Intrinsically safe explosion-proof detection system

Abstract

To provide a system capable of stably collecting data of a plurality of sensors.SOLUTION: An intrinsically safe explosion-proof type detection system 100 comprises a plurality of detectors 10 each of which includes detection units which determine whether a prescribed anomaly has been detected or not and an input / output unit which outputs a determination result to a controller 72 as a digital signal and transmits and receives digital signals to and from the controller 72. Further, the system includes: the controller 72 which relays signals transferred between the detectors 10 and a host device 80; a power supply unit 74 which supplies power to the detectors 10; a transceiver 76 which includes a plurality of signal transmission lines provided so as to connect the controller 72 and the input / output units and transfers signals between the host device 80 and the controller 72 and signals between a mobile robot 50 and the controller 72 via wireless communication; and the mobile robot 50 which moves around the transceiver 76 to collect monitoring and determination results of the detectors 10 from received digital signals and performs anomaly monitoring.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an intrinsically safe detection system. [Background technology]

[0002] In plants and factories, sensors for detecting abnormal conditions and sensors for collecting environmental information are installed mainly around equipment that is important for operation, and information transmission networks corresponding to these sensors are constructed.

[0003] On the other hand, in most non-critical locations, the relevant sensors are not installed, or the sensor measurement values ​​are only displayed on-site and not transmitted to a higher level (for example, Bourdon tube pressure gauges), and abnormalities and environmental checks are carried out by humans through patrol inspections.

[0004] Since a single plant may have tens of thousands to hundreds of thousands of such locations, this inspection work is extremely costly. For example, in a plant such as an oil refinery, inspections are carried out at tens of thousands of locations six to seven times per day. In particular, in recent years, the number of abnormalities at such locations has been increasing due to the aging of equipment, and there have been problems such as visual inspections not being able to detect abnormalities until they have become larger in scale.

[0005] Given the above background, there has been a strong demand for monitoring systems that use sensors to collect abnormal conditions and environmental information at such locations and store it on a higher-level network. As a result, various plant companies are researching monitoring systems and explosion-proof sensors with wireless transmission capabilities have been released on the market.

[0006] In addition, for sensors and monitoring equipment installed in hazardous areas (ZONE 0) specified in the Factory Electrical Equipment Explosion Prevention Guidelines or IEC (International Electrotechnical Commission) standards, various methods are specified for sending and receiving digital signals with a higher level device.

[0007] For example, when transmitting signals via wire, the Fieldbus standards PROFIBUS and FOUNDATION Fieldbus prescribe physical and data link layer specifications for hazardous locations (PA) (PROFIBUS-PA, etc.) Also, for Ethernet (registered trademark), a communication standard for local area networks, the Ethernet Advanced Physical Layer is defined as the physical layer standard in IEEE 802.3.

[0008] On the other hand, various standards have been established for wireless signal transmission in hazardous areas, mainly under the general term LPWA (Low Power Wide Area) (SigFox, LoRaWAN, Wi-SUN, etc.).

[0009] For example, Yokogawa Electric Corporation uses LoRaWAN in its intrinsically safe explosion-proof wireless sensors, and has commercialized the "Sushi Sensor (registered trademark)," which is a set of one type of sensor (one of vibration, temperature, or pressure) with a wireless module and battery pack.

[0010] Additionally, New Cosmos Electric Co., Ltd. and Azbil Kimmon Co., Ltd. have proposed sensor devices that can transmit wirelessly in dangerous locations.

[0011] The "Sushi Sensor (registered trademark)" manufactured by Yokogawa Electric Corporation mentioned above acquires environmental information and transmits the data to a higher level at any time interval (minutes to days). This sensor performs the above operations using only a built-in lithium thionyl chloride battery, and therefore aims to save energy by adopting low-power communication. [Prior art documents] [Patent documents]

[0012] [Patent Document 1] Japanese Patent Application Laid-Open No. 1993-227569 [Patent Document 2] Japanese Patent Application Laid-Open No. 1997-64796 [Patent Document 3] Japanese Patent Application Laid-Open No. 1997-65441 [Patent Document 4] Japanese Patent Application Laid-Open No. 2006-11642 [Patent Document 5] Japanese Patent Application Laid-Open No. 2010-182174 [Patent Document 6] Japanese Patent Application Laid-Open No. 2013-211829 [Patent Document 7] Japanese Patent Application Laid-Open No. 2016-71460 [Patent Document 8] Japanese Patent Application Laid-Open No. 2018-10346 [Patent Document 9] JP 2018-41125 A [Patent Document 10] Japanese Patent Application Publication No. 2018-128911 [Patent Document 11] Japanese Patent Application Publication No. 2019-193362 Summary of the Invention [Problem to be solved by the invention]

[0013] When multiple sensor devices are installed, it is necessary to collect sensor data from multiple sensor devices. In this case, it is possible to collect the data on a server via wireless communication.

[0014] At this time, if there is a problem with the server, it is not possible to collect sensor data, and therefore it is not possible to monitor the monitoring target of the sensor device during that time.

[0015] The present invention has been made to solve the above problems, and has as its object to provide an intrinsically safe explosion-proof detection system that can stably collect data from a plurality of sensors. [Means for solving the problem]

[0016] The intrinsically safe explosion-proof detection system according to a first aspect includes a detection unit that monitors environmental information or determines whether a predetermined abnormality has been detected based on sensor information detected by a sensor, and a plurality of detectors that include a wireless communication unit that transmits the monitoring results or determination results of the detection unit as digital signals to a parent transceiver via wireless communication and transmits and receives digital signals with the parent transceiver; a power supply unit that supplies power to each of the plurality of detectors; a transmission cable unit that connects the power supply unit and each of the plurality of detectors and supplies power from the power supply unit to the detectors; a parent transceiver that transmits and receives signals with each of the plurality of detectors via wireless communication and also transmits and receives signals with a host device and a data collection device, thereby relaying the exchange of signals between each of the plurality of detectors and the host device and between each of the plurality of detectors and the data collection device; and a mobile or portable data collection device that collects the monitoring results or determination results of the detection unit from the received digital signals and monitors its own system.

[0017] The intrinsically safe explosion-proof detection system according to the second aspect includes a detection unit that monitors environmental information or determines whether a predetermined abnormality has been detected based on sensor information detected by a sensor, and a plurality of detectors that include a wireless communication unit that transmits the monitoring results or determination results of the detection unit as digital signals to a parent transceiver unit via wireless communication and transmits and receives digital signals with the parent transceiver unit, and that transmits and receives signals to and from each of the plurality of detectors via wireless communication, and that transmits and receives signals to and from a host device and a data collection device, thereby relaying the transmission and reception of signals between each of the plurality of detectors and the host device and the data collection device. a power supply unit that supplies power to each of the plurality of detectors; a transmission cable unit that is provided to connect the power supply unit and each of the plurality of detectors and supplies power from the power supply unit to the detectors; a controller that controls the supply of power from the power supply unit to each of the plurality of detectors in accordance with a monitoring cycle or detection cycle that is predetermined for the environmental information or the type of predetermined abnormality in the detector; and a mobile or portable data collection device that collects the monitoring results or judgment results of the detection unit from the received digital signals and monitors its own system.

[0018] An intrinsically safe explosion-proof detection system according to a third aspect is an intrinsically safe explosion-proof detection system including an intrinsically safe explosion-proof detector, a parent transceiver, and a mobile or portable data collection device, wherein the intrinsically safe explosion-proof detector includes a detection unit that monitors environmental information or determines whether a predetermined abnormality has been detected based on sensor information detected by a sensor, a wireless communication unit that transmits the monitoring result or determination result by the detection unit to the parent transceiver as a digital signal via wireless communication and transmits and receives the digital signal to and from the parent transceiver, a power supply unit that supplies power, and a predetermined signal for the environmental information or the type of the predetermined abnormality. and a controller that controls the supply of power from the power supply unit in accordance with a monitoring period or detection period set by the parent transceiver, and the parent transceiver transmits and receives signals to and from the intrinsically safe explosion-proof detector via wireless communication, and also transmits and receives signals to and from a host device and the data collection device, thereby relaying the transmission and reception of signals between the host device and the intrinsically safe explosion-proof detector, and between the intrinsically safe explosion-proof detector and the data collection device, and the data collection device collects the monitoring results or judgment results of the detection unit from the received digital signals and monitors its own system.

[0019] An intrinsically safe explosion-proof detection system according to a fourth aspect is an intrinsically safe explosion-proof detection system including an intrinsically safe explosion-proof detector, a parent transceiver, and a mobile or portable data collection device, wherein the intrinsically safe explosion-proof detector includes a connection terminal for connection to a sensor, a detection unit that monitors environmental information or determines whether a predetermined abnormality has been detected based on sensor information detected by the sensor connected to the connection terminal, a cycle memory unit that stores a predetermined monitoring cycle or detection cycle for each type of the environmental information or the predetermined abnormality, and a wireless communication unit that transmits the monitoring result or determination result by the detection unit as a digital signal to the parent transceiver by wireless communication and transmits and receives digital signals to and from the parent transceiver. and a controller that controls the supply of power from the power supply unit in accordance with the environmental information or the monitoring period or the detection period corresponding to the type of specified abnormality, wherein the parent transceiver wirelessly transmits and receives signals to and from the intrinsically safe explosion-proof detector, and also transmits and receives signals to and from a host device and the data collection device, thereby relaying the transmission and reception of signals between the host device and the intrinsically safe explosion-proof detector, and relaying the transmission and reception of signals between the intrinsically safe explosion-proof detector and the data collection device, and the data collection device collects the monitoring results or judgment results of the detection unit from the received digital signals and monitors its own system.

[0020] An intrinsically safe explosion-proof detection system according to a fifth aspect is an intrinsically safe explosion-proof detection system including an intrinsically safe explosion-proof detector, a parent transceiver, and a mobile or portable data collection device, wherein the intrinsically safe explosion-proof detector has a connection terminal for connecting to a sensor, a sensor information acquisition process that is predetermined for each type of sensor, and an acquisition unit that acquires sensor information detected by the sensor by the acquisition process corresponding to the type of sensor connected to the connection terminal, a detection unit that monitors environmental information or determines whether or not a predetermined abnormality has been detected, wherein a detection process that monitors environmental information or determines whether or not a predetermined abnormality has been detected is predetermined for each type of environmental information or predetermined abnormality, and 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 type of environmental information or predetermined abnormality, and a digital signal that transmits a monitoring result or a determination result by the detection unit via wireless communication. a cycle memory unit that stores a predetermined monitoring cycle or detection cycle for each of the environmental information or the predetermined type of abnormality; a power supply unit that supplies power; and a controller that controls the supply of power from the power supply unit in accordance with the monitoring cycle or the detection cycle corresponding to the environmental information or the predetermined type of abnormality, wherein the parent transceiver transmits and receives signals to and from the intrinsically safe explosion-proof detector via wireless communication, and also transmits and receives signals to and from a host device and the data collection device, thereby relaying the exchange of signals between the host device and the intrinsically safe explosion-proof detector, and relaying the exchange of signals between the intrinsically safe explosion-proof detector and the data collection device, and the data collection device collects the monitoring results or judgment results of the detection unit from the received digital signals and monitors its own system. [Effects of the Invention]

[0021] According to the intrinsically safe explosion-proof detection system of one aspect of the present invention, it is possible to obtain the effect of stably collecting data from a plurality of sensors. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a block diagram showing the configuration of an intrinsically safe explosion-proof detection system according to a first embodiment of the present invention. [Figure 2] 1 is a schematic diagram showing a configuration of a cable portion according to a first embodiment of the present invention. [Figure 3] 1 is a graph showing the change in current in a transmission system using Manchester coded bus powering. [Figure 4] This is an image of detectors connected in a tree. [Figure 5] 1 is a graph showing voltage changes in a transmission system using Manchester coded bus powering; [Figure 6] 1 is a block diagram showing the configuration of a detector according to a first embodiment of the present invention. [Figure 7] FIG. 2 is a block diagram showing the configuration of a calculation processing unit of the detector according to the first embodiment of the present invention. [Figure 8] 1 is a block diagram showing a configuration of a mobile robot according to a first embodiment of the present invention. [Figure 9] FIG. 10 is a diagram showing the data structure of a transmission signal from a detector. [Figure 10] 4 is a flowchart showing a processing flow in a controller according to the first embodiment of the present invention. [Figure 11] 4 is a flowchart showing a processing flow in a controller according to the first embodiment of the present invention. [Figure 12] FIG. 10 is a sequence diagram showing the exchange of signals between a host device, a signal converter, and a detector in an intrinsically safe explosion-proof detection system under normal conditions. [Figure 13] FIG. 10 is a sequence diagram showing the exchange of signals between a host device, a signal converter, and a detector of an intrinsically safe explosion-proof detection system in the event of an abnormality. [Figure 14] (A) A graph showing the change in current of a single fire signal, (B) a graph showing the change in current of a single fire signal, and (C) a graph showing the change in current of a signal in which two fire signals are superimposed. [Figure 15]FIG. 10 is a sequence diagram showing the exchange of signals between a host device, a signal converter, and a detector in an intrinsically safe explosion-proof detection system when fire signals are output simultaneously. [Figure 16] FIG. 10 is an illustration of what happens when a cable breaks or shorts. [Figure 17] 3 is a flowchart showing a processing flow in the mobile robot according to the first embodiment of the present invention. [Figure 18] FIG. 10 is a block diagram showing the configuration of an intrinsically safe explosion-proof detection system according to a second embodiment of the present invention. [Figure 19] FIG. 10 is an illustration of what happens when a cable breaks or shorts. [Figure 20] FIG. 10 is a block diagram showing the configuration of a detector according to another example of an embodiment of the present invention. [Figure 21] FIG. 1 is a perspective view of piping in a plant. [Figure 22] FIG. 10 is a block diagram showing the configuration of an intrinsically safe explosion-proof detection system according to a third embodiment of the present invention. [Figure 23] FIG. 10 is a schematic diagram showing the configuration of a detector according to a third embodiment of the present invention. [Figure 24] 10 is a time chart showing the operation of a detector according to a third embodiment of the present invention. [Figure 25] FIG. 10 is a block diagram showing the configuration of a calculation processing unit of a detector according to a third embodiment of the present invention. [Figure 26] FIG. 10 is a block diagram showing the configuration of a signal transmitter / receiver according to a third embodiment of the present invention. [Figure 27] FIG. 4 is a sequence diagram showing the operation timing of each detector. [Figure 28] FIG. 10 is a schematic diagram showing the configuration of another example of the detector according to the third embodiment of the present invention. [Figure 29] FIG. 10 is a sequence diagram showing the operation timing of the detector. [Figure 30] FIG. 10 is a sequence diagram showing the exchange of signals between a host device, a signal transmitter / receiver, and a detector of the intrinsically safe explosion-proof detection system during polling. [Figure 31] FIG. 10 is a sequence diagram showing the exchange of signals between a higher-level device, a signal transmitter / receiver, and a detector in an intrinsically safe explosion-proof detection system when a single detector performs periodic control. [Figure 32] FIG. 10 is a sequence diagram showing the exchange of signals between a host device, a signal transceiver, and a detector in an intrinsically safe explosion-proof detection system when transmission data is interfered with. [Figure 33] FIG. 10 is a block diagram showing the configuration of an intrinsically safe explosion-proof detection system according to a fifth embodiment of the present invention. [Figure 34] FIG. 10 is a schematic diagram showing the configuration of a detector according to a fifth embodiment of the present invention. [Figure 35] FIG. 11 is a diagram showing the configuration of a connection terminal of a detector according to a fifth embodiment of the present invention. [Figure 36] FIG. 11 is a block diagram showing the configuration of a calculation processing unit of a detector according to a fifth embodiment of the present invention. [Figure 37] FIG. 4 is a sequence diagram showing the operation timing of each detector. [Figure 38] 10 is a time chart showing the operation of a detector according to a fifth embodiment of the present invention. [Figure 39] 4 is a time chart showing the exchange of signals between a detector and a sensor unit according to the embodiment of the present invention. [Figure 40] 10 is a time chart showing the operation of a detector according to a fifth embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0023] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0024] <Outline of the embodiment of the present invention> An embodiment of the present invention relates to the configuration and operation of an intrinsically safe explosion-proof detection system that detects fires or abnormal temperatures in dangerous locations (locations containing flammable gas vapors or flammable dust) and transmits the information to a higher-level device and a mobile robot via wireless communication.

[0025] In addition, the wireless base station and each detector operate in sleep mode (current consumption: approximately 300 nA) for the most part, and enter running mode (current consumption: several μA to several hundred μA) only when acquiring environmental data (temperature, vibration, pressure, gas concentration, sound, impact, rotation speed, liquid level, etc.) at the installation location.

[0026] Although the time required to acquire the above environmental data varies depending on the detector, it is approximately 60 to 90 seconds per acquisition. Even if it is performed 6 to 8 times a day, the running mode per day is only about 5 minutes, with the majority of the time spent in sleep mode.

[0027] Switching to running mode can be achieved by using the built-in timer of the microcontroller of each detector, or by a polling interrupt from the signal transmitter / receiver. After acquiring environmental data and transmitting it to the signal transmitter / receiver, the detector re-enters sleep mode.

[0028] For example, in the above microcontroller, the CPU, flash memory, and most peripheral functions can be stopped, and only the clock can be operated, thereby enabling the above operations to be performed with extremely low power consumption.

[0029] Another effective method is to provide each detector with a sequential circuit and control the start of its operation from the signal transmitter / receiver. This means that there is only one detector connected to the cable from the power supply unit (battery unit), and only the operating current of that detector is consumed.

[0030] Signal transmission between each detector and the wireless base station uses the specified low-power radio frequency band, specifically the sub-GHz frequency band for specified low-power radio telemetry, telecontrol, and data transmission.

[0031] Furthermore, the frequency band of the LTE (Long Term Evolution) wireless system is used for signal transmission between the wireless master device and the higher-level device.

[0032] Here, examples of monitoring or detection cycles by detectors are listed below. As described below, depending on the information collected, measures are taken such as shortening the detection cycle according to the type of detector when a pre-alarm is determined, or conversely, transitioning to a longer detection cycle if a normal state continues for a long period of time. Therefore, the network cycle is determined by the detector with the longest detection cycle.

[0033] When the type of detection is flame detection, the high-speed detection type has a detection cycle of 50 ms. In this case, a flame is detected in 3 seconds and recovery is achieved in 30 seconds. In the standard type, the detection cycle is 500 ms. In this case, if a flame is detected for 1 to 2 consecutive cycles, the system will transition to pre-alarm, and then transition to the same detection cycle as the high-speed detection type.

[0034] Furthermore, if the detector 10 also detects the position of a flame, it will make a position determination in 10 seconds after the above flame determination.

[0035] Furthermore, when the type of detection is flame abnormality detection, abnormal temperature detection (high temperature type), and monitoring temperatures in the range of 240 to 480°C, the detection cycle is 60 seconds. If the monitored temperature is equal to or higher than the set value, it is determined to be a high-temperature object, and if it is determined to be a high-temperature object for 1 to 2 consecutive cycles, it will transition to a pre-alarm, and if it is determined to be a high-temperature object for 10 consecutive minutes, for example, it will be determined to be an abnormal temperature.

[0036] When the type of detection is flame abnormality detection, abnormal temperature detection (low temperature type), and the temperature range of 80 to 200°C is monitored, the detection cycle is 1 hour. If the monitored temperature is above the set value, it is determined to be an abnormal temperature object, and if it is determined to be an abnormal temperature object for 1 to 2 consecutive cycles, it will transition to pre-alarm, and if it is determined to be an abnormal temperature object for, for example, 3 consecutive hours, it will be determined to be an abnormal temperature object.

[0037] Furthermore, when the type of detection content is temperature detection, temperature monitoring (high temperature type) and monitoring temperatures in the range of 240 to 480°C, the monitoring cycle is 60 seconds. Furthermore, when the type of detection content is temperature monitoring (low temperature type) and monitoring temperatures in the range of 80 to 200°C, the monitoring cycle is 1 hour.

[0038] Furthermore, when the type of detection is gas leak detection, the detection cycle is 50 ms, similar to the high-speed flame detection type, or 500 ms, similar to the standard type.

[0039] If the type of detection is liquid leakage detection, the detection cycle is 1 hour. If the monitored resistance value is below the threshold for 5 consecutive hours, a pre-alarm will occur, and if the monitored resistance value is determined to be below the threshold for 10 to 24 consecutive hours, it will be determined that a liquid leakage has been detected.

[0040] If the type of detection is impact detection, the detection cycle is 1 ms. If the monitored acceleration is equal to or greater than the threshold for 5 ms consecutively, a pre-alarm occurs, and if the monitored acceleration is determined to be equal to or greater than the threshold for 10 to 24 ms consecutively, it is determined that an impact has been detected.

[0041] Furthermore, in an embodiment of the present invention, a mobile robot is used that moves around each detector in turn and collects data from each detector. This makes it possible to collect and inspect data from each detector even if a malfunction such as a breakdown occurs in the host device that collects data from each detector, and also makes it possible to collect data and inspect the required parts when necessary without relying on the host device.

[0042] In addition, compared to detectors, mobile robots can charge their power supplies on an hourly or daily basis, and their power supplies can be replaced, but they still require a motor to move. Therefore, mobile robots are equipped with intrinsically safe explosion-proof motors and barriers to keep the voltage and current at a constant level in the motor drive section.

[0043] [First embodiment] <System configuration> An intrinsically safe explosion-proof detection system according to a first embodiment of the present invention will be described below.

[0044] As shown in Fig. 1, an intrinsically safe explosion-proof detection system 100 according to a first embodiment of the present invention includes a plurality of detectors 10, a wireless master unit 68, a host device 80, and a mobile robot 50. A plurality of sets, each consisting of a plurality of detectors 10 and a wireless master unit 68, are provided. The wireless master unit 68 includes a barrier 70, a controller 72, a power supply unit 74, and a transceiver 76. The mobile robot 50 is an example of a mobile data collection device, and the transceiver 76 is an example of a master unit transceiver.

[0045] The power supply unit 74 and the plurality of detectors 10 are connected by a cable unit 90 .

[0046] The host device 80 includes one or more of a host computer 82, a DCS / PLC 84, and a control panel 86, and a wireless transceiver 88. The host device 80 and the controller 72 are connected via wireless communication using the LTE (Long Term Evolution) wireless frequency band. The detector 10, the wireless master unit 68, and the mobile robot 50 are installed in a dangerous location, and the host device 80 is installed in a non-hazardous location.

[0047] The controller 72 relays and converts the transmission and reception of digital signals between the detectors 10 and the transceiver 76. The power supply unit 74 supplies power to each detector 10 via a cable unit 90. The power supply unit 74 is configured with a primary battery or a secondary battery.

[0048] The transceiver 76 includes an LTE wireless module 761 that transmits and receives signals between the higher-level device 80 and the controller 72 by wireless communication using the LTE wireless frequency band, and a specified low-power wireless module 762 that transmits and receives signals between the detector 10 and the controller 72 by wireless communication using the specified low-power wireless frequency band. The specified low-power wireless module 762 further transmits and receives signals between the controller 72 and the mobile robot 50 by wireless communication using the specified low-power wireless frequency band.

[0049] A plurality of detectors 10 installed in hazardous locations are connected to a cable section 90 via a T-branch connector 90C, and receive power from a power supply section 74 via a barrier 70 and the cable section 90. The barrier 70 limits the energy supplied to the detectors 10, and suppresses overvoltage and overcurrent that may occur in the event of a break or short circuit to a level that will not cause a spark that could lead to ignition. The controller 72 also converts transmission signals between the detectors 10 and the higher-level device 80, and monitors the status of the cable section 90 (monitoring for breaks and short circuits in the cable section 90, etc.).

[0050] 1 shows a bus connection centered around one cable section 90, but a tree structure is also possible. Also, the detector 10 may be connected to the cable section 90 by a 2P connector.

[0051] <Signal transmission (detector → signal converter)> As shown in FIG. 2, the cable section 90 includes a signal transmission line 90B for transmitting digital signals and supplying power from the power supply section 74 to the detector 10.

[0052] The detectors 10 transmit signals (unique address, fire signal, abnormal temperature signal, status information, etc.) to the controller 72 via wireless communication using a specified low-power radio frequency band and via a signal transmission line 90B. Here, the transmission method used for the signal transmission line 90B is Manchester-coded Bus Powered (MBP), which transmits Manchester-coded transmission signals on a power line. MBP supplies a basic consumption current to each detector 10, and also supplies a communication current (e.g., 6 mA) to the detector 10 that transmits the signal, and transmits the current signal with current modulation (e.g., ±6 mA) in the detector 10 (see FIG. 3).

[0053] Data transmission is performed at a low transmission speed of approximately 30 kbps at most. For example, the transmission speed of digital signals is set to 10 kbps to 30 kbps. At this speed, there is no need to consider impedance matching (signal reflection due to branching of the transmission line) except for long-distance transmission (several tens of kilometers or more), and detectors 10 can be arranged in a tree configuration (see Figure 4).

[0054] The signals transmitted separately from the detectors 10 are converted into arbitrary transmission signals by the controller 72 and transmitted to the host device 80 by the LTE wireless module 761 .

[0055] <Signal transmission (signal converter → detector)> In the intrinsically safe explosion-proof detection system 100 according to this embodiment, signals (address / status confirmation signals, etc.) transmitted from the controller 72 to the detectors 10 are transmitted using both wireless communication using the specified low-power radio frequency band and transmission over the signal transmission line 90B. However, there is a limit to the maximum current that can be supplied in hazardous areas. If the current for MBP transmission were supplied to all detectors 10, the number of detectors 10 that can be connected to the cable section 90 would be significantly limited. For example, the allowable output current of the FISCO power supply for a detector 10 (equipment group IIC, protection level ia) installed in a hazardous area (ZONE 0) is 183 mA (@ output voltage 14 V), limiting the maximum number of detectors that can be connected to nine. Therefore, the first transmission method transmits signals by modulating the voltage applied to the detectors 10. For example, if the voltage applied to the detector 10 when not transmitting is 3 V, the voltage is reduced to 2.5 V during transmission, and a Manchester-coded voltage is transmitted using voltage modulation (communication voltage ±0.5 V) (see Figure 5). The applied current is calculated by multiplying the basic current consumption required for anomaly detection by the number of installed units (e.g., 1 mA / unit x 32 units = 32 mA). This method reduces current consumption during communication on the same line as the MBP transmission line, thereby increasing the number of detectors 10 that can be installed. This method enables simultaneous signal transmission to all detectors 10. However, the above method is only an example; other transmission methods, such as signal formation using high-frequency voltage modulation of 0.75 to 1.0 V, are also possible.

[0056] <Detector configuration> As shown in FIG. 6, detector 10 according to the first embodiment of the present invention includes first sensor 12 that detects infrared light in a band around 4.5 μm, which is the carbon dioxide resonance radiation band emitted by flames; second sensor 14 that detects infrared light in a band around 4.0 μm, which is a band with a shorter wavelength than the carbon dioxide resonance radiation band; third sensor 16 that detects infrared light in a band around 5.0 μm, which is a band with a longer wavelength than the carbon dioxide resonance radiation band; and fourth sensor 319 that detects light in a band around 3.0 μm, which is a band shorter than the above three bands, through monitoring window 331. The detector 10 also includes an amplifier 18 that amplifies the signal from the first sensor 12, an amplifier 21 that amplifies the signal from the second sensor 14, an amplifier 22 that amplifies the signal from the third sensor 16, an amplifier 321 that amplifies the signal from the fourth sensor 319, a switch 24 that switches the signals from the amplifiers 18, 21, 22, and 321, and an AD converter 26 that converts the signal from the switch 24 into a digital value. The detector 10 also includes an arithmetic processing unit 29 that performs processing to detect a flame or abnormal temperature, and an input / output unit 32.

[0057] The input / output unit 32 outputs the detection of a flame or abnormal temperature by the calculation processing unit 29 as a digital signal to the controller 72 using the specific low-power radio module 34 and the cable unit 90, and exchanges digital signals with the controller 72.

[0058] As shown in FIG. 6, the detector 10 is provided with a monitoring window 331 in a part of the housing 110A.

[0059] The first sensor 12 comprises a filter 12A that transmits infrared light in the band around 4.5 μm, which is the carbon dioxide resonance radiation band emitted by flames; an array sensor 12B that has detection elements arranged two-dimensionally to detect the infrared light that has passed through the filter 12A and convert it into an electrical signal with a DC component; and an optical lens 12C that is positioned in front of the filter 12A.

[0060] The second sensor 14 comprises a filter 14A that transmits infrared light in a band around 4.0 μm, which is a band with a wavelength shorter than the carbon dioxide resonance radiation band; an array sensor 14B that has detection elements arranged two-dimensionally to detect the infrared light that has passed through the filter 14A and convert it into an electrical signal with a DC component; and an optical lens 14C that is positioned in front of the filter 14A.

[0061] The third sensor 16 comprises a filter 16A that transmits infrared light in a band around 5.0 μm, which is a band with a wavelength longer than the carbon dioxide resonance radiation band; an array sensor 16B that has detection elements arranged two-dimensionally to detect the infrared light that has passed through the filter 16A and convert it into an electrical signal with a DC component; and an optical lens 16C that is positioned in front of the filter 16A.

[0062] The fourth sensor 319 includes a filter 318A that transmits light in the short wavelength range, which is at least a part of the range including the visible light range of 4.0 μm or less, out of the natural light that has passed through the monitoring window 331, and a detection element 318B that detects the light that has passed through the filter 318A and converts it into an electrical signal of a DC component.

[0063] Each detection element of the array sensor 12B is arranged to correspond to each detection element of the array sensor 14B and each detection element of the array sensor 16B.

[0064] In addition, array sensors 12B, 14B, and 16B detect infrared light at a predetermined monitoring angle (e.g., 90 degrees), and the corresponding detection elements of array sensor 12B, array sensor 14B, and array sensor 16B detect infrared light from the same predetermined area.

[0065] Furthermore, optical lenses 12C, 14C, and 16C each consist of one or more lenses. It is desirable that optical lenses 12C, 14C, and 16C each consist of two or more lenses. This is to ensure that the detection elements of array sensor 12B, array sensor 14B, and array sensor 16B are focused as flatly as possible over the wide monitoring angles. Furthermore, to reduce loss due to lens reflection, the sensitivity of the detection elements can be increased by depositing an anti-reflection coating (AR coating) on ​​the lenses. Lens materials include sapphire, chalcogenide glass, silicon, and germanium.

[0066] In order to reliably capture a weak electrical signal that detects infrared light in the carbon dioxide resonance radiation band around 4.5 μm, a sensor identical to the first sensor 12 may be further provided.

[0067] The detection elements of the first sensor 12 to the fourth sensor 319 are composed of thermopiles, but they may also be composed of other photovoltaic type elements such as InAsSb elements, microbolometer elements that utilize resistance changes, or photoconductive type elements such as PbSe. Compared to thermopiles and microbolometers, other elements have extremely fast infrared detection speeds. Therefore, even with the same circuit configuration, by increasing the AD conversion speed, it is possible to construct a detector that can detect flames extremely quickly.

[0068] The amplifiers 18, 21, 22, and 321 independently amplify the electrical signals of the detection elements of the first sensor 12, the second sensor 14, the third sensor 16, and the fourth sensor 319, respectively.

[0069] The switch 24 includes a switch section (not shown) that sequentially switches over a fixed period of time between the electrical signals individually amplified by the amplifiers 18, 21, 22, and 321 to combine them into one electrical signal, and outputs the combined electrical signal. Note that instead of providing the switch 24, an AD conversion section may be provided for each of the amplifiers 18, 20, 22, and 322, and the amplified electrical signals may be individually converted into digital values ​​and output to the arithmetic processing section 29.

[0070] The arithmetic processing unit 29 is configured with a CPU. When the arithmetic processing unit 29 is explained in terms of functional blocks divided into each function realization means, as shown in Fig. 7, the arithmetic processing unit 29 includes a signal acquisition unit 40, a detection unit 44, and an input / output control unit 46.

[0071] The signal acquisition unit 40 acquires the value of the electrical signal from each detection element of the first sensor 12, the value of the electrical signal from each detection element of the second sensor 14, the value of the electrical signal from each detection element of the third sensor 16, and the value of the electrical signal from the detection element 318B of the fourth sensor 319 from the signal output from the AD conversion unit 26.

[0072] The detection unit 44 determines whether a flame or abnormal temperature has been detected for each detection element of the array sensor 12B based on the value of the electrical signal from each detection element of the first sensor 12, the value of the electrical signal from each detection element of the second sensor 14, and the value of the electrical signal from each detection element of the third sensor 16, which have been acquired by the signal acquisition unit 40. Note that the method of determination is similar to the method described in Patent Document (WO 2018 / 198504), and therefore description thereof will be omitted.

[0073] Furthermore, the detection unit 44 determines, as the fire position, a predetermined position for a detection element determined to have detected a flame among the detection elements of the array sensor 12B.

[0074] The predetermined positions for the detection elements may be set by measuring the detection position in real space for each detection element using a position measuring device when the detector 10 is installed.

[0075] The detection unit 44 determines the scale W, which is the spatial size of the flame, based on the value of the electrical signal from the detection element that is determined to have detected the flame.

[0076] When it is determined that a fire has been detected, the detection unit 44 controls the input / output control unit 46 to notify the location of the fire. For example, the input / output control unit 46 causes a fire signal to be transmitted to the controller 72 via the specified low-power wireless module 34 and the cable unit 90.

[0077] Furthermore, when the value of the electrical signal from the detection element of the third sensor 16 and the value of the electrical signal from the detection element 318B of the fourth sensor 319 satisfy a predetermined condition, the detection unit 44 determines that the monitoring window 331, the third sensor 16, the fourth sensor 319, the amplifiers 18, 21, 22, 321, the switch 24, the AD conversion unit 26, or the arithmetic processing unit 29 is in an abnormal state, and controls the input / output control unit 46 to notify the abnormal state. For example, the input / output control unit 46 causes a signal indicating window dirt or other abnormality to be transmitted to the controller 72 via the specified low-power wireless module 34 and the cable unit 90.

[0078] <Mobile robot> The mobile robot 50 according to the first embodiment of the present invention moves to the vicinity of each wireless master device 68 in turn, collects the judgment results of each detector 10 from the digital signals received from the wireless master devices 68, and monitors for abnormalities in its own system, including abnormalities in the power supply unit 74 of the wireless master device 68.

[0079] As shown in FIG. 8, the mobile robot 50 includes a power supply unit 51, a control unit 52, a motor drive unit 53, a position detection unit 54, an image capture unit 55, a distance measurement unit 56, a power saving control unit 57, a host wireless communication unit 58, a sensor wireless communication unit 59, and a memory unit 60.

[0080] The power supply unit 51, control unit 52, motor drive unit 53, position detection unit 54, image capture unit 55, distance measurement unit 56, power saving control unit 57, upper level wireless communication unit 58, sensor wireless communication unit 59, and memory unit 60 are connected to each other by a bus 62.

[0081] The power supply unit 51 includes a primary battery, a secondary battery, a charge control unit, a solar power generation unit, and a power supply inspection unit. The primary battery and secondary battery supply power to each unit of the mobile robot 50. The charge control unit controls the secondary battery to be charged using an externally supplied power source or power generated by the solar power generation unit. The power supply inspection unit inspects the primary battery and secondary battery for abnormal conditions, including insufficient power.

[0082] The control unit 52 controls the operation of each part of the mobile robot 50.

[0083] The motor drive unit 53 includes a plurality of motors, a drive unit for driving each motor, a motor control unit for controlling the driving of each motor, and a motor inspection unit for inspecting each motor for abnormal conditions. Each motor is a two-axis or three-axis motor.

[0084] The position detection unit 54 includes a radio wave receiving unit that receives radio waves from a GNSS (Global Navigation Satellite System) such as a GPS (Global Positioning System) to detect the position of the mobile robot 50, and an inspection unit that inspects the radio wave receiving unit for abnormal conditions.

[0085] The image capturing unit 55 includes a visible light camera, an infrared camera, a lighting unit, a photography control unit, an image data collection unit, and an inspection unit. The visible light camera captures visible light images of the mobile robot 50's surroundings. The infrared camera captures infrared light images of the mobile robot 50's surroundings. The illumination unit irradiates the mobile robot 50's surroundings with illumination light. The photography control unit controls the visible light camera, the infrared camera, and the lighting unit. The image data collection unit collects visible light images captured by the visible light camera and infrared light images captured by the infrared camera and stores them in the memory unit 60. By storing the collected visible light images and infrared light images in the memory unit 60, they can be analyzed at a later date. For example, they can be used to detect cracks in pipes, liquid leaks, changes in temperature distribution and discoloration of equipment installed in a plant, and oil leaks in drained liquids. Furthermore, based on the abnormality information detected by each detector, the collected visible light images and infrared light images can be used to reconfirm the abnormality information. The inspection unit also inspects the visible light camera, the infrared camera, and the lighting unit for abnormal conditions.

[0086] The distance measurement unit 56 measures the distance to obstacles around the mobile robot 50. This allows the mobile robot 50 to avoid unexpected obstacles that appear on its patrol route and to check for the presence or absence of obstacles.

[0087] The power saving control unit 57 periodically turns on the power of the mobile robot 50 and controls the power to be turned off after a set time has elapsed.

[0088] The host wireless communication unit 58 includes an LTE wireless communication unit that performs wireless communication using the LTE wireless frequency band, a communication control unit, and a communication inspection unit. The communication control unit controls wireless communication between the LTE wireless communication unit and the host device 80. The communication inspection unit inspects the LTE wireless communication unit and the communication control unit for abnormal states.

[0089] The sensor wireless communication unit 59 includes a specified low-power wireless communication unit that performs wireless communication using the specified low-power wireless frequency band, a communication control unit, and a communication inspection unit. The communication control unit controls wireless communication between the specified low-power wireless communication unit and the controller 72. The communication inspection unit inspects the specified low-power wireless communication unit and the communication control unit for abnormal conditions.

[0090] The storage unit 60 stores patrol route information, position detection information, sensor installation position information, camera installation position information, camera image data collection information, inspection data information, software update information, schedule management information, and wireless communication management information.

[0091] The patrol route information is information representing the route for patrolling around each of the multiple wireless base stations 68. The position detection information is information representing the position of the mobile robot 50 detected by the position detection unit 54. The sensor installation position information is information representing the installation position of each of the multiple wireless base stations 68. The camera installation position information is information representing the installation positions and shooting directions of the visible light camera and infrared camera of the image capturing unit 55, and information representing the positions where the collected visible light images were captured and the positions where the collected infrared light images were captured.

[0092] The camera image data collection information is a collection of visible light images taken by a visible light camera and infrared light images taken by an infrared camera.

[0093] The inspection data information is information that indicates the results of inspecting the abnormal states of each part of the mobile robot 50.

[0094] The software update information is information relating to software updates for the controller 72 and each detector 10 that have received commands from the higher-level device 80 .

[0095] The schedule management information is information relating to the detection cycle of each controller 72.

[0096] The wireless communication management information is information necessary for wireless communication in the upper wireless communication unit 58 and information necessary for wireless communication in the sensor wireless communication unit 59, such as the address of the upper device 80 and the addresses of each controller 72.

[0097] <Effects of intrinsically safe explosion-proof detection system> Next, the operation of the intrinsically safe explosion-proof detection system 100 according to the first embodiment of the present invention will be described.

[0098] First, each detector 10 installed in the intrinsically safe explosion-proof detection system 100 is assigned an individual address. As a result, data transmission between the detector 10 and the controller 72 involves sending and receiving signals that combine the address with various information. For example, if 32 detectors 10 are connected to the cable section 90, the address section is expressed in 5 bits, followed by several bits of status information (fire signal, abnormal temperature, window dirt, fire location, etc.) (Fig. 9). This address can be changed as desired by signal transmission from the higher-level device 80 or by using a dip switch or the like installed in the detector 10.

[0099] <Controller operation> At this time, the controller 72 of the wireless master device 68 of the intrinsically safe explosion-proof detection system 100 repeatedly executes the processing routines shown in FIGS.

[0100] In step S101, the controller 72 starts counting by a timer to measure whether a time corresponding to the detection period of the detector 10 has elapsed.

[0101] In step S102, the controller 72 determines whether or not a time corresponding to the detection cycle of the detector 10 has elapsed. When the count by the timer reaches the time corresponding to the detection cycle of the detector 10, the process proceeds to step S103.

[0102] In step S103, the controller 72 turns on the power of the wireless base station 68. Specifically, because the timer of the wireless base station 68 is always powered on, the controller 72 turns on the power of the components of the wireless base station 68 other than the timer. In step S104, the controller 72 checks the status of the wireless base station 68 of the intrinsically safe explosion-proof detection system 100. This status check includes checking for abnormal conditions, including insufficient capacity of the power supply unit 74.

[0103] In step S105, the controller 72 supplies power from the power supply unit 74 to the detector 10 from which data is to be collected, and turns on the power to the detector 10. The controller 72 then collects data indicating the status and detection results of the detector 10. Thereafter, the controller 72 stops the power supply from the power supply unit 74 to the detector 10 from which data is to be collected, and turns off the power to the detector 10.

[0104] In step S106, the controller 72 determines whether or not the process of step S105 has been executed for all detectors 10. If there is a detector 10 for which the process of step S105 has not been executed, the process returns to step S105 with that detector 10 as the collection target. On the other hand, if the process of step S105 has been executed for all detectors 10, the process proceeds to step S107.

[0105] In step S107, the controller 72 transmits data indicating the status and detection results of each detector 10 to the higher-level device 80 via the LTE wireless module 761, and also transmits data indicating the status and detection results of each detector 10 to the mobile robot 50 via the specified low-power wireless module 762. At this time, if the transmission cannot be confirmed, the controller 72 repeats the transmission up to, for example, four times.

[0106] In step S108, the controller 72 determines whether or not a command has been received from the higher-level device 80 via the LTE wireless module 761. If a command has not been received from the higher-level device 80, the process proceeds to step S110. On the other hand, if a command has been received from the higher-level device 80, the process proceeds to step S109.

[0107] In step S109, the controller 72 performs processing in accordance with the command received from the higher-level device 80. For example, the controller 72 performs processing in accordance with the command, such as updating the software of the controller 72 or changing the setting conditions for data collection.

[0108] In step S110, the controller 72 determines whether or not a command has been received from the mobile robot 50 via the specified low-power wireless module 762. If a command has not been received from the mobile robot 50, the process proceeds to step S112. On the other hand, if a command has been received from the mobile robot 50, the process proceeds to step S111.

[0109] In step S111, the controller 72 performs processing in response to a command received from the mobile robot 50. For example, the controller 72 performs processing in response to a command such as changing more detailed software of the controller 72, changing setting conditions for data collection, or checking operation using maintenance software. In this way, the higher-level device 80 can perform operation checks that are not possible with the higher-level device 80 or check operation by changing settings.

[0110] In step S112, the controller 72 resets the timer count, and in step S113, the controller 72 turns off the power to the wireless master device 68.

[0111] According to the above processing routine, the process of detecting a flame or an abnormal temperature is repeatedly executed at regular intervals by each detector 10. Also, the process of determining an abnormal state of the detector 10 is repeatedly executed at regular intervals by each detector 10.

[0112] At this time, in the intrinsically safe explosion-proof detection system 100, the following data is normally exchanged.

[0113] <Data transfer (normal)> In the intrinsically safe explosion-proof detection system 100, under normal circumstances, the status of each detector 10 is checked in a polling manner. Specifically, the controller 72 outputs a status information request signal to each detector 10 (each address) in turn (S1), and the designated detector 10 outputs the relevant information (address and no abnormality / window dirt / other abnormality, etc.) (S2). This is performed for each detector 10 in address order, and upon completion of one cycle, the collected status information is transmitted via wireless communication to the host device 80 and the mobile robot 50. This is repeated in a fixed time cycle (Fig. 12).

[0114] This status check makes it possible to identify the location of a broken wire, which will be described later. The location of a broken wire can be identified based on the number and addresses of the detectors 10 that do not respond to the status information request signal from the controller 72.

[0115] As described above, by periodically diagnosing the functions of the detector 10 and the network and transmitting the diagnostic results to the host device 80 and the mobile robot 50 via wireless communication, not only can the reliability of the intrinsically safe explosion-proof detection system 100 be improved, but maintenance costs, etc. can also be reduced.

[0116] Furthermore, when the detector 10 detects a flame or an abnormal temperature, or when it is determined that the detector 10 is in an abnormal state, the following data is exchanged in the intrinsically safe explosion-proof detection system 100.

[0117] <Data exchange (when fire is detected, when abnormal temperature is detected, when abnormal condition is determined)> When an abnormal condition is detected by any detector 10, that detector 10 outputs the relevant information (address and fire signal / abnormal temperature signal, etc.) to the controller 72 (S3), as shown in Fig. 13. Upon receiving this signal input, the controller 72 transmits a fire signal, an abnormal temperature signal, an abnormal condition signal, etc. to the host device 80 and the mobile robot 50 via the transceivers 76 and 88 (S4). In addition, at the point in time when the address information of the signal is transmitted, the controller 72 outputs a signal to all detectors 10 indicating that a signal has been transmitted from the detector 10 at that address (S5). Upon receiving the signal transmission, all detectors 10 except for the detector 10 in question stop outputting the fire signal, abnormal temperature signal, or abnormal condition signal until a given time period has elapsed, and if there is a detector 10 that has detected an abnormality before the given time period (on the order of milliseconds) has elapsed, the detector 10 outputs a fire signal, abnormal temperature signal, or abnormal condition signal after the given time period has elapsed. This makes it possible to prevent loss or communication failure due to overlap of signals output with a slight time difference from multiple detectors 10. The above-mentioned time can be changed arbitrarily according to the amount of signal to be transmitted (for example, it can be made short when the output information is only a fire signal, abnormal temperature signal, or abnormal state signal, and long when abnormal position information, temperature information, etc. are also output).

[0118] If the controller 72 does not transmit an acknowledgement signal to the detector 10 after a certain period of time has elapsed, the detector 10 will output a fire signal or the like again, repeating this process until the acknowledgement signal is transmitted. If two or more detectors 10 output a fire signal or the like at the same time, or if a fire signal or the like is output from any detector 10 while a detector 10 status check is in progress, a signal combining the two or more signals will be input to the controller 72 (FIG. 14). In this case, since there is a possibility that the signal cannot be restored and lost depending on the conditions, the status of each detector 10 is checked in a polling manner. Specifically, as shown in FIG. 15, when the controller 72 determines that multiple detectors 10 have output signals, it outputs address and status information request signals to all detectors 10 in sequence (S6), and each specified detector 10 outputs the relevant information (address and no abnormality / fire signal, etc.) (S7). This is performed for each detector 10 in address order, and when a fire signal, abnormal temperature signal, or abnormal condition signal is confirmed, the information is transmitted by wireless communication to the host device 80 and the mobile robot 50 (S8). Note that one method for the controller 72 to determine that outputs have been made from multiple detectors 10 is to monitor the output current from the power supply using MBP transmission, for example, and make the determination based on the increase in that current.

[0119] Therefore, when any signal is input via this transmission method, the status of each detector 10 is checked in a polling format, similar to the MBP described above, to ensure reliable transmission. However, this method is just one example, and other methods, such as Carrier Sense Multiple Access / Collision Detection (CSMA / CD), in which the detectors 10 monitor the status of the signals flowing through the cable section 90 and adjust the right to use the line, can also be applied. As described above, by using polling, which is simple and has high transmission reliability, it is possible to prevent the loss of fire signals from the detectors 10 and communication failures, and improve the reliability of data exchange in both transmission methods.

[0120] <Measures against disconnection / short circuits> If a break or short circuit occurs in the cable section 90, any detector 10 may be unable to monitor (such as a state where no power is supplied or no signal is transmitted) (Fig. 16). The intrinsically safe explosion-proof detection system 100 monitors for breaks and short circuits using the following method, and transmits a break / short circuit alarm to the host device 80 via wireless communication.

[0121] (disconnection monitoring) As described above, in the intrinsically safe explosion-proof detection system 100, the status of the detector 10 is checked at regular intervals. Therefore, if there is no response to a status information request signal from the controller 72, a break in the wire is suspected. Since a unique address is assigned to the detector 10, if a break occurs in the cable section 90 as shown in FIG. 16(A) or in a branch line of the cable section 90 as shown in FIG. 16(B), the controller 72 can identify the location of the break based on the address that has not responded after one cycle of status checks.

[0122] (short circuit monitoring) In the intrinsically safe explosion-proof detection system 100, if a short circuit occurs on the cable section 90 as shown in Figure 16(C) or on a branch line of the cable section 90 as shown in Figure 16(D), it is not possible to identify the location of the short circuit, but it is possible to detect the short circuit by monitoring the short-circuit current with the controller 72 or the power supply section 74.

[0123] <Mobile robot movement> The power saving control unit 57 of the mobile robot 50 of the intrinsically safe explosion-proof detection system 100 turns on the power of the mobile robot 50 at a predetermined cycle, and the control unit 52 executes the processing routine shown in Figure 17.

[0124] In step S120, the control unit 52 of the mobile robot 50 controls the motor drive unit 53 to move to the vicinity of the wireless base station 68 from which data is to be collected, based on the patrol route information, sensor installation position information, and position detection information.

[0125] In step S121, the control unit 52 of the mobile robot 50 determines whether or not data indicating the status and determination results of each detector 10 has been collected from the digital signals received from the target wireless master devices 68. When data indicating the status and determination results of each detector 10 has been collected from the digital signals received from the target wireless master devices 68, the process proceeds to step S122.

[0126] In step S122, the control unit 52 of the mobile robot 50 determines, from the digital signal received from the wireless master device 68 from which data is to be collected, whether or not the data indicating the status and determination results of each detector 10 collected in step S121 has already been transmitted to the host device 80. For example, if the digital signal received from the wireless master device 68 from which data is to be collected contains information indicating that the data indicating the status and determination results of each detector 10 has already been transmitted to the host device 80, the process proceeds to step S124. On the other hand, if the digital signal received from the wireless master device 68 from which data is to be collected contains information indicating that the data indicating the status and determination results of each detector 10 has not yet been transmitted to the host device 80, the process proceeds to step S123.

[0127] In step S123, the control unit 52 of the mobile robot 50 transmits to the host device 80 the data indicating the status and determination results of each detector 10 and wireless master device 68 collected in step S121.

[0128] In step S124, the control unit 52 of the mobile robot 50 determines whether or not there are any commands to the wireless master devices 68 and each detector 10 from which data is to be collected. For example, if there are any commands to the wireless master devices 68 and each detector 10 from which data is to be collected, such as to change the software in more detail in the controller 72, to change the setting conditions for data collection, or to check operation using maintenance software, the process proceeds to step S125. On the other hand, if there are no commands to the wireless master devices 68 and each detector 10 from which data is to be collected, the process proceeds to step S126.

[0129] In step S126, the control unit 52 of the mobile robot 50 determines whether or not the processing of steps S120 to S125 has been executed for all wireless base stations 68. If the processing of steps S120 to S125 has been executed for all wireless base stations 68, the process proceeds to step S129. On the other hand, if there is a wireless base station 68 for which the processing of steps S120 to S125 has not been executed, the process proceeds to step S127, with that wireless base station 68 being the collection target.

[0130] In step S127, the control unit 52 of the mobile robot 50 determines whether or not it is possible to collect data from the next wireless master device 68 that is to be the target of collection within the set power-on time. If it is possible to collect data from the next wireless master device 68 that is to be the target of collection within the set power-on time, the process returns to step S120. On the other hand, if it is not possible to collect data from the next wireless master device 68 that is to be the target of collection within the set power-on time, the process proceeds to step S128.

[0131] In step S128, the power is turned off until the next cycle, and when the power is turned on in the next cycle, the process returns to step S120.

[0132] In step S129, the power is turned off and the processing routine ends.

[0133] <Power supply battery maintenance> In the intrinsically safe explosion-proof detection system 100, if it is determined that the power supply unit 74 is in an abnormal state based on the status of the wireless master unit 68 collected by the mobile robot 50, the primary battery of the power supply unit 74 is replaced or the secondary battery is charged. In this case, since the number of power supply units 74 is small compared to the number of detectors 10, the effort required for battery maintenance of the power supply units 74 is reduced. Note that the power supply unit 74 may be an external power source as long as intrinsic safety is ensured, in which case battery maintenance is not required, further reducing management costs.

[0134] As described above, according to the intrinsically safe explosion-proof detection system of the embodiment of the present invention, the wireless master unit transmits the digital signals sent from each detector to a higher-level device and a mobile robot that has moved to the vicinity, thereby making it possible to stably collect data from multiple detectors.

[0135] Furthermore, the mobile robot can collect status information, including abnormalities in the power supply, from the wireless master device, thereby reducing the management costs of the power supply unit.

[0136] Furthermore, by supplying power from the power supply unit to a plurality of detectors via the signal transmission line, the number of power supply units can be reduced, thereby reducing the management costs of the power supply units.

[0137] In addition, each of the detector and wireless base station transmits and receives digital signals using wireless communication in the specific low-power radio frequency band and a cable section, thereby providing a highly reliable intrinsically safe explosion-proof detection system with a simple configuration.

[0138] In addition, the cable section ensures that fire or abnormal temperature detected by the detector is transmitted to the host device and mobile robot even if a malfunction (disconnection or short circuit) occurs in the cable section, thereby realizing an intrinsically safe explosion-proof detection system with a high level of safety.

[0139] It also enables the creation of a fire / abnormal temperature monitoring environment in the most technically demanding dangerous areas (ZONE 0) at low cost.

[0140] Furthermore, multiple detectors installed in hazardous locations are connected to a single cable with a T-branch, and perform half-duplex communication with a host device installed in a non-hazardous location via wireless communication using a specified low-power radio frequency band and the cable. Specifically, signals transmitted from the detectors to the signal converter (unique address, fire signal, abnormal temperature signal, status information, etc.) are transmitted redundantly as two types of signals: a current signal powered by a Manchester-coded bus and a wireless communication signal using a specified low-power radio frequency band. Furthermore, signals transmitted from the signal converter to the detectors (address, status confirmation signal, etc.) are transmitted redundantly as two types of signals: a voltage signal generated by modulating the voltage applied to the detector and a wireless communication signal using a specified low-power radio frequency band. This ensures that fire signals or abnormal temperatures can be reliably transmitted to the host device and the mobile robot.

[0141] Furthermore, by using the voltage transmission based on the voltage modulation, it is possible to reduce the current supplied to the dangerous location, and the number of detectors that can be installed in the dangerous location can be increased.

[0142] Furthermore, by implementing voltage modulation-based voltage transmission at a low transmission speed of around several tens of kbps, a network capable of tree branching can be created.

[0143] In addition, the functions of the detector and network are periodically diagnosed by polling from the signal converter, and the results are transmitted to the host device and mobile robot via wireless communication, thereby improving the reliability of the intrinsically safe explosion-proof detection system and reducing maintenance costs, etc.

[0144] In addition, when fire signals or other signals are output simultaneously from multiple detectors, polling from the signal converter prevents communication failure of the fire signals and improves the reliability of data transmission.

[0145] [Second embodiment] <System configuration> An intrinsically safe explosion-proof detection system according to a second embodiment of the present invention will be described below. Note that parts having the same configuration as those in the first embodiment will be assigned the same reference numerals and descriptions thereof will be omitted.

[0146] 18, an intrinsically safe explosion-proof detection system 200 according to the second embodiment of the present invention includes a plurality of detectors 10, wireless master devices 68A and 68B, a host device 80, and a mobile robot 50. A plurality of sets, each consisting of a plurality of detectors 10 and a wireless master device 68A and 68B, are provided. The wireless master device 68A includes a barrier 70A, a controller 72A, a power supply unit 74A, and a transceiver 76A. The wireless master device 68B includes a barrier 70B, a controller 72B, a power supply unit 74B, and a transceiver 76B.

[0147] The controller 72A and the plurality of detectors 10 are connected by a cable portion 290A, and the controller 72B and the plurality of detectors 10 are connected by a cable portion 290B. The power supply portions 74A and 74B are formed by primary or secondary batteries.

[0148] As described above, in this embodiment, a first intermediate configuration including cable portion 290A and wireless base station 68A, and a second intermediate configuration including cable portion 290B and wireless base station 68B are provided. Accordingly, each detector 10 has two input / output units 32 and two specified low-power wireless modules 34, and one input / output unit 32 is connected to the first intermediate configuration and outputs a digital signal indicating that a flame has been detected by processing unit 29 to controller 72A via cable portion 290A, and also transmits a digital signal indicating that a flame has been detected by processing unit 29 to controller 72A from one specified low-power wireless module 34, thereby exchanging digital signals with controller 72A. In addition, the other input / output unit 32 is connected to the second intermediate configuration, and outputs a digital signal indicating that a flame has been detected by the arithmetic processing unit 29 to the controller 72B via the cable unit 290B, and also transmits a digital signal indicating that a flame has been detected by the arithmetic processing unit 29 to the controller 72B via the other specific low-power radio module 34, thereby exchanging digital signals with the controller 72B.

[0149] The cable portions 290A and 290B include a signal transmission line 90B, similar to the cable portion 90 of the first embodiment.

[0150] In the intrinsically safe explosion-proof detection system 200, the lines from the cable sections 290A and 290B to the transceivers 76A and 76B are duplicated. By duplicating the network in this way, it is possible to avoid a state in which monitoring becomes impossible due to a disconnection or short circuit (FIG. 19). Specifically, when the controller 72A or 72B detects a disconnection or short circuit in one of the networks using a method similar to that of the first embodiment, it sends a short circuit alarm to the upper device 80 via wireless communication and automatically switches the transmission line to the other network. This makes it possible to avoid a state in which fire / abnormal temperature monitoring becomes impossible due to a disconnection or short circuit, and to build a highly reliable fire monitoring environment.

[0151] Since a unique address is assigned to the detector 10, if a break occurs on the cable portion 290B as shown in Fig. 19(A) or on a branch line of the cable portion 290B as shown in Fig. 19(B), the location of the break can be identified by the controller 72B based on the address that does not respond after one cycle of status check. Also, if a short circuit occurs on the cable portion 290B as shown in Fig. 19(C) or on a branch line of the cable portion 290B as shown in Fig. 19(D), it is not possible to identify the location of the short circuit, but it is possible to detect the short circuit by monitoring the short-circuit current with the controller 72B or the power supply unit 74B.

[0152] As described above, the intrinsically safe explosion-proof detection system according to the second embodiment provides further redundancy by duplicating communication between the detector and the wireless base station, thereby realizing a highly reliable network for fire or abnormal temperature monitoring at low cost. In this case, the signal transmission system becomes a quadruple system. Due to the duplication, the fire or abnormal temperature monitoring environment can continue even in the event of a wire break or short circuit. In actual operation, a detector equipped with two cable connectors can be used as a standard product, and customers can choose whether or not to use duplication depending on the safety integrity level (SIL) and cost required.

[0153] <Modification> The present invention is not limited to the above-described embodiment, and various modifications and applications are possible without departing from the spirit and scope of the present invention.

[0154] For example, the detector 10 has been described as detecting a flame or an abnormal temperature, but the present invention is not limited thereto. For example, the detector 10 may be configured to detect thinning of pipes in a plant. In this case, as shown in Fig. 20, the detector 10A includes an arithmetic processing unit 112A, which is a CPU having a function of controlling power consumption, a connection terminal 18A for connecting to a sensor unit 20A, barriers 69A and 70A, an ultrasonic pulse generating unit 22A, an ultrasonic echo signal receiving unit 24A, a selector switch 26A, a power supply connection terminal 73A for connecting to an external power supply unit 28A, an input / output unit 32A, and a specified low-power wireless module 34A.

[0155] The external power supply unit 28A is a thermoelectric power generation module that generates power using a temperature difference using a thermoelectric element and supplies power to the detector 10 A. Note that the external power supply unit 28A may be a power generation module other than a thermoelectric power generation module, such as a solar cell.

[0156] The sensor unit 20A includes a plurality of ultrasonic transducers 20B. The number of ultrasonic transducers 20B is determined based on the diameter of the plant's piping. For example, if the plant's piping is narrow, two to three ultrasonic transducers 20B are provided, whereas if the plant's piping is wide, a dozen or so ultrasonic transducers 20B are provided. As shown in FIG. 21 , the ultrasonic transducers 20B are attached to the surface of the plant piping PH. A thermoelectric element 28B of an external power supply unit 28A is attached to the surface of the plant piping PH. A thermal insulation material HO is attached to the plant piping PH so as to cover the ultrasonic transducers 20B and the thermoelectric element 28B. FIG. 21 is a perspective view of the plant piping PH, with the thermal insulation material HO visible through the viewfinder. The thermoelectric element 28B of the external power supply unit 28A may be attached to the surface of the thermal insulation material HO. The external power supply unit 28A and the power supply unit 74 may be used together.

[0157] The ultrasonic pulse generating unit 22A generates an ultrasonic pulse in any one of the plurality of ultrasonic transducers 20B connected by the changeover switch 26A.

[0158] The ultrasonic echo signal receiving unit 24A receives an ultrasonic echo signal when an ultrasonic pulse is generated in any one of the plurality of ultrasonic transducers 20B connected by the changeover switch 26A.

[0159] When the arithmetic processing unit 112A is explained in terms of functional blocks divided into function realization means, the arithmetic processing unit 112A includes a pulse control unit 40A, an echo signal analysis unit 44A, and a switching control unit 46A.

[0160] The pulse control unit 40A controls the ultrasonic pulse generating unit 22A to generate ultrasonic pulses.

[0161] The echo signal analysis unit 44A analyzes the ultrasonic echo signal received from the ultrasonic transducer 20B, and determines the state of thinning of the plant piping PH at the location where the ultrasonic transducer 20B is placed.

[0162] With the above configuration, the detector 10A is powered by the temperature difference power generation of the external power supply unit 28A, so it is battery-free or does not require battery replacement for a long period of time, reducing running costs. Since not only the ultrasonic vibrator 20B but also the thermoelectric element 28B of the external power supply unit 28A are attached to the plant piping that is to be judged for wall thinning, the external power supply unit 28A is easily installed.

[0163] The present invention may also be applied to a system that outputs an alarm indicating that a predetermined abnormality has been detected when a predetermined threshold value or higher is reached, such as in a gas detector or temperature sensor. For example, the present invention may be applied to a system that outputs an alarm indicating that a predetermined abnormality has been detected when humidity, pressure, vibration, impact, gas concentration, sound, ultrasound, liquid level, or rotation detected by a sensor is equal to or higher than a threshold value. The present invention may also be applied to a system that outputs an alarm when a liquid leak is detected based on sensor information detected by a sensor. The present invention may also be applied to an intrinsically safe explosion-proof detection system that uses field devices, multiple of which are installed in a cascade in hazardous locations, as detectors.

[0164] Although the example has been described in which MBP is used as the transmission method for the cable section, the present invention is not limited to this, and for example, Manchester code using voltage modulation or Ethernet (registered trademark) may be used. When Ethernet (registered trademark) is used as the first transmission method, power can be supplied over the communication line using a technology called PoE (Power over Ethernet).

[0165] [Third embodiment] <Outline of the embodiment of the present invention> An embodiment of the present invention relates to an intrinsically safe explosion-proof detection system that uses a detector to monitor environmental information (temperature, vibration, pressure, gas concentration, sound, impact, rotation speed, etc.) and detect various abnormal conditions (fire, temperature abnormality, leakage of hazardous materials, gas leak, etc.) at hazardous locations specified in the Factory Electrical Equipment Explosion Protection Guidelines or IEC (International Electrotechnical Commission) standards, and wirelessly transmits the signals to a higher level at the hazardous location.

[0166] The system has the following properties:

[0167] (1) Multiple detectors (several to around 100) are connected to one bus line, and environmental information / abnormal conditions are transmitted to a higher-level device and a mobile robot.

[0168] (2) By bundling the above detectors into a single signal transceiver, power supply unit (battery unit), and wireless transceiver, the cost of the detector itself can be reduced, and the communication volume and usage fees for wireless devices can be reduced.

[0169] (3) The operation of detectors, signal transmitters and receivers, and wireless transmitters and receivers connected to a single power supply unit (battery unit) is intrinsically safe as specified in the Factory Electrical Equipment Explosion Protection Guidelines or IEC (International Electrotechnical Commission) standards, and is performed with extremely low current consumption (in the order of μA), so that the entire system, including the power supply unit, can be installed in a hazardous location.

[0170] (4) The low current consumption extends the battery life to approximately 15 to 20 years, reducing the running costs associated with battery replacement.

[0171] (5) By combining wireless and wired communication, highly reliable wired communication can be achieved even in areas of the plant where wireless communication is difficult.

[0172] <System configuration> An intrinsically safe explosion-proof detection system according to a third embodiment of the present invention will be described below.

[0173] 22, an intrinsically safe explosion-proof detection system 300 according to the third embodiment of the present invention includes a plurality of detectors 310, a plurality of wireless master devices 368, a host wireless transceiver 378, a host device 380, and a mobile robot 50. A plurality of bus lines 388 are provided, each consisting of the plurality of detectors 310 and the wireless master devices 368. The wireless master device 368 includes a barrier 370, a controller 372, a power supply unit 373, and a transceiver 374.

[0174] The controller 372 and the multiple detectors 310 are connected by a cable section 90. The transceiver 374 includes an LTE wireless module 3741 that transmits and receives signals between the higher-level device 380 and the controller 372 by wireless communication using the LTE wireless frequency band, and a specified low-power wireless module 3742 that transmits and receives signals between the detectors 310 and the controller 372 by wireless communication using the specified low-power wireless frequency band. The specified low-power wireless module 3742 further transmits and receives signals between the controller 372 and the mobile robot 50 by wireless communication using the specified low-power wireless frequency band.

[0175] The host device 380 includes one or more of a host computer 382, ​​a DCS / PLC 384, and a relay panel 386. The host device 380 is connected to a host wireless transceiver 378, which transmits and receives signals between the host device 380 and the wireless master device 368 via wireless communication using the LTE wireless frequency band. The detector 310, the wireless master device 368, and the mobile robot 50 are installed in a dangerous location, and the host wireless transceiver 378 and the host device 380 are installed in a non-hazardous location.

[0176] The controller 372 relays the exchange of digital signals between the detectors 310 and the host device 380, and also relays the exchange of digital signals between the detectors 310 and the mobile robot 50. The power supply unit 373 supplies power to each detector 310 via the cable unit 90.

[0177] 22, a plurality of detectors 310 installed in a hazardous location are connected to a single cable 90 via a T-branch connector 90C, and transmit signals to a higher-level device 380 and the mobile robot 50 via a wireless master unit 368 also installed in the hazardous location. The detectors 310 are also supplied with power via the cable 90 from a power supply unit 373 (battery unit) also installed in the hazardous location.

[0178] Here, the barrier 370 serves to limit the energy supplied to the detector 310 and suppress overvoltage or overcurrent that occurs in the event of a break or short circuit to a level that will not cause a spark that could lead to ignition. The controller 372 also serves to convert transmission signals between each detector 310 and the transceiver 374, and monitors the network status (monitoring for breaks and short circuits in the cable section 90, etc.).

[0179] Furthermore, information collected by the wireless master devices 368 of the multiple bus lines 388 is transmitted to the upper wireless transceiver 378 and aggregated on the host computer 382 or the cloud via Ethernet or the like. Alternatively, information collected by the wireless master devices 368 of the multiple bus lines 388 is transmitted to the mobile robot 50, transmitted from the mobile robot 50 to the upper wireless transceiver 378, and aggregated on the host computer 382 or the cloud via Ethernet or the like.

[0180] In addition, multiple (several to approximately 100) various detectors 310 are connected to the cable section 90 of the bus line 388, and depending on the type of content to be detected, environmental information (temperature, vibration, pressure, gas concentration, sound, ultrasound, impact, rotation speed, liquid level, etc.) and various abnormal conditions (fire, temperature abnormality, leakage of hazardous materials, gas leak, etc.) are transmitted to the mobile robot 50 and the higher-level device 380.

[0181] Although FIG. 22 shows a bus connection centered around one cable section 90, a tree structure is also possible.

[0182] As shown in FIG. 2 above, the cable section 90 includes a signal transmission line 90B that is provided to connect the controller 372 and the input / output section of the detector 310, which will be described later, for transmitting digital signals and supplying power from the power supply section 373 to the detector 310.

[0183] The detector 310 transmits signals (unique address / fire signal / abnormal temperature signal / status information, etc.) to the controller 372 via the signal transmission line 90B, and also transmits signals (unique address / fire signal / abnormal temperature signal / status information, etc.) to the controller 372 via wireless communication using the frequency band of a specified low-power radio.

[0184] <Detector configuration> Each detector 310 includes a calculation processing unit 312, which is a CPU with a power consumption control function, an input / output unit 314, an operation unit 316, a connection terminal 318 for connecting to a sensor unit 320, and a specified low-power wireless module 327 (see FIG. 23). The input / output unit 314 includes an address identification unit 324 and a barrier 322. The wireless base station 368 and each detector 310 spend most of their time in sleep mode (current consumption: several hundred nA) or with the CPU stopped and the power off, and only switch to running mode (current consumption: several μA to several hundred μA) when acquiring environmental information. Furthermore, although the acquisition cycle of the environmental information differs depending on the detector 310, each time they enter running mode, they last approximately 60 to 90 seconds, and spend most of the day in standby mode (see FIG. 24). As shown in the figure, each detector 310 may diagnose itself at each of the above-mentioned cycles and output functional information (diagnostic information) together with the acquired information to the controller 372. Note that an RE microcomputer (SOTB) manufactured by Renesas Electronics Corporation is available as a CPU having the function of controlling the power consumption.

[0185] <Configuration of the detector's calculation processing unit> The arithmetic processing unit 312 of the detector 310 is configured with a CPU. When the arithmetic processing unit 312 is explained using functional blocks divided into function realization means, as shown in Fig. 25, the arithmetic processing unit 312 includes a signal acquisition unit 326, a detection unit group 328, a detection content type setting unit 330, an input / output control unit 332, and a sensor information storage unit 334.

[0186] The signal acquisition unit 326 acquires a signal from the sensor unit 320 .

[0187] The detector group 328 includes a temperature abnormality detector 328A, a flame abnormality detector 328B, a gas leakage abnormality detector 328C, a liquid leakage abnormality detector 328D, a vibration / impact abnormality detector 328E, and a temperature detector 328F.

[0188] When the connected sensor unit 320 is a plurality of detection elements that detect infrared rays having different wavelength ranges, the temperature anomaly detection unit 328A monitors the temperature based on the sensor information acquired by the signal acquisition unit 326. For example, the temperature anomaly detection unit 328A calculates the slope of a line connecting the signal amounts of two detection elements that detect infrared rays having different wavelength ranges, and monitors the temperature using the relationship between the calculated slope and the temperature. Then, the temperature anomaly detection unit 328A determines that an abnormal temperature has been detected when the monitored temperature is equal to or higher than a threshold value. Note that the sensor unit 320 may be a thermocouple sensor.

[0189] When the connected sensor unit 320 is a plurality of detection elements that detect infrared rays having different wavelength ranges, the flame abnormality detection unit 328B determines whether or not a flame has been detected based on the sensor information acquired by the signal acquisition unit 326. Note that the determination method is the same as the method described in the patent document (WO 2018 / 198504), and therefore a description thereof will be omitted.

[0190] When the connected sensor unit 320 is a gas sensor that detects a predetermined gas, the gas leak abnormality detection unit 328C monitors the concentration of the predetermined gas based on the sensor information acquired by the signal acquisition unit 326. Then, when the monitored gas concentration is equal to or greater than a threshold, the gas leak abnormality detection unit 328C determines that a gas leak has been detected.

[0191] For example, when the resistance value changes due to contact of the connected sensor unit 320 with leaked liquid, the liquid leakage abnormality detection unit 328D monitors the change in the resistance value based on the sensor information acquired by the signal acquisition unit 326. Then, when the resistance value is equal to or less than a threshold value, the liquid leakage abnormality detection unit 328D determines that a liquid leakage has been detected.

[0192] When the connected sensor unit 320 is an acceleration sensor, the vibration and impact abnormality detection unit 328E monitors the acceleration based on the sensor information acquired by the signal acquisition unit 326. Then, when the monitored acceleration is equal to or greater than a threshold, the vibration and impact abnormality detection unit 328E determines that an impact has been detected.

[0193] When the connected sensor unit 320 is a detection element such as a thermocouple, the temperature detection unit 328F monitors the temperature based on the sensor information acquired by the signal acquisition unit 326, in the same way as the temperature abnormality detection unit 328A.

[0194] In response to the operation of the operation unit 316, the detection content type setting unit 330 sets one of the temperature abnormality detection unit 328A, the flame abnormality detection unit 328B, the gas leak abnormality detection unit 328C, the liquid leak abnormality detection unit 328D, the vibration and impact abnormality detection unit 328E, and the temperature detection unit 328F as the detection unit to be activated.

[0195] The input / output control unit 332 outputs the detection contents by the detection unit group 328 as a digital signal to the controller 372 via the cable unit 90, and also transmits the detection contents by the detection unit group 328 as a digital signal to the controller 372 via the specified low-power wireless module 327, thereby exchanging digital signals with the controller 372.

[0196] The sensor information storage unit 334 stores threshold values ​​according to the type of detection content used by the temperature abnormality detection unit 328A, the flame abnormality detection unit 328B, the gas leak abnormality detection unit 328C, the liquid leak abnormality detection unit 328D, and the vibration / impact abnormality detection unit 328E.

[0197] <Controller configuration> 26, the controller 372 includes a signal transmitting / receiving unit 352, a cycle memory unit 354, a detection content type setting unit 356, and a cycle management unit 358. The cycle management unit 358 is an example of a power supply control unit.

[0198] The signal transmitting / receiving unit 352 relays the exchange of digital signals between each detector 310 and the host device 380 , and also relays the exchange of digital signals between each detector 310 and the mobile robot 50 .

[0199] The cycle storage unit 354 stores a monitoring cycle or a detection cycle for each type of detection content by the detector 310.

[0200] The detection content type setting unit 356 accepts an operation of an operation unit (not shown) provided in the controller 372 and sets the type of detection content to be performed by each detector 310.

[0201] Here, examples of monitoring or detection cycles for each type of detection content are listed below. As described below, depending on the collected information, measures are taken such as shortening the detection cycle according to the type of detector when a pre-alarm is determined, or conversely, transitioning to a longer detection cycle if a normal state continues for a long period of time. Therefore, as shown in Figure 27, the network cycle is determined by the detector 310 with the longest detection cycle.

[0202] When the type of detection is flame detection, the high-speed detection type has a detection cycle of 50 ms. In this case, a flame is detected in 3 seconds and recovery is achieved in 30 seconds. In the standard type, the detection cycle is 500 ms. In this case, if a flame is detected for 1 to 2 consecutive cycles, the system will transition to pre-alarm, and then transition to the same detection cycle as the high-speed detection type.

[0203] Furthermore, if the detector 310 also detects the position of a flame, it will make a position determination 10 seconds after the above flame determination.

[0204] Furthermore, when the type of detection is flame abnormality detection, abnormal temperature detection (high temperature type), and monitoring temperatures in the range of 200 to 480°C, the detection cycle is 60 seconds. If the monitored temperature is equal to or higher than the set value, it is determined to be a high-temperature object, and if it is determined to be a high-temperature object for 1 to 2 consecutive cycles, it will transition to a pre-alarm, and if it is determined to be a high-temperature object for 10 consecutive minutes, for example, it will be determined to be an abnormal temperature.

[0205] When the type of detection is flame abnormality detection, abnormal temperature detection (low temperature type), and the temperature range of 80 to 200°C is monitored, the detection cycle is 1 hour. If the monitored temperature is above the set value, it is determined to be an abnormal temperature object, and if it is determined to be an abnormal temperature object for 1 to 2 consecutive cycles, it will transition to pre-alarm, and if it is determined to be an abnormal temperature object for, for example, 3 consecutive hours, it will be determined to be an abnormal temperature object.

[0206] Furthermore, when the type of detection content is temperature detection, temperature monitoring (high temperature type), and the temperature range to be monitored is 200 to 480°C, the monitoring cycle is 60 seconds. When the type of detection content is temperature monitoring (low temperature type), and the temperature range to be monitored is 80 to 200°C, the monitoring cycle is 1 hour.

[0207] Furthermore, when the type of detection is gas leak detection, the detection cycle is 50 ms, similar to the high-speed flame detection type, or 500 ms, similar to the standard type.

[0208] If the type of detection is liquid leakage detection, the detection cycle is 1 hour. If the monitored resistance value is below the threshold for 5 consecutive hours, a pre-alarm will occur, and if the monitored resistance value is determined to be below the threshold for 10 to 24 consecutive hours, it will be determined that a liquid leakage has been detected.

[0209] If the type of detection is vibration or impact detection, the detection cycle is 1 ms. If the monitored acceleration is equal to or greater than the threshold for 5 ms consecutively, a pre-alarm occurs, and if the monitored acceleration is determined to be equal to or greater than the threshold for 10 ms to 24 ms consecutively, it is determined that vibration or impact has been detected.

[0210] The cycle management unit 358 controls the supply of power from the power supply unit 373 to each of the multiple detectors 310 in accordance with a monitoring cycle or detection cycle that is predetermined for the type of detection content of the detector 310 .

[0211] In the above, the information on the monitoring results or the determination results is transmitted to the controller 372 at regular intervals, but it is also possible to transmit highly urgent information (such as fire information) immediately.

[0212] 24 shows that each detector 310 transitions to running mode in response to a command from controller 372, but it is also effective to provide a sequential feed circuit or the like in each detector 310 and control the start of operation from controller 372. In this case, there appears to be only one detector 310 connected to cable section 90, and only the operating current of that detector 310 is the current consumed, thereby further reducing the current consumed by the entire system.

[0213] Furthermore, there may be cases where the current consumption of various detectors 310 is large or where it is desired to install only one detector at a location away from the cable section 90. In such cases, the one detector may be configured as detector 310A shown in FIG. 28.

[0214] <Configuration of another example of the detector> The detector 310A includes an arithmetic processing unit 312, a specified low-power radio module 327A, a cycle management unit 316A, an operation unit 316, a connection terminal 318, barriers 322, 322A, a power supply unit 326A, and a cycle memory unit 354A (see FIG. 28). The specified low-power radio module 327A includes a radio receiving unit 228, a radio transmitting unit 330A, and an antenna 332A. The cycle management unit 316A is an example of a controller. A CPU having a function of controlling current consumption functions as the arithmetic processing unit 312. An RE microcomputer (SOTB) manufactured by Renesas Electronics Corporation is an example of such a CPU.

[0215] The period management unit 316A has an internal clock generation unit, a real-time clock, or a counter, and activates the arithmetic processing unit 312 at intervals of a monitoring period or a detection period determined according to the type of detection content, transmits various information to the host device 380 and the mobile robot 50, and then stops the arithmetic processing unit 312. When the detector 310A is on standby, only the clock generation unit, the real-time clock, or the counter of the period management unit 316A operates.

[0216] The power supply unit 326A supplies power to each unit of the detector 310A via the barrier 322 and the cycle management unit 316A. The power supply unit 326A also supplies power to the wireless receiving unit 228 via the barrier 322.

[0217] The wireless receiving unit 228 acquires signals received by the antenna 332A from the wireless master device 368 and the mobile robot 50 via wireless communication using the specified low-power radio frequency band, and outputs the signals to the arithmetic processing unit 312.

[0218] The wireless transmitting unit 330A transmits the signal output from the arithmetic processing unit 312 to the wireless master device 368 and the mobile robot 50 via the antenna 332A by wireless communication using a specified low-power radio frequency band.

[0219] The cycle storage unit 354A stores a monitoring cycle or a detection cycle for each type of detection content by the detector 310.

[0220] In some cases, such as with a detector that detects abnormal conditions, it may be necessary to store sensor information (live information) in the device to determine abnormalities. In this case, the RAM information in the microcontroller is deleted when the CPU is stopped or the power is turned off, as shown in Figure 24, so a write process to ROM is added (Figure 29).

[0221] <Bus line configuration> In the intrinsically safe explosion-proof detection system 300 according to the embodiment of the present invention, signals (unique address / environmental information / abnormality information, etc.) are exchanged between each detector 310 and the controller 372 via wireless communication using a specified low-power radio frequency band and signal transmission line 90B.

[0222] The transmission method using the signal transmission line 90B uses Manchester-coded bus powered (MBP), which transmits Manchester-coded transmission signals on a power line. MBP supplies each detector 10 with a basic consumption current / voltage and modulates the current / voltage to generate a Manchester-coded digital signal. For example, if the voltage applied to the detector 310 during non-transmission is 3.0 V, the voltage is reduced to 2.0 V during transmission, and a digital signal is generated by voltage modulation (±0.5 V) (FIG. 5). The same applies to current modulation: a communication current (e.g., 6 mA) is supplied, and a digital signal is generated by current modulation (e.g., ±6 mA) at the detector (FIG. 3). Regarding the modulation, the transmission from the detector 310 to the controller 372 may be current-modulated, while the transmission from the controller 372 to the detector 310 may be voltage-modulated.

[0223] Furthermore, data transmission is performed at a low transmission speed of approximately 30 kbps at most. At this speed, there is no need to consider impedance matching (signal reflection due to branching of the transmission line), and the detectors 310 can be arranged in a tree configuration (Figure 4). The amount of data transmitted back and forth through this network is approximately several tens of bits, and the above transmission speed is fully sufficient for practical use.

[0224] In this way, by providing redundancy for signal transmission using two different transmission methods, the reliability of this network can be improved.

[0225] The above transmission method is an example, and other methods are also possible, such as a transmission method in which a signal is formed by high-frequency voltage modulation of 2.0 to 3.0 [V].

[0226] <Low current consumption> In the embodiment of the present invention, power-saving control of detectors 310 and 310A and various types of power-saving communications are used, which allows not only each detector 310 and 310A but also wireless master unit 368 to meet the intrinsically safe explosion-proof specifications stipulated in the Factory Electrical Equipment Explosion Protection Guidelines or IEC (International Electrotechnical Commission) standards, and the entire intrinsically safe explosion-proof detection system 300 is installed in that location.

[0227] Here, an example of calculation of the total current consumption required by the intrinsically safe explosion-proof detection system 300 per day when 100 detectors 310 are connected to one cable section 90 will be shown below.

[0228] First, the calculation conditions are as follows: Wired communication is LVDS (350mV, 3.5mA, 30kbps), and wireless communication is LPWA (20mW, 4.4kbps). The detector's operating power consumption is 2V, 0.5mA, and its sleep power consumption is 2V, 3.5μA. The detector's communication capacity is approximately 100 bits, and approximately 100 units can be connected. Communication occurs eight times a day (once every three hours), and the battery capacity is 5Ah.

[0229] Regarding battery capacity, the battery power is 5 [Ah] x 3 [V] = 15 [Wh].

[0230] The amount of power consumed by wired communication (LVDS) per day is calculated as follows: The time required for one transmission is 100 bits divided by 30 kbps = 3.33 ms. If all 100 devices communicate back and forth, the time required is 3.33 ms x 100 devices x 2 = 0.67 seconds. Note that the "x2" is added assuming one polling. If the above is done 8 times a day, it will take 0.67 [s] × 8 [times] = 5.36 [s] ≒ 5.5 [s]. The power consumption is 5.0 [s] ÷ 3600 [s / h] × 3.5 [mA] × 350 [mA] × 350 [mV] = 1.9 × 10 -6 [Wh].

[0231] The detector's daily power consumption is calculated as follows: The daily power consumption per unit is: Operating power consumption + Standby power consumption = [0.5 [mA] x 2 [V] x 90 s / 86400 s x 8 times)] + [3.5 [μA] x 2 [V] x 24 h] = 8.33 x 10 -6 [Wh]+1.68×10 -4 [Wh]=1.77×10 -4 [Wh]. Therefore, the daily power consumption per 100 units is 1.77 x 10 -4 [Wh] × 100 ≒ 1.8 × 10 -2 [Wh].

[0232] The current consumption of wireless communication (LPWA) per day is calculated as follows: First, the transmission volume is 100 [bit] x 100 [units] = 10,000 [bit]. The time required for transmission is 10,000 [bit] ÷ 4.4 [kbps] x 2.5 = 4.5 [s]. Note that the "x2" is used to assume one polling. If the above is done 8 times a day, it takes 4.5 [s] x 8 [times] = 36 [s]. The power consumption is 31.5 [s] ÷ 3600 [s / h] x 20 [mW] = 2.0 x 10 -4 [Wh]. Considering standby power consumption, it is 2.0 x 10 -4 [Wh]×1.01=2.02×10- 4 [Wh]. In other words, standby power of about 1 / 100 of the communication power is required at all times.

[0233] The power consumption per day is LVDS current consumption + detector power consumption + LPWA current consumption = 1.9 x 10 -6 [Wh]+1.8×10 -2 [Wh]+2.02×10 -4 [Wh]=18.2×10 -3 It becomes [Wh].

[0234] Therefore, the operating time under the above calculation conditions is 15 [Wh] ÷ (18.2 × 10 -3 [Wh]) ÷ 365 = 2.2 years.

[0235] In the above calculation example, when comparing the current consumption for each operation (wired communication / detector operation / detector standby / wireless communication), the current consumption when the detector is standby is dominant, and the extent to which this current can be reduced determines the operating years of the intrinsically safe explosion-proof detection system 300.

[0236] As shown in the above calculation example, if the standby power is 3.5 μA, for example, the intrinsically safe explosion-proof detection system 300 can be operated for approximately two years without battery replacement by using one commercially available battery (black smoke fluoride lithium battery, battery capacity [5 Ah], size AA). On the other hand, if the standby power is reduced to 400 nA (using a Renesas Electronics RE microcomputer and operating only the clock in deep software standby mode), the intrinsically safe explosion-proof detection system 300 can be operated for approximately 14 years in the same environment without battery replacement.

[0237] The above-mentioned intrinsically safe explosion-proof specifications allow for parallel connection of batteries provided that measures are taken that do not impair intrinsic safety; if two batteries are connected in parallel, the intrinsically safe explosion-proof detection system 300 can operate for approximately 20 years without the need for battery replacement.

[0238] <Effects of intrinsically safe explosion-proof detection system> Next, the operation of the intrinsically safe explosion-proof detection system 300 according to the third embodiment of the present invention will be described.

[0239] First, an individual address is assigned to each detector 310 installed in the intrinsically safe explosion-proof detection system 300. As a result, signals that combine addresses and various information are exchanged during data transmission between the detectors 310 and the controller 372. For example, if 100 detectors 310 are connected to the cable section 90, the address section is expressed in 7 bits, followed by several bits of environmental information.

[0240] Furthermore, various sensor units 320 are connected to each of the detectors 310 and 310A, and the type of detection content is set by the operation unit 316.

[0241] The controller 372 also accepts an operation on an operation unit provided in the controller 372 and sets the type of detection content to be performed by each detector 310.

[0242] Furthermore, the detectors 310 and 310A repeatedly execute the process of monitoring environmental information or determining whether a predetermined abnormality has been detected at each monitoring period or detection period according to the type of detection content.

[0243] Specifically, the cycle management unit 358 of the controller 372 controls the supply of power from the power supply unit 373 to each of the multiple detectors 310 in accordance with a monitoring cycle or detection cycle predetermined for the type of detection content of the detector 310. As shown in FIG. 24 , upon receiving power, the detector 310 first activates the calculation processing unit 312 (S41), stores the address included in the received signal (S42), and acquires sensor information from the sensor unit 320 (S43). Based on the sensor information, the detector checks the state of the sensor unit 320 and performs calculations (S44). If the type of detection content is the detection of a predetermined abnormality, the calculation value is compared with a threshold value predetermined for the type of detection content to determine whether the predetermined abnormality exists (S45). The result of monitoring the environmental information according to the type of detection content, or the result of determination as to whether the predetermined abnormality has been detected, is then transmitted to the controller 372 via wireless communication using the specified low-power radio frequency band and the cable unit 90 (S46). Then, the calculation processing unit 312 is stopped (S47). Then, the cycle management unit 358 of the controller 372 stops the supply of power to the detector 310, and when the next monitoring cycle or detection cycle begins, power is again supplied from the power supply unit 373 to the detector 310.

[0244] 29, when the detector 310A determines, using the clock generating unit of the cycle management unit 316A, that a monitoring cycle or a detection cycle determined according to the type of detection content has been reached, it supplies power from the power supply unit 326A and activates the arithmetic processing unit 312 (S51, S52). If the address included in the received signal matches this address, it stores the address included in the received signal (S53). It acquires sensor information from the sensor unit 320, checks the state of the sensor unit 320 based on the sensor information, and performs calculations. If the type of detection content is the detection of a predetermined abnormality, it compares the calculated value with a threshold value predetermined for the type of detection content to determine whether the predetermined abnormality has occurred. Then, the wireless transmitter 330A transmits the environmental information monitoring results or the determination result of whether a predetermined abnormality has been detected according to the type of detection content to the wireless master device 368 (S54). The result of monitoring the environmental information or the result of determining whether a predetermined abnormality has been detected is written to ROM (S55), and the clock generation unit of the cycle management unit 316A is reset and a timer is set (S56). The cycle management unit 316A then stops the supply of power from the power supply unit 326A and stops the arithmetic processing unit 312 (S57). When the cycle management unit 316A determines using the clock generation unit that the next monitoring cycle or detection cycle has arrived, it again supplies power from the power supply unit 326A and starts up the arithmetic processing unit 312.

[0245] <Data exchange (polling)> The transmission method differs depending on the control method for the monitoring or detection cycle. For example, when the cycle is controlled by the controller 372, data is transmitted by polling (inquiry) from the controller 372 (FIG. 30).

[0246] Specifically, the controller 372 outputs an information acquisition request signal to each detector 310 (each address) in turn (S181), and the designated detector 310 outputs the relevant information (address and environmental information / no abnormality / abnormality, etc.) (S182). This is performed for each detector 310 in address order, and when one cycle is completed, the collected information is output to the host device 380 and the mobile robot 50. This is repeated in a fixed time cycle.

[0247] By acquiring this information, it is possible to identify the location of the disconnection, which will be described later. The location of the disconnection can be identified based on the number and addresses of the detectors 310 that do not respond to the information acquisition request signal from the controller 372.

[0248] As described above, by periodically diagnosing the functions of the detector 310 and the network and transmitting the results to the host device 380 and the mobile robot 50, not only can the reliability of the intrinsically safe explosion-proof detection system 300 be improved, but maintenance costs, etc. can also be reduced.

[0249] <Data transfer (when data reception fails)> On the other hand, when periodic control is performed for each individual detector 310A, data is transmitted from each detector 310A to the controller 372 at any periodic interval (Fig. 31). However, with this method, each detector 310A transmits data independently, which creates the risk of interference or loss of transmitted data. Therefore, if the controller 372 is unable to receive data normally, it polls the detector 310A to instruct it to retransmit the data.

[0250] 32, when the controller 372 determines that there has been output from a plurality of detectors 310, it outputs an address and an information acquisition request signal to all of the detectors 310 in order (S201), and each designated detector 310 outputs the relevant information (address and monitoring information / no abnormality / abnormality, etc.) (S202). This is performed for each detector 310 in address order, and the relevant information is output to the host device 380 and the mobile robot 50.

[0251] It should be noted that this information acquisition request signal does not need to be transmitted to all detectors 310A, and may be transmitted only to detectors of high importance or those that are determined to be prone to collision based on the cycle of each detector 310A. For example, in Fig. 32, the controller 372 polls the detectors 310(1), 310(3), and 310(4).

[0252] <Measures against disconnection / short circuits> If a break or short circuit occurs in the cable section 90, any detector 310 may be unable to monitor (such as a state where no power is supplied or no signal is transmitted) (similar to FIG. 16 above). The intrinsically safe explosion-proof detection system 300 monitors for breaks and short circuits using the following method, and outputs a break / short circuit alarm to the host device 380 and the mobile robot 50.

[0253] (disconnection monitoring) In the intrinsically safe explosion-proof detection system 300, as described above, an information acquisition request is made to the detector 310 at regular intervals. Therefore, if there is no response to an information acquisition request signal from the controller 372, a break in the wire is suspected. Since a unique address is assigned to the detector 310, if a break occurs in the cable part 90 as in FIG. 16(A) above, or if a break occurs in a branch line of the cable part 90 as in FIG. 16(B) above, the controller 372 can identify the location of the break based on the address that has not responded after one cycle of information acquisition requests.

[0254] (short circuit monitoring) In the intrinsically safe explosion-proof detection system 300, if a short circuit occurs on the cable section 90, as in Figure 16(C) above, or if a short circuit occurs on a branch line of the cable section 90, as in Figure 16(D) above, it is not possible to identify the location of the short circuit, but it is possible to detect the short circuit by monitoring the short-circuit current using the controller 372 or the power supply section 373.

[0255] As described above, according to the intrinsically safe explosion-proof detection system 300 of the third embodiment, by controlling the supply of power from the power supply unit 373 to each of the multiple detectors 310 in accordance with a monitoring cycle or detection cycle that is predetermined for the environmental information monitored by the detector 310 or the type of abnormality detected, the intrinsically safe explosion-proof detection system 300 can be operated for a long period of time without battery replacement, and the management costs of the power supply unit can be reduced.

[0256] Furthermore, the detector 310A, which performs its own periodic management, controls the supply of power from the power supply unit according to a predetermined monitoring period or detection period for the environmental information to be monitored or the type of abnormality to be detected, thereby enabling the intrinsically safe explosion-proof detection system 300 to operate for a long period of time without the need to replace batteries, thereby reducing the management costs of the power supply unit.

[0257] In addition, each of the detector and wireless base station transmits and receives digital signals using wireless communication using the specified low-power radio frequency band and a cable section, thereby providing a highly reliable intrinsically safe explosion-proof detection system with a simple configuration.

[0258] In addition, the cable section ensures that fire or abnormal temperature detected by the detector is transmitted to the host device and mobile robot even if a malfunction (disconnection or short circuit) occurs in the cable section, thereby realizing an intrinsically safe explosion-proof detection system with a high level of safety.

[0259] It also enables the creation of a fire / abnormal temperature monitoring environment in the most technically demanding dangerous areas (ZONE 0) at low cost.

[0260] Furthermore, multiple detectors installed in hazardous locations are connected to a single cable with a T-branch, and perform half-duplex communication with a host device via a wireless master device installed in a non-hazardous location. Specifically, signals transmitted from the detectors to the wireless master device (unique address, fire signal, abnormal temperature signal, status information, etc.) are transmitted redundantly as two types of signals: a current signal powered by a Manchester-coded bus and a wireless signal using a specified low-power radio frequency band. Furthermore, signals transmitted from the wireless master device to the detectors (address, status confirmation signal, etc.) are transmitted redundantly as two types of signals: a voltage signal generated by modulating the voltage applied to the detector and a wireless signal using a specified low-power radio frequency band. This ensures that fire signals or abnormal temperatures can be reliably transmitted to the host device and the mobile robot.

[0261] Furthermore, by using the voltage transmission based on the voltage modulation, it is possible to reduce the current supplied to the dangerous location, and the number of detectors that can be installed in the dangerous location can be increased.

[0262] Furthermore, by transmitting signals through the cable at a low transmission speed of around several tens of kbps, a network capable of tree branching can be created.

[0263] In addition, by polling from the signal transmitter / receiver, the functions of the detector and network are periodically diagnosed and transmitted to the host device and mobile robot, thereby improving the reliability of the intrinsically safe explosion-proof detection system and reducing maintenance costs, etc.

[0264] In addition, when fire signals or other signals are output simultaneously from multiple detectors, polling from the signal transmitter / receiver prevents communication failure of the fire signals and improves the reliability of data transmission.

[0265] [Fourth embodiment] <System configuration> An intrinsically safe explosion-proof detection system according to a fourth embodiment of the present invention will be described below. Note that parts having the same configuration as those in the third embodiment will be assigned the same reference numerals and descriptions thereof will be omitted.

[0266] 22, an intrinsically safe explosion-proof detection system 400 according to the fourth embodiment of the present invention includes a plurality of detectors 310, wireless master devices 368A and 368B, a host device 380, and a mobile robot 50. The wireless master device 368A includes a barrier 370A, a controller 372A, a power supply unit 373A, and a transceiver 374A. The wireless master device 368B includes a barrier 370B, a controller 372B, a power supply unit 373B, and a transceiver 374B.

[0267] Controller 372A and the plurality of detectors 310 are connected by cable portion 490A, and controller 372B and the plurality of detectors 310 are connected by cable portion 490B.

[0268] As described above, in the present embodiment, a first intermediate configuration including cable unit 490A and wireless base station 368A and a second intermediate configuration including cable unit 490B and wireless base station 368B are provided. Accordingly, each detector 310 has two input / output units 314, one of which is connected to the first intermediate configuration and outputs the monitoring result or determination result by processing unit 312 to controller 372A as a digital signal via cable unit 490A, and also transmits a digital signal that processing unit 312 has detected a flame to controller 372A via specified low-power wireless module 327, and exchanges digital signals with controller 372A. In addition, the other input / output unit 314 is connected to the second intermediate configuration, and outputs the monitoring results or judgment results by the arithmetic processing unit 312 to the controller 372B as a digital signal via the cable unit 490B, and also transmits the detection of a flame by the arithmetic processing unit 312 to the controller 372B as a digital signal via the specified low-power radio module 327, and exchanges digital signals with the controller 372B.

[0269] The cable portions 490A and 490B include a signal transmission line 390A and a signal transmission line 390B, similar to the cable portion 390 of the first embodiment.

[0270] In the intrinsically safe explosion-proof detection system 400, the lines from the cable sections 490A and 490B to the power supply sections 373A and 373B are duplicated. By duplicating the network in this way, it is possible to avoid a state in which monitoring becomes impossible due to a disconnection or short circuit (as in FIG. 19 above). Specifically, when the controller 372A or 372B detects a disconnection or short circuit in one of the networks using a method similar to that of the third embodiment, it outputs a short circuit alarm to the host device 380 and the mobile robot 50, and automatically switches the transmission line to the other network. This makes it possible to avoid a state in which fire / abnormal temperature monitoring becomes impossible due to a disconnection or short circuit, and creates a highly reliable fire monitoring environment.

[0271] Since a unique address is assigned to detector 310, if a break occurs on cable portion 490B as in Fig. 19(A) above, or if a break occurs on a branch line of cable portion 490B as in Fig. 19(B) above, the location of the break can be identified by controller 372B based on the address that does not respond after one cycle of information acquisition. Also, if a short circuit occurs on cable portion 490B as in Fig. 19(C) above, or if a short circuit occurs on a branch line of cable portion 490B as in Fig. 19(D) above, the location of the short circuit cannot be identified, but the short circuit can be detected by monitoring the short-circuit current by controller 372B or power supply unit 373B.

[0272] As described above, the intrinsically safe explosion-proof detection system according to the fourth embodiment provides further redundancy by duplicating communication between the detector and the wireless base station, thereby realizing a highly reliable network for fire or abnormal temperature monitoring at low cost. In this case, the signal transmission system becomes a quadruple system. Due to the duplication, the fire or abnormal temperature monitoring environment can continue even in the event of a wire break or short circuit. In actual operation, a detector equipped with two cable connectors can be used as a standard product, and customers can choose whether or not to implement duplication depending on the safety integrity level (SIL) and cost required.

[0273] <Modification> The present invention is not limited to the third and fourth embodiments described above, and various modifications and applications are possible without departing from the spirit and scope of the present invention.

[0274] For example, the example described above is one in which a detector is provided with a detection unit for each type of detection content, but this is not limited to this. If the type of detection content of the detector is known from the beginning, the detector may be configured to have only the detection unit corresponding to that type of detection content.

[0275] In addition, although an example has been described in which the type of content detected by detectors 310 and 310A is set by operating the operation unit, detectors 310 and 310A may be configured to automatically recognize the type of content monitored and the type of content detected by the connected sensor unit.

[0276] Although the example has been described in which MBP is used as the transmission method for the cable section, the present invention is not limited to this, and for example, Manchester code using voltage modulation or Ethernet (registered trademark) may be used. When Ethernet (registered trademark) is used as the first transmission method, power can be supplied over the communication line using a technology called PoE (Power over Ethernet).

[0277] The detectors 310 and 310A may monitor humidity, pressure, vibration, impact, gas concentration, sound, ultrasound, liquid level, or rotation as environmental information. The detectors 310 and 310A may also determine whether or not an abnormality related to humidity, pressure, vibration, sound, ultrasound, liquid level, or rotation has been detected as a predetermined abnormality.

[0278] Furthermore, when the detector monitors ultrasonic waves or determines whether an ultrasonic abnormality has been detected, it may include, similar to the detector 10A shown in FIG. 20 , a connection terminal 18A for connecting to a sensor unit 20A, barriers 69A and 70A, an ultrasonic pulse generator 22A, an ultrasonic echo signal receiver 24A, a selector switch 26A, and a power connection terminal 73A for connecting an external power supply unit 28A. The external power supply unit 28A is a thermoelectric power generation module that generates power using a thermoelectric element due to a temperature difference and supplies power to the detector. The sensor unit 20A includes multiple ultrasonic transducers 20B, and the ultrasonic transducers 20B are attached to the surface of the plant piping PH. The thermoelectric elements 28B of the external power supply unit 28A are attached to the surface of the plant piping PH. The echo signal analysis unit 44A analyzes ultrasonic echo signals received from the ultrasonic transducers 20B and determines the state of wall thinning of the plant piping PH at the locations where the ultrasonic transducers 20B are located.

[0279] [Fifth embodiment] <Outline of the embodiment of the present invention> An embodiment of the present invention relates to an intrinsically safe explosion-proof detection system that uses a detector to monitor environmental information (temperature, vibration, pressure, gas concentration, sound, ultrasound, impact, rotation speed, etc.) and detect various abnormal conditions (fire, temperature abnormality, leakage of hazardous materials, gas leak, etc.) at hazardous locations specified in the Factory Electrical Equipment Explosion Prevention Guidelines or IEC (International Electrotechnical Commission) standards, and wirelessly transmits the signals to a higher level at the hazardous location.

[0280] The system has the following properties:

[0281] (1) One group contains multiple detectors (several to around 100), each of which transmits environmental information / abnormal conditions to a higher-level device and a mobile robot via wireless communication.

[0282] (2) By making the specifications of the various sensor parts exempt from the inspection of the intrinsically safe explosion-proof specifications stipulated in the Factory Electrical Equipment Explosion-Proof Guidelines or IEC (International Electrotechnical Commission) standards, the entire system, including the sensor parts, can be installed in hazardous locations at low cost.

[0283] (3) The detector operates with extremely low current consumption (in the order of μA) that meets the intrinsically safe explosion-proof specifications stipulated in the Factory Electrical Equipment Explosion-Proof Guidelines or IEC (International Electrotechnical Commission) standards, thereby extending battery life and reducing the running costs associated with battery replacement.

[0284] <System configuration> An intrinsically safe explosion-proof detection system according to a fifth embodiment of the present invention will be described below.

[0285] 33, an intrinsically safe explosion-proof detection system 500 according to the fifth embodiment of the present invention includes a plurality of detectors 510, a plurality of wireless master units 576, a host wireless transceiver 578, a host device 580, and a mobile robot 50. In addition, a plurality of detector groups 588 each consisting of a plurality of detectors 510 are provided.

[0286] The host device 580 includes one or more of a host computer 582, a DCS / PLC 584, and a relay panel 586. The host device 580 is connected to a host wireless transceiver 578, which is connected to a wireless master device 576 via LTE wireless communication, and the wireless master device 576 is connected to a specified low-power wireless module 573 via specified low-power wireless communication. The wireless master device 576 is also connected to the mobile robot 50 that has moved to the vicinity via specified low-power wireless communication. The detector 510 is installed in a dangerous location, and the wireless master device 576, the host wireless transceiver 578, the host device 580, and the mobile robot 50 are installed in a non-hazardous location. The wireless master device 576 may be installed in a dangerous location.

[0287] Furthermore, the information collected by the detector group 588 to the wireless master device 576 is ultimately transmitted to the upper wireless transceiver 578 together with information collected by multiple wireless master devices 576 wirelessly connected to different detector groups 588, and is then aggregated on the host computer 582 or the cloud via Ethernet or the like. Furthermore, the information collected by the wireless master device 576 from the detector group 588 is transmitted to the mobile robot 50 that has moved to the vicinity of the wireless master device 576, and is then transmitted from the mobile robot 50 to the upper wireless transceiver 578, and is then aggregated on the host computer 582 or the cloud via Ethernet or the like. Note that the specified low-power wireless module 573 may directly exchange data with the upper wireless transceiver 578 and the mobile robot 50 without going through the wireless master device 576.

[0288] The detector group 588 includes multiple (several to approximately 100) various detectors 510, which transmit environmental information (temperature, vibration, pressure, gas concentration, sound, ultrasound, impact, rotation speed, liquid level, etc.) and various abnormal conditions (fire, temperature abnormality, leakage of hazardous materials, gas leak, etc.) to the higher-level device 580 and the mobile robot 50 depending on the type of content to be detected.

[0289] The detector 510 transmits signals (unique address / fire signal / abnormal temperature signal / status information, etc.) to the wireless master device 576 by wireless communication using a specified low-power wireless frequency band.

[0290] The wireless base station 576 includes a specified low-power wireless module 562, a controller 564, and an LTE wireless module 566. The specified low-power wireless module 562 performs wireless communication with the specified low-power wireless module 573. The controller 564 relays the exchange of digital signals between the detector 510 and the higher-level device 580. The controller 564 also relays the exchange of digital signals between the detector 510 and the mobile robot 50. The LTE wireless module 566 performs wireless communication with the higher-level wireless transceiver 578.

[0291] <Detector configuration> Each detector 510 includes an arithmetic processing unit 512 which is a CPU having the function of controlling power consumption, an operation unit 516, a connection terminal 518 for connecting to a sensor unit 520, a counter unit 524, barriers 568, 570, an antenna 571, a power supply connection terminal 572 for connecting an external power supply, a specified low-power radio module 573, and a power supply unit 574 (see Figure 34).

[0292] Each detector 510 spends most of its time in sleep mode, or with the CPU stopped or powered off, and transitions to running mode (current consumption: several μA to several hundred μA) only when acquiring environmental information. Although the cycle for acquiring the environmental information differs depending on the detector 510, each time it enters running mode it lasts for approximately 60 to 90 seconds, and it spends most of the day in standby mode. Each detector 510 may also diagnose itself at each of the above-mentioned cycles and transmit functional information (diagnostic information) together with the acquired information to the host device 580 and the mobile robot 50. The RE microcomputer (SOTB) manufactured by Renesas Electronics Corporation is an example of a CPU having the function of controlling the power consumption.

[0293] The operation unit 516 accepts settings for the type of sensor unit 520 and the type of detection content by the detector 510 .

[0294] The counter unit 524 has a clock generating unit, a real-time clock, or a counter, and supplies power from the power supply unit 574 or an external power source at intervals of a monitoring period or a detection period determined according to the type of detection content, starts the arithmetic processing unit 512, causes it to transmit various information to the upper device 580 and the mobile robot 50, and then stops the power supply and stops the arithmetic processing unit 512. When the detector 510 is in standby mode, only the clock generating unit, the real-time clock, or the counter of the counter unit 524 operates.

[0295] The barriers 568 and 570 limit the energy supplied to the arithmetic processing unit 512, and serve to suppress overvoltage or overcurrent that occurs in the event of a break or short circuit to a level that does not generate sparks that could lead to ignition.

[0296] The specified low-power radio module 573 transmits and receives digital signals to and from the wireless base station 576 by wireless communication using the specified low-power radio frequency band via the antenna 571. The specified low-power radio module 573 also acquires signals received by wireless communication from the wireless base station 576 and outputs them to the calculation processing unit 512.

[0297] Power supply unit 574 supplies power to each unit of detector 510 via barrier 570 and counter unit 524. Power supply unit 574 also supplies power to specified low-power wireless module 573 via barrier 570. A power generation module is used as the external power supply. For example, similar to external power supply unit 28A shown in FIG. 20 above, it is a thermoelectric power generation module that generates power using a thermoelectric element due to a temperature difference and supplies power to detector 510. Note that the external power supply may be a power generation module other than a thermoelectric power generation module, such as a solar cell. Furthermore, when targeting plant piping, a thermoelectric element of the external power supply may be attached to the surface of the plant piping, similar to FIG. 21 above.

[0298] In some cases, such as in the case of a detector that detects abnormal conditions, it may be necessary to store sensor information (live information) in the device in order to determine abnormalities. In this case, the RAM information in the microcontroller is deleted when the CPU is stopped or the power is turned off, and a write process to SRAM577 is performed.

[0299] <Configuration of detector connection terminals> As shown in FIG. 35, the connection terminal 518 includes a power supply terminal 5181, a GND connection terminal 5182, a first sensor input terminal 5183, a second sensor input terminal 5184, a first output signal terminal 5185, a second output signal terminal 5186, an analog input terminal 5187, and a chip select terminal 5188.

[0300] Depending on the type of sensor unit 520, some or all of the power supply terminal 5181, GND connection terminal 5182, first sensor input terminal 5183, second sensor input terminal 5184, first output signal terminal 5185, second output signal terminal 5186, analog input terminal 5187, and chip select terminal 5188 are connected to the sensor unit 520. Each terminal of the connection terminals 518 may be connected directly to the sensor unit 520, or may be connected to the sensor unit 520 via a transmission cable or the like.

[0301] The power supply terminal 5181 and the GND connection terminal 5182 are connected to a power supply control unit 538, which will be described later. The first sensor input terminal 5183, the second sensor input terminal 5184, the first output signal terminal 5185, the second output signal terminal 5186, the analog input terminal 5187, and the chip select terminal 5188 are connected to a signal acquisition unit 526, which will be described later.

[0302] <Configuration of the detector's calculation processing unit> The arithmetic processing unit 512 of the detector 510 is configured with a CPU. When the arithmetic processing unit 512 is explained using functional blocks divided into function realization means, as shown in Fig. 36, the arithmetic processing unit 512 includes a signal acquisition unit 526, a detection unit group 528, an input / output data management unit 530, a cycle management unit 532, a received signal management unit 534, a transmitted signal management unit 536, and a power control unit 538.

[0303] The signal acquisition unit 526 acquires a signal from the sensor unit 520 via the connection terminal 518 and the barrier 568 .

[0304] The signal acquisition unit 526 includes an infrared signal acquisition unit 526A, an acceleration signal acquisition unit 526B, a resistance signal acquisition unit 526C, a temperature signal acquisition unit 526D, a humidity signal acquisition unit 526E, a gas signal acquisition unit 526F, a pressure signal acquisition unit 526G, and an ultrasonic signal acquisition unit 526H.

[0305] When the connected sensor unit 520 is a plurality of detection elements that detect infrared rays having different wavelength ranges, the infrared signal acquisition unit 526A acquires sensor information indicating the intensity of the detected infrared rays from the plurality of detection elements.

[0306] When the connected sensor unit 520 is an acceleration sensor, the acceleration signal acquisition unit 526B acquires sensor information representing acceleration.

[0307] The resistance value signal acquiring section 526C acquires sensor information representing a resistance value when the connected sensor section 520 is a liquid leakage sensor whose resistance value changes when it comes into contact with leaked liquid.

[0308] When the connected sensor unit 520 is a temperature sensor (for example, a thermocouple), the temperature signal acquisition unit 526D acquires sensor information representing the temperature.

[0309] When the connected sensor unit 520 is a humidity sensor, the humidity signal acquisition unit 526E acquires sensor information indicating humidity.

[0310] When the connected sensor unit 520 is a gas sensor, the gas signal acquisition unit 526F acquires sensor information indicating the concentration of a specific gas.

[0311] When the connected sensor unit 520 is a pressure sensor, the pressure signal acquisition unit 526G acquires sensor information representing pressure.

[0312] When the connected sensor unit 520 is an ultrasonic sensor, the ultrasonic signal acquisition unit 526H acquires sensor information representing the received ultrasonic waves. In this case, the sensor unit 520 may be the same as the sensor unit 20A shown in FIG. 16 above.

[0313] The detection unit group 528 includes a flame temperature detection unit 528A, a vibration and impact detection unit 528B, a liquid leakage detection unit 528C, a temperature detection unit 528D, a humidity detection unit 528E, a gas leakage detection unit 528F, a pressure detection unit 528G, and an ultrasonic detection unit 528H.

[0314] The flame temperature detection unit 528A monitors the temperature based on the sensor information acquired by the infrared signal acquisition unit 526A. For example, the slope of a line connecting the signal amounts of two detection elements that detect infrared rays in different wavelength ranges is calculated, and the temperature is monitored using the relationship between the calculated slope and the temperature. The flame temperature detection unit 528A then determines that an abnormal temperature has been detected if the monitored temperature is equal to or greater than a threshold value. Alternatively, the flame temperature detection unit 528A determines whether a flame has been detected based on the sensor information acquired by the infrared signal acquisition unit 526A. Note that the determination method is similar to the method described in Patent Document (WO 2018 / 198504), and therefore description thereof will be omitted.

[0315] The vibration and impact detection unit 528B monitors the acceleration based on the sensor information acquired by the acceleration signal acquisition unit 526B. Then, the vibration and impact detection unit 528B determines that an impact has been detected when the monitored acceleration is equal to or greater than a threshold value.

[0316] The liquid leakage detector 528C monitors the change in the resistance value based on the sensor information acquired by the resistance value signal acquirer 526C, and determines that a liquid leakage has been detected when the resistance value is equal to or less than a threshold value.

[0317] The temperature detection unit 528D monitors the temperature based on the sensor information acquired by the temperature signal acquisition unit 526D. Then, the temperature detection unit 528D determines that an abnormal temperature has been detected when the monitored temperature is equal to or higher than a threshold value.

[0318] The humidity detection unit 528E monitors the humidity based on the sensor information acquired by the humidity signal acquisition unit 526E. Then, the humidity detection unit 528E determines that abnormal humidity has been detected when the monitored humidity is equal to or greater than a threshold value.

[0319] The gas leak detection unit 528F monitors the concentration of a specific gas based on the sensor information acquired by the gas signal acquisition unit 526F. Then, the gas leak detection unit 528F determines that a gas leak has been detected when the monitored gas concentration is equal to or greater than a threshold value.

[0320] The pressure detection unit 528G monitors the pressure based on the sensor information acquired by the pressure signal acquisition unit 526G. Then, the pressure detection unit 528G determines that an abnormal pressure has been detected when the monitored pressure is equal to or greater than a threshold value.

[0321] The ultrasonic wave detection unit 528H monitors information related to the received ultrasonic waves based on the sensor information acquired by the ultrasonic signal acquisition unit 526H. In this case, the ultrasonic wave detection unit 528H may include the ultrasonic pulse generation unit 22A, ultrasonic echo signal reception unit 24A, changeover switch 26A, pulse control unit 40A, echo signal analysis unit 44A, and changeover control unit 46A of the detector 10A shown in FIG.

[0322] The input / output data management unit 530 accepts the setting of the type of sensor unit 520 in response to the operation of the operation unit 516, and sets one of the infrared signal acquisition unit 526A, acceleration signal acquisition unit 526B, resistance signal acquisition unit 526C, temperature signal acquisition unit 526D, humidity signal acquisition unit 526E, gas signal acquisition unit 526F, pressure signal acquisition unit 526G, and ultrasonic signal acquisition unit 526H as the unit to be operated.

[0323] In addition, input / output data management unit 530 accepts the setting of the type of detection content by detector 510 in response to the operation of operation unit 516, and sets one of flame temperature detection unit 528A, vibration and impact detection unit 528B, liquid leak detection unit 528C, temperature detection unit 528D, humidity detection unit 528E, gas leak detection unit 528F, pressure detection unit 528G, and ultrasonic detection unit 528H as the detection unit to be activated.

[0324] The input / output data management unit 530 has a threshold memory unit (not shown) that stores threshold values ​​used by each of the flame temperature detection unit 528A, the vibration / impact detection unit 528B, the liquid leak detection unit 528C, the temperature detection unit 528D, the humidity detection unit 528E, the gas leak detection unit 528F, the pressure detection unit 528G, and the ultrasonic detection unit 528H.

[0325] In addition, in response to operation of the operation unit 516, when abnormality detection is set in any of the flame temperature detection unit 528A, vibration and impact detection unit 528B, liquid leakage detection unit 528C, temperature detection unit 528D, humidity detection unit 528E, gas leakage detection unit 528F, and pressure detection unit 528G, the input / output data management unit 530 outputs the corresponding threshold value data.

[0326] The cycle management unit 532 has a cycle memory unit (not shown) that stores a monitoring cycle or detection cycle and a sensor cycle for each type of detection content by the detector 510, and outputs the monitoring cycle or detection cycle corresponding to the type of detection content in question and the sensor cycle corresponding to the type of sensor unit 520 in question to the power supply control unit 538 and the detection unit group 528 in response to operation of the operation unit 516.

[0327] Here, examples of monitoring or detection cycles for each type of detection content are listed below. As described below, depending on the collected information, measures are taken such as shortening the detection cycle according to the type of detector when a pre-alarm is determined, or conversely, transitioning to a longer detection cycle if a normal state continues for a long period of time. For example, as shown in Figure 37, each detector 510 operates at a monitoring or detection cycle according to the type of detection content.

[0328] When the type of detection is flame detection, the high-speed detection type has a detection cycle of 50 ms. In this case, a flame is detected in 3 seconds and recovery is achieved in 30 seconds. In the standard type, the detection cycle is 500 ms. In this case, if a flame is detected for 1 to 2 consecutive cycles, the system will transition to pre-alarm, and then transition to the same detection cycle as the high-speed detection type.

[0329] Furthermore, if the detector 510 also detects the position of a flame, it will make a position determination 10 seconds after the above flame determination.

[0330] Furthermore, when the type of detection is flame abnormality detection, abnormal temperature detection (high temperature type), and monitoring temperatures in the range of 200 to 480°C, the detection cycle is 60 seconds. If the monitored temperature is equal to or higher than the set value, it is determined to be a high-temperature object, and if it is determined to be a high-temperature object for 1 to 2 consecutive cycles, it will transition to a pre-alarm, and if it is determined to be a high-temperature object for 10 consecutive minutes, for example, it will be determined to be an abnormal temperature.

[0331] When the type of detection is flame abnormality detection, abnormal temperature detection (low temperature type), and the temperature range of 80 to 200°C is monitored, the detection cycle is 1 hour. If the monitored temperature is above the set value, it is determined to be an abnormal temperature object, and if it is determined to be an abnormal temperature object for 1 to 2 consecutive cycles, it will transition to pre-alarm, and if it is determined to be an abnormal temperature object for, for example, 3 consecutive hours, it will be determined to be an abnormal temperature object.

[0332] Furthermore, when the type of detection content is temperature detection, temperature monitoring (high temperature type), and the temperature range to be monitored is 200 to 480°C, the monitoring cycle is 60 seconds. When the type of detection content is temperature monitoring (low temperature type), and the temperature range to be monitored is 80 to 200°C, the monitoring cycle is 1 hour.

[0333] Furthermore, when the type of detection is gas leak detection, the detection cycle is 50 ms, similar to the high-speed flame detection type, or 500 ms, similar to the standard type.

[0334] If the type of detection is liquid leakage detection, the detection cycle is 1 hour. If the monitored resistance value is below the threshold for 5 consecutive hours, a pre-alarm will occur, and if the monitored resistance value is determined to be below the threshold for 10 to 24 consecutive hours, it will be determined that a liquid leakage has been detected.

[0335] If the type of detection is vibration or impact detection, the detection cycle is 1 ms. If the monitored acceleration is equal to or greater than the threshold for 5 ms consecutively, a pre-alarm occurs, and if the monitored acceleration is determined to be equal to or greater than the threshold for 10 ms to 24 ms consecutively, it is determined that vibration or impact has been detected.

[0336] The power supply control unit 538 controls the supply of power from the power supply unit 574 or the external power supply in accordance with a monitoring cycle or a detection cycle that is predetermined for the type of detection content of the detector 510. The power supply control unit 538 also controls the supply of power from the power supply unit 574 or the external power supply to the sensor unit 520 in accordance with a sensor cycle that is predetermined for the type of sensor unit 520.

[0337] The transmission signal management unit 536 outputs the contents of detection by the detection unit group 28 as a digital signal to the wireless transmission unit 573B.

[0338] The received signal management unit 534 sends and receives digital signals transmitted from the host device 580 and the mobile robot 50 .

[0339] The wireless receiving unit 573A acquires a signal received by the antenna 571 from the wireless master device 576 through wireless communication using the specified low-power wireless frequency band, and outputs the signal to the arithmetic processing unit 512.

[0340] Wireless transmitting unit 573B transmits the signal output from arithmetic processing unit 512 to wireless master device 576 via antenna 571 by wireless communication using a specified low-power radio frequency band.

[0341] <Configuration of specific low-power wireless module> In this embodiment, specified low-power wireless module 562 transmits and receives signals (unique address / environmental information / anomaly information, etc.) between detector 510 and wireless master device 576 by wireless transmission.

[0342] The transmission method used is LPWA (Low Power Wide Area), a specified low-power radio. LPWA is a general term for communication methods that transmit wirelessly over short distances of a few kilometers to 10 kilometers with extremely low current consumption (about 20 mA), and mainly uses the sub-GHz band.

[0343] <Low current consumption> In the embodiment of the present invention, power-saving control of the detector 510 and various types of power-saving communications are used, which allows each detector 510 to meet the intrinsically safe explosion-proof specifications stipulated in the Factory Electrical Equipment Explosion Protection Guidelines or IEC (International Electrotechnical Commission) standards, and the entire intrinsically safe explosion-proof detection system 500 is installed in that location.

[0344] The electrical specifications of the various sensors connected to the detector 510 as the sensor unit 520 are 1.5 V or less, 100 mA or less, and 25 mW or less. This allows the specifications of the various sensor units 520 to be exempt from the inspection of the intrinsically safe explosion-proof specifications specified in the Factory Electrical Equipment Explosion-Proof Guidelines or the IEC (International Electrotechnical Commission) standards. Note that it is not necessary for all types of sensor units 520 to have the specifications of 1.5 V or less, 100 mA or less, and 25 mW or less; some types of sensor units 520 may have the specifications of 1.5 V or more, 100 mA or more, or 25 mW or more. In this case, the sensor units 520 of those types may be inspected for the intrinsically safe explosion-proof specifications specified in the Factory Electrical Equipment Explosion-Proof Guidelines or the IEC (International Electrotechnical Commission) standards.

[0345] <Effects of intrinsically safe explosion-proof detection system> Next, the operation of the intrinsically safe explosion-proof detection system 500 according to the embodiment of the present invention will be described.

[0346] First, an individual address is assigned to each of the detectors 510 installed in the intrinsically safe explosion-proof detection system 500. As a result, signals that combine addresses and various information are exchanged in data transmission between the detectors 510 and the host device 580 and the mobile robot 50. For example, if 100 detectors 510 are included, the address section is expressed in 7 bits, followed by several bits of environmental information.

[0347] Furthermore, various types of sensor units 20 are connected to each detector 510, and the type of sensor unit 520 and the type of detection content are set by the operation unit 516.

[0348] For example, when the operation unit 516 sets multiple detection elements that detect infrared rays as the type of sensor unit 520 and sets detection of abnormal temperature as the type of detection content, the infrared signal acquisition unit 526A and the flame temperature detection unit 528A are set as the targets to be activated.

[0349] The infrared signal acquisition unit 526A acquires sensor information indicating the intensity of the detected infrared rays for each sensor cycle for the detection element that detects the infrared rays. The flame temperature detection unit 528A determines whether the temperature is abnormal or not using a threshold value for the abnormal temperature for each detection cycle for the detection of the abnormal temperature.

[0350] Furthermore, when the operation unit 516 is used to set the temperature sensor as the type of sensor unit 520 and temperature monitoring as the type of detection content, the temperature signal acquisition unit 526D and the temperature detection unit 528D are set as targets to be operated.

[0351] The temperature signal acquisition unit 526D acquires sensor information indicating the temperature at each sensor cycle of the temperature sensor. The temperature detection unit 528D outputs the acquired sensor information indicating the temperature at each monitoring cycle of the temperature.

[0352] In this way, the detector 510 repeatedly performs the process of monitoring environmental information or determining whether a predetermined abnormality has been detected at each monitoring period or detection period according to the type of detection content.

[0353] Specifically, as shown in FIG. 38 , when the detector 510 determines, using the clock generating unit of the counter unit 524, that a monitoring period or a detection period determined according to the type of detection content has been reached, it supplies power from the power supply unit 574 and activates the arithmetic processing unit 512 (S551, S552). Then, if the address included in the received signal matches the address of the detector 510, it stores the address included in the received signal (S553). It acquires sensor information from the sensor unit 520, checks the state of the sensor unit 520 based on the sensor information, and performs calculations. If the type of detection content is the detection of a predetermined abnormality, it compares the calculated value with a threshold value predetermined for the type of detection content to determine whether the predetermined abnormality has occurred. Then, the wireless transmitter 573B transmits the environmental information monitoring results or the determination result of whether the predetermined abnormality has been detected according to the type of detection content to the wireless master device 576 (S554). Then, the result of monitoring the environmental information or the result of determining whether a predetermined abnormality has been detected is written to the SRAM 577 (S555), the clock generating unit of the counter unit 524 is reset, and a timer is set (S556). The power supply control unit 538 then stops the supply of power from the power supply unit 574 and stops the arithmetic processing unit 512 (S557). When the power supply control unit 538 determines using the clock generating unit of the counter unit 524 that the next monitoring cycle or detection cycle has arrived, it again supplies power from the power supply unit 574 and starts up the arithmetic processing unit 512.

[0354] Furthermore, the data exchange between the sensor unit 520 and the detector 510 in the operation of S554 above will be described with reference to Fig. 39. The exchange shown in Fig. 39 is repeated every sensor cycle.

[0355] First, the detector 510 requests data from the sensor unit 520 (S581), and supplies power to the sensor unit 520 to activate the sensor unit 520 (S582). Then, the detector 510 sets conditions for the sensor unit 520 according to the type of detection content (S583), and checks the state of the sensor unit 520 (S584).

[0356] Then, the sensor unit 520 acquires sensor information (S585) and outputs the acquired sensor information to the detector 510 (S586).

[0357] 40 will be used to explain data exchange when transmitting data from the detector 510 to the host device 580 and the mobile robot 50. Note that, although data transmission to the host device 580 will be explained below, the same applies to data transmission to the mobile robot 50.

[0358] First, when the detector 510 transmits data to the host device 580 (S591), it transitions to a receive mode for a certain period of time and waits until it receives an ACK message from the host device 580 (S592). Then, when it receives an ACK message from the host device 580 (S593), it ends the receive mode and the detector 510 is powered off.

[0359] If an ACK message is not received from the host device 580 even after a certain period of time has elapsed since the detector switched to the receive mode, the detector will wait in the receive mode for another certain period of time. If an ACK message is not received from the host device 580 during this certain period of time, the detector will end the receive mode and turn off the power to the detector 510. Then, at the next transmission, the data for which no ACK message was received will be transmitted together with the data at that time.

[0360] If the receiving mode is ended without receiving an ACK message a predetermined number of times (for example, three times), it is determined that the transmission is faulty, and the detector 510 determines that an abnormal state exists.

[0361] Furthermore, if the host device 580 fails to receive data from the detector 510 a predetermined number of times in succession, it also determines that the detector 510 is experiencing a transmission failure.

[0362] As described above, according to the intrinsically safe explosion-proof detection system 500 of the fifth embodiment, the wireless master unit transmits the digital signals transmitted from each detector to a higher-level device and a mobile robot that has moved to the vicinity, thereby enabling stable collection of data from multiple detectors.

[0363] Furthermore, by having the detector 510 control the supply of power from the power supply unit in accordance with a predetermined monitoring cycle or detection cycle for the environmental information being monitored or the type of abnormality being detected, the intrinsically safe explosion-proof detection system 500 can be operated for a long period of time without the need for battery replacement, thereby reducing the management costs of the power supply unit.

[0364] Additionally, each detector 510 can be adapted to monitor different types of environmental information or detect different types of abnormalities.

[0365] <Modification> The present invention is not limited to the fifth embodiment described above, and various modifications and applications are possible without departing from the spirit and scope of the present invention.

[0366] For example, at least one of the multiple detectors may function as a wireless master device, collect transmission data from the other detectors, and transmit the data collectively to the host device and the mobile robot. In this case, all of the detectors have the function of acting as a wireless master device, and the detector designated as the wireless master device is capable of transmitting and receiving data, while the remaining detectors are dedicated to transmission. After the detector designated as the wireless master device has completed collecting transmission data from other detectors with different monitoring or detection periods and transmitted the data to the host device and the mobile robot, it designates at least one of the other detectors as the next wireless master device, and then becomes dedicated to transmission.

[0367] In addition, although an example has been described in which the type of sensor unit 520 and the type of content detected by the detector 510 are set by operating the operation unit, the detector 510 may be configured to automatically recognize the type of connected sensor unit, the type of content monitored, and the type of content detected.

[0368] The detector 510 may monitor sound, liquid level, or rotation as environmental information. The detector 510 may also determine whether or not an abnormality related to sound, liquid level, or rotation has been detected as a predetermined abnormality.

[0369] In addition, in the above-described first to fifth embodiments, the combination of the frequency band of the specified low-power radio and the frequency band of the LTE radio system has been described as an example, but the present invention is not limited to this. For example, a combination of frequency bands of two specified low-power radio systems that are different may be used.

[0370] Although the electrical specifications of the sensor are described as 1.5 V or less, 100 mA or less, and 25 mW or less, this is not limiting. The electrical specifications of the power generation module may be configured as 1.5 V or less, 100 mA or less, and 25 mW or less.

[0371] Although the mobile robot 50 is used as the data collection device in the above example, the present invention is not limited to this. A portable data collection device may also be used. In this case, for example, a person carrying the portable data collection device may move around the vicinity of multiple wireless base stations in sequence.

[0372] In addition, although the mobile robot 50 has been described as monitoring abnormalities in its own system, including abnormalities in the power supply unit 74 of the wireless master device 68, the present invention is not limited to this. The mobile robot 50 may also monitor the normal state of its own system (collect information that the system is functioning normally). [Explanation of symbols]

[0373] 10, 10A detector 20, 20A sensor part 26 Conversion unit 28 Detection Group 29 Processing unit 28A external power supply section 28B Thermoelectric element 34, 34A Specific low-power wireless module 44 Detection unit 50 Mobile Robot 68, 576 Wireless base station 72, 72A, 72B, 372, 372A, 564 Controller 74, 74A, 74B power supply section 100, 200, 300, 400, 500 Intrinsically safe explosion-proof detection system 310, 310A detector 312 Processing Unit 316A Cycle Management Department 320 Sensor unit 326A power supply section 327, 327A, 562, 573, 762, 3742 Specific low-power radio modules 328 Detection Unit Group 354, 354A period storage section 358 Cycle Management Department 373, 373A, 373B power supply section 510 Detector 512 Processing Unit 518 connection terminal 520 Sensor unit 524 Counter 526 Signal Acquisition Unit 528 Detection Group 532 Cycle Management Department 538 Power supply control unit 566, 761, 3741 LTE wireless modules 574 Power supply section 588 detectors HO insulation material PH plant piping

Claims

1. A detection unit that monitors environmental information or determines whether a predetermined abnormality has been detected based on sensor information detected by the sensor; and a wireless communication unit that transmits the monitoring result or the determination result by the detection unit to the master transceiver as a digital signal via wireless communication, and transmits and receives the digital signal to and from the master transceiver; a plurality of detectors including a power supply unit that supplies power to each of the plurality of detectors; a transmission cable section that is provided to connect the power supply section and each of the plurality of detectors and supplies power from the power supply section to the detector; a plurality of master transceivers that transmit and receive signals to and from each of the plurality of detectors via wireless communication, and also transmit and receive signals to and from a host device and a mobile robot, thereby relaying the transmission and reception of signals between each of the plurality of detectors and the host device, and between each of the plurality of detectors and the mobile robot; a mobile robot that moves sequentially to positions corresponding to the plurality of master transceivers, a mobile robot that collects monitoring results or determination results by the detection unit from the digital signal received from the parent transceiver and monitors its own system, the received digital signal includes information indicating that the monitoring result or the determination result by the detection unit has been transmitted to the higher-level device, or information indicating that the monitoring result or the determination result by the detection unit has not yet been transmitted to the higher-level device, The mobile robot determines whether the collected monitoring results or judgment results by the detection unit have been transmitted to the host device, and when it determines that the collected monitoring results or judgment results by the detection unit have not been transmitted to the host device, it transmits the collected monitoring results or judgment results by the detection unit to the host device. Intrinsically safe explosion-proof detection system.

2. A detection unit that monitors environmental information or determines whether a predetermined abnormality has been detected based on sensor information detected by the sensor; and a wireless communication unit that transmits the monitoring result or the determination result by the detection unit to the master transceiver as a digital signal via wireless communication, and transmits and receives the digital signal to and from the master transceiver; a plurality of detectors including a plurality of master transceivers that transmit and receive signals to and from each of the plurality of detectors via wireless communication, and also transmit and receive signals to and from a host device and a mobile robot, thereby relaying the transmission and reception of signals between each of the plurality of detectors and the host device, and between each of the plurality of detectors and the mobile robot; a power supply unit that supplies power to each of the plurality of detectors; a transmission cable section that is provided to connect the power supply section and each of the plurality of detectors and supplies power from the power supply section to the detector; a controller that controls the supply of power from the power supply unit to each of the plurality of detectors in accordance with a monitoring period or a detection period that is predetermined for the environmental information or the type of the predetermined abnormality in the detector; a mobile robot that moves sequentially to positions corresponding to the plurality of master transceivers, a mobile robot that collects monitoring results or determination results by the detection unit from the digital signal received from the parent transceiver and monitors its own system, the received digital signal includes information indicating that the monitoring result or the determination result by the detection unit has been transmitted to the higher-level device, or information indicating that the monitoring result or the determination result by the detection unit has not yet been transmitted to the higher-level device, The mobile robot determines whether the collected monitoring results or judgment results by the detection unit have been transmitted to the host device, and when it determines that the collected monitoring results or judgment results by the detection unit have not been transmitted to the host device, it transmits the collected monitoring results or judgment results by the detection unit to the host device. Intrinsically safe explosion-proof detection system.

3. 3. The intrinsically safe explosion-proof detection system according to claim 2, wherein any or all of the detector, the power supply unit, the controller, the parent unit transceiver, and the transmission cable unit are installed in a hazardous location (ZONE 0) specified in the Factory Electrical Equipment Explosion Prevention Guidelines or IEC (International Electrotechnical Commission) standards.

4. An intrinsically safe explosion-proof detection system including an intrinsically safe explosion-proof detector, a plurality of parent transceivers, and a mobile robot, The intrinsically safe explosion-proof detector is a detection unit that monitors environmental information or determines whether a predetermined abnormality has been detected based on sensor information detected by the sensor; a wireless communication unit that transmits a monitoring result or a determination result by the detection unit to the master transceiver as a digital signal via wireless communication, and transmits and receives the digital signal to and from the master transceiver; a power supply unit that supplies power; a controller that controls the supply of power from the power supply unit in accordance with a predetermined monitoring period or detection period for the environmental information or the predetermined type of abnormality; Including, each of the plurality of master transceivers transmits and receives signals to and from the intrinsically safe explosion-proof detector by wireless communication, and also transmits and receives signals to and from a host device and the mobile robot, thereby relaying the transmission and reception of signals between the host device and the intrinsically safe explosion-proof detector, and between the intrinsically safe explosion-proof detector and the mobile robot; the mobile robot moves to positions corresponding to the plurality of parent transceivers in order, collects monitoring results or judgment results by the detection unit from the digital signals received from the parent transceivers, and monitors its own system; the received digital signal includes information indicating that the monitoring result or the determination result by the detection unit has been transmitted to the higher-level device, or information indicating that the monitoring result or the determination result by the detection unit has not yet been transmitted to the higher-level device, The mobile robot determines whether the collected monitoring results or judgment results by the detection unit have been transmitted to the host device, and when it determines that the collected monitoring results or judgment results by the detection unit have not been transmitted to the host device, it transmits the collected monitoring results or judgment results by the detection unit to the host device. Intrinsically safe explosion-proof detection system.

5. An intrinsically safe explosion-proof detection system including an intrinsically safe explosion-proof detector, a plurality of parent transceivers, and a mobile robot, The intrinsically safe explosion-proof detector is a connection terminal for connecting to the sensor; a detection unit that monitors environmental information or determines whether a predetermined abnormality has been detected based on sensor information detected by the sensor connected to the connection terminal; a cycle storage unit that stores a predetermined monitoring cycle or detection cycle for each of the environmental information or each of the predetermined types of abnormality; a wireless communication unit that transmits a monitoring result or a determination result by the detection unit to the master transceiver as a digital signal via wireless communication, and transmits and receives the digital signal to and from the master transceiver; a power supply unit that supplies power; a controller that controls the supply of power from the power supply unit in accordance with the environmental information or the monitoring period or the detection period corresponding to the type of the predetermined abnormality; Including, each of the plurality of master transceivers transmits and receives signals to and from the intrinsically safe explosion-proof detector by wireless communication, and also transmits and receives signals to and from a host device and the mobile robot, thereby relaying the transmission and reception of signals between the host device and the intrinsically safe explosion-proof detector, and between the intrinsically safe explosion-proof detector and the mobile robot; the mobile robot moves to positions corresponding to the plurality of parent transceivers in order, collects monitoring results or judgment results by the detection unit from the digital signals received from the parent transceivers, and monitors its own system; the received digital signal includes information indicating that the monitoring result or the determination result by the detection unit has been transmitted to the higher-level device, or information indicating that the monitoring result or the determination result by the detection unit has not yet been transmitted to the higher-level device, The mobile robot determines whether the collected monitoring results or judgment results by the detection unit have been transmitted to the host device, and when it determines that the collected monitoring results or judgment results by the detection unit have not been transmitted to the host device, it transmits the collected monitoring results or judgment results by the detection unit to the host device. Intrinsically safe explosion-proof detection system.

6. An intrinsically safe explosion-proof detection system including an intrinsically safe explosion-proof detector, a plurality of parent transceivers, and a mobile robot, The intrinsically safe explosion-proof detector is a connection terminal for connecting to the sensor; an acquisition unit that acquires sensor information detected by the sensor through a predetermined acquisition process corresponding to the type of the sensor connected to the connection terminal, the acquisition process being determined in advance for each type of the sensor; a detection unit that monitors environmental information or determines whether a predetermined abnormality has been detected, wherein a detection process that monitors the environmental information or determines whether a predetermined abnormality has been detected is predetermined for each type of the environmental information or the predetermined abnormality; a detection unit that monitors the environmental information or determines whether a predetermined abnormality has been detected by the detection process corresponding to the environmental information or the type of the predetermined abnormality; a wireless communication unit that transmits a monitoring result or a determination result by the detection unit to a master transceiver as a digital signal via wireless communication, and transmits and receives the digital signal to and from the master transceiver; a cycle storage unit that stores a predetermined monitoring cycle or detection cycle for each of the environmental information or each of the predetermined types of abnormality; a power supply unit that supplies power; a controller that controls the supply of power from the power supply unit in accordance with the environmental information or the monitoring period or the detection period corresponding to the type of the predetermined abnormality; Including, each of the plurality of master transceivers transmits and receives signals to and from the intrinsically safe explosion-proof detector by wireless communication, and also transmits and receives signals to and from a host device and the mobile robot, thereby relaying the transmission and reception of signals between the host device and the intrinsically safe explosion-proof detector, and between the intrinsically safe explosion-proof detector and the mobile robot; the mobile robot moves to positions corresponding to the plurality of parent transceivers in order, collects monitoring results or judgment results by the detection unit from the digital signals received from the parent transceivers, and monitors its own system; the received digital signal includes information indicating that the monitoring result or the determination result by the detection unit has been transmitted to the higher-level device, or information indicating that the monitoring result or the determination result by the detection unit has not yet been transmitted to the higher-level device, The mobile robot determines whether the collected monitoring results or judgment results by the detection unit have been transmitted to the host device, and when it determines that the collected monitoring results or judgment results by the detection unit have not been transmitted to the host device, it transmits the collected monitoring results or judgment results by the detection unit to the host device. Intrinsically safe explosion-proof detection system.

7. 3. The intrinsically safe explosion-proof detection system according to claim 1, wherein the standby current consumption of said detector or said master transceiver is 300 nA or less.

8. 8. The intrinsically safe explosion-proof detection system according to claim 1, wherein the monitoring of the system itself monitors abnormalities in the power supply unit.

9. The intrinsically safe explosion-proof detection system according to any one of claims 1 to 8, wherein the power supply unit is composed of a primary battery, a secondary battery, or a power generation module.

10. 10. The intrinsically safe explosion-proof detection system according to claim 9, wherein the power generation module has electrical specifications of 1.5 V or less, 100 mA or less, and 25 mW or less.

11. The intrinsically safe explosion-proof detection system according to any one of claims 1 to 10, wherein the detection unit monitors temperature, humidity, pressure, vibration, impact, gas concentration, sound, ultrasound, liquid level, or rotation as the environmental information, or determines whether or not an abnormality related to temperature, humidity, pressure, vibration, impact, gas concentration, sound, ultrasound, liquid level, or rotation, a fire, thinning, gas leak, or liquid leak has been detected as the specified abnormality.

12. The intrinsically safe explosion-proof detection system according to any one of claims 1 to 11, wherein the electrical specifications of the sensor are 1.5 V or less, 100 mA or less, and 25 mW or less.

13. 7. The intrinsically safe explosion-proof detection system according to claim 5, wherein data transmission between the sensor and the connection terminal is performed by analog current transmission or analog voltage transmission at a voltage of 1.5 V or less and 25 mW or less.

14. 7. The intrinsically safe explosion-proof detection system according to claim 5 or 6, wherein data transmission between the sensor and the connection terminal is performed by balanced transmission with a voltage of 1.5 V or less, a current of 100 mA or less, and a power of 25 mW or less. Tem.

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