying unit, the frequency of detecting the state quantity of the fluid is set higher in the first time slot in which fewer disturbance factors are expected than in the second time slot. Further, in the abnormality detection unit, when monitoring the state quantity of the fluid in the first time period and the second time period, there is a mechanism for determining that there is no abnormality when monitoring the state quantity of the fluid in the first time period. The range of the predetermined first allowable value is narrower than the range of the predetermined second allowable value for determining that there is no abnormality when monitoring the state quantity of the fluid in the second time period.

With this configuration, the detection of an abnormality occurring in the state quantity of the fluid is performed intensively and frequently in the first time period when there are few disturbance factors. Therefore, it is possible to accurately detect an abnormality occurring in the state quantity of the fluid. Further, in the second time period, the frequency of detection of the state quantity of the fluid is low, so that the consumption of the battery of the battery-powered sensor can be suppressed while the necessary minimum monitoring is continued.

Therefore, according to the anomaly detection device using the battery-powered sensor of the aspect, it is possible to suppress battery consumption and accurately detect an anomaly occurring in the state quantity of the fluid.

FIG. 1 is an explanatory diagram showing an abnormality detection device using a battery-powered sensor according to a first embodiment. FIG. 2 is a graph showing changes in gas pressure over time periods of a day according to the first embodiment. FIG. 3 is a graph showing changes in gas pressure during startup of the device to be detected according to the first embodiment. FIG. 4 is a graph showing changes in gas pressure after the device to be detected starts to stop, according to the first embodiment. FIG. 5 is a flowchart showing an abnormality detection method by the abnormality detection device according to the first embodiment; 6 is a flow chart showing the start-up routine of FIG. 5 according to the first embodiment; FIG. 7 is a flow chart showing the stop routine of FIG. 5 according to the first embodiment; FIG. FIG. 8 is an explanatory diagram showing an abnormality detection device using a battery-powered sensor according to the second embodiment.

A preferred embodiment of the abnormality detection device using the battery-powered sensor described above will be described with reference to the drawings.
<Embodiment 1>
As shown in FIG. 1, the abnormality detection device 1 using the battery-powered sensor 2 of the present embodiment uses the battery-powered sensor 2 that operates by receiving power from the battery 21 to detect the fluid flowing through the detection target device 3 or the pipe 4. is detected, and an abnormality occurring in this state quantity is detected. The anomaly detection device 1 includes a time zone setting section 11 , a detection frequency varying section 12 and an anomaly detection section 13 .

As shown in FIGS. 2 to 4, in the time period setting unit 11, the increase/decrease amount, increase/decrease rate, and increase/decrease frequency of the state quantity of the fluid due to disturbance in the time period of one day are within a predetermined assumed variation range. A first time period t1 predicted to be contained and a second time period t2 predicted to possibly deviate from a predetermined assumed fluctuation range of the increase/decrease amount, increase/decrease speed, or increase/decrease frequency of the state quantity of the fluid due to disturbance. set. The detection frequency varying unit 12 compares the frequency with which the battery-powered sensor 2 detects the state quantity of the fluid in the first time period t1 to the frequency with which the battery-powered sensor 2 detects the state quantity of the fluid in the second time period t2. configured to be elevated.

As shown in FIG. 2, the abnormality detection unit 13 detects the state quantity of the fluid detected by the battery-powered sensor 2 in the first time slot t1 when it is out of the range of predetermined first tolerance values k1a and k1b. , an abnormality occurring in the state quantity of the fluid is detected, and the state quantity of the fluid detected by the battery-powered sensor 2 in the second time period t2 is set to a second allowable value wider than the range of the first allowable values k1a and k1b. It is configured to detect an abnormality that occurs in the state quantity of the fluid when it is out of the range of k2.

The abnormality detection device 1 using the battery-powered sensor 2 of this embodiment will be described in detail below.
(Abnormality detection device 1)
The abnormality detection device 1 monitors state quantities of fluids such as air, steam, and cooling water used in a factory, and detects whether there are any abnormalities in these state quantities. The abnormality detection device 1 of this embodiment detects the presence or absence of an abnormality occurring in the pressure P of the gas A as the state quantity of the fluid. The abnormality detection device 1 is configured using a computer such as a PLC (programmable logic controller, sequencer). When the abnormality detection device determines that there is an abnormality in the pressure P, the abnormality may be displayed by a display device, an abnormality warning may be issued by an alarm device, or the like.

(Battery type sensor 2)
As shown in FIG. 1, the battery-powered sensor 2 is installed in the piping 4 of various detection target devices 3, and unlike the wired power supply type sensor that requires a wired power supply, the battery-powered sensor 2 can be easily installed without performing electrical work in the facility. can be used Moreover, the battery-powered sensor 2 has the advantage that it can be used even in places where electrical work is difficult.

Moreover, the battery-powered sensor 2 is portable to various places, and is used by temporarily attaching it to the piping 4 of the device 3 to be detected as required. The battery-powered sensor 2 receives power from the battery 21 and operates while the wired sensor operates by receiving power from a commercial power source.

The battery 21 used in the battery-powered sensor 2 may be either a primary battery or a secondary battery (storage battery) housed inside the battery-powered sensor 2 . Alternatively, the battery-powered sensor 2 may be configured to receive power from a storage battery connected to the solar panel 22 indicated by the dashed line in FIG. The storage battery in this case may be arranged outside the battery-powered sensor 2 .

The battery-powered sensor 2 of this embodiment is connected to the abnormality detection device 1 by a signal line for sending a state quantity signal. It should be noted that, as will be described in detail in a second embodiment described later, the battery-powered sensor 2 is actually assumed to be used in a place where electrical work is difficult, and a state quantity signal is transmitted wirelessly to the abnormality detection device 1. It may be configured to

(Detection target device 3 and piping 4)
As shown in FIGS. 1 and 2, the device 3 to be detected in this embodiment is a compressor 3 that includes a pump that is driven by a motor, a tank that stores pressurized gas, and the like. Gas A such as air pressurized to a predetermined target pressure Pr by the compressor 3 flows through the pipe 4 through which the state quantity of the fluid is detected by the battery-powered sensor 2 of the present embodiment. The battery-powered sensor 2 detects the pressure P of the gas A in the pipe 4 as a state quantity.

The pressure P of the gas A in the pipe 4 is controlled by the compressor 3 to be the target pressure Pr, and fluctuates according to the operation of various facilities 5 using the gas A. When detecting the presence or absence of an abnormality in the pressure P of the gas A as a state quantity of the fluid, the operation of the various equipment 5 becomes a disturbance factor for abnormality detection as a factor that changes the pressure P of the gas A. . For example, when a large amount of the gas A in the pipe 4 is temporarily used in the facility 5, the pressure P of the gas A in the pipe 4 is temporarily lowered.

In addition to the compressor 3, the detection target device 3 may be various devices such as a pump, a tank, and the like that send out fluid. The pipe 4 may be various pipes through which a fluid flows, other than the pipe 4 connected to the detection target device 3 . The fluid can be either gas A or liquid. In addition to the pressure P, temperature, flow rate, and the like are also available as fluid state quantities for which an abnormality is detected by the abnormality detection device 1 .

(Time zone setting unit 11)
As shown in FIG. 1, in the time period setting unit 11, the time period for performing abnormality detection in one day is divided into a first time period t1 and a second time period t2. In the time period setting unit 11, the time period in which the operation of the equipment 5 has a large influence on the pressure P of the gas A as a disturbance factor is defined as the second time period t2, which is distinguished from the first time period t1. In other words, the first time period t1 is set to the first time period t1 when there is relatively little disturbance that changes the pressure P of the gas A, and the second time period is set to the second time period t1 It is set to band t2. Fluctuations in the pressure P of the gas A due to the start-up and stoppage of the compressor 3 are not included in the disturbance because similar pressure histories are obtained in similar time zones every day.

As shown in FIG. 2, the first time period t1 is predicted to be a time period in which there are few disturbance factors that cause the pressure P of the gas A to fluctuate. Therefore, when the pressure P of the gas A flowing through the pipe 4 fluctuates more than expected in the first time period t1, it means that the pressure P of the gas A flowing through the pipe 4 is abnormal. , an abnormality such as a gap, a leak hole, or a crack in the pipe 4, and an abnormality in the compressor 3 that supplies the gas A at a predetermined pressure P to the pipe 4. The abnormality detection device 1 detects an abnormality occurring in the pressure P of the gas A with high accuracy in the first time period t1.

Fluctuations occurring in the pressure P as the state quantity of the gas A in the pipe 4 are the amount of increase or decrease as the range in which the absolute value of the pressure P increases or decreases, the rate of increase or decrease as the range of speed in which the pressure P changes, or the change in the pressure P. It can be regarded as the increase/decrease frequency as the range of the number of times to change. In particular, when the pressure P of the gas A drops rapidly, the increase/decrease amount and increase/decrease speed increase, and when the pressure P of the gas A repeatedly decreases, the increase/decrease frequency increases (increases).

If any one of the amount of increase/decrease, the speed of increase/decrease, and the frequency of increase/decrease increases due to disturbance, it is considered that the operation of the equipment 5 using the gas A flowing through the pipe 4 has a large influence. Therefore, the time period in which the increase/decrease amount, increase/decrease speed, and increase/decrease frequency of the pressure P of the gas A due to disturbance are all predicted to fall within a predetermined assumed fluctuation range is defined as the first time period t1, and the other time period is the second time period. distinguished as t2.

The first time period t1 in the time period setting unit 11 can be set as a timing at which disturbance factors that change the pressure P as the state quantity of the gas A are considered to be few. The first time period t1 is, for example, during startup of the detection target device 3, within a predetermined time ta after the startup of the detection target device 3, within a predetermined time tb before the detection target device 3 stops, or within a predetermined time tb before the detection target device 3 stops. may be set within a predetermined time after the start of stop. During these times, the equipment 5 using the gas A does not operate, and the pressure history when there is no abnormality is considered to be stable. It is ideal for monitoring how

As shown in FIG. 3, during startup of the compressor 3 as the device 3 to be detected, the pressure P of the gas A rises at a predetermined speed until it reaches the target pressure Pr. At this time, when there is no abnormality in the compressor 3 or the pipe 4 connected to the compressor 3, the rising speed of the pressure P detected by the battery-powered sensor 2 arranged in the pipe 4 is within a predetermined range as a normal range. It is within the range of the first allowable value k1a. For example, when the rising speed of the pressure P of the gas A detected in the first time period t1 is slower than the range of the first allowable value k1a, the abnormality detection unit 13 detects the abnormality of the pressure P as the compressor 3 or It is possible to detect that an abnormality has occurred in the pipe 4 . It is considered that the facility 5 using the gas A is not operating while the compressor 3 is starting up, and there are few disturbance factors that fluctuate the pressure P of the gas A. The start-up time (during start-up) of the compressor 3 is set, for example, as a time period of about 30 minutes in the morning (from 6:00 to 9:00).

The range of the first allowable value k1a for the rising speed of the pressure P can be obtained by actually measuring the range of the normal rising speed of the pressure P when starting the compressor 3 and storing it in the abnormality detection device 1 . The rate of increase of the pressure P may be the change in the pressure P within a predetermined period of time after the compressor 3 is started. Further, the rising speed of the pressure P may be regarded as a rising curve of the pressure P as the start-up relation map M1. In this case, when the compressor 3 is started (started up), the normal rise curve of the pressure P is actually measured and stored in the abnormality detection device 1 . Then, when the value of the pressure P of the gas A at each time after the start of the compressor 3 detected in the first time period t1 is lower than the range of the predetermined first allowable value k1a from the rising curve of the pressure P Furthermore, the abnormality detection unit 13 can detect that the compressor 3 or the pipe 4 is abnormal.

The predetermined time as the first time period t<b>1 after the compressor 3 is activated may be a time period preset in the time period setting unit 11 . Also, this predetermined time may be a predetermined time after a command to start the compressor 3 is transmitted to the compressor 3 from a control device such as a sequencer that controls the compressor 3 .

As shown in FIG. 2, even within a predetermined time ta after the compressor 3 is started up, in most cases the equipment 5 using the gas A is not in operation. Moreover, in most cases, the operation of the facility 5 using the gas A has already stopped within the predetermined time tb before the compressor 3 stops. Therefore, during these predetermined times ta and tb, there are few disturbance factors, and it is suitable for detecting an abnormality in the pressure P of the gas A.

As shown in FIG. 4, after the compressor 3 starts to stop moving, the gas A remains in the pipe 4 connected to the compressor 3, and the pressure P of the gas A in the pipe 4 gradually increases. declining. The predetermined time as the first time period t<b>1 after the compressor 3 starts to stop may be a time period preset in the time period setting unit 11 . Also, this predetermined time may be a predetermined time after a command to stop the compressor 3 is sent to the compressor 3 from a control device such as a sequencer that controls the compressor 3 .

Then, when there is no abnormality in the pipe 4 connected to the compressor 3, the rate of decrease of the pressure P detected by the battery-powered sensor 2 arranged in the pipe 4 is a predetermined first allowable value as a normal range. falls within the range of k1b. For example, when the rate of decrease of the pressure P is faster than the range of the first allowable value k1b, the abnormality detection unit 13 can detect that an abnormality has occurred in the pipe 4 as an abnormality of the pressure P. . When the compressor 3 is stopped, for example, it is set as a time period of about one hour at night (18:00 to 21:00).

The range of the first allowable value k1b for the rate of decrease of the pressure P can be obtained by actually measuring the range of the rate of decrease of the normal pressure P in the pipe 4 after stopping the operation of the compressor 3 and storing it in the abnormality detection device 1. good. The rate of decrease of the pressure P may be the change in the pressure P within a predetermined time period after the compressor 3 is stopped. Further, the rate of decrease of the pressure P may be regarded as a decrease curve of the pressure P as the relationship map M2 at stop. In this case, after the compressor 3 is stopped, the normal pressure P drop curve is actually measured and stored in the abnormality detection device 1 . Then, when the value of the pressure P of the gas A at each time after the compressor 3 is stopped, which is detected in the first time period t1, is lower than the range of the predetermined first allowable value k1b from the decrease curve of the pressure P Furthermore, the abnormality detection unit 13 can detect that the pipe 4 has an abnormality.

As shown in FIG. 2, the operation status of the facility 5 is monitored during a predetermined time ta after the startup of the detection target device 3 and a predetermined time tb before the detection target device 3 is stopped, which are set as the first time period t1. and appropriately determined as the time during which the facility 5 is not in operation. The anomaly detection device 1 repeatedly learns, over a plurality of days, the time periods during which the pressure P of the gas A fluctuates more during the day, and determines the first time period t1 and the second time period t2. A learning unit 14 may be further provided.

As shown in FIG. 1, the learning unit 14 repeatedly detects the pressure P as the state quantity of the gas A by the battery-powered sensor 2 over a period of several days, may be configured to specify a time period during which there is a possibility that the value will deviate from the expected fluctuation range. Then, even during the time period when the equipment 5 is in operation, the time period in which the increase/decrease amount, increase/decrease rate, and increase/decrease frequency of the pressure P of the gas A due to disturbance is predicted to fall within the assumed fluctuation range is defined as the first time period. It may be included in band t1.

(Detection frequency variable unit 12)
As shown in FIG. 1, the detection frequency varying unit 12 is configured to vary the frequency at which the battery-powered sensor 2 detects the pressure P of the gas A between the first time period t1 and the second time period t2. . In the first time period t1, the detection frequency is increased because there are few disturbance factors when detecting an abnormality.

As shown in FIGS. 2 to 4, the detection frequency variable unit 12 of the present embodiment sets the first sampling interval s1, which is the time interval at which the battery-powered sensor 2 detects the pressure P of the gas A in the first time period t1, to It is configured to be shorter than the second sampling interval s2 at which the battery-powered sensor 2 detects the pressure P of the gas A in the second time period t2. In other words, the abnormality detection unit 13 detects the pressure P of the gas A by the battery-powered sensor 2 at the first sampling interval s1 during the first time period t1, and detects the pressure P of the gas A during the second time period t2. The pressure P of the gas A is detected by the battery-powered sensor 2 at a second sampling interval s2 longer than one sampling interval s1.

The first sampling interval s1 may be set, for example, between 30 seconds and 10 minutes, and the second sampling interval s2 may be set, for example, between 10 minutes and 120 minutes. The second sampling interval s2 may be set to be, for example, 2 to 20 times the first sampling interval s1.

By detecting the pressure P of the gas A at the first sampling interval s1 in the first time period t1, an abnormality occurring in the pressure P of the gas A can be quickly and appropriately detected. On the other hand, in the second time period t2, by detecting the pressure P of the gas A at the second sampling interval s2, it is possible to moderate the consumption of the battery 21 while continuing the necessary minimum monitoring.

In addition, in order to appropriately suppress the usage of the battery 21 in the battery-powered sensor 2, based on the capacity of the battery 21, the length of time the first time period t1 continues, the first sampling interval s1, the second time period The length of time that t2 lasts, the second sampling interval s2, etc. may be determined. More specifically, if the capacity of the battery 21 and the amount of power and standby power required for one detection and communication of the pressure P of the gas A are known, the length of time that the first time period t1 continues, The duration (life) of the battery 21 can be determined by setting the number of times of detection/communication per unit time based on the duration of the first sampling interval s1 and the second time period t2 and the second sampling interval s2. Accordingly, in order to achieve the target service life of the battery 21, the length of time that the first time period t1 continues, the length of time that the first sampling interval s1 continues, the length of time that the second time period t2 continues, and the 2 sampling intervals s2 may be determined.

(Abnormality detection unit 13)
As shown in FIG. 1, the abnormality detection unit 13 detects the state of the pressure P of the gas A detected by the battery-powered sensor 2 from the start of the compressor 3 until a predetermined time has elapsed since the compressor 3 stopped. Monitor. In the first time period t1, since there are few disturbance factors due to the operation of the equipment 5, the range of the predetermined first allowable values k1a and k1b that serve as the reference for abnormality detection can be narrowed down as narrow as possible. As a result, the accuracy of abnormality detection of the pressure P of the gas A in the first time period t1 can be improved.

On the other hand, in the second time period t2, since there are many disturbance factors, it is not possible to perform highly accurate abnormality detection especially when using a battery-powered sensor that has a large restriction on the detection frequency of the state quantity such as the pressure P. . However, in the second time period t2, the range of the second allowable value k2, which is wider than the range of the first allowable values k1a and k1b, is used as a reference for detecting an abnormality. By performing the abnormality detection of the pressure P of the gas A by the abnormality detection unit 13 even in the second time period t2, it is possible to monitor whether or not the pressure P of the gas A has a serious abnormality.

The first permissible value k1a set during startup of the detection target device 3 may be determined as a predetermined range of values larger and smaller than the values in the startup relation map M1. The first allowable value k1b, which is set within a predetermined time period after the detection target device 3 starts to stop, may be set as a predetermined range of values larger and smaller than the values in the stop time relationship map M2. The first permissible value set within a predetermined time ta after startup of the detection target device 3 and within a predetermined time tb before stopping the detection target device 3 is a predetermined value larger or smaller than the value of the target pressure Pr. should be defined as the range of

The first allowable value k1a may be changed so as to increase with the lapse of time from after the compressor 3 is started up until the start-up is completed, taking account of the accumulation of errors. Also, the first allowable value k1b may be changed so as to increase with the lapse of time after the compressor 3 starts to stop, taking into account the accumulation of errors. Similarly, the second allowable value k2 may be changed so as to increase with the passage of time in the second time period t2. In particular, when monitoring the leakage of the gas A, in order to more closely monitor the side where the pressure P decreases, the rising curve of the pressure P, the decreasing curve of the pressure P, or the target pressure Pr is used as a reference, The allowable downward swing may be smaller than the allowable upward swing.

(Abnormality detection method by abnormality detection device 1)
An example of an abnormality detection method by the abnormality detection device 1 will be described below with reference to the flow charts of FIGS. 5 to 7. FIG. In the time zone setting unit 11 of the present embodiment, the first time zone t1 is set during startup of the compressor 3 and within a predetermined time after the compressor 3 starts to stop. It is assumed that the abnormality detection device 1 is always activated.

In the abnormality detection device 1, the abnormality detection unit 13 determines whether or not the start-up time of the compressor 3 has come (step S101 in FIG. 5). In step S101, it may be determined whether or not it has been detected that the compressor 3 has started up. For example, in step S101, it may be determined whether or not a signal for starting up the compressor 3 has been input to the abnormality detection device 1, or whether or not there has been a timing at which the pressure P rises significantly. When the compressor 3 starts up, a start-up routine is executed (step S102).

In the start-up routine, the abnormality detection unit 13 detects that it is in the first time period t1, and the battery-powered sensor 2 starts detecting the pressure P of the gas A in the pipe 4 at the first sampling interval s1 ( Step S201 in FIG. 6). Next, the value of the pressure P at each point in time from the startup start point is compared with the pressure at each corresponding point in the rising curve of the startup relation map M1 (step S202). In FIG. 3, the value of pressure P at each time point is indicated by symbol p.

Next, it is determined whether the pressure P at each time point is within the range of a predetermined first allowable value k1a for the rising curve (step S203). When the pressure P at each time point is within the range of the first allowable value k1a for the rising curve, the abnormality detection unit 13 does not detect the pressure P abnormality. On the other hand, when the pressure P at each time point is not within the range of the first allowable value k1a for the upward curve, the abnormality detection unit 13 detects abnormality of the pressure P (step S204). In this case, a display device, an alarm device, or the like is used to call attention.

After that, steps S201 to S205 are repeatedly executed until a predetermined start-up time elapses (step S205). When the start-up time has elapsed, the start-up routine (S102) ends.

Further, in the abnormality detection device 1, the abnormality detection unit 13 determines whether or not the stop time of the compressor 3 has come (step S103 in FIG. 5). In step S103, it may be determined whether or not it has been detected that the compressor 3 has stopped. For example, in step S103, it may be determined whether or not a signal to stop the compressor 3 has been input to the abnormality detection device 1, or whether or not there has been a timing when the fluctuation of the pressure P has become extremely small. . When the compressor 3 stops, a stop routine is executed (step S104).

In the stop routine, the abnormality detection unit 13 detects that it is in the first time period t1, and the battery-powered sensor 2 starts detecting the pressure P of the gas A in the pipe 4 at the first sampling interval s1 (Fig. 7 step S301). Next, the value of the pressure P at each point in time from the stop start time is collated with the pressure at each corresponding point in the decrease curve of the stop time relationship map M2 (step S302). In FIG. 4, the value of pressure P at each time point is indicated by symbol p.

Next, it is determined whether the pressure P at each time point is within the range of the predetermined first allowable value k1b for the decrease curve (step S303). When the pressure P at each time point is within the range of the first allowable value k1b for the decrease curve, the abnormality detection unit 13 does not detect the pressure P abnormality. On the other hand, when the pressure P at each time point is not within the range of the first allowable value k1b for the decrease curve, the abnormality detection unit 13 detects abnormality of the pressure P (step S304). In this case, a display device, an alarm device, or the like is used to call attention.

Thereafter, steps S301 to S305 are repeatedly executed until a predetermined stop time elapses (step S305). When the stop time has passed, the stop routine (S104) ends. The stop routine may be repeatedly executed until the compressor 3 is started up instead of being repeatedly executed until a predetermined stop time elapses.

Further, in the abnormality detection device 1, when neither startup nor stop of the compressor 3 is detected (steps S101 and S103), the abnormality detection section 13 is in the second time period t2. to detect. Then, the battery-powered sensor 2 starts detecting the pressure P of the gas A in the pipe 4 at the second sampling interval s2 (step S105 in FIG. 5).

Next, it is determined whether the pressure P detected in the second time period t2 is within the range of a predetermined second allowable value k2 (step S106). When the pressure P is within the range of the second allowable value k2, the abnormality detection unit 13 does not detect the pressure P abnormality. On the other hand, when the pressure P is not within the range of the second allowable value k2, the abnormality detection unit 13 detects abnormality of the pressure P (step S107). In this case, a display device, an alarm device, or the like is used to call attention. Steps S105 to S107 are repeatedly executed during the second time period t2 except when the compressor 3 is started up and stopped.

In this embodiment, it is assumed that the second time period t<b>2 is the time period except for the predetermined time period during startup of the compressor 3 and after it is stopped, and the abnormality detection by the abnormality detection device 1 is continued. Besides this, the abnormality detection by the abnormality detection device 1 is stopped after the abnormality detection when the compressor 3 is stopped (after the execution of the stop routine S104 is finished) and until the compressor 3 is restarted. may

Also, the first time period t1 may be set only while the compressor 3 is starting up, or may be set only for a predetermined time after the compressor 3 is stopped. Also, the first time period t1 may be set to three or more time periods including within a predetermined time ta after the compressor 3 is started up and within a predetermined time tb before the compressor 3 is stopped.

(Effect)
In the abnormality detection device 1 using the battery-powered sensor 2 of the present embodiment, the time period setting unit 11, the detection frequency changing unit 12, and the abnormality detection unit 13 are provided, so that the detection is performed in a time period when it is expected that there are few disturbance factors. , the pressure P of the gas A is mainly detected. Specifically, in the time period setting unit 11, the first time period t1 in which disturbance factors affecting the pressure P of the gas A are expected to be small, and the pressure P of the gas A A second time period t2 is set in which it is predicted that there will be many disturbance factors affecting the . The disturbance factor appears as an increase/decrease amount, an increase/decrease speed, or an increase/decrease frequency of the pressure P of the gas A.

In the detection frequency varying unit 12, the frequency of detecting the pressure P of the gas A is increased in the first time period t1 in which disturbance factors are expected to be few, compared to the second time period t2. Then, in the abnormality detection unit 13, when the pressure P of the gas A is monitored during the first time period t1 and the second time period t2, an abnormality is detected when the pressure P of the gas A is monitored during the first time period t1. The range of predetermined first allowable values k1a and k1b for determining that there is no abnormality is set to a predetermined second allowable value k2 for determining that there is no abnormality when monitoring the pressure P of the gas A in the second time period t2. is narrower than the range of

With this configuration, the detection of an abnormality occurring in the pressure P of the gas A is performed with high frequency and intensively during the first time period t1 when there are few disturbance factors. Therefore, an abnormality occurring in the pressure P of the gas A can be detected with high accuracy. Further, in the second time period t2, the detection frequency of the pressure P of the gas A is low, so that the battery consumption of the battery-powered sensor 2 can be suppressed while the necessary minimum monitoring is continued.

Therefore, according to the abnormality detection device 1 using the battery-powered sensor 2 of this embodiment, the consumption of the battery 21 can be suppressed, and an abnormality occurring in the pressure P of the gas A can be accurately detected.

<Embodiment 2>
In this embodiment, as shown in FIG. 6, an abnormality detection device 1 using a wireless battery-powered sensor 2 is shown. The battery-powered sensor 2 of this embodiment communicates with the abnormality detection device 1 wirelessly. In this embodiment, there is no signal line between the abnormality detection device 1 and the battery-powered sensor 2 . The anomaly detection device 1 of the present embodiment further includes detection means for detecting the presence or absence of factors that block radio waves for wireless communication. The abnormality detection unit 13 of the present embodiment stops detection of an abnormality occurring in the pressure P of the gas A as the state quantity of the fluid by the battery-powered sensor 2 while the detection means detects that there is a factor that blocks radio waves. is configured to

When the signal communication between the battery-powered sensor 2 and the abnormality detection device 1 is performed wirelessly, physical obstruction between the battery-powered sensor 2 and the abnormality detection device 1 prevents the battery-powered sensor from 2 is not correctly transmitted to the abnormality detection device 1 . For example, wireless communication may be interrupted by the opening and closing of a door provided in the factory, or may be interrupted by the comings and goings of people. In these cases, a monitoring sensor 6 for monitoring the opening and closing of the door or the entry and exit of a person is used as the detection means. While the monitoring sensor 6 detects that the radio wave as a radio signal is blocked by a door or a person, the abnormality detection unit 13 detects the pressure P of the gas A detected by the battery-powered sensor 2. , anomaly detection is not performed. In FIG. 6, symbols Y schematically indicate factors such as doors and people that may block radio waves.

Further, when signal communication is performed wirelessly between the battery-powered sensor 2 and the abnormality detection device 1, the battery-powered sensor may be affected by electromagnetic wave noise when various equipments 5 that emit electromagnetic waves operate. It is conceivable that the pressure P of the gas A by the sensor 2 is not correctly transmitted to the abnormality detection device 1 . In this case, as detection means, the abnormality detection device 1 is provided with a reception section 15 for receiving a trigger signal indicating operation of various facilities 5 . While the receiver 15 is receiving the trigger signal, the abnormality detector 13 does not perform abnormality detection depending on the pressure P of the gas A detected by the battery-powered sensor 2 .

In the abnormality detection device 1 of this embodiment, it is possible not to detect an abnormality occurring in the pressure P of the gas A when an erroneous detection is expected to occur in the wireless battery-powered sensor 2 . As a result, even when the wireless battery-powered sensor 2 is used, the accuracy of detecting an abnormality occurring in the pressure P of the gas A can be improved.

Moreover, in this embodiment, since the wireless battery-powered sensor 2 is used, there is no need to perform wiring work between the battery-powered sensor 2 and the abnormality detection device 1 . Therefore, the abnormality detection device 1 can be effectively used even in places where wiring work is difficult.

Other configurations, effects, and the like in the abnormality detection device 1 of the present embodiment are the same as the configuration, effects, and the like of the first embodiment. Also in the present embodiment, constituent elements indicated by the same reference numerals as those in the first embodiment are the same as those in the first embodiment.

The present invention is not limited to only each embodiment, and further different embodiments can be configured without departing from the scope of the invention. In addition, the present invention includes various modifications, modifications within the equivalent range, and the like.

REFERENCE SIGNS LIST 1 anomaly detection device 11 time period setting unit 12 detection frequency variable unit 13 anomaly detection unit 14 learning unit 2 battery-powered sensor 21 battery 3 device to be detected (compressor)
4 Piping 5 Equipment A Gas P Pressure

Claims (5)

An abnormality detection device that uses a battery-powered sensor that operates by receiving power from a battery to detect a state quantity of a fluid flowing through a detection target device or a pipe, and detects an abnormality that occurs in the state quantity,
A first time period in which the increase/decrease amount, increase/decrease speed, and increase/decrease frequency of the state quantity due to a disturbance are predicted to fall within a predetermined assumed fluctuation range, and the increase/decrease amount, increase/decrease of the state quantity due to the disturbance, in a time period of one day. a time period setting unit configured to set a second time period during which the speed or increase/decrease frequency is likely to deviate from the assumed fluctuation range;
a detection frequency variable unit that increases the frequency with which the battery-powered sensor detects the state quantity in the first time period compared to the frequency with which the battery-powered sensor detects the state quantity in the second time period;
When the state quantity detected by the battery-powered sensor is out of the range of a predetermined first allowable value in the first time period, an abnormality occurring in the state quantity is detected and the second time period is detected. an anomaly detection unit that detects an anomaly occurring in the state quantity when the state quantity detected by the battery-powered sensor falls outside a range of a second allowable value that is wider than the range of the first allowable value; An anomaly detection device using a battery-powered sensor comprising: The battery-powered sensor detects the pressure of the fluid as the state quantity,
The first time period in the time period setting unit is during startup of the detection target device, in which the amount of change, the speed of change, or the frequency of change of the state quantity due to disturbance is predicted to fall within a predetermined assumed variation range. 2. The battery according to claim 1, which is set within a predetermined time after starting up the detection target device, within a predetermined time before stopping the detection target device, or within a predetermined time after starting to stop the detection target device. Abnormality detection device using a type sensor. The detection frequency varying unit sets a time interval at which the battery-powered sensor detects the state quantity in the first time period to be shorter than a time interval at which the battery-powered sensor detects the state quantity in the second time period. 3. An abnormality detection device using the battery-powered sensor according to claim 1 or 2, which is configured to When the state quantity is repeatedly detected by the battery-powered sensor, the amount of increase or decrease, the speed of increase or decrease, or the frequency of increase or decrease of the state quantity due to disturbance is likely to deviate from the assumed fluctuation range, and the first The anomaly detection device using a battery-powered sensor according to any one of claims 1 to 3, further comprising a learning unit that determines the time period and the second time period. The battery-powered sensor communicates wirelessly with the abnormality detection device,
The anomaly detection device further comprises detection means for detecting the presence or absence of a factor that blocks the radio waves of the wireless communication,
The abnormality detection unit is configured to stop detection of an abnormality occurring in the state quantity by the battery-powered sensor while the detection means detects that there is a factor that blocks the radio waves. An abnormality detection device using the battery-powered sensor according to any one of 1 to 4.

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