CN202018435U - Wireless gas sensor - Google Patents
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- CN202018435U CN202018435U CN201120123944XU CN201120123944U CN202018435U CN 202018435 U CN202018435 U CN 202018435U CN 201120123944X U CN201120123944X U CN 201120123944XU CN 201120123944 U CN201120123944 U CN 201120123944U CN 202018435 U CN202018435 U CN 202018435U
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Abstract
A wireless gas sensor belongs to the technical field of gas sensors and solves the problem of zero drift existed in the present gas sensor. A power management module provides work power supply for a sensing unit, a signal conditioning circuit and a ZigBee module, wherein the detection signal output end of the sensing unit is connected with the detection signal input end of the signal conditioning circuit; the detection signal output end of the signal conditioning circuit is connected with the detection signal input end of the ZigBee module; the ZigBee module is used for transmitting detection signals by an antenna via a transmission path; the storage signal input end and the storage signal output end of a storer are connected with those of the ZigBee module; and the timing signal input end and the timing signal output end of a timer are connected with those of the ZigBee module. The wireless gas sensor provided by the utility model is used for monitoring gas in a coal mine.
Description
Technical field
The utility model relates to a kind of wireless gas sensor, belongs to the firedamp sensor technical field.
Background technology
Along with the development of coal industry, safety problem becomes the matter of utmost importance that needs solution.In the China's coal-mine security incident, the injures and deaths number that gas explosion accident causes accounts for more than 50% of all major accident number of casualties, becomes the biggest obstacle that realizes safety in production.The maximum harm that gas disaster coal supply mine belt comes is to threaten personnel in the pit's life, destroys mine facility, forces mine to stop production, and needs to drop into a large amount of manpower and materials rescue and relief works.Therefore, gas detected in real time in the coal mine production safety system seem extremely important,, need high performance wireless gas sensor if will realize the dynamic continuous detecting of gas.
Problems such as existing firedamp sensor ubiquity life-span weak point, poor stability, regulating cycle weak point, concrete manifestation is as follows:
1, detecting element serviceable life is short: because existing detecting element poor-performing on average can only use 3 to 6 months, descend, in time find again if element is active, and light precise decreasing then, heavy then present " extremely popping one's head in ", promptly gas is not reacted.
2, the accuracy of sensor and the linearity do not reach the fundamental error scope of product vertification regulation regulation, and error is too big between indicated value and the actual value, or low side is accurate, and be high-end inaccurate, or high-end accurate, and low side is inaccurate.
3, unstable properties, display digit daps: the element that has had just lost efficacy within a few minutes be subjected to gas (as about the 2%) impact of higher concentration in measurement range after, though the not inefficacy that has, element sensitivity significantly descends.
When 4, sensor was given a shock (as blowing out or motional collision) and wind speed variable effect, numeral was beated, and zero point drift causes job insecurity.
For above-mentioned reasons, firedamp sensor all needs adjustment once weekly, and frequent adjustment can make the movement of sensor make moist and then influence the performance and the life-span of sensor instrument.
The characteristics of comprehensive home and abroad colliery security system, along with the increase of the pit mining degree of depth, the extendability of existing sensing system and the dirigibility of existing communication network are not strong, have caused the renewal speed of the information safety system that has existed not enough.Owing to production program is followed the distribution situation of downhole coal mine and is changed, the extendability of cable network does not catch up with the actual requirement of exploitation, make that the data reliability of network and real-time can not get guaranteeing, be difficult to guarantee the timely transmission of the detection data of important secure data, control data and downhole gauges.Existing radio network technique is not suitable for the concrete application of mine safety system.
Because the networked degree of mine safety infotech is not high, downhole safety information can not in time pass to aboveground security control center, causes coal mining accident frequently to take place.Existing mine safety infosystem is set up by cable network mostly, variation day by day along with coal mining, physical arrangement under the coal mine is changing with rapid changepl. never-ending changes and improvementsly, the cable network transmission system that originally designed is difficult to accomplish monitor completely covering, rebulid new wired network system, on cost, on the manpower, aspects such as extendability all do not meet the development of actual conditions.
Sensor is the instrument that obtains information, be one of three big pillars of infotech (comprising sensing and control technology, mechanics of communication and computer technology), it is positioned at infosystem foremost, and the quality of its characteristic, the reliability of output information are most important to the total system quality.
The intelligence sensor system is a modern complex art, and it is the new and high technology that the world today is developing rapidly with sensor, computing machine and the mechanics of communication construction system that organically combines.The intelligence sensor system compares with traditional sensors, has following characteristics:
1. high precision
The intelligence sensor system is owing to adopt microcomputer management and data processing, thereby can adopt multiple scheme to guarantee its high precision, not only can revise various deterministic system errors by software, but also can suitably replenish stochastic error, reduction noise, improve sensor accuracy greatly.
2. high reliability
Some unreliable factor of traditional structure has been eliminated in the miniaturization of integrated sensor system, has improved the interference free performance of total system; It has self diagnosis, self calibration and data storage function (also having adaptation function for Structure with Intelligent Structure System) simultaneously, has good stable.
3. high performance price ratio
Under the requirement of same precision, the multifunctional intellectual sensor is compared with the common sensor of simple function, and the ratio of performance to price obviously improves, and is especially more obvious after adopting more cheap single-chip microcomputer.
4. multifunction
Intelligence sensor can be realized the measurement of multisensor multi-parameter comprehensive, expansion measurement able to programme and usable range; Certain adaptive ability is arranged,, correspondingly change the form of range and output data according to the change of detected object or condition; Have the Interface for digital communication function, directly send into far computing machine and handle; Has the several data output form, adaptive various application systems.
Advantages such as the carrier catalysis firedamp sensor is highly sensitive with it, measurement range is big, frequency response range is wide, volume is little are widely used in the methane Concentration Measurement System in colliery.But also exist " drift " and the bigger shortcoming of temperature influence nonlinearity erron, thereby influenced the measuring accuracy of sensor.Improved B P neural network has good non-linear approximation capability, is widely used in the gamma correction of sensor; ZigBee is a kind of low complex degree, low-power consumption, low cost, low data rate, short distance two-way wireless communication technology, can realize the wireless transmission of sensing data.
The utility model content
The utility model is in order to solve the problem that there is zero point drift in existing firedamp sensor, a kind of wireless gas sensor to be provided.
Wireless gas sensor described in the utility model by power management module, sensing unit, signal conditioning circuit, ZigBee module, deposit all devices and timer is formed,
Power management module provides working power for sensing unit, signal conditioning circuit and ZigBee module, the detection signal output terminal of sensing unit connects signal conditioning circuit detection signal input end, signal conditioning circuit detection signal output terminal connects the detection signal input end of ZigBee module, and the ZigBee module is launched by the emission path detection signal from antenna;
The storage signal input/output terminal of depositing all devices connects the storage signal I/O of ZigBee module; The timing signal input/output terminal of timer connects the timing signal I/O of ZigBee module.
The utility model has the advantages that: the ZigBee building block technique that the utility model adopts is as a kind of new short-range communication technique, simple because of agreement, cost is low, low in energy consumption, characteristics such as networking is easy, and the communication mode of firedamp sensor is mentioned one than on the higher aspect.
The utility model adopts the carrier catalysis sensor as sensing unit, there are zero point drift and the big defective of nonlinearity erron at existing carrier catalysis firedamp sensor, the intelligence of utilizing single chip circuit to carry out zero point drift is proofreaied and correct, single chip circuit can adopt Improved B P neural network that sensor is carried out gamma correction, solved the zero point drift problem of existing carrier catalysis firedamp sensor, make stable working state, performance is better, and prolong serviceable life.
Description of drawings:
Fig. 1 is the schematic block circuit diagram of wireless gas sensor of the present utility model;
Fig. 2 is the physical circuit schematic diagram that embodiment four described employing MC13193 type radio frequency chips are realized radio circuit 4-1;
Fig. 3 is the circuit theory diagrams of embodiment six described signal conditioning circuits 3.
Embodiment
Embodiment one: below in conjunction with Fig. 1 present embodiment is described, present embodiment by power management module 1, sensing unit 2, signal conditioning circuit 3, ZigBee module 4, deposit all devices 5 and timer 6 is formed,
The storage signal input/output terminal of depositing all devices 5 connects the storage signal I/O of ZigBee module 4; The timing signal input/output terminal of timer 6 connects the timing signal I/O of ZigBee module 4.
Embodiment two: present embodiment is for to the further specifying of embodiment one, and described ZigBee module 4 is made up of radio circuit 4-1 and single chip circuit (4-2),
The detection signal input end of single chip circuit (4-2) is the detection signal input end of ZigBee module 4, the signal I/O of single chip circuit (4-2) connects the signal input output end of radio circuit 4-1, and the emission path of radio circuit 4-1 is the emission path of ZigBee module 4.Other is identical with embodiment one.
Embodiment three: present embodiment is for to the further specifying of embodiment two, and it is the single chip circuit of MC9S08GT60 that described single chip circuit (4-2) adopts model; It is the radio circuit of MC13193 that described radio circuit 4-1 adopts model.Other is identical with embodiment two.
Radio frequency chip MC13193 in the present embodiment is the rf chip of the base band data modulator-demodular unit that meets the IEEE802.15.4 standard of Freescale company exploitation.This chip performance is stable, and power consumption is very low, adopts the CMOS design of economical and efficient, needs external module hardly.
The Specifeca tion speeification of MC13193 is as follows: working band scope 2.4000～2.4835GHz; Adopt the direct sequence spread spectrum mode of IEEE802.15.4 code requirement; Data rate reaches 250Kbps, and chip rate reaches 2Mchips/s; Adopt the O-QPSK modulation system; 4 μ A sleep modes; High receiving sensitivity (92dbm); Anti-adjacent channel interference performance strong (39db); Inside is integrated with VCO, LAN, PA and power rectifier, and the employing low voltage power supply (2V～3.4V); The output power programmed controlled; Interface configuration easy (4 bus SPI interface) with control microprocessor; Developing instrument is complete, provides development kit and demonstration external member; Adopt the QFN-32 encapsulation, physical dimension has only 5mm * 5mm.
The MC13193 chip also has the digital core of an optimization, helps to reduce the processing power of single-chip microcomputer, shortens the performance period.Inner integrated 4 timing comparators can be used to reduce cost it with lower, the cheap single-chip microcomputer of performance, interrupt maintenance service widely and make mcu programming more easy.
It is that it is doing well aspect the low-power consumption power saving that single chip circuit (4-2) adopts the reason of MC9S08GT60, and under mal-condition stable work in work.
Embodiment four: below in conjunction with Fig. 2 present embodiment is described, present embodiment is for to the further specifying of embodiment three, and the concrete annexation of the radio circuit that described employing model is MC13193 is:
Two emission of radio frequency signals antennas of described radio circuit 4-1 are connected with second capacitor C 2, the 3rd capacitor C 3 of connecting between the other end of first capacitor C, 1, the second capacitor C 2 of connecting between one end of second capacitor C 2 and the input pin RFIN+ of radio frequency chip MC13193 and the input pin RFIN-of radio frequency chip MC13193;
Connect successively between the input pin RFIN+ of radio frequency chip MC13193 and the analog electrical seedbed GND first resistance R 1, the first transformer W101 and the 4th capacitor C 4, the second transformer W102 and first resistance R 1 and the first transformer W101 are in parallel;
After being connected, three NC pins of radio frequency chip MC13193 connect digital power ground;
Described radio circuit 4-1 two radio frequency receiving antennas connect with the 5th capacitor C 5, the emission path of radio frequency chip MC13193 is two radiofrequency signal output terminal PAO+ and PAO-, one end of the 5th capacitor C 5 connects radiofrequency signal output terminal PAO+, the other end of the 5th capacitor C 5 connects radiofrequency signal output terminal PAO-, and first inductance L 1 is in parallel with the 5th capacitor C 5;
Be connected the 3rd transformer W103 between radiofrequency signal output terminal PAO-and the VDDA, be connected the 4th transformer W104 between radiofrequency signal output terminal PAO+ and the VDDA, the tenth capacitor C 10 of connecting between VDDA and the analog electrical seedbed GND;
Connect crystal oscillator X1 between the pin XTAL1 of radio frequency chip MC13193 and the pin XTAL2, the 12 capacitor C 12 of connecting between the 6th capacitor C 6 of connecting between the end of crystal oscillator X1 and the digital power ground, the other end of crystal oscillator X1 and digital power ground.Other is identical with embodiment three.
The MC13193 chip mainly partly and with interface microcontroller partly is made up of frequency synthesizer, power management in simulation reception radiating portion, digital modulation and demodulation part, the sheet.
MC9S08GT60 and MC13193 that Freescale company produces can be good at compatibility, and it adopts 4 line SPI to realize both sides' radio communication, and MC9S08GT60 adopts holotype, and MC13193 adopts from pattern.For transmitter module, the signal that send is delivered to the MC13193 by the SPI oral instructions from MC9S08GT60, and process spread spectrum O-QPSK launches from antenna by the emission path after being modulated to carrier wave.For receiver module, receive the radiofrequency signal of coming from antenna and obtain original data through demodulation, despreading, be sent to MC9S08GT60 by the SPI interface again, thus the transmitting-receiving of the information of realization.
MC9S08GT60 self has 10 A/D converters of 8 passages, and precision satisfies system requirements fully, and the sampled signal of sensor can directly enter MC9S08GT60 by signal conditioning circuit 3 and carry out the A/D conversion.Deposit all devices 5 and be mainly used to store ephemeral data and the emulated data result that sensing unit 2 is gathered.Timer 6 is responsible for setting wakeup time to MC9S08GT60, makes the MC9S08GT60 timing acquiring detect data.
The radiofrequency signal of MC13193 adopts the method for difference input and output, and what antenna adopted is the balance track antenna that is complementary with input and output.The radiofrequency signal that receives from antenna is sent on the first transformer W101 and the second transformer W102 by the arrowband matching network of being made up of first capacitor C 1, second capacitor C 2 and the 3rd capacitor C 3, by transformer it is decomposed on two the radiofrequency signal input pin RFIN+ and RFIN-that two paths of differential signals is sent to the MC13193 chip; The two-way radiofrequency signal of launching, is sent on the antenna and launches through synthetic one road signal behind the 3rd transformer W103 and the 4th transformer W104 from two the radiofrequency signal output terminal PAO+ and the PAO-output of chip.
The pin PAO+ of radio frequency chip MC13193 requires to be connected with VDDA with PAO-, and its connection realizes by the 3rd transformer W103 and the 4th transformer W104.This is the successful balance/imbalance transformer reference design of passing through.
Consider the influence of crystal oscillator X1, when printed board is set type, the position of crystal oscillator X1 should be positioned as close to the XTAL1 and the XTAL2 pin of MC13193 chip communication quality.The value of the 5th capacitor C 5, the 6th capacitor C 6 should be consistent with crystal oscillator X1 load capacitance, and the crystal oscillator frequency of MC13193 chip appointment is 16MHz, and degree of stability need be between ± 40ppm.
The VDDA of MC13193 chip, VDDLO1, VDDLO2, VDDD, VDDVCD pin are the output of chip internal power management part, are used for powering to other parts of chip.Relatively stricter to the requirement of the shunt capacitance of these several outputs in actual applications, equally should be in the design printed board with their position of shunt capacitance as far as possible near corresponding output pin.
The 4 line SPI interfaces of singlechip chip MC9S08GT60 by standard carry out read-write operation to the internal register of MC13193, thereby finish control and data communication to MC13193, the SPI interface can be worked under 8MHZ or littler frequency just can satisfy the request for utilization of chip.
Interruption on the MC13193 is passed through
Pin and MC9S08GT60's
Pin links to each other, and when MC13193 goes up the generation interruption, MC9S08GT60 will capture this interruption, and judges that according to the interrupt status register of MC13193 what has taken place interrupts, and corresponding break in service is provided.
In the utility model, with MC13193's
Pin links to each other with the GPIO mouth of MC9S08GT60 and makes MC9S08GT60 can control the mode of operation of MC13193 at an easy rate.
Be input pin, low level is effective, and by this pin, MC9S08GT60 can force to convert to idle pulley from park mode with MC13193.
MC9S08GT60 links to each other by the RXTXEN pin of a GPIO mouth and MC13193, be used for the transmitting-receiving operation of initialization MC13193, this pin high level is effective, it will be continued to be set to high level when sending by the SPI interface or receiving data, put lowly after finishing again, enter idle pulley.
MC9S08GT60 passes through a GPIO mouth and MC13193's
Pin links to each other, in order to when being necessary MC13193 is carried out reset operation.RST is a resetting pin, and MC9S08GT60 can be by this pin MC13193 that resets.
MC13193 can produce programmable clock output, and MC9S08GT60 is designed to use the inside and outside clock, and by CLKO, MC9S08GT60 can use the reference clock of MC13193 output, this clock is by the control of SPI interface programming, and its default value is 32.786KHz (16MHz/488).
Embodiment five: present embodiment is for to the further specifying of embodiment three or four, and described sensing unit 2 adopts the carrier catalysis sensors.Other is identical with embodiment three or four.
In the utility model, sensing unit 2 adopts the carrier catalysis sensor.Simulating signal by the output of carrier catalysis sensor enters single-chip microcomputer MC9S08GT60,8 logical 10 ADCs integrated by inside carry out the A/D conversion, and MC9S08GT60 is connected with MC13193 and will launches by MC13193 after treatment from the signal of sensor acquisition by the SPI mouth.Control signal to sensor can receive into from the antenna of MC13193, is sent on the MC9S08GT60 by SPI, delivers on the sensor by the GPIO oral instructions through after the judgment processing of MC9S08GT60, to finish the control to sensor.MC9S08GT60 finishes MC13193 transmitting-receiving control and needed MAC layer operation simultaneously.
The sensitive element that the carrier catalysis sensor uses has two kinds of platinum filament catalysis element and carrier catalyst elements.The platinum filament catalysis element is generally made spiral winding with the platinum filament of purity very high (99.99%), and platinum filament is carried out special processing, and platinum filament is a catalyzer, is again well heater.This catalysis element is simple in structure, and good stability is subjected to the sulfide poisoning to influence little.But the catalytic of platinum filament is low, must just can make element work at high temperature more than 900 ℃, and not only power consumption is big, and high temperature can cause element surface evaporation, makes that platinum filament attenuates, resistance increases, instrument zero drift.In addition, platinum filament catalysis element physical strength is low, because the influence of vibration or deadweight, its geometric configuration will change, and also will change the parameter of sensor, the accuracy that influence detects.1954, Britain mining safety research institute (SMRE) developed carrier catalyst element, and it has overcome the deficiency of platinum filament catalysis element, is widely used in the colliery.
Carrier catalyst element generally by a band sensitive element (being commonly called as black element) of catalyzer and one not with compensating element, (the being commonly called as white element) formation of catalyzer.The structure of two carrier catalyst elements is all identical with size.The innermost layer of carrier catalyst element is the platinum wire coil circle, and the outside is the catalysis shell that carrier and catalyzer form.Be heated by platinum filament behind certain electric current, component temperature raises, and is used for the heatable catalytic shell, and it is temperature required to keep the gas catalyst combustion reaction, and the while is the double as temperature-sensing element again, detects the variation of catalysis skin temperature in catalytic reaction.The effect of carrier is to make catalyzer have good dispersion degree, and enough reaction areas are provided.Normally used is K type aluminium oxide, is hard vesicular material through the good K type aluminium oxide of handling, and has the surface area of tens square metres of every grams.Catalyzer commonly used is platinum (Rt), palladium (Pd), thorium elements such as (Th).
When adopting catalysis element to detect gas, as long as keep methane has q.s in air gas mixture oxygen, and keep the certain high temperature condition, under the effect of catalyzer, methane will produce flameless burning at element surface.
According to Catalysis Principles, because the existence of catalyst Pt, Pd, this course of reaction has reduced the energy of activation of gas and oxygen generation chain reaction, near the active centre of catalyst surface, the methane molecule inner structure that is adsorbed has been left steady state (SS) and has been activated cracking, thus the carrying out of accelerating chain reaction.Heat is emitted in flameless burning in the catalytic reaction process, has increased the resistance value of sensitive element platinum filament, by the Wheatstone bridge metering circuit, can measure its carrier catalyst element resistance change.
Embodiment six: below in conjunction with Fig. 3 present embodiment is described, present embodiment is for to the further specifying of embodiment five, and signal conditioning circuit 3 concrete annexations are:
Two detection signal output terminals of described sensing unit 2 are two detection signal output terminals of carrier catalysis sensor, the one one capacitor C 11 of connecting between output terminal of these two detection signal output terminals and the in-phase input end of one-level instrument amplifier D1,
Series connection the one one resistance R 11 between the in-phase input end of one-level instrument amplifier D1 and the inverting input, another output terminal of described two detection signal output terminals connects the inverting input of one-level instrument amplifier D1, series connection the 21 resistance R 21 between the 1st pin of one-level instrument amplifier D1 and the 8th pin;
The output terminal of one-level instrument amplifier D1 connects an end of the 31 resistance R 31, and the other end of the 31 resistance R 31 connects an end of the 31 capacitor C 31, and the other end of the 31 capacitor C 31 connects the in-phase input end of secondary instrument amplifier D2,
Be connected resistance R 51 on May Day between the other end that is connected the 21 capacitor C 21, the 31 resistance R 31 between the other end of described the 31 resistance R 31 and the analog electrical seedbed and the output terminal of secondary instrument amplifier D2,
Be connected the 41 resistance R 41 between the in-phase input end of secondary instrument amplifier D2 and the analog electrical seedbed,
Be connected the 61 resistance R 61 between the inverting input of secondary instrument amplifier D2 and the analog electrical seedbed, be connected resistance R 71 July 1st between the inverting input of described secondary instrument amplifier D2 and the output terminal,
The output terminal of secondary instrument amplifier D2 connects the in-phase input end of three grades of instrument amplifier D3, be connected the 81 resistance R 81 between the in-phase input end of three grades of instrument amplifier D3 and the analog electrical seedbed, three grades of instrument amplifier D3 inverting inputs connect the adjustable end of adjustable resistance R111, the end of adjustable resistance R111 connects the positive power source terminal of three grades of instrument amplifier D3, the other end of adjustable resistance R111 connects the output terminal of three grades of instrument amplifier D3, be connected the 91 resistance R 91 between the detection signal input end of the output terminal of three grades of instrument amplifier D3 and described single chip circuit (4-2), be connected the 11 resistance R 101 between the detection signal input end of single chip circuit (4-2) and the analog electrical seedbed.Other is identical with embodiment five.
The amplifier of amplifier section comprises general integrated operational amplifier, instrumentation amplifier, gain-programmed amplifier, isolated amplifier.General integrated operational amplifier is the very large integrated chip of a kind of open-loop gain, and after the composition closed loop, its output characteristics and closed loop gain are determined by external components and parts and structure; Instrumentation amplifier has advantages such as high input impedance, low maladjustment voltage, low temperature coefficient of deviation, enlargement factor are precise and stable, low output impedance, thereby is used widely in the small-signal of intelligence instrument amplifies; Adopt gain-programmed amplifier, select different gains, can make A/D converter signal full scale reach homogenization, and improve the precision of multi-channel data acquisition by programmed control; Isolated amplifier plays the isolation between input, output and the power supply, and it mainly contains photoelectricity and isolates and two kinds of measures of transformer isolation.
Shown in Figure 3, the voltage output end of the Wheatstone bridge of carrier catalysis sensor directly is connected with the input end of signal conditioning circuit 3, promptly as the signal source of signal conditioning circuit 3.One-level instrument amplifier D1 selects the special high-accuracy instrument three amplifier AD620 of AD company for use.AD620 is that it has the characteristics of low skew, high-gain, high cmrr, is specially adapted to the amplification sensor signal by three difference instrumentation amplifiers that accurate amplifier is integrated.Because a large amount of low-frequency noise intensity that sensor receives are much larger than its received ultrasonic signal, so must connect a passive high three-way filter between sensor and AD620.Though increased the power consumption of sensor like this, can remedy by increasing enlargement factor in the back.The second level is an active bandwidth-limited circuit.Can filter most of ground unrest that the front wave filter do not filter and the noise that produces by device or circuit in this one-level.Here select tape is logical is 38～42KHz.Secondary instrument amplifier D2 and three grades of instrument amplifier D3 adopt the OP777 of AD company, and it is a ultraprecise low noise amplifier, have extremely low voltage and current skew and very high gain stability.The third level is a general in-phase amplification circuit.After amplifying through the third level, the scope of signal becomes-3.3～+ 3.3V, again through the resistance of two 20K Ω, and connect+make the ADC sampled signal that is input to single-chip microcomputer become 0～3.3V behind the bias voltage of 3.3v.
The carrier catalysis sensor is realized interface through signal conditioning circuit 3 and ZigBee module 4, has promptly finished the hardware design of wireless senser.Can finish the wireless transmission of sensor signal between the wireless senser, become the terminal in the wireless sensor network.
Wireless senser can use powered battery, and will be contained on the module, requires the battery volume very little, so battery capacity can not be too big, and radio communication needs battery that enough big electric current is provided, and power consumption is bigger.After electric energy exhausts, if can not in time change power supply or charge the battery, then the life-span of sensor economize on electricity is just depended on the life-span of power supply, must manage to reduce the power consumption of sensor, prolong the sensor reliably working time, so low-power consumption becomes the focus of design of node.According to radio frequency chip MC13193 and the microprocessor MC9S08GT60 of the Freescale of sensor employing in the utility model, with the service time of No. 5 powered battery analysis nodes of two joints.
Carrier catalysis type firedamp sensor can be selected KG-8 type carrier catalysis type firedamp sensor for use, this sensor can be measured the gas density in 0～5% concentration range, its drift is no more than 0.8mV, and mainly utilize single-chip microcomputer to carry out sensor zero point from normal moveout correction with based on two parts of gamma correction of Improved B P neural network, realize in conjunction with software by MC9S08GT60.Because the algorithm that utilizes Improved B P neural network to carry out gamma correction is very complicated, on single-chip microcomputer, implement the comparison difficulty, therefore can at first carry out emulation on computers to measurement data, emulated data is made form, be stored among the Flash of single-chip microcomputer, obtain related data by the mode of tabling look-up, be easy to realize.
Diversity at present various mine safety products, and the polytrope in space, down-hole in the process of coal mining, the utlity model has the function of compatible existing mine safety system data transmission mode, have good dirigibility, the ability of extensibility and ad-hoc network.Because special applied environment under the mine, such as the environmental impact in the external world, more wide factors such as coverage have proposed very high requirement for the data transmission of underground wireless network.The utility model is from the angle of wireless route and dirigibility networking, design philosophy in conjunction with low-power consumption, advanced person's wireless network protocol is introduced into the mine safety system, communicate agreement research, make that the data transmission performance and the efficient of mine safety system are all improved greatly, also done a basis, thereby improved the infotech process of China's whole colliery industry, reduced the required cost of system extension for further studying from now on.
KG-8 type firedamp sensor, concrete principle of work is identical with common carrier catalysis sensor, and its performance index are shown in table 2-1, and wherein LEL (Low Explosive Limit) represents lower explosive limit.
The utility model has carried out intelligent correction in conjunction with the actual conditions in colliery to sensor " drift " problem, utilizes Improved B P neural network that sensor is carried out gamma correction, can pass through the MATLAB emulation experiment, reaches re-set target.Use Freescale single-chip microcomputer MC9S08GT60 and radio frequency chip MC13193 and built a hardware platform, i.e. ZigBee module 4 based on the ZigBee technology.This ZigBee module 4 is stable, reliable, has strong communication function, and communication distance is in tens meters scope.Design the interface of sensor and ZigBee module, realized the radio communication of sensing data.
Table 1KG-8 type catalytic combustion type methane transducer performance index
The utility model can be widely used in the detection of coal mine gas concentration with the advantage of its low cost, low-power consumption, for realizing that Safety of Coal Mine Production provides the prerequisite guarantee, has broad application prospects.It combines the ZigBee technology with the coal-mine gas sensor is effective, realize the firedamp sensor wireless penetration; Low cost, the low power dissipation design of wireless intelligence sensor have been realized.
Claims (6)
1. wireless gas sensor is characterized in that: it by power management module (1), sensing unit (2), signal conditioning circuit (3), ZigBee module (4), deposit all devices (5) and timer (6) is formed,
Power management module (1) is that sensing unit (2), signal conditioning circuit (3) and ZigBee module (4) provide working power, the detection signal output terminal of sensing unit (2) connects signal conditioning circuit (3) detection signal input end, signal conditioning circuit (3) detection signal output terminal connects the detection signal input end of ZigBee module (4), and ZigBee module (4) is launched by the emission path detection signal from antenna;
The storage signal input/output terminal of depositing all devices (5) connects the storage signal I/O of ZigBee module (4); The timing signal input/output terminal of timer (6) connects the timing signal I/O of ZigBee module (4).
2. wireless gas sensor according to claim 1 is characterized in that: described ZigBee module (4) is made up of radio circuit (4-1) and single chip circuit (4-2),
The detection signal input end of single chip circuit (4-2) is the detection signal input end of ZigBee module (4), the signal I/O of single chip circuit (4-2) connects the signal input output end of radio circuit (4-1), and the emission path of radio circuit (4-1) is the emission path of ZigBee module (4).
3. wireless gas sensor according to claim 2 is characterized in that: it is the single chip circuit of MC9S08GT60 that described single chip circuit (4-2) adopts model; It is the radio circuit of MC13193 that described radio circuit (4-1) adopts model.
4. wireless gas sensor according to claim 3 is characterized in that: the concrete annexation of the radio circuit that described employing model is MC13193 is:
Two emission of radio frequency signals antennas of described radio circuit (4-1) are connected with second electric capacity (C2), the 3rd electric capacity (C3) of connecting between first electric capacity (C1) of connecting between one end of second electric capacity (C2) and the input pin RFIN+ of radio frequency chip MC13193, the other end of second electric capacity (C2) and the input pin RFIN-of radio frequency chip MC13193;
Connect successively between the input pin RFIN+ of radio frequency chip MC13193 and analog electrical seedbed (GND) first resistance (R1), first transformer (W101) and the 4th electric capacity (C4), second transformer (W102) is in parallel with first resistance (R1) and first transformer (W101);
After being connected, three NC pins of radio frequency chip MC13193 connect digital power ground;
Described radio circuit (4-1) two radio frequency receiving antennas connect with the 5th electric capacity (C5), the emission path of radio frequency chip MC13193 is two radiofrequency signal output terminal PAO+ and PAO-, one end of the 5th electric capacity (C5) connects radiofrequency signal output terminal PAO+, the other end of the 5th electric capacity (C5) connects radiofrequency signal output terminal PAO-, and first inductance (L1) is in parallel with the 5th electric capacity (C5);
Be connected the 3rd transformer (W103) between radiofrequency signal output terminal PAO-and the VDDA, be connected the 4th transformer (W104) between radiofrequency signal output terminal PAO+ and the VDDA, the tenth electric capacity (C10) of connecting between VDDA and analog electrical seedbed (GND);
Connect crystal oscillator (X1) between the pin XTAL1 of radio frequency chip MC13193 and the pin XTAL2, the 12 electric capacity (C12) of connecting between the 6th electric capacity (C6) of connecting between one end of crystal oscillator (X1) and the digital power ground, the other end of crystal oscillator (X1) and digital power ground.
5. according to claim 3 or 4 described wireless gas sensors, it is characterized in that: described sensing unit (2) adopts the carrier catalysis sensor.
6. wireless gas sensor according to claim 5 is characterized in that: the concrete annexation of signal conditioning circuit (3) is:
Two detection signal output terminals of described sensing unit (2) are two detection signal output terminals of carrier catalysis sensor, the one one electric capacity (C11) of connecting between output terminal of these two detection signal output terminals and the in-phase input end of one-level instrument amplifier (D1)
Series connection the one one resistance (R11) between the in-phase input end of one-level instrument amplifier (D1) and the inverting input, another output terminal of described two detection signal output terminals connects the inverting input of one-level instrument amplifier (D1), series connection the 21 resistance (R21) between the 1st pin of one-level instrument amplifier (D1) and the 8th pin;
The output terminal of one-level instrument amplifier (D1) connects an end of the 31 resistance (R31), the other end of the 31 resistance (R31) connects an end of the 31 electric capacity (C31), the other end of the 31 electric capacity (C31) connects the in-phase input end of secondary instrument amplifier (D2)
Be connected the 21 electric capacity (C21) between the other end of described the 31 resistance (R31) and the analog electrical seedbed, be connected resistance on May Day (R51) between the other end of the 31 resistance (R31) and the output terminal of secondary instrument amplifier (D2),
Be connected the 41 resistance (R41) between the in-phase input end of secondary instrument amplifier (D2) and the analog electrical seedbed,
Be connected the 61 resistance (R61) between the inverting input of secondary instrument amplifier (D2) and the analog electrical seedbed, be connected the resistance July 1st (R71) between the inverting input of described secondary instrument amplifier (D2) and the output terminal,
The output terminal of secondary instrument amplifier (D2) connects the in-phase input end of three grades of instrument amplifiers (D3), be connected the 81 resistance (R81) between the in-phase input end of three grades of instrument amplifiers (D3) and the analog electrical seedbed, three grades of instrument amplifiers (D3) inverting input connects the adjustable end of adjustable resistance (R111), one end of adjustable resistance (R111) connects the positive power source terminal of three grades of instrument amplifiers (D3), the other end of adjustable resistance (R111) connects the output terminal of three grades of instrument amplifiers (D3), be connected the 91 resistance (R91) between the detection signal input end of the output terminal of three grades of instrument amplifiers (D3) and described single chip circuit (4-2), be connected the 11 resistance (R101) between the detection signal input end of single chip circuit (4-2) and the analog electrical seedbed.
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| CN201120123944XU CN202018435U (en) | 2011-04-25 | 2011-04-25 | Wireless gas sensor |
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| CN201120123944XU CN202018435U (en) | 2011-04-25 | 2011-04-25 | Wireless gas sensor |
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| CN102595656A (en) * | 2012-02-27 | 2012-07-18 | 苏州明上系统科技有限公司 | Zigbee wireless communication relay |
| CN102592425A (en) * | 2012-02-27 | 2012-07-18 | 苏州明上系统科技有限公司 | Zigbee wireless communication manager |
| CN102620644A (en) * | 2012-03-15 | 2012-08-01 | 李建国 | Zigbee-based micro strain measurement unattended engineering monitoring system |
| CN102937036A (en) * | 2012-11-16 | 2013-02-20 | 上海电机学院 | Method and device for monitoring gas on basis of BP (back propagation) neural network |
| CN103266911A (en) * | 2013-05-20 | 2013-08-28 | 山东天盛矿用电气设备有限公司 | Multifunctional wireless sensor for mineral automatic water spraying and dust falling device |
| CN104269039A (en) * | 2014-09-28 | 2015-01-07 | 合肥工业大学 | Wireless humidity sensor |
| CN104358589A (en) * | 2014-11-25 | 2015-02-18 | 山东中煤电器有限公司 | Wireless sensing device powered by mine power source |
| CN104713985A (en) * | 2013-12-17 | 2015-06-17 | 徐通 | Wireless sensor-based mine environment harmful gas detection system |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102595656A (en) * | 2012-02-27 | 2012-07-18 | 苏州明上系统科技有限公司 | Zigbee wireless communication relay |
| CN102592425A (en) * | 2012-02-27 | 2012-07-18 | 苏州明上系统科技有限公司 | Zigbee wireless communication manager |
| CN102620644A (en) * | 2012-03-15 | 2012-08-01 | 李建国 | Zigbee-based micro strain measurement unattended engineering monitoring system |
| CN102620644B (en) * | 2012-03-15 | 2014-08-13 | 李建国 | Zigbee-based micro strain measurement unattended engineering monitoring system |
| CN102937036A (en) * | 2012-11-16 | 2013-02-20 | 上海电机学院 | Method and device for monitoring gas on basis of BP (back propagation) neural network |
| CN103266911A (en) * | 2013-05-20 | 2013-08-28 | 山东天盛矿用电气设备有限公司 | Multifunctional wireless sensor for mineral automatic water spraying and dust falling device |
| CN103266911B (en) * | 2013-05-20 | 2016-04-27 | 山东天盛矿用电气设备有限公司 | A kind of automatic sprinkling dust suppression device for mines multifunction wireless senser |
| CN104713985A (en) * | 2013-12-17 | 2015-06-17 | 徐通 | Wireless sensor-based mine environment harmful gas detection system |
| CN104713985B (en) * | 2013-12-17 | 2016-08-17 | 淮安信息职业技术学院 | A kind of Minepit environment harmful gas detection system based on wireless senser |
| CN104269039A (en) * | 2014-09-28 | 2015-01-07 | 合肥工业大学 | Wireless humidity sensor |
| CN104358589A (en) * | 2014-11-25 | 2015-02-18 | 山东中煤电器有限公司 | Wireless sensing device powered by mine power source |
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