WO2014000469A1 - 实时定位方法及定位服务器 - Google Patents

实时定位方法及定位服务器 Download PDF

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Publication number
WO2014000469A1
WO2014000469A1 PCT/CN2013/072646 CN2013072646W WO2014000469A1 WO 2014000469 A1 WO2014000469 A1 WO 2014000469A1 CN 2013072646 W CN2013072646 W CN 2013072646W WO 2014000469 A1 WO2014000469 A1 WO 2014000469A1
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WO
WIPO (PCT)
Prior art keywords
signal
information
terminal
signal strength
positioning
Prior art date
Application number
PCT/CN2013/072646
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English (en)
French (fr)
Inventor
张军平
蒋文婷
Original Assignee
华为技术有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from CN201210218756.4A external-priority patent/CN103517407B/zh
Application filed by 华为技术有限公司 filed Critical 华为技术有限公司
Publication of WO2014000469A1 publication Critical patent/WO2014000469A1/zh

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W64/00—Locating users or terminals or network equipment for network management purposes, e.g. mobility management
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S5/00—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations
    • G01S5/02—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations using radio waves
    • G01S5/0252—Radio frequency fingerprinting
    • G01S5/02521—Radio frequency fingerprinting using a radio-map
    • G01S5/02524—Creating or updating the radio-map
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S5/00—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations
    • G01S5/0009—Transmission of position information to remote stations
    • G01S5/0018—Transmission from mobile station to base station
    • G01S5/0036—Transmission from mobile station to base station of measured values, i.e. measurement on mobile and position calculation on base station

Definitions

  • the present invention relates to the field of positioning technologies, and in particular, to a real-time positioning method and a positioning server. ⁇ Background technique ⁇
  • RTS Real Time Location System
  • ⁇ Time of Arrival
  • TDOA Time Difference of Arrival
  • RSS Received Signal Strength
  • the TOA positioning technique needs to measure the propagation time of the transmitting node to the target, calculate the distance based on the known signal propagation speed and the measured propagation time, and obtain the target position.
  • the specific implementation scheme is as follows:
  • the TOA positioning method In order to locate the target, the TOA positioning method needs to obtain the distance from the at least 3 transmitting nodes to the target.
  • the time required for a transmitting node to reach the target can be calculated, and the transmission can be calculated from the transmitting.
  • the distance the node reached the target As shown in Fig. 1, the distances of the three transmitting nodes P1, P2 and P3 to the target are Dl, D2 and D3, respectively.
  • the most intuitive way to determine the target position is to find the intersection of the three circles with the radius of the distance as the center of the emission point. As shown in the figure, the intersection point is T, that is, the intersection point T is the position of the target.
  • TOA-based algorithms to determine the position of the target such as CN (Closest-Neighbor) and Residual Weighting (RWGH).
  • Time synchronization requirements are high, that is, all hair is required
  • the shoot and receive nodes maintain accurate time synchronization. Therefore, higher power consumption and hardware configuration are required.
  • the two transmitting nodes simultaneously transmit signals simultaneously, and the distance is calculated by measuring the time difference between the two signals reaching the target.
  • the specific implementation plan is as follows:
  • the TDOA locates the target by measuring the time difference between the radio signals of different transmitting nodes reaching the target being located.
  • the time difference is directly converted into a distance difference based on the known propagation speed.
  • the distance difference between the transmitting nodes P1 and P2 to the target T is P 1; 2 , the position of the target T will be in focus with Pl, P2, and the distance difference between the two focal points is 3 ⁇ 4 P 1; On the hyperbola.
  • the distance difference between the transmitting nodes P1 and P3 to the target T is P 2 , 3 , the position of the target T will be on the hyperbola with the P 2 , 3 being the focus of the difference between the two focal points and the distance between the two focal points.
  • the position of the target can be estimated by the intersection of two or more sets of hyperbolic curves. As shown in Fig. 2, since the distance difference should be positive, the intersection of the multiple sets of hyperbolic curves should fall on the curve of the X positive semi-axis interval. The intersection point T meets the requirements, so T is the target position.
  • TDOA positioning technology does not need to perform global clock synchronization for all nodes like TOA positioning technology, but still needs to synchronize the clock of the transmitting node.
  • the hardware and power consumption requirements High, costly.
  • the multipath propagation and shadowing effects of the signal limit the accuracy.
  • the principle of RSS-based positioning technology is to use the law that the signal will decay during the propagation process, and convert the transmission loss into distance according to the theoretical and empirical signal attenuation model. For example, as shown in FIG. 3, the signal strengths transmitted by the transmitting nodes P1, P2, and P3 are known, the signal strength at the target T is measured, and the distance between the transmitting node and the target is calculated according to the attenuation value of the signal, thereby determining that the signal is positioned. The location of the target. In indoor environments, due to multipath propagation and obstacles, signal strength tends to change with the environment, resulting in reduced positioning accuracy.
  • the embodiment of the invention provides a real-time positioning method and a positioning device, which can utilize a received message
  • the positioning technology of the intensity is used for positioning, and at the same time, the influence of the environment on the received signal strength is reduced in the real-time positioning process, and the positioning accuracy is improved.
  • a method for real-time positioning includes: acquiring signal strength and direction information of a first signal sent by an access point, where a signal strength and direction information of the first signal is sent by the terminal to be sent to the access point. Locating a signal; finding, in the calibration information, a direction of the second signal that is the same as or closest to the direction of the first signal, the calibration information including a plurality of sets of directions, signal strengths, and relationship data between the positions, wherein The direction of the signal and the direction of the second signal are directions when the terminal is to be transmitted or received; if the direction of the second signal having the same or closest direction as the direction of the first signal is found in the calibration information, in the calibration information Selecting the obtained signal strength associated with the direction of the second signal; if the selected signal strength associated with the direction of the second signal is the same as or closest to the signal strength of the first signal, obtaining the direction of the second signal, Location information associated with signal strength; sending location information to the recipient to complete the pre-determination The positioning of the end
  • a real-time positioning apparatus including: a first acquiring module, configured to acquire signal strength and direction information of a first signal sent by an access point, where a signal strength and direction information of the first signal is to be located a positioning signal sent by the terminal to the access point; a searching module, configured to search, in the calibration information, a direction of the second signal that is the same or closest to the direction of the first signal, the calibration information includes multiple sets of directions and signal strengths measured in advance And the relationship data between the locations, where the direction of the first signal and the direction of the second signal are directions when the terminal is to be sent or received by the positioning terminal; and the selecting module is configured to search for the calibration information in the search module.
  • the signal strength associated with the direction of the second signal is selected in the calibration information; the second obtaining module is used to select the selected module When the signal strength associated with the direction of the two signals is the same as or closest to the signal strength of the first signal Acquires a second signal direction, position information associated with the signal strength; transmitting means for transmitting the location information to the receiving side, a predetermined terminal to complete the positioning.
  • the embodiment of the present invention is characterized in that it is susceptible to environmental influences when positioning based on the received signal strength.
  • the pre-measurement is included first.
  • Calibration information of the plurality of sets of directions, signal strengths, and relationship data between the locations is stored in the location server.
  • the location server obtains signal strength and direction information of the first signal sent by the access point, where the signal strength and direction information of the first signal is sent by the terminal to be located. Then, the signal strength and direction information of the first signal are fingerprint-aligned with the calibration information.
  • Obtaining location information associated with the direction and signal strength of the second signal, and obtaining the location information is a location coordinate of the terminal to be located, and transmitting the location information to the receiver to complete positioning of the terminal to be located.
  • the direction of the first signal and the direction of the second signal are directions when the terminal is to be transmitted or received.
  • FIG. 1 is a schematic diagram of a prior art arrival time positioning technique
  • FIG. 2 is a schematic diagram of a prior art arrival time difference positioning technique
  • FIG. 3 is a schematic diagram of a prior art receiving signal strength localization technique
  • FIG. 4 is a schematic diagram of a network structure of an embodiment of a real-time positioning system according to the present invention.
  • FIG. 5 is a system block diagram of the positioning system shown in Figure 4.
  • FIG. 6 is a schematic flow chart of an embodiment of a real-time positioning method according to the present invention.
  • FIG. 7 is a schematic structural view of an embodiment of a real-time positioning device of the present invention.
  • the embodiment of the invention adopts a scheme for measuring signal strength, that is, the positioning technology of RSS to perform positioning, and at the same time, the RSS positioning technology is susceptible to environmental changes and indoor multipath effects, and the defect is improved, the environmental impact is reduced, and the receiving is eliminated.
  • Signal Strength Indicator Receiveived Signal Strength
  • RSSI Received Signal Strength
  • FIG. 4 is a schematic diagram of a network structure of an embodiment of a real-time positioning system according to the present invention.
  • the real-time positioning system includes: a positioning server 41, an access point (Access Point, ⁇ ) 42, and a desire The terminal 43 and the switch 44 are located.
  • the real-time positioning system further includes: a positioning display terminal 45.
  • the number of access points 42 is three or more; the terminal 43 to be located is a mobile terminal configured with a gyroscope; the switch 44 can be replaced with an Ethernet hub.
  • the gyroscope is also called the angular velocity sensor, and the measured physical quantity is the deflection, that is, the rotational angular velocity when tilting.
  • the operation flow of the real-time positioning system is that the positioning server 41 and the access point 42 first form a local area network through the switch 44 or the Ethernet hub, and then the positioning terminal 43 accesses the positioning server 41 by accessing the access point 42 within the local area network.
  • the location server 41 locates the terminal 43 to be located according to the signal strength information sent by the access terminal 42 to be located, and sends the location information to the location server 45 for query by the user.
  • IEEE 802.1 1 is the most authoritative standard for wireless local area networks.
  • wireless local area networks complying with the 802.11 protocol utilize existing WLAN devices in the room for positioning.
  • the connection between the parts of the system is such that the plurality of access points 42 are connected to the location server 41 through the switch 44 in a wired manner.
  • the location terminal 43 accesses the network in a wireless manner by accessing the access point 42 to locate the display terminal 45. It is connected to the location server 41 in a wired or wireless manner.
  • each part of the positioning system is that the positioning server 41 is used to store the calibration information, and the positioning algorithm is run to obtain the position information of the positioned device.
  • the positioning display terminal 45 is a PC or other portable device that can access the wireless local area network, and is used to access the positioning server 41 to view the result of the positioning.
  • the positioning terminal 43 is a device that needs to be positioned in the positioning system, and may be a customized tag, a portable device or a WIFI mobile phone.
  • the positioning system can locate the position of the person or the item, and the person only needs to carry the mobile terminal, etc., and only the tag is placed on the item, and the positioning system can be used for positioning.
  • the embodiment of the invention is based on fingerprinting of RSS, including two stages of field measurement and real-time positioning.
  • FIG. 5 is a system block diagram of the positioning system shown in FIG. 4.
  • the positioning server 41 includes: a calibration unit 411, a database 412, a positioning engine 413, and a data processing and filtering unit 414.
  • the positioning process of the positioning system shown in Figure 5 is: in the field measurement phase, field measurement is performed to obtain field measurement data, such as RSSI information, and the field measurement data is recorded in a file, and the field measurement data in the file is stored in the positioning server.
  • the calibration unit 411 in the location server 41 calibrates the field test data to obtain the calibrated RSSI information (RSSI probability model).
  • RSSI probability model calibrated RSSI information
  • the location server 41 acquires RSSI information in real time through the wireless local area network, and processes and filters the data obtained in real time through the data processing and filtering unit 414.
  • the positioning engine 413 processes and filters the data and the fingerprint database.
  • the RSSI information is compared, the location of the terminal 43 to be located is calculated, and the location information is recorded in the database 412.
  • the location server 41 After the user submits a request for querying the location or other event through the webpage on the location display terminal 45, the location server 41 responds to the request, queries the database 412, and returns the query result to the location display terminal 45 for viewing by the user.
  • the calibration unit 411 retrieves the field measurement data from the database 412 and performs calibration, establishes a fingerprint database, and then sends the corrected information to the positioning engine. 413. After the location engine 413 estimates the location information, the location information is stored in the database 412.
  • the calibration unit 411 sends the information in the constructed fingerprint database to the positioning engine 413, and after the positioning engine 413 estimates the location information,
  • the location coordinates are stored in database 412.
  • FIG. 6 is a schematic flowchart of an embodiment of a real-time positioning method according to the present invention.
  • the real-time positioning method in this embodiment includes the following steps:
  • Step 601 Obtain signal strength and direction information of the first signal sent by the access point, where The signal strength and direction information of the first signal is a positioning signal that is sent by the terminal to the access point.
  • the access point collects the signal strength information of the terminal to be located.
  • uplink positioning is used. The specific process is as follows:
  • probe request To locate the terminal to periodically send a probe request (probe request);
  • the role of the probe request to send the probe request is to use the probe request frame to scan the 802.11 network in the area according to the 802.11 protocol.
  • the sending period of the probe request depends on the terminal to be located. If the gyroscope is set on the positioning terminal, the gyroscope can measure the direction information of the terminal to be located, and the positioning terminal sends the measured direction information to the positioning server.
  • the AP in the same local area network as the terminal to be located detects the signal strength of the received probe request
  • the C AP sends the detected signal strength and the corresponding AP flag to the positioning server. Among them, to determine the location of the terminal to be located, three or more APs are required to send their detected signal strength to the positioning server.
  • Step 602 Search, in the calibration information, a direction of the second signal that is the same as or closest to the direction of the first signal, where the calibration information includes a plurality of sets of directions, signal strengths, and relationship data between the positions, where The direction of the signal and the direction of the second signal are directions when the terminal is to be transmitted or received;
  • the process of obtaining calibration information is as follows:
  • the field measurement data includes the position coordinates of the measurement point, the signal strength of the terminal receiving the second information, and the direction information of the second signal.
  • the specific acquisition method of the field measurement data is as follows:
  • the calibration information is generated by using a downlink calibration method, and the flow is: A. Send a beacon (beacon);
  • the AP periodically sends beacons to all terminals in its LAN area.
  • the specific measurement points are randomly selected by the user. For better measurement results, the distribution of specific measurement points should be relatively uniform.
  • the signal to be located is used to detect the signal strength of the downlink signal beacon frame sent by the AP, and the direction information of the downlink signal sent by the AP is measured by the gyroscope;
  • the terminal to be positioned can be measured multiple times in a certain direction to obtain a set of signal strength and direction information.
  • the direction in which the terminal is to be rotated can be rotated to obtain multiple sets of signal strength and direction information. To achieve measurements in multiple directions for each AP.
  • the positioning terminal stores the position coordinate information of the measuring point, the measured signal strength and the direction information into an XML file;
  • the XML file includes position coordinate information under multiple measurement points, measured signal strength and direction information, and signal strength and direction information in multiple directions under the same measurement point.
  • Step 603 If it is found that there is a direction of the second signal that is the same or the closest to the direction of the first signal in the calibration information, the signal strength associated with the direction of the second signal is selected in the calibration information;
  • the calibration RSSI information in multiple directions for each AP is recorded. As shown in Table 1, the RSSI information of n APs at n angles is measured, and the RSSI information collection is calibrated.
  • the positioning server obtains the direction information from the terminal to be located, and selects the calibration RSSI information in the appropriate direction from the fingerprint database to compare and calculate the position coordinates of the terminal.
  • the calibration RSSI information in which direction is selected is divided into two cases. One case is to search for the same direction as the terminal to be located in the direction set A shown in Table 1, as the direction angle of the terminal 1 in Table 2 is ⁇ . When the value of ⁇ is found to be equal to ⁇ in the set ⁇ , the aligned RSSI information at the ⁇ angle is selected for comparison when the comparison is performed.
  • AP represents the access point to which the signal is sent;
  • ⁇ represents the angle;
  • R represents the received signal strength in different directions of the access point.
  • the direction set ⁇ cannot be searched for the same direction as the terminal to be located.
  • the direction angle of the terminal 2 in Table 2 is ⁇ , and ⁇ ⁇ ( ⁇ 2, ⁇ 3) is found.
  • ⁇ and ⁇ respectively represent the direction information sent by the terminal in real-time positioning.
  • Step 604 if the selected signal strength associated with the direction of the second signal is the same as or closest to the signal strength of the first signal, acquiring location information associated with the direction and signal strength of the second signal; When performing the positioning comparison, if the same calibration RSSI value is matched, the position corresponding to the calibration RSSI value can be considered as a candidate position. If matching to multiple candidate locations, the screening is continued and the closest candidate location is estimated as the final location.
  • Step 605 Send location information to the receiver to complete positioning of the pre-determined terminal.
  • the present invention can also perform positioning in a downlink positioning manner in the real-time positioning phase. Specifically, the beacon frame detection signal strength RSSI sent by the terminal through the surrounding AP is determined, and at the same time, the gyroscope on the terminal is to be measured to measure the direction information, for example, the north is determined to be the positive direction, and the direction of the terminal to be positioned is measured to be 30 degrees. After the terminal is located to obtain the required RSSI information and direction information, the information is transmitted to the positioning server through the wireless local area network.
  • the positioning server After receiving the RSSI information and the direction information, the positioning server filters out the RSSI information of the AP that does not belong to the positioning system, and then compares the RSSI information collected in real time after filtering with the calibration information in various directions in the fingerprint database. The position coordinates of the terminal.
  • the present invention provides a real-time positioning method based on a gyroscope.
  • the gyroscope is used to provide auxiliary direction information, and the multi-directional data acquisition is used to locate the terminal to be located.
  • the positioning terminal is rotated at a plurality of angles at the same position, and the RSSI information of the beacons sent by the plurality of APs is collected for each angle, and the direction of each rotation of the terminal to be positioned is also measured using the gyroscope. .
  • the direction information and the RSSI information are recorded together in an XML file.
  • the positioning server collects the RSSI information of the terminal to be located and the direction information measured by the gyroscope in real time, and processes and filters the real-time collected information to compare with the stored corrected RSSI information in multiple directions. Calculate the position coordinate information of the terminal to be located.
  • the present invention is compared with the existing RSS positioning technology, and the improvement is that the existing RSS positioning technology is susceptible to environmental changes and multipath effects, such as: door switches and human walking.
  • the present invention uses a gyroscope to assist in measuring the direction information in the positioning system, and uses the measured RSSI information in each direction to more accurately locate the terminal position. For example: In the field test phase, multiple measurements in multiple directions are used to reduce the influence of environmental factors and to measure more accurate RSSI information; In the real-time positioning phase, adding the direction information of the terminal to be located can more accurately compare the RSSI information to calculate a more accurate position.
  • the real-time positioning method of the present invention can also be applied to a wireless sensor network for indoor or outdoor positioning.
  • Its positioning system includes a fixed infrastructure portion and a movable terminal portion, which are referred to as anchor nodes and blind nodes, respectively.
  • the anchor nodes are usually connected to the positioning server through ZigBee or gateway nodes to form a large network.
  • FIG. 7 is a schematic structural diagram of an embodiment of a real-time positioning device according to the present invention.
  • the real-time positioning device includes: a first obtaining module 71, a searching module 72, a selecting module 73, a second obtaining module 74, a sending module 75, and receiving Module 76, storage module 77, and calibration module 78.
  • the first obtaining module 71, the searching module 72, the selecting module 73, the second obtaining module 74, and the sending module 75 all belong to the positioning server 41 shown in FIG.
  • the search module 72 and the selection module 73 perform the same work as the positioning engine 413 shown in FIG.
  • the first obtaining module 71 is configured to obtain signal strength and direction information of the first signal sent by the access point, where the signal strength and direction information of the first signal is a positioning signal that is sent by the terminal to the access point; And receiving signal strength information of the flag and the detected uplink signal from the at least three access points, and acquiring direction information from the terminal to be located, where the uplink signal is at least three access points And receiving, respectively, an uplink signal of the terminal to be located; or receiving signal strength information and corresponding direction information of the downlink signal of the at least three access points detected by the terminal to be located.
  • the searching module 72 is configured to search, in the calibration information, a direction of the second signal that is the same as or closest to the direction of the first signal, where the calibration information includes a plurality of sets of directions, signal strengths, and relationship data between the positions, where The direction of the first signal and the direction of the second signal are sent or received by the terminal to be located The direction when the signal is received;
  • the selecting module 73 is configured to: when the searching module 72 searches for the direction of the second signal that is the same or the closest to the direction of the first signal, select the searched signal associated with the direction of the second signal in the calibration information.
  • the second obtaining module 74 is configured to acquire, when the signal strength associated with the direction of the second signal selected by the selecting module 73 is the same as or closest to the signal strength of the first signal, acquire the direction and signal strength associated with the second signal. location information;
  • the sending module 75 is configured to send the location information to the receiver to complete the positioning of the pre-targeting terminal.
  • the sending module 75 sends the location information to the receiving party.
  • the sending module 75 first sends the location information to the database 412 shown in FIG. 5, and then The database 412 then returns the location information to the location display terminal 45 shown in FIG. 5 in accordance with the location request of the user.
  • the receiving module 76 is configured to acquire field measurement data from the terminal, where the field measurement data includes location coordinates of the measurement point, signal strength of the terminal receiving the second information, and direction information of the second signal, and select an area to be located.
  • the plurality of measurement points are obtained by performing field measurement by using the terminal; wherein the field measurement data includes a signal strength of the downlink signal detected by the terminal in multiple directions at each measurement point, a corresponding direction, and position information at the measurement point.
  • the storage module 77 is configured to store the obtained field test data in a database; specifically, the field test data obtained in the file is recorded into a file, and the field test data in the file is stored in a database of the location server, where the file may be Is an extensible language file.
  • the calibration module 78 is configured to calibrate the field test data stored in the database to obtain calibration information.
  • the working process of each module is: in the real-time positioning process, the first obtaining module 71 first obtains the signal strength and direction information of the first signal sent by the access point, and then obtains the first information through the searching module 72 and the selecting module 73.
  • the signal strength and direction information of the second signal of the signal having the same or the closest direction as the direction information, after obtaining the above result, the second obtaining module 74 acquires the position information associated with the direction and signal strength of the second signal, and
  • the location information is sent to the receiver through the sending module 75, and the positioning of the pre-determined terminal is completed.
  • the signal strength, the direction information, and the location information of the second signal belong to the calibration information in the positioning server, and the obtaining manner is: first, the receiving module 76 selects multiple measurement points in the area to be located and performs field measurement by using the terminal to obtain The field measurement data is then stored in the database of the location server by the storage module 77, and the calibration data stored in the database is calibrated by the calibration module 78 to obtain calibration information.
  • the embodiment of the present invention is characterized by being susceptible to environmental influences when positioning based on the received signal strength.
  • the first set includes multiple pre-measured directions, signal strength, and The calibration information of the relationship data between the locations is stored in the location server.
  • the location server obtains signal strength and direction information of the first signal sent by the access point, where the signal strength and direction information of the first signal is sent by the terminal to be located. Then, the signal strength and direction information of the first signal are fingerprint-aligned with the calibration information.
  • Obtaining location information associated with the direction and signal strength of the second signal, and obtaining the location information is a location coordinate of the terminal to be located, and transmitting the location information to the receiver to complete positioning of the terminal to be located.
  • the direction of the first signal and the direction of the second signal are directions when the terminal is to be transmitted or received.
  • the present invention can be implemented by means of software plus a necessary general hardware platform, and of course, can also be through hardware, but in many cases the former is a better implementation.
  • the technical solution of the present invention which is essential or contributes to the prior art, may be embodied in the form of a software product stored in a storage medium such as a floppy disk, a hard disk, a flash memory or Read-only memory, etc., includes instructions for causing a terminal device to perform the methods set forth in various embodiments of the present invention.

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Abstract

本发明公开了一种实时定位方法及定位服务器，所述定位方法包括：获取访问接入点发送的第一信号的信号强度与方向信息，其中，所述第一信号的信号强度与方向信息为欲定位终端发送至访问接入点的定位信号；在定位服务器的校准信息中查找，若存在与所述第一信号的方向及信号强度相同或最接近的第二信号的方向及信号强度；则获取与第二信号的方向、信号强度相关联的位置信息，其中，所述第一信号的方向和第二信号的方向为欲定位终端发送或接收信号时的方向；向接收方发送所述位置信息，完成预定位终端的定位。通过上述方式，能够提高定位的准确性。

Description

实时定位方法及定位 Λ良务器
【技术领域】
本发明涉及定位技术领域， 特别是涉及一种实时定位方法及定位服务器。 【背景技术】
随着无线局域网的普及，室内的实时定位系统（ Real Time Location system , RTLS )在近几年来变得流行。 它的应用前景十分广泛， 涉及到各个行业。 如： 可应用于在医院内定位医务人员或者设备， 可应用于在仓库定位储存的产品， 还可应用于在一栋大楼内定位贵重物品。
各种利用无线局域网的定位技术被用来进行室内定位， 根据定位方法的不 同， 现有主要技术有到达时间 （Time of Arrival , ΤΟΑ )、 到达时间差 （Time Difference of Arrival, TDOA )和基于接收的信号强度（ Received Signal Strength , RSS )的定位技术。 发明人经过长期研究发现， 以上三种定位技术均存在不同技 术缺陷， 如下描述：
TOA定位技术需要测量出发射节点到目标的传播时间， 根据已知的信号传 播速度和测量到的传播时间， 计算出距离， 得到目标的位置。 具体实现方案如 下：
为了定位到目标的位置， TOA定位方法需要得到至少 3个发射节点到目标 的距离， 在已知信号传播速度的情况下， 测量某个发射节点到达目标所需要的 时间，可计算出从该发射节点到达目标的距离。如图 1所示，三个发射节点 Pl、 P2和 P3其分别到达目标的距离为 Dl、 D2和 D3。在计算出至少三个距离之后， 最直观的确定目标位置的方法是求以发射点为圓心， 以距离为半径的三个圓的 交点。 如图所示， 交点为 T, 即该交点 T就是目标的位置。 除了这种几何算法， 还有其它基于 TOA 的算法来确定目标的位置， 如： CN ( Closest-Neighbor )和 残差加权 ( Residual Weighting, RWGH )等。
对于 TOA定位方法， 其存在的缺陷为： 时间同步要求高， 即需要所有的发 射和接收节点保持精确的时间同步。 因此， 需要较高的功耗和硬件配置。 在室 内的环境下， 无线电的传播存在多径效应， ^艮难找到从发射节点到目标的瞄准 线， 因此， 定位精度会有所降低。
对于 TDOA定位技术， 则主要是由两个发射节点同时发送信号， 通过测量 出两信号到达目标的时间差来计算距离。 具体实现方案如下：
TDOA通过测量不同发射节点的无线电信号到达被定位目标的时间差， 来 对目标进行定位。 根据已知的传播速度， 直接把时间差转化为距离差。 如图 2 所示，发射节点 P1和 P2到目标 T的距离差为 P1;2时，目标 T的位置会在以 Pl、 P2为焦点、 与两焦点距离差为常 ¾ P1;2的双曲线上。 发射节点 P1和 P3到目标 T的距离差为 P2,3时， 目标 T的位置会在以以 P2、 P3为焦点、 与两焦点距离差 为常数 P2,3的双曲线上。通过两组或者多组双曲线相交，可以估算出目标的位置， 如图 2所示， 由于距离差应当为正值， 所以多组双曲线的交点应当落在 X正半 轴区间的曲线上， 交点 T符合要求， 因此， T为目标位置。
对于 TDOA定位技术，其存在的缺陷为： TDOA定位技术虽不像 TOA定位 技术那样需要对所有节点进行全局的时钟同步， 但仍需要对发射节点进行时钟 同步， 同样， 对硬件和功耗的要求高， 成本大。 信号的多径传播和阴影效应使 得精度提高受到限制。
而基于 RSS的定位技术的原理则是利用信号在传播过程中会出现衰减的规 律， 根据理论的和经验的信号衰减模型将传输损耗转化为距离。 如： 如图 3 所 示， 已知发射节点 Pl、 P2和 P3发射的信号强度，测量出目标 T处的信号强度， 根据信号的衰减值计算出发射节点与目标的距离， 从而确定出被定位目标的位 置。在室内环境中， 由于多径传播和障碍物，信号强度往往随着环境发生变化， 导致定位精度降低。
【发明内容】
本发明实施例提供一种实时定位方法及定位装置， 能够利用基于接收的信 号强度的定位技术进行定位， 同时在实时定位过程中降低环境对接收信号强度 的影响， 提高定位精度。
一方面提供一种实时定位方法， 包括： 获取访问接入点发送的第一信号的 信号强度与方向信息， 其中， 第一信号的信号强度与方向信息为欲定位终端发 送至访问接入点的定位信号； 在校准信息中查找与第一信号的方向相同或最接 近的第二信号的方向， 校准信息包括预先测量的多组方向、 信号强度以及位置 之间的关联关系数据， 其中， 第一信号的方向和第二信号的方向为欲定位终端 发送或接收信号时的方向； 若查找得到校准信息中存在与第一信号的方向相同 或最接近的第二信号的方向， 则在校准信息中选取查找得到的与第二信号的方 向关联的信号强度； 若选取得到的与第二信号的方向关联的信号强度与第一信 号的信号强度相同或最接近， 则获取与第二信号的方向、 信号强度相关联的位 置信息； 向接收方发送位置信息， 完成预定位终端的定位。
另一个方面提供一种实时定位装置， 包括： 第一获取模块， 用于获取访问 接入点发送的第一信号的信号强度与方向信息， 其中， 第一信号的信号强度与 方向信息为欲定位终端发送至访问接入点的定位信号； 查找模块， 用于在校准 信息中查找与第一信号的方向相同或最接近的第二信号的方向， 校准信息包括 预先测量的多组方向、 信号强度以及位置之间的关联关系数据， 其中， 第一信 号的方向和第二信号的方向为欲定位终端发送或接收信号时的方向； 选取模块， 用于在查找模块查找得到校准信息中存在与第一信号的方向相同或最接近的第 二信号的方向时， 在校准信息中选取查找得到的与第二信号的方向关联的信号 强度； 第二获取模块， 用于在选取模块选取得到的与第二信号的方向关联的信 号强度与第一信号的信号强度相同或最接近时， 获取与第二信号的方向、 信号 强度相关联的位置信息； 发送模块， 用于向接收方发送位置信息， 完成预定位 终端的定位。
区别于现有技术的情况， 本发明实施例针对基于接收的信号强度的定位技 术进行定位时， 易受环境影响的特点， 在实时定位前， 首先将包括预先测量的 多组方向、 信号强度以及位置之间的关联关系数据的校准信息存储于定位服务 器中。 在实时定位时， 定位服务器获取访问接入点发送的第一信号的信号强度 与方向信息， 其中， 第一信号的信号强度与方向信息为欲定位终端发送。 然后 将第一信号的信号强度与方向信息与校准信息进行指纹比对， 若校准信息中存 在与第一信号的方向信息与信号强度相同或最接近的第二信号的方向信息与信 号强度， 则获取与第二信号的方向、 信号强度相关联的位置信息， 获取的位置 信息为欲定位终端的位置坐标， 并将该位置信息发送至接收方， 完成欲定位终 端的定位。 其中， 第一信号的方向和第二信号的方向为欲定位终端发送或接收 信号时的方向。 通过上述方式， 能够利用基于接收的信号强度的定位技术进行 定位， 同时在实时定位过程中降低环境对接收信号强度的影响。
【附图说明】
图 1是现有技术一种到达时间定位技术的示意图；
图 2是现有技术一种到达时间差定位技术的示意图；
图 3是现有技术一种接收信号强度定位技术的示意图；
图 4是本发明实时定位系统一实施例的网络结构示意图；
图 5是图 4所示定位系统的系统框图；
图 6是本发明实时定位方法一实施例的流程示意图；
图 7是本发明实时定位装置一实施例的结构示意图。
【具体实施方式】
下面结合附图和实施例对本发明进行详细说明。
由于 TOA和 TDOA定位技术对时钟同步要求高， 因此不适合室内低成本、 低功耗的定位。 本发明实施例采用测量信号强度的方案， 即 RSS的定位技术来 进行定位， 同时对 RSS定位技术易受环境变化和室内多径效应的影响， 这一缺 陷进行改善， 降低环境影响， 消除接收的信号强度指示（Received Signal Strength Indication, RSSI ) 的测量误差， 提高定位的准确性。
如图 4所示， 图 4是本发明实时定位系统一实施例的网络结构示意图， 在 本实施例中， 实时定位系统包括： 定位服务器 41、 访问接入点 （ Access Point , ΑΡ ) 42、 欲定位终端 43以及交换机 44。
其中， 实时定位系统还包括： 定位显示终端 45。
其中， 访问接入点 42的数量为三个或三个以上； 欲定位终端 43为配置有 陀螺仪的移动终端； 可利用以太网集线器来替换交换机 44。
其中， 陀螺仪又叫角速度传感器， 测量的物理量是偏转， 即倾斜时的转动 角速度。
实时定位系统的操作流程为， 首先定位服务器 41与访问接入点 42通过交 换机 44或以太网集线器组成局域网， 然后欲定位终端 43在局域网范围内通过 访问接入点 42访问定位服务器 41。定位服务器 41根据访问接入点 42采集的欲 定位终端 43发送的的信号强度信息， 对欲定位终端 43进行定位， 并将位置信 息发送至定位服务器 45 , 供用户查询。
在本实施例中， IEEE 802.1 1是无线局域网最权威的标准， 本实施例在遵循 802.11协议的无线局域网 （Wireless Local Area Networks , WLAN ) 中， 利用了 室内已有的 WLAN设备来进行定位。 系统中各部分的连接方式为， 多个访问接 入点 42通过交换机 44与定位服务器 41通过有线的方式相连， 欲定位终端 43 以无线的方式通过访问接入点 42访问网络， 定位显示终端 45 以有线或无线的 方式与定位服务器 41相连。
定位系统各部分的功能为， 定位服务器 41用于存储校准信息， 以及运行定 位算法得出被定位设备的位置信息。 定位显示终端 45是 PC机或者其它可以接 入无线局域网的便携设备， 用来访问定位服务器 41 , 查看到定位的结果。 欲定 位终端 43在定位系统中是需要定位的设备， 可以是定制的标签（tag )、 便携机 或 WIFI手机等。定位系统可以定位人或者物品的位置，人只需携带移动终端等， 物品上只需安放 tag等， 就可以通过定位系统来进行定位。 本发明实施例是基于 RSS的指纹定位， 包括场测和实时定位两个阶段。 具 体定位方式如图 5所示， 图 5为图 4所示定位系统的系统框图， 如图所示， 定 位服务器 41 包括： 校准单元 411、 数据库 412、 定位引擎 413以及数据处理与 滤波单元 414。
图 5 所示定位系统的定位过程为， 在场测阶段， 进行场测获取场测数据， 如 RSSI信息等， 将获得场测数据记录到文件中， 再将文件中的场测数据存储于 定位服务器 41的数据库 412中， 其中， 文件可以是可扩展语言文件（Extensible Markup Language , XML ), 定位服务器 41中的校准单元 411对场测数据进行 校准， 获得校准后的 RSSI信息 （RSSI概率模型）， 此时指纹库被建立。
在实时定位阶段， 定位服务器 41通过无线局域网实时地获取 RSSI信息， 并对实时获得的数据通过数据处理与滤波单元 414进行处理和滤波， 定位引擎 413将处理和滤波后的数据与指纹库中的 RSSI信息进行比对， 计算出欲定位终 端 43的位置， 并将位置信息记录到数据库 412中。
用户在定位显示终端 45 上通过网页提交查询位置的请求或者其它事件后， 定位服务器 41响应请求， 查询数据库 412, 并将查询结果返回到定位显示终端 45上， 供用户查看。
其中，在实时定位阶段， 当定位服务器 41通过无线局域网实时地获取 RSSI 信息后，校准单元 411从数据库 412中调取场测数据并进行校准，建立指纹库， 然后将校准后信息发送至定位引擎 413 , 定位引擎 413估算出位置信息后， 将位 置信息存入数据库 412。
也可以是在实时定位阶段， 当定位服务器 41 通过无线局域网实时地获取 RSSI信息后，校准单元 411将已构建好的指纹库中的信息发送至定位引擎 413 , 定位引擎 413估算出位置信息后， 将位置坐标存入数据库 412。
具体的定位方法， 请参阅图 6。 图 6是本发明实时定位方法一实施例的流程 示意图， 本实施例的实时定位方法包括以下步骤：
步骤 601 , 获取访问接入点发送的第一信号的信号强度与方向信息， 其中， 第一信号的信号强度与方向信息为欲定位终端发送至访问接入点的定位信号； 在实时定位阶段， 访问接入点采集欲定位终端的信号强度信息， 在本实施 例中， 采用上行定位的方式， 具体流程如下：
A. 欲定位终端定时发送探查请求（ probe request );
欲定位终端发送 probe request的作用为，根据 802.11协议，利用 probe request 帧来扫描所在区域内的 802.11网络。
其中， probe request的发送周期取决于欲定位终端。 欲定位终端上设置有陀 螺仪， 陀螺仪能够测量出欲定位终端的方向信息， 欲定位终端将测量出的方向 信息发送至定位服务器。
B. 与欲定位终端在同一局域网内的 AP检测接收到的 probe request的信号 强度；
C AP将检测到的信号强度及与之相对应的 AP标志发送至定位服务器。 其中，要确定欲定位终端的位置， 需要三个或三个以上的 AP向定位服务器 发送其检测到的信号强度。
步骤 602 ,在校准信息中查找与第一信号的方向相同或最接近的第二信号的 方向， 校准信息包括预先测量的多组方向、 信号强度以及位置之间的关联关系 数据， 其中， 第一信号的方向和第二信号的方向为欲定位终端发送或接收信号 时的方向；
其中， 校准信息的获取过程如下：
A. 选择需要定位的区域中的多个测量点并利用终端进行场测， 获得场测数 据， 场测数据包括测量点的位置坐标、 终端接收第二信息的信号强度及第二信 号的方向信息；
B. 将获得的场测数据存储于定位服务器的数据库中；
C. 对存储于数据库中的场测数据进行校准， 以获取校准信息。
如上所述， 场测数据的具体获取方式为：
在本实施例中， 校准信息的产生采用下行校准的方式， 其流程为： A. AP发 送信标 ( beacon );
根据 802.11协议的规定， AP会周期性向其所在局域网区域内的所有终端发 送 beacon†贞。
B. 在需要定位的区域， 即 AP所覆盖的区域， 选择特定的测量点， 并记录 该地点的位置， 即位置坐标信息；
特定测量点为用户的随机选择， 为获得较好的测量效果， 特定测量点的分 布应比较均匀。
C. 在特定的测量点利用欲定位终端检测 AP发送的下行信号 beacon帧的信 号强度， 并通过陀螺仪测量出 AP发送的下行信号的方向信息；
其中，在某一特定测量点，欲定位终端可以在某个特定方向上， 测量多次， 获得一组信号强度和方向信息。
其中， 在某一特定测量点， 欲定位终端可旋转自身的方向， 获得多组信号 强度和方向信息。 以实现对每个 AP多个方向上的测量。
D.欲定位终端将测量点的位置坐标信息， 测量的信号强度及方向信息存储 至 XML文件中；
XML文件包括多个测量点下的位置坐标信息，测量的信号强度及方向信息， 以及同一测量点下的多个方向的信号强度和方向信息。
E. 将 XML文件导入定位服务器的数据库中。
步骤 603 ,若查找得到校准信息中存在与第一信号的方向相同或最接近的第 二信号的方向， 则在校准信息中选取查找得到的与第二信号的方向关联的信号 强度；
在校准阶段指纹库里记录了对于每个 AP多个方向上的校准 RSSI信息， 如 表 1所示， 测量了 n个 AP在 n个角度下的 RSSI信息， 校准 RSSI信息用集合
Rii(iE Z, i>0)来表示， 方向用集合 A = {β1,β2,β3, βη}。 在实时定位阶段， 定 位服务器会从欲定位终端得到方向信息， 并且从指纹库中选取合适的方向上的 校准 RSSI信息进行对比， 计算出终端的位置坐标。 选取哪个方向上的校准 RSSI信息分为两种情况，一种情况是在表 1所示方 向集合 A中搜索到与欲定位终端相同的方向， 如表 2中的终端 1的方向角度为 α, 在集合 Α中发现 βΐ的值与 α相等， 则在进行比对时， 选取 βΐ角度下的校准 RSSI信息进行比对。
Figure imgf000011_0001
表 1
注： AP代表发送信号的访问接入点； β代表角度； R代表访问接入点不同 方向上接收的信号强度。
另一种情况是在方向集合 Α中搜索不到与欲定位终端相同的方向， 如表 2 中的终端 2的方向角度为 γ, 发现 γ Ε (β2, β3), 此时， 则需要选取最接近 γ方向 上的校准 RSSI信息， 即选取使得 d = |γ-βί|值最小的 βί方向角度下的校准 RSSI 信息。
Figure imgf000011_0002
表 2
注： α与 γ分别代表实时定位中， 欲定位终端发送的方向信息。
步骤 604,若选取得到的与第二信号的方向关联的信号强度与第一信号的信 号强度相同或最接近，则获取与第二信号的方向、信号强度相关联的位置信息； 在进行定位比对时，若匹配到相同的校准 RSSI值，可以认为对应校准 RSSI 值的位置就是一个候选位置。 若匹配到多个候选位置则继续进行筛选， 估算出 最接近的候选位置， 作为最终位置。
步骤 605, 向接收方发送位置信息， 完成预定位终端的定位。
其中，本发明在实时定位阶段还可采用下行定位的方式进行定位。具体为， 欲定位终端通过周围 AP发送的 beacon帧检测信号强度 RSSI, 同时， 欲定位终 端上的陀螺仪测量出方向信息， 例如规定北为正方向， 测量出欲定位终端的方 向为 30度。 欲定位终端获得所需要的 RSSI信息和方向信息后， 通过无线局域 网把信息传送给定位服务器。
定位服务器收到 RSSI信息和方向信息后， 过滤掉不属于定位系统的 AP的 RSSI信息， 然后将过滤后实时采集的 RSSI信息与指纹库里已有的各个方向的 校准信息进行比对， 计算得到终端的位置坐标。
综上所述， 本发明提供一种基于陀螺仪的实时定位方法。 在基于 RSS定位 技术的基础上， 使用陀螺仪提供辅助的方向信息， 以多方向数据采集来定位欲 定位终端。 具体为， 在场测阶段， 欲定位终端在同一位置旋转多次角度， 针对 每个角度都收集多个 AP发送的 beacon的 RSSI信息， 同时， 还使用陀螺仪测量 出欲定位终端每次旋转的方向。 测量结束后， 将方向信息和 RSSI信息一并记录 到 XML文件中。 在定位阶段， 定位服务器实时地收集欲定位终端的 RSSI信息 和陀螺仪测量出来的方向信息， 对实时采集的信息进行处理与滤波后， 与存储 的多个方向上检测到的校准 RSSI信息作对比，计算出欲定位终端的位置坐标信 息。
通过上述阐述，本发明与现有 RSS定位技术相比，其进步之处为：现有 RSS 定位技术容易受到环境变化和多径效应的影响， 如： 门的开关和人的走动等。 为了克服上述缺点， 本发明在定位系统中使用陀螺仪辅助测量出方向信息， 利 用测量出的各个方向上的 RSSI信息来更准确的定位出终端位置。 如： 在场测阶 段,使用多方向的多次测量来减少环境因素影响，测量出更为准确的 RSSI信息； 在实时定位阶段， 加入欲定位终端的方向信息， 能更准确的进行 RSSI信息的比 对， 以计算出更精确的位置。
其中， 本发明的实时定位方法还可应用于无线传感器网络中， 进行室内或 者室外的定位。 其定位系统包括固定的基础设施部分和可移动的终端部分， 分 别称为锚节点和盲节点。 锚节点一般通过 ZigBee或网关节点连接到定位服务器 上， 组成一个大的网络。
利用无线传感器网络定位时， 也可以使用测量信号强度， 并辅助方向信息 来进行定位。 如： 在场测时， 对于信号强度的测量， 针对同一个锚节点在不同 的方向进行多次测量， 并通过螺旋仪记录下方向信息。
图 7是本发明实时定位装置一实施例的结构示意图， 如图所示， 实时定位 装置包括： 第一获取模块 71、 查找模块 72、 选取模块 73、 第二获取模块 74、 发送模块 75、 接收模块 76、 存储模块 77以及校准模块 78。
其中， 第一获取模块 71、 查找模块 72、 选取模块 73、 第二获取模块 74及 发送模块 75都属于图 5所示的定位服务器 41。查找模块 72和选取模块 73所进 行的工作与图 5所示定位引擎 413所做的工作相同。
上述各模块的功能和工作流程如下：
第一获取模块 71用于获取访问接入点发送的第一信号的信号强度与方向信 息， 其中， 第一信号的信号强度与方向信息为欲定位终端发送至访问接入点的 定位信号； 具体用于接收来自至少三个访问接入点的标志及其所检测得到的上 行信号的信号强度信息， 以及获取来自所述欲定位终端的方向信息， 所述上行 信号是至少三个访问接入点分别接收的欲定位终端的上行信号； 或用于接收欲 定位终端所检测到至少三个访问接入点的下行信号的信号强度信息及相应的方 向信息。
查找模块 72用于在校准信息中查找与第一信号的方向相同或最接近的第二 信号的方向， 校准信息包括预先测量的多组方向、 信号强度以及位置之间的关 联关系数据， 其中， 第一信号的方向和第二信号的方向为欲定位终端发送或接 收信号时的方向；
选取模块 73用于在查找模块 72查找得到校准信息中存在与第一信号的方 向相同或最接近的第二信号的方向时， 在校准信息中选取查找得到的与第二信 号的方向关联的信号强度；
第二获取模块 74用于在选取模块 73选取得到的与第二信号的方向关联的 信号强度与第一信号的信号强度相同或最接近时， 获取与第二信号的方向、 信 号强度相关联的位置信息；
发送模块 75 用于向接收方发送位置信息， 完成预定位终端的定位； 其中， 发送模块 75向接收方发送位置信息包括， 发送模块 75将位置信息首先发送至 图 5所示的数据库 412,然后数据库 412再根据用户的定位请求将位置信息返回 到图 5所示的定位显示终端 45上。
接收模块 76用于获取来自终端的场测数据， 所述场测数据包括所述测量点 的位置坐标、 终端接收第二信息的信号强度及第二信号的方向信息， 并且由选 择需要定位的区域中的多个测量点并利用终端进行场测而获得； 其中， 场测数 据包括每个测量点处终端在多个方向上检测到的下行信号的信号强度、 相应方 向以及测量点处位置信息。
存储模块 77用于将获得的场测数据存储于数据库中； 具体用于将获得的场 测数据记录到文件中， 再将文件中的场测数据存储于定位服务器的数据库中， 其中， 文件可以是可扩展语言文件。
校准模块 78用于对存储于数据库中的场测数据进行校准，以获取校准信息。 上述各模块的工作流程为， 在实时定位过程中， 第一获取模块 71首先获取 访问接入点发送的第一信号的信号强度与方向信息， 然后通过查找模块 72和选 取模块 73获得与第一信号的信号强度与方向信息相同或最接近的第二信号的信 号强度与方向信息， 在获得上述结果后， 第二获取模块 74获取与第二信号的方 向、 信号强度相关联的位置信息， 并将该位置信息通过发送模块 75发送至接收 方， 完成预定位终端的定位。 其中， 第二信号的信号强度、 方向信息与位置信息属于定位服务器中的校 准信息， 其获得方式为， 首先接收模块 76选择需要定位的区域中的多个测量点 并利用终端进行场测， 获得场测数据， 然后存储模块 77将获得的场测数据存储 于定位服务器的数据库中， 并利用校准模块 78对存储于数据库中的场测数据进 行校准， 从而获得校准信息。
区别于现有技术的情况， 本发明实施例针对基于接收的信号强度的定位技 术进行定位时， 易受环境影响的特点， 在实时定位前， 首先将包括预先测量的 多组方向、 信号强度以及位置之间的关联关系数据的校准信息存储于定位服务 器中。 在实时定位时， 定位服务器获取访问接入点发送的第一信号的信号强度 与方向信息， 其中， 第一信号的信号强度与方向信息为欲定位终端发送。 然后 将第一信号的信号强度与方向信息与校准信息进行指纹比对， 若校准信息中存 在与第一信号的方向信息与信号强度相同或最接近的第二信号的方向信息与信 号强度， 则获取与第二信号的方向、 信号强度相关联的位置信息， 获取的位置 信息为欲定位终端的位置坐标， 并将该位置信息发送至接收方， 完成欲定位终 端的定位。 其中， 第一信号的方向和第二信号的方向为欲定位终端发送或接收 信号时的方向。 通过上述方式， 能够利用基于接收的信号强度的定位技术进行 定位， 同时在实时定位过程中降低环境对接收信号强度的影响。
通过以上实施方式的描述， 本领域的技术人员可以清楚地了解到本发明可 借助软件加必需的通用硬件平台的方式来实现， 当然也可以通过硬件， 但很多 情况下前者是更佳的实施方式。 基于这样的理解， 本发明的技术方案本质上或 者说对现有技术做出贡献的部分可以以软件产品的形式体现出来， 该软件产品 存储在一个存储介质中， 如： 软盘、硬盘、 闪存或只读内存等， 包括若干指令， 用以使得一台终端设备执行本发明各个实施例所阐述的方法。
以上所述仅为本发明的实施例， 并非因此限制本发明的专利范围， 凡是利 用本发明说明书及附图内容所作的等效结构或等效流程变换， 或直接或间接运 用在其它相关的技术领域， 均同理包括在本发明的专利保护范围内。

Claims

权利要求
1.一种实时定位方法， 其特征在于， 包括：
获取访问接入点发送的第一信号的信号强度与方向信息， 其中， 所述第一 信号的信号强度与方向信息为欲定位终端发送至访问接入点的定位信号；
在校准信息中查找与所述第一信号的方向相同或最接近的第二信号的方向, 所述校准信息包括预先测量的多组方向、 信号强度以及位置之间的关联关系数 据， 其中， 所述第一信号的方向和第二信号的方向为欲定位终端发送或接收信 号时的方向；
若查找得到所述校准信息中存在与第一信号的方向相同或最接近的第二信 号的方向， 则在所述校准信息中选取查找得到的与第二信号的方向关联的信号 强度；
若选取得到的与第二信号的方向关联的信号强度与第一信号的信号强度相 同或最接近， 则获取与所述第二信号的方向、 信号强度相关联的位置信息；
向接收方发送所述位置信息。
2.根据权利要求 1所述的方法， 其特征在于：
所述校准信息的获取步骤包括：
获取来自终端的场测数据， 所述场测数据包括所述测量点的位置坐标、 终 端接收第二信息的信号强度及第二信号的方向信息， 并且由选择需要定位的区 域中的多个测量点并利用终端进行场测而获得；
将获得的场测数据存储于数据库中；
对存储于数据库中的场测数据进行校准， 以获取校准信息。
3.根据权利要求 2所述的方法， 其特征在于：
所述将获得的场测数据存储于数据库中的步骤具体是指： 将获得的场测数 据记录到文件中， 再将所述文件里的场测数据存储于数据库中， 其中， 所述文 件可以是可扩展语言文件。
4.根据权利要求 2所述的方法， 其特征在于：
所述场测数据包括每个测量点处终端在多个方向上检测到的下行信号的信 号强度、 相应方向以及测量点处位置信息。
5.根据权利要求 1所述的方法， 其特征在于：
所述获取访问接入点发送的第一信号的信号强度与方向信息的步骤具体是 指： 接收来自所述至少三个访问接入点的标志及其所检测得到的上行信号的信 号强度信息， 以及获取来自所述欲定位终端的方向信息， 所述上行信号是至少 三个访问接入点分别接收的欲定位终端的上行信号。
6.根据权利要求 1所述的方法， 其特征在于：
所述获取访问接入点发送的第一信号的信号强度与方向信息的步骤具体是 指： 接收欲定位终端所检测到至少三个访问接入点的下行信号的信号强度信息 及相应的方向信息。
7.—种定位服务器， 其特征在于， 包括：
第一获取模块， 用于获取访问接入点发送的第一信号的信号强度与方向信 息， 其中， 所述第一信号的信号强度与方向信息为欲定位终端发送至访问接入 点的定位信号；
查找模块， 用于在校准信息中查找与所述第一信号的方向相同或最接近的 第二信号的方向， 所述校准信息包括预先测量的多组方向、 信号强度以及位置 之间的关联关系数据， 其中， 所述第一信号的方向和第二信号的方向为欲定位 终端发送或接收信号时的方向；
选取模块， 用于在所述查找模块查找得到所述校准信息中存在与第一信号 的方向相同或最接近的第二信号的方向时， 在所述校准信息中选取查找得到的 与第二信号的方向关联的信号强度；
第二获取模块， 用于在所述选取模块选取得到的与第二信号的方向关联的 信号强度与第一信号的信号强度相同或最接近时， 获取与所述第二信号的方向、 信号强度相关联的位置信息； 发送模块， 用于向接收方发送所述位置信息， 完成预定位终端的定位。
8.根据权利要求 7所述的定位服务器， 其特征在于， 所述定位服务器包括： 接收模块， 用于获取来自终端的场测数据， 所述场测数据包括所述测量点 的位置坐标、 终端接收第二信息的信号强度及第二信号的方向信息， 并且由选 择需要定位的区域中的多个测量点并利用终端进行场测而获得；
存储模块， 用于将获得的场测数据存储于数据库中；
校准模块，用于对存储于数据库中的场测数据进行校准，以获取校准信息。
9.根据权利要求 8所述的定位服务器， 其特征在于：
所述存储模块具体用于将获得的场测数据记录到文件中， 再将所述文件里 的场测数据存储于数据库中， 其中， 所述文件可以是可扩展语言文件。
10.根据权利要求 8所述的定位服务器， 其特征在于：
所述场测数据包括每个测量点处终端在多个方向上检测到的下行信号的信 号强度、 相应方向以及测量点处位置信息。
11.根据权利要求 7所述的定位服务器， 其特征在于：
所述第一获取模块具体用于接收来自所述至少三个访问接入点的标志及其 所检测得到的上行信号的信号强度信息， 以及获取来自所述欲定位终端的方向 信息， 所述上行信号是至少三个访问接入点分别接收的欲定位终端的上行信号。
12.根据权利要求 7所述的定位服务器， 其特征在于：
所述第一获取模块具体用于接收欲定位终端所检测到至少三个访问接入点 的下行信号的信号强度信息及相应的方向信息。
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