JP2021174247A - Intrinsically safe explosion-proof detector and intrinsically safe explosion-proof detection system - Google Patents

Abstract

To provide an intrinsically safe explosion-proof detector and an intrinsically safe explosion-proof system capable of addressing various types of environmental information to be monitored or various types of abnormalities to be detected.SOLUTION: An intrinsically safe explosion-proof detector 10 includes: a connection terminal 18; a signal acquisition unit 26 with a process for acquiring sensor information preset for each type of sensor; a group of detection units 28 with a detection process for monitoring environmental information or determining whether or not a predetermined abnormality has been detected preset for each type of environmental information or predetermined abnormality; and a wireless transmitting/receiving unit 73 that converts the monitoring results or determination results into digital signals and transmits the digital signals to a host device through wireless communication.SELECTED DRAWING: Figure 4

Description

The present invention relates to an intrinsically safe explosion-proof detector and an intrinsically safe explosion-proof detection system.

In plants and factories, sensors for detecting abnormal conditions and sensors for collecting environmental information are provided mainly on equipment important for operation and operation, and an information transmission network corresponding to the sensors is constructed.

On the other hand, for non-important parts, most of them are not provided with the sensor, or the sensor measurement value is only displayed on site and is not transmitted to the upper level (for example, Bourdon pipe pressure gauge), and a patrol inspection by a person is performed. We are checking for abnormalities and the environment at.

Here, since there are tens of thousands to hundreds of thousands of such locations in one plant, this confirmation work is a great cost. For example, in a plant such as an oil refinery, tens of thousands of plants are carried out 6 to 7 times a day every day. In particular, in recent years, the number of abnormalities at the relevant location has increased due to the aging of equipment, and there have been problems such as not being able to be detected until the scale of the abnormality is expanded by visual inspection alone.

From the above background, there are many requests for a monitoring system that collects abnormal conditions and environmental information with sensors and stores it in the upper network, and each plant company is conducting research on monitoring systems and wireless transmission functions. The provided explosion-proof sensor is on the market.

In addition, for sensors and monitoring equipment installed in dangerous places (ZONE 0) specified by the explosion-proof guidelines for factory electrical equipment, various methods for exchanging and receiving digital signals with the higher level are specified.

For example, when signal transmission is performed by wire, the specifications of the physical layer and data link layer are defined for dangerous places (for PA) in PROFIBUS and FOUNDATION Fieldbus, which are the standards of Fieldbus (PROFIBUS-PA, etc.). .. Also, regarding Ethernet, which is a communication standard of Local Area Network, the specifications of the layer are being studied under the name of Advanced Physical Layer, and it is expected that it will be added to IEEE 802 at the end of 2020.

On the other hand, specific low-power radios are mainly used for radio signal transmission in dangerous places, and various standards are defined as a general term for LPWA (Low Power Wide Area) (SigFox, LoRaWAN, Wi-SUN, etc.).

For example, LoRaWAN is used in the intrinsically safe explosion-proof wireless sensor manufactured by Yokogawa Electric Co., Ltd., and a wireless module and a battery pack are set in one type of sensor (one of vibration, temperature, and pressure). "Sushi Sensor (registered trademark)" has been commercialized.

In addition, New Cosmos Electric Co., Ltd. and Azbil Kimmon Co., Ltd. have proposed sensor devices capable of wireless transmission in dangerous places.

In addition, for the above-mentioned "Sushi Sensor (registered trademark)" manufactured by Yokogawa Electric Corporation, environmental information is acquired and data is transmitted to a higher level at arbitrary time intervals (minutes to days). Since this sensor performs the above operation only with the built-in lithium thionyl chloride battery, power saving is achieved by adopting power saving communication.

Japanese Unexamined Patent Publication No. 1993-227569 Japanese Unexamined Patent Publication No. 1997-64796 Japanese Unexamined Patent Publication No. 1997-6541 Japanese Unexamined Patent Publication No. 2006-11642 Japanese Unexamined Patent Publication No. 2010-182174 Japanese Unexamined Patent Publication No. 2013-21182 Japanese Unexamined Patent Publication No. 2016-71460 JP-A-2018-10346 Japanese Unexamined Patent Publication No. 2018-41125 JP-A-2018-10346 JP-A-2018-128911 Japanese Unexamined Patent Publication No. 2019-193362

However, the sensor devices currently on the market are expensive, and there is a problem that the initial cost is high when they are installed in all the above inspection points. In addition, the above equipment has a short life (several years to a maximum of about 10 years) because a small battery is selected mainly on the premise that the battery is built in the sensor, and the running cost related to replacement increases as the number of installed units increases. There was a problem that could not be ignored.

The present invention has been made to solve the above problems, and is an intrinsically safe explosion-proof detector and an intrinsically safe explosion-proof type that can deal with various types of environmental information to be monitored or various types of abnormalities to be detected. The purpose is to provide a detection system.

In order to achieve the above object, the intrinsically safe explosion-proof detector according to the present invention has a connection terminal for connecting to a sensor and a sensor information acquisition process for each type of the sensor. By the acquisition process corresponding to the type of the sensor connected to the connection terminal, the acquisition unit that acquires the sensor information detected by the sensor, the monitoring of the environmental information, or the determination of whether or not a predetermined abnormality is detected. The detection process for monitoring the environmental information or determining whether or not a predetermined abnormality has been detected is predetermined for each type of the environmental information or the predetermined abnormality. The detection unit that monitors the environmental information or determines whether or not a predetermined abnormality has been detected by the detection process corresponding to the environmental information or the predetermined abnormality type, and the monitoring result or the determination result by the detection unit , And a transmission / reception unit that converts the digital signal into a digital signal and transmits the digital signal to a higher-level device by wireless communication.

The intrinsically safe explosion-proof detection system according to the present invention includes a plurality of the above-mentioned intrinsically safe explosion-proof detectors, and a unique address is assigned to each of the plurality of intrinsically safe explosion-proof detectors in advance. The digital signal sent and received between the intrinsically safe explosion-proof detector and the higher-level device includes the address of the intrinsically safe explosion-proof detector.

According to the intrinsically safe explosion-proof detector and the intrinsically safe explosion-proof detection system, which is one aspect of the present invention, it is possible to deal with various types of environmental information to be monitored or various types of abnormalities to be detected.

It is a block diagram which shows the structure of the intrinsically safe explosion-proof detection system which concerns on embodiment of this invention. It is the schematic which shows the structure of the detector which concerns on embodiment of this invention. It is a figure which shows the structure of the connection terminal of the detector which concerns on embodiment of this invention. It is a block diagram which shows the structure of the arithmetic processing part of the detector which concerns on embodiment of this invention. It is a sequence diagram which shows the operation timing of each detector. It is a figure for demonstrating the position of LPWA in wireless transmission. It is a time chart which shows the operation of the detector which concerns on embodiment of this invention. It is a time chart which shows the exchange of the signal between the detector and the sensor part which concerns on embodiment of this invention. It is a time chart which shows the operation of the detector which concerns on embodiment of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

<Outline of Embodiment of the present invention>
In the embodiment of the present invention, environmental information is monitored (temperature, vibration, pressure, gas concentration, sound, impact, rotation speed, etc.) by a detector at a dangerous place specified by an explosion-proof guideline for factory electrical equipment. It relates to an intrinsically safe explosion-proof detection system that detects various abnormal conditions (fire, temperature abnormality, leakage of dangerous substances, gas leak, etc.) and wirelessly transmits the signal to the upper level at the same dangerous location.

This system has the properties listed below.

(1) One group includes a plurality of (several to 100) detectors, each of which transmits environmental information / abnormal state to a higher level by wireless communication.

(2) By excluding the specifications of various sensor parts from the verification of the intrinsically safe explosion-proof specifications specified in the factory electrical equipment explosion-proof guidelines, the entire system including the sensor parts can be installed in dangerous places at low cost. ..

(3) By executing the detector operation with an extremely low current consumption (μA order) that meets the intrinsically safe explosion-proof specifications specified in the factory electrical equipment explosion-proof guidelines, battery life is extended and running costs related to battery replacement are also reduced. Reduce.

<System configuration>
Hereinafter, the intrinsically safe explosion-proof detection system according to the first embodiment of the present invention will be described.

As shown in FIG. 1, the intrinsically safe explosion-proof detection system 100 according to the first embodiment of the present invention includes a plurality of detectors 10, a plurality of radio slave units 76, a host radio transmitter / receiver 78, and the like. It is equipped with a higher-level system 80. Further, a plurality of detector groups 88 including a plurality of detectors 10 are provided.

The host system 80 includes one or more of a host computer 82, a DCS / PLC 84, and a relay board 86. The upper system 80 is connected to the upper wireless transmitter / receiver 78, and the upper wireless transmitter / receiver 78 is connected to the wireless transmitter / receiver 73 by wireless communication via the wireless slave unit 76. The detector 10 is installed in a dangerous place, and the wireless slave unit 76, the upper wireless transmitter / receiver 78, and the upper system 80 are installed in a non-dangerous place. The wireless handset 76 may be installed in a dangerous place.

Further, the information collected from the detector group 88 to the wireless slave unit 76 is finally higher than the information collected by the plurality of wireless slave units 76 wirelessly connected to the detector group 88 different from the above. It is transmitted to the wireless transmitter / receiver 78 and aggregated on the host computer 82 or the cloud via Ethernet or the like. The wireless transmitter / receiver 73 may directly exchange data with the host wireless transmitter / receiver 78 without going through the wireless slave unit 76.

The detector group 88 includes a plurality of various detectors 10 (several to 100), and environmental information (temperature, vibration, pressure, gas concentration, etc.) is included according to the type of content to be detected. Sound, impact, rotation speed, liquid level height, etc.) and various abnormal conditions (fire, temperature abnormality, dangerous substance leakage, gas leakage, etc.) are transmitted to the host system 80.

The detector 10 transmits signals (unique address / fire signal / abnormal temperature signal / state information, etc.) to the wireless slave unit 76 by wireless communication.

The wireless slave unit 76 includes a lower wireless transmitter / receiver 62, a signal converter 64, and an upper wireless transmitter / receiver 66. The lower wireless transmitter / receiver 62 performs wireless communication with the wireless transmitter / receiver unit 73. The signal converter 64 relays the transmission and reception of digital signals between the detector 10 and the host system 80. The upper wireless transmitter / receiver 66 performs wireless communication with the upper wireless transmitter / receiver 78.

<Detector configuration>
Each detector 10 has an arithmetic processing unit 12, which is a CPU having a function of controlling power consumption, an operation unit 16, a connection terminal 18 for connecting to the sensor unit 20, a counter unit 24, a barrier 68, and the like. 70, an antenna 71, a power supply connection terminal 72 for connecting an external power supply, a wireless transmission / reception unit 73, and a power supply unit 74 are included (see FIG. 2).

Most of the detectors 10 spend most of their time in sleep mode, CPU stopped, or power off, and shift to running mode (current consumption: several μA to several 100 μA) only when environmental information is acquired. Further, although the acquisition cycle of the environmental information differs depending on the detector 10, the running mode is about 60 to 90 [s] each time, and most of the day is spent in the standby mode. Further, each detector 10 may diagnose the detector 10 itself at each of the above cycles and transmit the functional information (diagnosis information) together with the acquired information to the host system 80. As a CPU having a function of controlling the power consumption, there is a RE microcomputer (SOTB) manufactured by Renesas Electronics Electronics Corporation.

The operation unit 16 accepts the setting of the type of the sensor unit 20 and the type of the detection content by the detector 10.

The counter unit 24 has a clock generation unit, a real-time clock, or a counter, and supplies power from the power supply unit 74 or an external power source at intervals of monitoring cycles or detection cycles determined according to the type of detection content. The arithmetic processing unit 12 is started to transmit various information to the host system 80, and then the power supply is stopped and the arithmetic processing unit 12 is stopped. When the detector 10 is on standby, only the clock generation unit, the real-time clock, or the counter of the counter unit 24 operates.

The barriers 68 and 70 play a role of limiting the energy supplied to the arithmetic processing unit 12 and suppressing the overvoltage and overcurrent generated at the time of disconnection or short circuit to a level at which sparks leading to ignition do not occur.

The wireless transmission / reception unit 73 transmits / receives a digital signal to / from the host system 80 by wireless communication using the antenna 71. Further, the wireless transmission / reception unit 73 acquires a signal received by wireless communication from the host system 80 and outputs the signal to the arithmetic processing unit 12.

The power supply unit 74 supplies electric power to each unit of the detector 10 via the barrier 70 and the counter unit 24. Further, the power supply unit 74 supplies electric power to the wireless transmission / reception unit 73 via the barrier 70.

In some cases, such as a detector that detects an abnormal state, it is necessary to store sensor information (live information) in the device for determining the abnormality. In this case, since the RAM information in the microcomputer is deleted when the CPU is stopped or the power is turned off, the writing process to the SRAM 77 is performed.

<Configuration of detector connection terminal>
As shown in FIG. 3, the connection terminals 18 include a power supply terminal 181 and a GND connection terminal 182, a first sensor input terminal 183, a second sensor input terminal 184, a first output signal terminal 185, and a second. It includes an output signal terminal 186, an analog input terminal 187, and a chip select terminal 188.

Power supply terminal 181, GND connection terminal 182, first sensor input terminal 183, second sensor input terminal 184, first output signal terminal 185, second output signal, depending on the type of sensor unit 20. A part or all of the terminal 186, the analog input terminal 187, and the chip select terminal 188 are connected to the sensor unit 20.

Further, the power supply terminal 181 and the GND connection terminal 182 are connected to the power supply control unit 38 described later. The first sensor input terminal 183, the second sensor input terminal 184, the first output signal terminal 185, the second output signal terminal 186, the analog input terminal 187, and the chip select terminal 188 will be described later. It is connected to the signal acquisition unit 26.

<Structure of arithmetic processing unit of detector>
The arithmetic processing unit 12 of the detector 10 is composed of a CPU. When the arithmetic processing unit 12 is described by a functional block divided for each function realizing means, as shown in FIG. 4, the arithmetic processing unit 12 includes a signal acquisition unit 26, a detection unit group 28, an input / output data management unit 30, and a cycle. It includes a management unit 32, a reception signal management unit 34, a transmission signal management unit 36, and a power supply control unit 38.

The signal acquisition unit 26 acquires a signal from the sensor unit 20 via the connection terminal 18 and the barrier 68.

The signal acquisition unit 26 includes an infrared signal acquisition unit 26A, an acceleration signal acquisition unit 26B, a resistance value signal acquisition unit 26C, a temperature signal acquisition unit 26D, a humidity signal acquisition unit 26E, a gas signal acquisition unit 26F, a pressure signal acquisition unit 26G, and The ultrasonic signal acquisition unit 26H is provided.

When the connected sensor unit 20 is a plurality of detection elements that detect infrared rays having different wavelength ranges, the infrared signal acquisition unit 26A acquires sensor information indicating the intensity of the detected infrared rays from the plurality of detection elements. do.

The acceleration signal acquisition unit 26B acquires sensor information representing acceleration when the connected sensor unit 20 is an acceleration sensor.

The resistance value signal acquisition unit 26C acquires sensor information representing the resistance value when the connected sensor unit 20 is a liquid leakage sensor whose resistance value changes when it comes into contact with the leaked liquid.

The temperature signal acquisition unit 26D acquires sensor information representing the temperature when the connected sensor unit 20 is a temperature sensor (for example, a thermocouple).

The humidity signal acquisition unit 26E acquires sensor information indicating humidity when the connected sensor unit 20 is a humidity sensor.

When the connected sensor unit 20 is a gas sensor, the gas signal acquisition unit 26F acquires sensor information indicating the concentration of the specific gas.

The pressure signal acquisition unit 26G acquires sensor information representing the pressure when the connected sensor unit 20 is a pressure sensor.

When the connected sensor unit 20 is an ultrasonic sensor, the ultrasonic signal acquisition unit 26H acquires sensor information representing the received ultrasonic waves.

The detection unit group 28 includes a flame temperature detection unit 28A, a vibration impact detection unit 28B, a liquid leakage detection unit 28C, a temperature detection unit 28D, a humidity detection unit 28E, a gas leakage detection unit 28F, and a pressure detection unit. It is equipped with 28G and a detection unit 28H for ultrasonic waves.

The flame temperature detection unit 28A monitors the temperature based on the sensor information acquired by the infrared signal acquisition unit 26A. For example, the slope of a straight line obtained by connecting the signal amounts of two detection elements that detect infrared rays having different wavelength ranges is obtained, and the temperature is monitored from the obtained slope using the relationship between the slope and the temperature. .. Then, the flame temperature detection unit 28A determines that the abnormal temperature has been detected when the monitored temperature is equal to or higher than the threshold value. Alternatively, the flame temperature detection unit 28A determines whether or not the flame has been detected based on the sensor information acquired by the infrared signal acquisition unit 26A. Since the determination method is the same as the method described in Patent Document (International Publication No. 2018/198504), the description thereof will be omitted.

The vibration impact detection unit 28B monitors the acceleration based on the sensor information acquired by the acceleration signal acquisition unit 26B. Then, the vibration impact detection unit 28B determines that the impact has been detected when the monitored acceleration is equal to or greater than the threshold value.

The liquid leakage detection unit 28C monitors the change in the resistance value based on the sensor information acquired by the resistance value signal acquisition unit 26C. Then, the liquid leakage detection unit 28C determines that the liquid leakage has been detected when the resistance value is equal to or less than the threshold value.

The temperature detection unit 28D monitors the temperature based on the sensor information acquired by the temperature signal acquisition unit 26D. Then, the temperature detection unit 28D determines that the abnormal temperature has been detected when the monitored temperature is equal to or higher than the threshold value.

The humidity detection unit 28E monitors the humidity based on the sensor information acquired by the humidity signal acquisition unit 26E. Then, the humidity detection unit 28E determines that the abnormal humidity has been detected when the monitored humidity is equal to or higher than the threshold value.

The gas leak detection unit 28F monitors the concentration of a specific gas based on the sensor information acquired by the gas signal acquisition unit 26F. Then, the gas leak detection unit 28F determines that the gas leak has been detected when the monitored gas concentration is equal to or higher than the threshold value.

The pressure detection unit 28G monitors the pressure based on the sensor information acquired by the pressure signal acquisition unit 26G. Then, the pressure detection unit 28G determines that the abnormal pressure has been detected when the monitored pressure is equal to or higher than the threshold value.

The ultrasonic detection unit 28H monitors the information regarding the ultrasonic waves received by the ultrasonic waves based on the sensor information acquired by the ultrasonic signal acquisition unit 26H.

The input / output data management unit 30 accepts the setting of the type of the sensor unit 20 according to the operation of the operation unit 16, and receives the infrared signal acquisition unit 26A, the acceleration signal acquisition unit 26B, the resistance value signal acquisition unit 26C, and the temperature signal acquisition. Any one of the unit 26D, the humidity signal acquisition unit 26E, the gas signal acquisition unit 26F, the pressure signal acquisition unit 26G, and the ultrasonic signal acquisition unit 26H is set as the operation target.

Further, the input / output data management unit 30 accepts the setting of the type of detection content by the detector 10 according to the operation of the operation unit 16, and receives the flame temperature detection unit 28A, the vibration impact detection unit 28B, and the liquid leakage. Any one of the detection unit 28C, the temperature detection unit 28D, the humidity detection unit 28E, the gas leak detection unit 28F, the pressure detection unit 28G, and the ultrasonic wave detection unit 28H is set as the operation target.

The input / output data management unit 30 includes a flame temperature detection unit 28A, a vibration impact detection unit 28B, a liquid leakage detection unit 28C, a temperature detection unit 28D, a humidity detection unit 28E, a gas leakage detection unit 28F, and a pressure detection unit. It has a threshold storage unit (not shown) that stores a threshold used in each of the detection unit 28G and the ultrasonic detection unit 28H.

Further, the input / output data management unit 30 has a flame temperature detection unit 28A, a vibration impact detection unit 28B, a liquid leakage detection unit 28C, a temperature detection unit 28D, and a humidity detection unit according to the operation of the operation unit 16. When abnormality detection is set by any of 28E, the gas leak detection unit 28F, and the pressure detection unit 28G, the data of the corresponding threshold value is output.

The cycle management unit 32 has a cycle storage unit (not shown) that stores the monitoring cycle or the detection cycle and the sensor cycle for each type of detection content by the detector 10, and corresponds to the operation of the operation unit 16. The monitoring cycle or detection cycle according to the type of detection content to be detected and the sensor cycle according to the type of the corresponding sensor unit 20 are output to the power supply control unit 38 and the detection unit group 28.

Here, an example of a monitoring cycle or a detection cycle for each type of detection content is listed below. As shown below, depending on the information to be collected, the detection cycle according to the type of detector may be shortened in the pre-alarm judgment, or conversely, if the normal state continues for a long period of time, it may be possible to shift to a longer detection cycle. Take measures such as For example, as shown in FIG. 5, each detector 10 operates in a monitoring cycle or a detection cycle according to the type of detection content.

When the type of detection content is flame detection, the high-speed detection type has a detection cycle of 50 ms. In this case, the flame is determined in 3s and restored in 30s. In the standard type, the detection cycle is 500 ms. In this case, when a flame is detected for 1 to 2 consecutive cycles, the pre-alarm shifts to the pre-alarm, and then shifts to the same detection cycle as the high-speed detection type.

When the detector 10 also detects the position of the flame, the position is determined in 10 s after the above flame determination.

Further, when the type of detection content is flame abnormality detection, abnormal temperature detection (high temperature type), and the temperature in the range of 200 to 480 ° C. is monitored, the detection cycle is 60 s. If the monitored temperature is equal to or higher than the set value, it is judged to be a high temperature object, and if it is judged to be a high temperature object for 1 to 2 cycles, it shifts to a pre-alarm, for example, it is judged to be a high temperature object for 10 minutes in a row. If so, it is determined that the temperature is abnormal.

When the type of detection content is flame abnormality detection, abnormal temperature detection (low temperature type), and the temperature in the range of 80 to 200 ° C. is monitored, the detection cycle is 1 h. If the monitored temperature is equal to or higher than the set value, it is judged to be an abnormal temperature object, and if it is judged to be an abnormal temperature object for 1 to 2 consecutive cycles, it shifts to a pre-alarm. If it is determined to be present, it is determined that the temperature is abnormal.

Further, when the type of detection content is temperature detection, temperature monitoring (high temperature type) is performed, and the temperature in the range of 200 to 480 ° C. is monitored, the monitoring cycle is 60 s. Further, when the type of detection content is temperature monitoring (low temperature type) and the temperature in the range of 80 to 200 ° C. is monitored, the monitoring cycle is 1h.

When the type of detection content is gas leak detection, the detection cycle is 50 ms as in the high-speed flame detection type, or 500 ms as in the standard type.

Further, when the type of detection content is liquid leakage detection, the detection cycle is 1h. When the monitored resistance value is continuously below the threshold value for 5 hours, the process shifts to the pre-alarm, and when it is determined that the resistance value monitored continuously for 10 hours to 24 hours is below the threshold value, it is determined that a liquid leak has been detected. ..

Further, when the type of detection content is vibration impact detection, the detection cycle is 1 ms. When the monitored acceleration is continuously equal to or higher than the threshold value for 5 ms, the process shifts to the pre-alarm, and when it is determined that the monitored acceleration for 10 ms to 24 ms is continuously equal to or higher than the threshold value, it is determined that a vibration impact has been detected.

The power supply control unit 38 controls the supply of electric power from the power supply unit 74 or an external power source according to a monitoring cycle or a detection cycle predetermined for the type of detection content of the detector 10. Further, the power supply control unit 38 controls the supply of electric power from the power supply unit 74 or the external power source to the sensor unit 20 according to a sensor cycle predetermined for the type of the sensor unit 20.

The transmission signal management unit 36 outputs the detection content of the detection unit group 28 as a digital signal to the wireless transmission unit 73B.

The received signal management unit 34 sends and receives digital signals transmitted from the host system 80.

The wireless receiving unit 73A acquires a signal received by wireless communication from the host system 80 by the antenna 71 and outputs the signal to the arithmetic processing unit 12.

The wireless transmission unit 73B transmits the signal output from the arithmetic processing unit 12 to the host system 80 by wireless communication by the antenna 71.

<Configuration of lower wireless transmitter / receiver>
In the present embodiment, the lower wireless transmitter / receiver 62 sends / receives signals (unique address / environmental information / abnormality information, etc.) between the detector 10 and the wireless slave unit 76 by wireless transmission.

As a transmission method, LPWA (Low Power Wide Area), which is a specific low power radio, is used. LPWA is a general term for a communication method for wirelessly transmitting a short distance of about several km to 10 km with an extremely low current consumption (about 20 mA), and mainly uses a sub GHz band (920 MHz or the like) (see FIG. 6).

<Low current consumption>
In the embodiment of the present invention, the power saving control of the detector 10 and various power saving communications are used. As a result, each detector 10 can satisfy the intrinsically safe explosion-proof specification defined by the factory electrical equipment explosion-proof guideline, and the entire intrinsically safe explosion-proof detection system 100 is installed at the location.

The electrical specifications of the various sensors connected to the detector 10 as the sensor unit 20 are 1.5 V or less, 100 mA or less, and 25 mW or less. As a result, the specifications of the various sensor units 20 can be excluded from the verification of the intrinsically safe explosion-proof specifications specified in the factory electrical equipment explosion-proof guidelines. The specifications of all types of sensor units 20 need not be 1.5 V or less, 100 mA or less, and 25 mW or less, and the specifications of some types of sensor units 20 are 1.5 V or less. As mentioned above, it may be 100 mA or more, or 25 mW or more. In this case, the sensor unit 20 of the type may be subject to the verification of the intrinsically safe explosion-proof specification specified in the factory electrical equipment explosion-proof guideline.

<Operation of intrinsically safe explosion-proof detection system>
Next, the operation of the intrinsically safe explosion-proof detection system 100 according to the embodiment of the present invention will be described.

First, an individual address is assigned to each of the detectors 10 installed in the intrinsically safe explosion-proof detection system 100. As a result, in the data transmission between the detector 10 and the host system 80, a signal including an address and various information is exchanged. As an example, when 100 detectors 10 are included, the address portion is represented by 7 bits, and several bits of environmental information are added after the address portion.

Further, various sensor units 20 are connected to each detector 10, and the operation unit 16 sets the type of the sensor unit 20 and the type of the detection content.

For example, when a plurality of detection elements for detecting infrared rays are set as the type of the sensor unit 20 by the operation unit 16 and detection of abnormal temperature is set as the type of detection content, the infrared signal acquisition unit 26A and the flame temperature detection are set. The unit 28A is set as an operation target.

Then, the infrared signal acquisition unit 26A acquires sensor information representing the intensity of the detected infrared rays for each sensor cycle for the detection element that detects infrared rays. Further, the flame temperature detection unit 28A determines whether or not the temperature is abnormal by using a threshold value related to the abnormal temperature for each detection cycle for detecting the abnormal temperature.

Further, when the temperature sensor is set as the type of the sensor unit 20 and the temperature monitoring is set as the type of the detection content by the operation unit 16, the temperature signal acquisition unit 26D and the temperature detection unit 28D are set as operation targets. NS.

Then, the temperature signal acquisition unit 26D acquires sensor information representing the temperature for each sensor cycle used as the temperature sensor. Further, the temperature detection unit 28D outputs sensor information representing the acquired temperature for each monitoring cycle for temperature monitoring.

In this way, the detector 10 repeatedly executes the process of monitoring the environmental information or determining whether or not a predetermined abnormality has been detected at each monitoring cycle or detection cycle according to the type of detection content.

Specifically, as shown in FIG. 7, the detector 10 determines that the monitoring cycle or the detection cycle determined according to the type of the detection content has been reached by using the clock generation unit included in the counter unit 24. , Power is supplied from the power supply unit 74 to start the arithmetic processing unit 12 (S51, S52). Then, when the address included in the received signal matches the address of the detector 10, the address included in the received signal is stored (S53). The sensor information from the sensor unit 20 is taken in, the state of the sensor unit 20 is checked based on the sensor information, and a calculation is performed. If the type of detection content is the detection of a predetermined abnormality, the calculated value is calculated. , It is determined whether or not the abnormality is the predetermined abnormality by comparing with a predetermined threshold value for the type of the detected content. Then, the wireless transmission unit 73B transmits the monitoring result of the environmental information or the determination result of whether or not a predetermined abnormality is detected according to the type of the detected content to the wireless slave unit 76 (S54). Then, the monitoring result of the environmental information or the determination result of whether or not a predetermined abnormality is detected is written to the SRAM 77 (S55), the clock generation unit of the counter unit 24 is reset, and the timer is set (S56). Then, the power supply control unit 38 stops the supply of electric power from the power supply unit 74, and stops the arithmetic processing unit 12 (S57). Then, when the power supply control unit 38 determines that the next monitoring cycle or detection cycle has come by using the clock generation unit of the counter unit 24, the power supply control unit 38 supplies the power from the power supply unit 74 again to cause the arithmetic processing unit 12 to operate. to start.

Further, the exchange of data between the sensor unit 20 and the detector 10 in the operation of S54 will be described with reference to FIG. The exchange shown in FIG. 8 is repeated every sensor cycle.

First, the detector 10 requests data from the sensor unit 20 (S81), supplies power to the sensor unit 20, and activates the sensor unit 20 (S82). Then, the detector 10 sets conditions for the sensor unit 20 according to the type of detection content (S83), and checks the state of the sensor unit 20 (S84).

Then, the sensor unit 20 acquires the sensor information (S85) and outputs the acquired sensor information to the detector 10 (S86).

Further, the exchange of data in the data transmission from the detector 10 to the host system 80 will be described with reference to FIG.

First, when data is transmitted from the detector 10 to the host system 80 (S91), the mode shifts to the reception mode for a certain period of time, and waits until an ACK message is received from the host system 80 (S92). Then, when the ACK message is received from the host system 80 (S93), the reception mode is terminated and the detector 10 is turned off.

If the ACK message is not received from the host system 80 even after a certain period of time has passed since the system shifts to the reception mode, the system waits in the reception mode for a further period of time. If the ACK message is not received from the host system 80 within this fixed period, the reception mode is terminated and the detector 10 is turned off. Then, at the next transmission, the data for which the ACK message was not received is transmitted together with the data at that time.

When the reception mode is terminated without receiving the ACK message a predetermined number of times (for example, three times), it is determined that the transmission is defective, and the detector 10 determines that the state is abnormal.

Further, when the host system 80 cannot continuously receive data from the detector 10 a predetermined number of times, it also determines that the detector 10 has a transmission failure.

As described above, according to the intrinsically safe explosion-proof detection system 100 according to the embodiment of the present invention, the detector 10 has a predetermined monitoring cycle or a predetermined monitoring cycle for the environmental information to be monitored or the type of abnormality to be detected. By controlling the power supply from the power supply unit according to the detection cycle, the intrinsically safe explosion-proof detection system 100 can be operated for a long period of time without battery replacement, and the management cost of the power supply unit can be reduced. can.

Further, each detector 10 can deal with various types of environmental information to be monitored or various types of abnormalities to be detected.

<Modification example>
The present invention is not limited to the above-described embodiment, and various modifications and applications are possible without departing from the gist of the present invention.

For example, at least one of the plurality of detectors may function as a wireless slave unit, collect transmission data of other detectors, collect them, and transmit them to a higher-level system. In this case, each detector has a function of becoming a wireless slave unit, the detector designated as the wireless slave unit can transmit and receive, and the remaining detectors are dedicated to transmission. The detector nominated as a wireless slave unit completes the collection of transmission data from other detectors with different monitoring cycles or detection cycles, and after transmitting to the host system, at least one of the other detectors The stand is nominated as the next wireless handset, and then dedicated to transmission.

Further, although the case where the type of the sensor unit 20 and the type of the detection content by the detector 10 are set by the operation of the operation unit has been described as an example, the type of the sensor unit to which the detector 10 is connected and the type of the monitoring content have been described. , The type of detection content may be automatically recognized.

The detector 10 may monitor sound or rotation as environmental information. Further, the detector 10 may determine whether or not an abnormality related to sound or rotation is detected as a predetermined abnormality.

10 Detector 12 Arithmetic processing unit 16 Operation unit 18 Connection terminal 20 Sensor unit 24 Counter unit 26 Signal acquisition unit 28 Detection unit group 30 Input / output data management unit 32 Cycle management unit 34 Received signal management unit 36 Transmission signal management unit 38 Power control Unit 73 Radio transmission / reception unit 74 Power supply unit 76 Wireless slave unit 80 High-level system 100 Intrinsic safety explosion-proof detection system

Claims (14)

Connection terminals for connecting to the sensor,
The sensor information acquisition process is predetermined for each type of the sensor, and the sensor information detected by the sensor is acquired by the acquisition process corresponding to the type of the sensor connected to the connection terminal. Department and
It is a detection unit that monitors environmental information or determines whether or not a predetermined abnormality has been detected, and monitors the environmental information or detects a predetermined abnormality for each type of the environmental information or the predetermined abnormality. The detection process that determines whether or not it is determined is predetermined.
A detection unit that monitors environmental information or determines whether or not a predetermined abnormality has been detected by the detection process corresponding to the environmental information or the predetermined type of abnormality.
A transmission / reception unit that converts the monitoring result or determination result by the detection unit into a digital signal and transmits the digital signal to a higher-level device by wireless communication.
Intrinsically safe detector including. A periodic storage unit that stores a predetermined monitoring cycle or detection cycle for each of the environmental information or the predetermined type of abnormality.
Power supply unit that supplies power and
A power supply control unit that controls the supply of electric power from the power supply unit according to the monitoring cycle or the detection cycle corresponding to the environmental information or the predetermined type of abnormality.
The intrinsically safe explosion-proof detector according to claim 1, further comprising. A sensor information storage unit that stores a threshold value for detecting the predetermined abnormality is further included for each type of the predetermined abnormality.
The intrinsically safe explosion-proof according to claim 1 or 2, wherein when determining whether or not the predetermined abnormality has been detected, the detection unit makes the determination using the threshold value corresponding to the type of the predetermined abnormality. Type detector. The intrinsically safe explosion-proof detector according to claim 2, wherein the power supply unit is composed of a primary battery or a secondary battery. The detection unit monitors humidity, pressure, vibration, shock, gas concentration, sound, ultrasonic waves, or rotation as the environmental information, or temperature, humidity, pressure, vibration, shock, as the predetermined abnormality. The intrinsically safe explosion-proof detector according to any one of claims 1 to 4, which determines whether or not an abnormality, fire, or liquid leakage related to gas concentration, sound, ultrasonic waves, or rotation is detected. One of claims 1 to 5, wherein any or all of the acquisition unit, the detection unit, and the transmission / reception unit are installed in a dangerous place (ZONE 0) specified by an explosion-proof guideline for factory electrical equipment. Described intrinsically safe explosion-proof detector. The intrinsically safe explosion-proof detector according to any one of claims 1 to 6, wherein the detection unit is configured by using a RE microcomputer (SOTB). The intrinsically safe explosion-proof detector according to any one of claims 1 to 7, wherein the electrical specifications of the sensor are 1.5 V or less, 100 mA or less, and 25 mW or less. The power supply control unit has a clock generation unit, a real-time clock, or a counter.
The intrinsically safe explosion-proof detector according to claim 2 or 4, wherein only the clock generation unit, the real-time clock, or the counter of the power supply control unit operates during standby of the intrinsically safe explosion-proof detector. A barrier for limiting the current and voltage supplied from the power supply unit, and
The intrinsically safe explosion-proof detector according to claim 2, 4, or 9, further comprising a barrier for limiting current and voltage provided between the sensor. The transmission / reception unit converts the monitoring result or determination result by the detection unit into a digital signal, and transmits the digital signal to a higher-level device via another intrinsically safe explosion-proof detector by wireless communication. The intrinsically safe explosion-proof detector according to any one of claims 10. The transmission / reception unit converts the monitoring result or determination result by the detection unit into a digital signal, and transmits the digital signal to a higher-level device by wireless communication directly or via a wireless slave unit. Item 1. The intrinsically safe explosion-proof detector according to any one of Item 11. A plurality of intrinsically safe explosion-proof detectors according to any one of claims 1 to 12 are included.
A unique address is assigned to each of the plurality of intrinsically safe explosion-proof detectors in advance.
The digital signal transmitted and received between the intrinsically safe explosion-proof detector and the higher-level device is an intrinsically safe explosion-proof detection system including the address of the intrinsically safe explosion-proof detector. Including a plurality of intrinsically safe explosion-proof detectors according to claim 12,
At least one of the plurality of intrinsically safe explosion-proof detectors functions as the wireless slave unit.
When the intrinsically safe explosion-proof detector functioning as the wireless slave unit transmits the digital signal from the plurality of intrinsically safe explosion-proof detectors to the higher-level device, the other intrinsically safe explosion-proof detector causes the above-mentioned. Intrinsically safe explosion-proof detection system that functions as a wireless slave unit.

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