A kind of for wireless senser base station and safety monitoring system under the coal mine
Technical field
The utility model relates to wireless sensor technology, and is particularly a kind of for wireless senser base station and safety monitoring system under the coal mine.
Background technology
The coal mine downhole safety supervisory control system has become the important means of coal mine downhole safety management, production and equipment control.The coal mine downhole safety supervisory control system mainly is comprised of transducer, transducer base station, face Surveillance center and transmission channel.Coal mine transducer kind commonly used mainly contains: environment parameter sensing device, manufacturing parameter transducer, equipment working condition and error protection transducer and electrical quantity sensor.Transducer is equivalent to the nerve endings of safety monitoring system, is responsible for measuring various parameters under the coal mine; The parameter that other parts are responsible for sensor measurement is obtained is carried out correct transmission and utilization.Therefore, can to obtain correct measuring-signal be the basis that the coal mine safety monitoring system normally plays a role to transducer.
The signal that sensor measurement obtains is transferred to the ground monitoring center by the transducer base station channel under the coal mine, transducer base station under coal mine can connect one or more transducers, the base station of communicating by letter between transducer and the ground monitoring center is served as in the transducer base station, adopts the wired connection mode between transducer base station and the ground monitoring center.Usually, the transducer base station under the coal mine is because volume is large, need special power supply to be fixed installation, be difficult for mobile, and sensor bulk is less, power supply flexibly, therefore easy for installation, be easy to mobile.Thereby have the people just to utilize movably characteristics of transducer, sensor node is placed in the safe environment, thereby so that when daily monitoring, communication under the fict coal mine to the ground monitoring center, to evade security monitoring, is carried out violation operation.
The utility model content
In view of this, the purpose of this utility model is to propose a kind of for wireless senser base station and the safety monitoring system that can position to wireless sensor node monitoring under the coal mine.
Of the present utility model for the wireless senser base station under the coal mine, comprise the radio receiving transmitting module, wire communication module, the alarm module that link to each other with controller respectively, it is characterized in that, also comprise the position coordinates monitoring modular, be used for according to described radio receiving transmitting module according to the current position coordinates that receives the relatively described base station of the described node of signal strength detection that sends from wireless sensor node, when judging that current position coordinates surpasses setting threshold, then described position coordinates monitoring modular starts alarm module to controller output signal.
The utility model is based on the improvement that now is used for the wireless senser base station under the coal mine, be applied in the utility model by the empirical model that the transmission of wireless signals loss is converted into distance, realized that the base station can be to the positioning function of the wireless sensor node in the coal mine, and when the position coordinates of node surpasses setting threshold, start alarm, prevented from sensor node is placed on the violation operation of evading security monitoring in the safe environment, can effectively stop the potential safety hazard of coal mine, take precautions against the generation of coal mine security incident, and the realization of wireless senser of the present utility model base station need not the additional hardware facility, and is with low cost.And known radio sensing network is realized the mode (infrared ray, GPS, ultrasonic wave and TOA etc.) of location and be not suitable in this application scenarios that specific demand arranged of coal mine: because of ultrared range error larger, and be subjected to the impact of temperature, humidity etc. larger, be not suitable under coal mine, using; And GPS can't use under coal mine; Although hyperacoustic range finding is very accurate, need to add the node size that reaches of hardware, the realization of increase system; TOA (Time of Arrival), be the distance of estimating time difference of utilizing node signal to arrive different base station node and base station, this mode must rely additional firmware, the cost compare height, its application scenarios is larger space scale, is not suitable for using under coal mine.
Based on of the present utility model for the wireless senser base station under the coal mine, the invention also discloses a kind of for the safety monitoring system under the coal mine, comprise the wireless senser base station, wireless senser, the ground monitoring center, it is characterized in that, described transducer base station also comprises the position coordinates monitoring modular, be used for according to described radio receiving transmitting module according to the current position coordinates that receives the relatively described base station of the described node of signal strength detection that sends from wireless sensor node, when judging that current position coordinates surpasses setting threshold, then described position coordinates monitoring modular is to controller output signal, and startup alarm module earthward Surveillance center sends warning.
To sum up, owing to adopted technique scheme, the beneficial effects of the utility model are: realized cheaply the position monitoring to the wireless sensor node in the coal mine, prevented from sensor node is placed on the violation operation of evading security monitoring in the safe environment, can effectively stop the potential safety hazard of coal mine, take precautions against the generation of coal mine security incident.
Description of drawings
Fig. 1 is the structured flowchart of wireless senser base station in the utility model.
Fig. 2 is the structure chart of wireless sensor node among the utility model embodiment.
Fig. 3 is the structure chart of wireless senser base station among the utility model embodiment.
Embodiment
Disclosed arbitrary feature in this specification is unless special narration all can be replaced by other equivalences or the alternative features with similar purpose.That is, unless special narration, each feature is an embodiment in a series of equivalences or the similar characteristics.
Referring to Fig. 1, by controller, radio receiving transmitting module, wire communication module, alarm module, sensor assembly, the position coordinates monitoring modular has consisted of the wireless senser base station for coal mine of the present utility model, wherein, position coordinates monitoring modular and controller can consist of by single-chip microcomputer is integrated, finish detection and localization and monitoring to wireless sensor node; Radio receiving transmitting module is used for finishing the radio communication between base station and the node; Wire communication module be used for to realize communicating by letter of base station and ground monitoring center; Sensor assembly is for detection of the residing environmental parameter in base station.
Embodiment
Referring to Fig. 2, the wireless sensor node in the utility model comprises network and transceiver unit by MC9S12NE64 single-chip microcomputer (comprising processor and memory cell), Zigbee module CC2420E-M(), gas sensor module (comprising transducer and D/A conversion unit), supply of electric power module and acousto-optic alarm module consist of.
Referring to Fig. 3, the radio receiving transmitting module of wireless senser of the present utility model base station is Zigbee module CC2420E-M; Controller is integrated manipulator LAN (Controller Area Network, CAN) C85IF020 single-chip microcomputer, comprise processor and memory, position coordinates monitoring modular of the present utility model is set in processor, in memory, writes signal strength signal intensity and the position coordinates mapping table of wireless sensor node of the present utility model; Wire communication module is the CAN bus transceiver; Alarm module is audible-visual annunciator, also comprises sensor assembly, the environmental parameter around namely the base station also can be detected.The wireless senser base station is a node on the CAN bus system, by wired connection mode and ground monitoring center to center communications.
When the Zigbee of base station module CC2420E-M behind the signal strength values S of correct receiving node current location, choose the distance measuring signal attenuation model of formula (1), signal strength values S is converted into distance, and then makes up node signal intensity and position coordinates mapping table:
S=-(10nlg (d)+A)+45 formula (1)
Wherein A is the absolute value of base station and node RSSI in the time of 1 meter, records A ≈ 40 in this experiment, and n is the radio signal propagation index, generally gets 2~4, and it is more excellent that the process test of many times is got 3.0 effects in the utility model.
In the utility model, wireless senser base station and node all use the rod-short antenna, and the base station placing height is about 2m.Fixed base stations, relative base station is mobile node gradually, draw through a large amount of experimental analyses, the signal strength values S that the base station receives node increase variation along with the relative distance d of node and base station in the scope of 30m is apparent in view, so test specification of the present utility model is limited to 0~30m.In the scope of 0~30m, the signal strength values S of node current location can be received in every interval 0.2m or 0.3m record base station, each position all receives the packet about 100, signal strength values S is carried out first average value processing, then make up node signal intensity and position coordinates mapping table based on formula (1), and this mapping table is write in the memory of C85IF020 single-chip microcomputer.
When node is worked, the position coordinates monitoring modular of base station is got the Minimum Mean Square Error of the signal strength signal intensity of obtaining, with the position coordinates that mates in signal strength signal intensity and the position coordinates mapping table be the current position coordinates of node, the Minimum Mean Square Error of the base station number of winning the confidence intensity is processed and is specially: (such as 104us) carries out the instantaneous value S that baseband I Q power integral obtains signal strength values S within a period of time
i, i.e. S
i=sum(I^2+Q^2); Then in about 1 second to n (getting n in the present embodiment is 8192) S
iAverage the mean value S that obtains signal strength signal intensity
All, i.e. S
All=sumS
i/ n provides S in 1 second simultaneously
iMaximum and S
iBe n S greater than a certain thresholding K(K
iArithmetic mean) time ratio, i.e. S
iGreater than the number of K/n).
The position coordinates monitoring modular is according to the Minimum Mean Square Error according to the signal strength signal intensity obtained, with the position coordinates that mates in signal strength signal intensity and the position coordinates mapping table be the current position coordinates of node.Work as the judgement current position coordinates when the position monitoring module of base station and surpass setting threshold (according to the applied environment of reality, setting threshold is in the present embodiment: node is at a distance of base station air line distance 5m), then described position coordinates monitoring modular is to controller output signal, start alarm module, be that position coordinate monitoring module is to controller outputting alarm signal, startup alarm module earthward Surveillance center sends warning, realizes the effective supervision to the violation operation of evading security monitoring.
The utility model is not limited to aforesaid embodiment.The utility model expands to any new feature or any new combination that discloses in this manual, and the arbitrary new method that discloses or step or any new combination of process.