CN102573058A

CN102573058A - System and method for accurately positioning wireless sensor network

Info

Publication number: CN102573058A
Application number: CN2012100128839A
Authority: CN
Inventors: 高细见; 杨亚雄; 杨亚齐; 汪启军; 金辉; 叶荫宇
Original assignee: 上海齐汇通讯技术有限公司
Priority date: 2012-01-16
Filing date: 2012-01-16
Publication date: 2012-07-11
Also published as: CN102573058B

Abstract

The embodiment of the invention discloses a system and a method for accurately positioning a wireless sensor network and is applied to the field of communication. The system comprises one or more positioned objects and a server, wherein each positioned object comprises an identification card used for performing information interaction with one or more wireless card readers which are arranged in a wireless card reading base station; respective relative distance relative to each wireless card reader is measured by using a symmetrical double-sided two-way ranging (SDS-TWR) algorithm; and the server is used for calculating and determining a coordinate position of each identification card by using a semidefinite programming algorithm according to the relative distance. Due to the SDS-TWR positioning technology and the semidefinite programming algorithm, the system has the advantages of high stability, high positioning accuracy, high operating rate and high expandability, is applicable to indoor accurate positioning, such as accurate positioning for underground coal mines, prison staff, commercial building personnel and assets and the like, and is also applicable to outdoor positioning, such as positioning in intelligent vehicle management, outdoor security patrol and the like.

Description

A kind of wireless sensor network Precise Position System and method

Technical field

The present invention relates to communication technique field, relate in particular to a kind of wireless sensor network Precise Position System and method.

Background technology

In recent years, pinpoint increasing demand increases, though GPS can obtain good positioning accuracy, under indoor environment, the gps signal decay is bigger, can't accurately locate.In addition, GPS also is easy to receive the influence of extraneous factor such as weather outdoor, thereby need utilize other technical scheme to replace GPS, for example indoor accurate position in the occasion that GPS can't locate.The indoor positioning market demand is bigger, and typical application is accurately location, Prison staff location, personnel's assets location, specific building etc. under the coal mine for example.

With the coal mine down-hole personnel navigation system is example; It should be able to be in time, the current intelligence with each area people of down-hole is reflected to the ground-based computer system accurately; Make administrative staff can grasp personnel in the pit's distribution situation and each miner's movement locus at any time, so that carry out more reasonably dispatching management.Especially, when accident took place, data and figure that the rescue personnel also can be provided according to personnel in the pit and equipment navigation system were understood the relevant personnel's situation rapidly, in time take to rescue accordingly measure, improve the efficient of emergency management and rescue work.Therefore, country pays much attention to the construction of mine personnel positioning system.Before 6 years; Coal academy of sciences Changzhou automation research institute just adopts the personnel positioning monitoring system of the RFID of 433M radio frequency; Again there be multi-form navigation system come out 2007 year thereafter; National security industry standard AQ6210-2007 " coal mine underground operators position monitoring and management system general technical specifications " and AQ1048-2007 " the coal mine underground operators management system is used and management regulation " issue is as the policy paper of research and development, production and on-the-spot use and management.Colliery equipment navigation system has also had some years, and each department require different, just require all collieries to equip before 3 years like Shanxi Province's coal office.State Council's promulgated by the State Council (2010) No. 23 " State Council is about the notices of further reinforcement enterprise security production work " requires " to force to carry out advanced and applicable technical equipment.The Technical facilities in production standard will formulated and implement to colliery, non-coal mine; Monitoring and controlling system, personnel in the pit's navigation system, urgent danger prevention system, compressed air self-help system, the technical equipments such as system and channel of communication of suing and labouring that supply water are installed, and within 3 years, are accomplished ".In August in the same year, (2010) No. 146 literary compositions of the total coal of national Work Safety Supervision Bureau safety supervision dress require that " all collieries of central enterprise and state-owned emphasis coal mining enterprise will be accomplished the construction of personnel in the pit's navigation system and improved work; Before the end of the year 2011, work is improved in the construction that personnel in the pit's navigation system will be accomplished in other all collieries." at present, the personnel location system of central enterprise and state-owned emphasis coal mining enterprise has been accomplished installation, but national local mine also have 10,000 surplus the place, estimate the location equipment that also do not have over half at least.

At present, the technical scheme of domestic realization indoor positioning mainly contains:

1, radio-frequency card (RFID) attendance checking system:

This scheme generally is at inlet a RFID card reader to be installed; Utilization is registered personnel the mode that the RFID radio-frequency card reads; And it can not be real-time the personnel's that report accurately particular location; Can navigate to floor rank or room level, come down to a kind of attendance checking system, be difficult to accomplish accurate location.

2, adopt the personnel location system of 2.4G RFID technology

Adopt the manufacturer of this scheme many, the high energy of its decipherment distance reaches 10-40 rice, and recognition speed is very fast, and the most outstanding advantage is low-power consumption, and wireless identification tag is in operate as normal more than 6 each months continuously under the situation of not changing battery.Positioning accuracy is directly proportional with the density of receiver, in order to realize high orientation precision, just needs the overall cost of higher system, so poor expandability.

3, adopt the Zigbee radio network technique

The wireless identification of this scheme distance is 50～100m, and recognition speed is fast, can two-way communication, but the power consumption of identification card is more much bigger than RFID, is unfavorable for the use under the special occasions.

Summary of the invention

The purpose of the embodiment of the invention is to the problem that exists in the above-mentioned background technology; A kind of wireless sensor network Precise Position System and method are proposed; Low with indoor position accuracy in the solution prior art, thus perhaps just need the lower problem of higher cost autgmentability if will reach high orientation precision.

In order to realize aforementioned goal of the invention, the embodiment of the invention provides a kind of wireless sensor network Precise Position System, and said system realizes through following technical scheme:

A kind of wireless sensor network Precise Position System, said system comprises:

One or more targets that are positioned; Said localizing objects comprises an identification card; Be used for being arranged at one or more that the wireless card reading device carries out the mutual of information in the wireless card reading base station, adopt bilateral bidirectional ranging algorithm SDS-TWR to measure separately relative distance with respect to each wireless card reading device;

Server is used for according to above-mentioned relative distance, adopts the Semidefinite Programming algorithm computation to confirm the coordinate position of each identification card.

Further preferably, said identification card specifically comprises:

The power management part is used for carrying out the management of Charge Management and/or power safety;

The radio frequency control section comprises output matching circuit, power monitoring, amplifier comparison circuit, receiving circuit, is used for sending the ranging data bag and receiving from the packet of card reader to measure the distance with the wireless card reading device to the wireless card reading device;

Processor unit is used for cooperating the radio frequency control section to find range, send/receiving radio data.

Further preferably, said receiving circuit comprises duplexer, filter, and said duplexer is used for controlling double antenna.

Further preferably, said identification card also comprises the power saving management module, is used for according to the power of the signal between identification card and the wireless card reading device, and the transmitting power of regulating Subscriber Identity Module automatically realizes power saving management.

In order to realize aforementioned goal of the invention, the embodiment of the invention provides a kind of wireless sensor network accurate positioning method, and said method is to realize through following technical scheme:

A kind of wireless sensor network accurate positioning method, said method comprises:

The identification card and one or more of being positioned is arranged at that the wireless card reading device carries out the mutual of information in the wireless card reading base station, and adopts bilateral bidirectional ranging algorithm SDS-TWR to measure separately the relative distance with respect to each wireless card reading device;

Server adopts the Semidefinite Programming algorithm computation to confirm the coordinate position of each identification card according to above-mentioned relative distance.

Further preferably, the bilateral bidirectional ranging algorithm of said employing SDS-TWR measurement specifically comprises with respect to the relative distance of each wireless card reading device separately:

Identification card sends first ranging data bag to the wireless card reading device, if the wireless card reading device has correctly received this packet, then return hardware and reply to Subscriber Identity Module, and request produces transmission delay T1;

Identification card calculates transmission delay T1, simultaneously these data is sent to the wireless card reading device, and the hardware of wait wireless card reading device is replied;

The wireless card reading device reads the relevant parameter that identification card is sent, and is the preparation of finding range for the second time of identification card and wireless card reading device;

The wireless card reading device is handled time-delay T2 through calculating, and T2 is sent to identification card;

Identification card receives the ranging data bag of wireless card reading device, sends hardware automatically and replys to the wireless card reading device, and the wireless card reading device will be replied according to said hardware and calculated propagation delay T3;

The wireless card reading device calculates propagation delay T3, and T3 is sent to identification card, and the hardware of wait identification card is replied;

Identification card reads the T3 that the wireless card reading device sends, and calculates processing time-delay T4;

Identification card is according to T1, T2, and T3, T4 calculate the relative distance of identification card and wireless card reading device.

Further preferably, said server adopts the Semidefinite Programming algorithm computation to confirm that the coordinate position of each identification card specifically comprises according to above-mentioned relative distance:

Paired distance between the identification card that measure to move and the mobile identification card that can communicate by letter or the fixed wireless card reader;

Paired distance between the node that utilizes known wireless card reading device or identification card position and measure is come the position of the every other identification card of computing network.

Further preferably, the paired distance between the said node that utilizes known wireless card reading device or identification card position and measure comes the position of the every other identification card of computing network specifically to comprise:

If mobile node is identification card set for N and stationary nodes are that the set of identification card or wireless card reading device is A, wherein position { a of stationary nodes _kK ∈ A} is given, the position { x of mobile node _iI ∈ N} is unknown, according to the paired distance that measures, measures through following formula:

$\begin{matrix} {| | a_{k} - x_{i} | |}_{2}^{2} = p_{ki}^{2}; (k, j) &Element; E_{a}; - - - (5) \\ {| | x_{i} - x_{i} | |}_{2}^{2} = d_{H}^{2}; (i, j &Element; E_{n}), i < j, - - - (6) \end{matrix}$

E wherein _aAnd E _nBe respectively between mobile node and the stationary nodes, and mobile node and mobile node between the set of existing measuring distance.

Further preferably, said method comprises:

Make that X is all position vector x that belong to N _iI ∈ N is as the matrix and the Y=X of row vector ^TX, Z=[I, X; X ^T, Y], note e _iBe that i component is 1, all the other components are 0 column vector, and then (5) and (6) two formulas are equivalent to

$\begin{matrix} (a_{k}; - e_{i}) {(a_{k}; - e_{i})}^{T} Z = p_{ki}^{2}; (k, j) &Element; E_{a}; - - - (7) \\ (0; e_{i} - e_{i}) {(0; e_{i} - e_{i})}^{T} Z = p_{H}^{2}; (i, j) &Element; E_{n} - - - (8) \end{matrix}$

Now with Y=X ^TX is lax to be Y>=X ^TX; Perhaps of equal valuely,

Z >=0 (being the Z positive semidefinite) (9)

The wireless sensor network Precise Position System of the embodiment of the invention adopts location technology and the positive semidefinite planning algorithm of SDS-TWR; Have advantages such as good stability, positioning accuracy height, fast operation and extensibility are strong; And can precision be controlled in the 1M; In addition, because the SDS-TWR location technology adopts the linear frequency modulation spread spectrum, the multipath that possibly exist in the reduction system to greatest extent disturbs, radio noise disturbs; Adopt in the method for measurement and come and go method of measurement; Reduced the location algorithm strict demand synchronous to system clock; The positive semidefinite planning algorithm uses method of convex programming that non-protruding optimization problem is similar to simultaneously, and the system after the optimization has the positioning accuracy height, the strong remarkable advantage of antijamming capability; Therefore be applicable to indoor accurate position; For example under the coal mine accurately the location, Prison staff accurately locatees, commercial building personnel assets are accurately located, (mine, tunnel, building) etc. searched and rescued in the scene of the accident, also is applicable to outdoor location, for example the location in the Vehicular intelligent management, outdoor security personnel patrol etc.

Description of drawings

Through the description of its exemplary embodiment being carried out below in conjunction with accompanying drawing, the above-mentioned feature and advantage of the present invention will become apparent and understand easily.

Fig. 1 is the framework sketch map of the embodiment of the invention 1 Precise Position System;

Fig. 2 accurately locatees the enforcement sketch map for a kind of downhole coal mine that is applied to of the embodiment of the invention;

Fig. 3 is an embodiment of the invention wireless card reading device framework sketch map;

Fig. 4 is an embodiment of the invention Subscriber Identity Module framework sketch map;

Fig. 5 is an embodiment of the invention SDS-TWR wireless distance finding work signaling schematic diagram;

Fig. 6 is an embodiment of the invention SDS-TWR wireless distance finding method flow diagram.

Embodiment

Below in conjunction with accompanying drawing the present invention is done further explain.

Further preferably, said identification card specifically comprises:

Typical application of the embodiment of the invention such as colliery Precise Position System further specify the workflow based on the optimized Algorithm Precise Position System below in conjunction with Figure of description 2.

As shown in Figure 2, its hardware is made up of following components: monitoring computer (each of industrial computer main frame and guest machine), coffret, mining transmission substation, wireless card reading base station, Subscriber Identity Module (containing label), systems soft ware and tandem type data-signal lightning protection device are formed.The monitoring main frame installs system monitoring software and background data base, shows all monitoring informations; Subscriber Identity Module is worn by underground work personnel or moving target; The wireless card reading base station is installed in the tunnel that need follow the tracks of and detect; Many wireless card reading base stations are connected with substation through RS-485 bus or wireless transmission method with series system.

As shown in Figure 2, at first according to the mine operational environment,, arrange the wireless card reading base station in same side, tunnel and sustained height along roadway direction, the concrete coordinate in wireless card reading base station just can be measured out when installing.The layout of wireless card reading base station need be considered the length in tunnel, the intersection situation in tunnel, and angle of inclination, tunnel etc., ultimate range is no more than 400m between two wireless card reading base stations.Adopt the RS485 bus to connect between two wireless card reading base stations or the wireless network connection, it is 2.4G that wireless network connects operating frequency, and RS485 bus baud rate is set to 9600bps.

After the staff who wears label card gets into the tunnel; At first carry out handshake exchange information between wireless card reading base station and the label card; Measure distance between the two then, upload onto the server the data that measure in the wireless card reading base station through the RS485 bus, and server end passes through optimized Algorithm; Data are handled, obtained the exact position coordinate of the relative wireless card reading of label card base station.Through the known coordinate of wireless card reading base station and the relative position coordinates between the label card of base station, calculate the exact position of label card at last in the tunnel.

Be illustrated in figure 3 as the composition sketch map of wireless card reading base station 2 in the embodiment of the invention Precise Position System.Among Fig. 3, power management part 27 can adopt the intrinsic safety electric source of mine LDO to be depressured to processor 26 desired operating voltages.Close under (perhaps other is unusual) situation when intrinsic safety electric source, power management part 27 switches to power supply above the LiMn2O4 chargeable pond automatically.In addition, power management part 27 can be carried out Charge Management to lithium manganate battery, specifically comprises:

Charging current control when cell voltage less than 3V the time, is adopted precharge, and charging current is 100mA; When cell voltage less than 4.1V the time, adopts constant current charge greater than 3V, the charging maximum current is 800mA, and software can be regulated the charging current size; When cell voltage less than 4.2V the time, adopts constant voltage charge greater than 4.1V, last lithium manganate battery voltage reaches 4.2V.Abnormal conditions such as power management part 27 also can be too high, too small towards electric current to the charging voltage that possibly occur in the charging process in addition, cell voltage is too high, cell voltage is too small are protected.

Processor unit 26 main effects are to carry out swap data with control unit 25, thereby realization wireless card reading device and Subscriber Identity Module are directly found range transmission broadcast message, functions such as transmission time information.Processor unit 26 realizes through the RS485 bus and the transmission sub-station communication, and processor unit 26 is also compatible in addition Ethernet interface is in order to subsequent expansion.Charge functions such as data download through USB interface.

Control unit 25 is made up of microprocessor STM8L151G6 and processor unit 26 communicates through UART and radio frequency control section 24 communicates control by spi bus.

The duplexer logic is by 24 controls of radio frequency control section; Antenna 22 is formed with antenna 21; These two antennas all are omni-directional, but under actual environment, antenna is difficult to accomplish hundred-percent omnidirectional at present; Therefore system design double antenna, the double antenna main purpose is to eliminate the RF blind area and reduce because the measuring distance reduction that wireless card reading base station and label card relative position bring, the influence of certainty of measurement variation.

Be illustrated in figure 4 as the fundamental block diagram of Subscriber Identity Module 3 in the embodiment of the invention Precise Position System.Power management part 36 main management lithium manganate batteries comprise Charge Management, power safety management etc. among Fig. 4.Processor unit 35 main effects are to cooperate radio frequency control section 34 to find range, send operations such as receiving wireless messages, power saving management, and wherein, power saving management comprises:

To the signal between Subscriber Identity Module and the wireless card reading device strong and weak (RSSI of main monitor user ' identification card), the transmitting power of regulating Subscriber Identity Module automatically, the maximum transmission power of Subscriber Identity Module is 16dbm, having 64 grades can adjust; The PA mode of operation of Subscriber Identity Module is a burst mode, and default setting is sleep 3 seconds, the work 1 second of wakeing up then, and periodic duty, the concrete length of one's sleep and operating time software can freely be provided with; When Subscriber Identity Module for a long time not and the wireless card reading device communicate, will extend gradually the length of one's sleep, for example sleep 30 seconds, the work 1 second of wakeing up then.

The PA part of radio frequency control section 34 is made up of output matching circuit, power monitoring, amplifier comparison circuit etc., can NA5TR1 power output maximum be adjusted to 16dbm; The receiving circuit of radio frequency control section 34 is made up of duplexer, filter etc., and peak response is-95dbm.Antenna 31 is controlled by duplexer 33 with antenna 32, and it acts on the double antenna of similar wireless card reading device.

Like Fig. 5 and Fig. 6 is the ranging process between wireless card reading base station in the embodiment of the invention Precise Position System (wireless card reading device) and the label card (Subscriber Identity Module).Ranging process mainly is exactly the process of a SDS-TWR (bilateral bidirectional ranging, Symmetric Double Side-Two Way Ranging).

Among Fig. 6, preparatory stages 51 condition is: system is in non-distance measuring states and wireless card reading device, Subscriber Identity Module has all completed successfully initialization.

Incipient stage 52; Subscriber Identity Module 3 will send packet to the wireless card reading device of specific address (MAC Address appointment); If the wireless card reading device has correctly received this packet, the wireless card reading device will return hardware and reply to Subscriber Identity Module, and request produces transmission delay T1.

1 stage 53 of replying is divided into following steps:

A1. Subscriber Identity Module will call RangingCallback_Ack () and calculate transmission delay T1; Subscriber Identity Module sends to the wireless card reading device with these data simultaneously; And the hardware of waiting for the wireless card reading device is replied; All do not reply if surpass 10ms wireless card reading device, just think and need restart this range finding failure.

B1. the wireless card reading device calls RangingCallback_Rx (), reads the relevant parameter that Subscriber Identity Module sends, and measures ready for the second time for Subscriber Identity Module and wireless card reading device.

C1. the wireless card reading device is handled time-delay T2 through calculating, and this parameter is passed to Subscriber Identity Module through RangingMode ().

At Fig. 5, among Fig. 6,2 stages 54 of replying can be divided into following steps:

A2. Subscriber Identity Module is received the packet of wireless card reading device, will send hardware automatically and reply to the wireless card reading device, and the wireless card reading device will be replied according to this and calculated propagation delay T3.

B2. the wireless card reading device utilizes RangingCallback_Ack () to calculate propagation delay T3, and these data are sent to Subscriber Identity Module, and the hardware of wait Subscriber Identity Module is replied.

C2. Subscriber Identity Module utilizes RangingCallback_Rx () to read the parameter that the wireless card reading device passes over, and calculates T4.

D2. the wireless card reading device is through calling RangingMode (), and T3 sends to Subscriber Identity Module with transmission delay.

E2. Subscriber Identity Module obtains T3 through calling RangingCallback_Rx (), and end user passes through T1, T2, and T3, T4 calculate the distance of Subscriber Identity Module and wireless card reading device.

F2. hypothesis is optimized card because the time error that the crystal deviation is brought is e _A, the assumed wireless card reader is because the time error that crystal error is brought is e _B, then the flight time between wireless card reading device and the Subscriber Identity Module is T under the ideal situation _t:

$T_{t} = \frac{1}{4} (T_{1} - T_{2} + T_{3} - T_{4})$

G2. consider the crystal error of Subscriber Identity Module and wireless card reading device:

$T_{t}^{SDS} = \frac{1}{4} ((T_{1} - T_{2}) (1 + e_{A}) + (T_{3} - T_{4}) (1 + e_{B}))$

H2. suppose T ₂=T ₄+ δ and T _tδ, then

$T_{t}^{SDS} \approx T_{t} + \frac{1}{4} δ (e_{A} - e_{B})$

I2. adopt the words of twice range measurement principle:

$T_{t}^{TW} \approx T_{t} + \frac{1}{2} δ (e_{A} - e_{B})$

Through contrasting: adopt method of measurement, compare has a clear superiority in.

After server end receives the distance value between identification card and the wireless card reading base station, through the position of positive semidefinite planning algorithm computation tag card (Subscriber Identity Module).Mobile node is that the position of Subscriber Identity Module is confirmed through two processes in the computing network.

First process is the paired distance of measuring between mobile node and mobile node that can exchange or the fixed-node (anchor point).The RF transceiver that the wireless sensor network supplier of IEEE-802.15.4 standard is obeyed in the utilization of corresponding transducer has the ability of measuring distance between the adjacent mobile node.Each transducer is collected range data and these data is sent to the location that engine of positioning is done second process.

The location of second process be utilize known anchor point position and the node that measures in pairs between distance come the position of the every other node of computing network.The WSN orientation problem of second process is the orientation problem that a multistep is transmitted in the above.It is belong on the mathematics with the problem of calculating.Simple triangulation or polygon method of measurement can't satisfy the demand of real application systems to accurate positioning property and coverage rate.A feasible method is near the distance of anchor point not only utilizing, but also near the distance of other nodes that can obtain signal using, the orientation problem that causes so-called multistep to transmit, it can improve accurate positioning property in a large number.

Yet, even the network that a very little multistep is transmitted confirms that accurately and expeditiously the position of node is the computational problem position of a difficulty.Adopt the Semidefinite Programming algorithm can use just ability consumer positioning identification card position of two wireless card reading devices.

Concrete implementation method is:

If mobile node set N and fixed-node (anchor point) set A, the wherein position { a of anchor point _kK ∈ A} is given, the position { x of mobile node _iI ∈ N} is unknown, needs to confirm through certain mode according to some distance that has measured in couples.

E wherein _aAnd E _nBe respectively between mobile node and the anchor point, and mobile node and mobile node between the set of existing measuring distance.Present target will utilize formula (5) and (6) to confirm the position { x of mobile node exactly _iI ∈ N}.This problem is seen on how much, is the friendship of a lot of hyperspheres, has been proved to be np hard problem, does not have the algorithm with polynomial-time complexity.When the scale of problem became bigger, finding the solution of it just became very difficult.

In order to make try to achieve former problem at short notice one approximate solution preferably, the embodiment of the invention is introduced following matrix, and attempt with it lax be a positive semidefinite planning problem.

Make that X is all position vector x that belong to N _iI ∈ N is as the matrix and the Y=X of row vector ^TX, Z=[I, X; X ^T, Y], if we remember e _iBe that i component is 1, all the other components are 0 column vector, and (5) and (6) two formulas are equivalent to so

Now with Y=X ^TX is lax to be Y>=X ^TX; Perhaps of equal valuely,

Z >=0 (being the Z positive semidefinite) (9)

(7)-(9) can be through setting up positive semidefinite planning; Find the solution at polynomial time with softwares such as sedumi again, obtain an approximate solution of former location problem, compare traditional multiple didactic algorithm; The positive semidefinite planning algorithm has the solving precision height, the clear superiority that antijamming capability is strong.

Because label card is compared in the wireless card reading base station, structure is complicated, so price also wants expensive a lot.Under some specific occasion, for example between two wireless card reading base stations, exist simultaneously under at least two label card situation, system can utilize the positive semidefinite planning algorithm to orient the position with one of them label as base station processes.Particularly under the more situation of wireless identification tag card, for example tens, system will select some label card to regard the base station; Measure with other label cards; Reduce the computational complexity of system like this, abandoned the value that some obviously departs from simultaneously, improved the accuracy of system location.

One of ordinary skill in the art of the present invention are appreciated that; The above embodiment of the present invention is merely one of the preferred embodiments of the present invention; Be the length restriction; Here can not all execution modes of particularize, any enforcement that can embody claim technical scheme of the present invention is all in protection scope of the present invention.

It should be noted that; Above content is to combine concrete execution mode to further explain that the present invention did; Can not assert that embodiment of the present invention only limits to this; Under above-mentioned guidance of the present invention, those skilled in the art can carry out various improvement and distortion on the basis of the foregoing description, and these improve or distortion drops in protection scope of the present invention.

Claims

1. a wireless sensor network Precise Position System is characterized in that, said system comprises:

2. the system of claim 1 is characterized in that, said identification card specifically comprises:

3. system as claimed in claim 2 is characterized in that said receiving circuit comprises duplexer, filter, and said duplexer is used for controlling double antenna.

4. like claim 2 or 3 described systems, it is characterized in that said identification card also comprises the power saving management module, be used for that the transmitting power of regulating Subscriber Identity Module automatically realizes power saving management according to the power of the signal between identification card and the wireless card reading device.

5. a wireless sensor network accurate positioning method is characterized in that, said method comprises:

6. method as claimed in claim 5 is characterized in that, the bilateral bidirectional ranging algorithm of said employing SDS-TWR measurement specifically comprises with respect to the relative distance of each wireless card reading device separately:

7. like claim 5 or 6 described methods, it is characterized in that said server adopts the Semidefinite Programming algorithm computation to confirm that the coordinate position of each identification card specifically comprises according to above-mentioned relative distance:

8. method as claimed in claim 7 is characterized in that, the paired distance between the said node that utilizes known wireless card reading device or identification card position and measure comes the position of the every other identification card of computing network specifically to comprise:

\begin{matrix} {| | a_{k} - x_{i} | |}_{2}^{2} = p_{ki}^{2}; (k, j) &Element; E_{a}; - - - (5) \\ {| | x_{i} - x_{i} | |}_{2}^{2} = d_{H}^{2}; (i, j &Element; E_{n}), i < j, - - - (6) \end{matrix}

9. method as claimed in claim 8 is characterized in that, said method comprises:

\begin{matrix} (a_{k}; - e_{i}) {(a_{k}; - e_{i})}^{T} Z = p_{ki}^{2}; (k, j) &Element; E_{a}; - - - (7) \\ (0; e_{i} - e_{i}) {(0; e_{i} - e_{i})}^{T} Z = p_{H}^{2}; (i, j) &Element; E_{n} - - - (8) \end{matrix}

And with Y=X ^TX is lax to be Y>=X ^TX; Perhaps of equal valuely,

Z >=0 (being the Z positive semidefinite).