CN101858750A - Intelligent positioning navigation system for assisting in rescue in large-size buildings - Google Patents

Abstract

The invention provides an intelligent positioning navigation system for assisting in rescue in large-size buildings. Based on a wireless ranging sensor integrating radio frequency communication technology with ultrasonic ranging technology, the intelligent positioning navigation system with multiple functions such as accurate positioning, information interaction, information record, path planning, video and audio in one and the like is constructed and used for dealing with possible terrorist attack, fire and other emergencies in the large-size buildings and rescuing trapped crowds within the shortest time. The system comprises a wireless ranging sensor node array, a mobile terminal and a remote server which are preset in the building, wherein the mobile terminal receives ranging information of the sensor node array; and the terminal can be accurately positioned by a triangulation method as long as ranging data among more than three positioning nodes is acquired, so that an optimal path is quickly planned for a user and related information is sent to the server for a monitoring center to observe. In the aspect of hardware and software design, low power consumption, accurate calculation of distance and position, a conflict avoidance algorithm and the like are realized.

Description

Be used for the auxiliary intelligent positioning navigation system of rescue in the building

Technical field

Technical field relates to radio communication, technology for radio frequency and ultrasonic measuring distance technology, and dijkstra's algorithm comes realizing route planning and navigation and appropriate mathematical idea about modeling

Background technology

At present, in order to tackle various artificial, natural accidents, the safety of maintain social stability and people's lives and properties presses for and a kind ofly can carry out the equipment of location, navigation and information service in real time accurately under indoor conditions, with activities such as the search of supporting interior of building, rescues.Gps system is present the most frequently used wireless location system, but gps signal can not cover building inside.And low based on the wireless location mode resolution of mobile communications network, positioning error is big.Ultrasound wave is traditional range finding sensor, can be used for the location, but the information that ultrasound wave obtains is more single, is not easy to recognition objective, is difficult to support the continuous precise location in big zone.In order to solve the Target Recognition problem, it is a kind of possible scheme that technology for radio frequency and ultrasonic measuring distance technology are integrated.The design just is based on a kind of like this thinking, for intelligent construction designs a kind of positioned internal and navigational system, improving the security level of intelligent mansion, and for intelligent mansion provides better management platform, and can be under special circumstances for uses such as public security, fire-fighting, rescues.Below be that works compared with prior art have only outstanding technical characterstic and marked improvement.

Summary of the invention

Based on wireless sensor network, it is our scheme that technology for radio frequency and ultrasonic measuring distance technology are integrated.This project just is based on a kind of like this thinking, for intelligent construction designs a kind of positioned internal and navigational system, to improve the security level of intelligent mansion., and for intelligent mansion provides better management platform, and can be under special circumstances for uses such as public security, fire-fighting, rescues.The design has designed and Implemented a Precise Position System that is used for the local environment, comprises that portable terminal and one provide the server of service and are arranged in indoor some sensor nodes for terminal.

This system can provide mobile services such as accurate location, navigation and timely information interaction for holder terminal.Terminal can real-time positioning also be user's navigation; Terminal and server can carry out information interaction by message; Terminal can send to server end by wireless network so that indicate, dispatch by camera collection video and compression; Server end provides functions such as information service, user management for terminal.Sensor node is used for receiving and sending rf ultrasound's signal, to realize positioning function.Below be project innovative technology and technological difficulties:

(1) algorithm is avoided in conflict

If radiofrequency signal RF ₁, RF ₂With ultrasonic signal US ₁, US ₂ Represent road sign 1 and 2 information respectively in same detection road sign reception, RF carrier road sign id information, probe node can be discerned RF ₁And RF ₂, and US does not carry any information, probe node can't be distinguished US ₁And US ₂, so because road sign 1,2 is inharmonious, conflict as shown in Figure 7 interference, US here can appear ₂Be received in RF ₁The back is at US ₁Before, because detector can't be discerned US ₁And US ₂, probe node is RF ₁And US ₂Time interval t mistake be used as RF ₁And US ₁The time interval, thereby cause measuring distance incorrect.

Above-mentioned conflict divides can be divided into two kinds, and a kind of is external RF signal conflict to occur in the middle of same detection road sign transmitting RF and the US, as shown in Figure 1; Another kind is external US signal conflict to occur in the middle of same detection road sign transmitting RF and the US, as shown in Figure 2.

In order to tackle conflict shown in Figure 1, because radio frequency that the detection road sign sends and ultrasonic signal can disappear in the time at Dus, each surveys the at first idle r random time of road sign section, then, open radio frequency and receive extraneous radiofrequency signal, if Dus does not receive any signal in the time, and the radio frequency loading is idle, begins to send self radio frequency and ultrasonic signal.

In order to tackle conflict shown in Figure 2, the probe node internal maintenance has the time of reception of nearest two radio-frequency informations, when probe node receives ultrasonic signal, judges whether to receive in the time more than a radio-frequency information at Dus, if abandon more than one, otherwise computed range.

(2) sensor dormancy mechanism

Working current under the complete again mode of operation of each sensor node is 20mA, working current under energy-saving mode is 40uA, and the normal span of working current is 40uA---between the 20mA, running current is 2mA, sensor node is in energy-saving mode in most of times, only keeps the transmission that a serial peripheral interface SPI (Serial Peripheral Interface) is used for radiofrequency signal under this pattern.

(3) apart from accurate Calculation

Be based on a kind of apart from location technology based on the location of TDOA (The Differential time Of Arrival), typical case's representative is Active Bat, AHLos, these systems calculate the distance of guiding between node and the receiver by formula S=V* Δ T to differ from radiofrequency signal and hyperacoustic time of arrival, under normal room temperature and humidity, the speed V1 of sound is about 344m/s, and the speed V2 of light is about 3 * 10 ⁸M/s.Because V2 is far longer than V1, so have $S\&cong;\mathrm{<figure-callout\; id="1"\; label="V"\; filenames="DEST\_PATH\_HSB00000033168600013.png"\; state="\{\{state\}\}">V</figure-callout>}1\&CenterDot;T,$ Then according to the element in the distance set that collects is used curve that meets the demands of least square method match.(referring to Fig. 3)

(4) the accurate orientation problem of moving target

In conjunction with the professional knowledge of fields of measurement, utilize the principle of triangulation location, in case receive more than three the effective information that guides node (contents such as position coordinates, ID numbering that comprise node), just can calculate the current location of moving target.

Each guides the formula that concerns between node and the receiver: ${(x-x_i)}^2+{(y-y_i)}^2+{(z-z_i)}^2={\mathrm{<figure-callout\; id="2"\; label="d\; i"\; filenames="DEST\_PATH\_HSB00000033168600013.png"\; state="\{\{state\}\}">d</figure-callout>}}_i^{}$

Basis on location: $A\stackrel{\&RightArrow;}{x}=b,$ Wherein:

$A=\left[\begin{array}{ccc}2(x_1-x_0)& 2(y_1-y_0)& 2{(z_{m-1}-z_0)}^2\\ 2(x_2-x_0)& 2(y_2-y_0)& 2{(z_{m-1}-z_0)}^2\\ ...& ...& ...\\ 2{(x_{m-1}-x_0)}^2& 2{(y_{m-1}-y_0)}^2& 2{(z_{m-1}-z_0)}^2\end{array}\right]$ $\stackrel{\&RightArrow;}{x}=\left[\begin{array}{c}x\\ y\\ z\end{array}\right]$

$\stackrel{\&RightArrow;}{b}=\left[\begin{array}{c}{x}_1^2-x_0^2+{\mathrm{<figure-callout\; id="1"\; label="y"\; filenames="DEST\_PATH\_HSB00000033168600013.png"\; state="\{\{state\}\}">y</figure-callout>}}_1^2-y_0^2+{\mathrm{<figure-callout\; id="1"\; label="z"\; filenames="DEST\_PATH\_HSB00000033168600013.png"\; state="\{\{state\}\}">z</figure-callout>}}_1^2-z_0^2-({\mathrm{<figure-callout\; id="1"\; label="d"\; filenames="DEST\_PATH\_HSB00000033168600013.png"\; state="\{\{state\}\}">d</figure-callout>}}_1^2-d_0^2)\\ x_2^2-x_0^2+{\mathrm{<figure-callout\; id="2"\; label="y"\; filenames="DEST\_PATH\_HSB00000033168600013.png"\; state="\{\{state\}\}">y</figure-callout>}}_2^2-y_0^2+{\mathrm{<figure-callout\; id="2"\; label="z"\; filenames="DEST\_PATH\_HSB00000033168600013.png"\; state="\{\{state\}\}">z</figure-callout>}}_2^2-z_0^2-({\mathrm{<figure-callout\; id="2"\; label="d"\; filenames="DEST\_PATH\_HSB00000033168600013.png"\; state="\{\{state\}\}">d</figure-callout>}}_2^2-d_0^2)\\ ...\\ x_{m-1}^2-x_0^2+y_{m-1}^2-y_0^2+z_{m-1}^2-z_0^2-(d_{m-1}^2-d_0^2)\end{array}\right]$ m≥4

Triangulation location location Calculation formula:

$\stackrel{\&RightArrow;}{x}={\left(A^{T}A\right)}^{-1}{A}^T\stackrel{\&RightArrow;}{b}$

(5) path planning and navigation

Portable terminal is at the auxiliary optimal path of determining down from the current location to the target location of locating information.In conjunction with the data structure of designed map, the Dijistra algorithm of application enhancements, search arrives the shortest path of each position, according to the path of searching record, obtains shortest path.(effect such as Fig. 4)

(6) map design;

The electronic chart of portable terminal should provide a close friend's interface with auxiliary positioning and navigation for the holder, existing electronic chart is being not suitable for indoor 3 D stereo application aspect display styles and the storage format, therefore plan the electronic chart of self-defined XML form, be stored in the file of XML form, the user can select different files to be applied to different maps, read in internal memory by XML reader (self defined class), and map is presented at portable terminal.

(7) video acquisition and transmission

Camera is collected the data around the portable terminal, shows at portable terminal then, and recompression radios to remote server by 802.11, and server is decompressed data again, reproduces video.Compression algorithm adopts h263, and data are compressed into yuv format from rgb format.Effect such as Fig. 5 Fig. 6 before and after the actual transmissions.

Description of drawings

External RF signal conflict appears in the middle of Fig. 1 same detection road sign transmitting RF and the US

External US signal conflict appears in the middle of Fig. 2 same detection road sign transmitting RF and the US

Fig. 3 point curve comparison diagram that looses of finding range

Fig. 4 route programming result figure

Fig. 5 compresses preceding video interception

Fig. 6 compresses the rear video sectional drawing

Fig. 7 portable terminal actual effect figure

The positioning principle figure of Fig. 8 system

Fig. 9 guides the information of node and receiver to transmit synoptic diagram

Figure 10 mobile terminal software process flow diagram

Figure 11 server software process flow diagram

Figure 12 sensor node placement model

Embodiment

(1) the realization principle of real-time high-precision indoor positioning

As shown in Figure 8, in indoor environment, arrange that according to certain rules several wireless sensor nodes are as director (Beacon), each guides node all to have the function of radio communication function and transmission, received ultrasonic signal, have unique ID numbering, intra-node has been stored corresponding positional information and its ID number.

As shown in Figure 9, after moving target enters this zone, self-contained receiver (Listener) can get access to ID number, positional information of contiguous guide node by the mode of radio communication, and can obtain receiver by the mode of supersonic sounding and guide air line distance between the node, in case obtain the contiguous guide nodal information more than 3, according to the distance between position, each guide node and the receiver of each guide node, utilize the triangle positioning principle, just can calculate the receiver current location of moving target just.Receiver is responsible for identification and is guided node and range finding, then these information is sent to the mobile terminal device that is attached thereto, and is finished the location Calculation of more complicated by the stronger portable terminal of computing power.

(2) sensor node placement model

(L is adjacent two and guides internodal distance according to L=Htan θ at interior of building in advance, H is the height in room, θ is hyperacoustic field angle) layout wireless distance finding sensor node array, after treating that wireless sensor network disposition finishes, open the server end total system and get final product normal operation.As shown in figure 12.

(3) mobile terminal software flow process

At first carry out basic initialization, the especially initialization of related hardware module and parameter setting during the mobile terminal software operation.Enter the master routine circulation then.Next start corresponding module.The main flow chart of mobile terminal software is described as follows as shown in figure 10:

System initialization: the display model of initialization basic display information and the basic control of program.

Master routine inlet: wait for after the program initialization that the user operates.

Main interface module: import map file information and be stored in the self-defined structure and demonstration; Wait for user's input command.

Navigation module: the positional information that Beacon transmits around being responsible for receiving, read the Listener serial data then, convert map reference to.

Video module: be responsible for the collection site image, and compress, pass to mixed-media network modules mixed-media.

Mixed-media network modules mixed-media: be responsible for to send video image after the compression to server end, the exchange of information between server and the portable terminal.

(4) server software flow process

Order according to the keeper imports map, user management, management map, information service.After finishing respective service, judge whether to withdraw from,, otherwise be back to state after the initialization if confirm to withdraw from then withdraw from.As Figure 11

Start server, the user needs to send message request to server end after opening portable terminal, is proved to be successful the back and provides related service for it, otherwise provide the reason of makeing mistakes.

User management: checking user, management application user etc.

Information service: receive message and send message, reply.

Consumer positioning: the position that shows designated user.The positional information of sending according to the user positions, and mark comes out on the server end interface.Support the convergent-divergent that map shows.

Management map: download map, import map, support to specifying the importing of map.

Claims (8)

1. one kind is used for the auxiliary intelligent positioning navigation system of rescue in the building, this system comprises three ingredients of wireless distance finding sensor node array, portable terminal, remote server end that are arranged in interior of building in advance, it is characterized in that the location navigation flow process is made up of following steps:

Step 1: self-contained receiver gets access to ID number, positional information of contiguous guide node by the mode of radio communication, and obtains receiver and guide distance between the node in conjunction with the mode of supersonic sounding;

Step 2: if obtain and three above location nodes (position coordinates of each location node all is to be recorded in intra-node in advance) between ranging data, just can calculate realize the on-site accurate location of holder terminal by triangulation location;

Step 3: can be rapidly for user's planning from current location to the optimal path of setting the destination, adopt camera to collect field scene information around the portable terminal, send to server after the compression and watch for Surveillance center; Server end provides functions such as user management, guiding commander for terminal.

2. by the described system of claim 1, it is characterized in that arranging the wireless distance finding sensor node array at interior of building according to L=Htan (L is adjacent two and guides internodal distance that H is the height in room, is hyperacoustic field angle) in advance.

3. by the described system of claim 1, it is characterized in that getting access to ID number, positional information of contiguous guide node, and obtain receiver and guide distance between the node in conjunction with the mode of supersonic sounding by the mode of radio communication.

4. by the described system of claim 1, it is characterized in that, the electronic chart of self-defined XML form, elements such as sign floor, room, flex point, the user can select to load and show different maps.

5. by the described system of claim 1, it is characterized in that being based on apart from location technology, according to the element in the distance set that collects is used curve that meets the demands of least square method match, range accuracy can reach centimetre-sized.

6. by the described system of claim 1, it is characterized in that utilizing 802.11 wireless networks to realize wireless telecommunications and video transmission.Adopting in the process of video transmission with the frame is that unit compresses, and reaching behind the server again, decompress(ion) reproduces video.

7. by the described system of claim 1, it is characterized in that and to determine an optimal path from the current location to the assigned address by path planning.

8. by the described system of claim 1, it is characterized in that using one or more levels relay station between base station and user, to carry out data forwarding by wireless mode.

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