TWI360659B - Method and system for wireless positioning - Google Patents

Description

1360659 PO7960015TW 24821twf.doc/n IX. Description of the invention: • [Technical field to which the invention pertains] * A The present invention relates to a positioning method and system, and in particular to a method and system for wirelessly positioning a target to be measured . [Prior Art] Mobile positioning technology is a popular communication research topic, and its related applications are numerous, such as car navigation monitors and personal home security care. • Under normal circumstances, we want to use the Global Positioning System (Gps) for positioning in an outdoor environment. (10) The scope of application is that the equipment held by the user must be in line with the satellite system (Line of Sight, L0S). In an indoor environment, because the device used by the Gps client cannot receive the radio signal from the satellite, the positioning function cannot be achieved. At present, the methods proposed by the prior art have the next job. For example, Taiwan Patent No. i247m proposes a positioning service method in a wireless network environment, and the purpose is to use the measured 的§号 strength to build the iL under the wireless network environment. An efficient location service method. This method uses known environmental information to calculate a detection point that can detect the intensity of the received h-number in this environment, and measures the signal strength received by the detection device and transmitted by the user device. Estimate the user's location based on the location algorithm and the above information. However, since this method does not have many detection points for actual construction, it is necessary to construct a virtual detection point' and estimate the received signal strength measured by it. In addition, US Patent Application No. US2004/0203841 proposes a method for determining the position of a mobile device, which aims to combine the mobile assistant switching type 1360659 P07960015TW 24821twf.doc/n (Mobile Assisted Handoff) measurement technology and the received signal strength, base station electromagnetic field. Relevant information such as effects, complete the positioning of the mobile device. The method is to design a processor under the mobile communication network to process the signals transmitted by the mobile device and its electromagnetic field distribution function. The user's position can be ascertained using the derived error function and related information. Here we consider the cellular mobile communication system. At the same time, this method must know the antenna field type of the user device to accurately solve the problem. In addition, U.S. Patent Application No. US 2004/0266465 proposes a self-calibration of a signal strength position system for the purpose of establishing a data communication system using signal strength measurement techniques and techniques for calculating the transmission time of the b-number. A positioning unit. This patent considers the distance between the transmitting end and the receiving end in a wireless network system environment, which can be determined in two ways. After the data is transmitted by the transmitter to the receiver (or accessp〇int), it waits for the acknowledge signal returned by the receiver. The distance between the transmitting end and the receiving end can be determined according to the transmission delay time of the signal. Alternatively, the signal strength received by the wireless accessor is measured, and a correction unit is established, and the measured signal power is corrected in a timely manner. According to the known relationship, the distance between the transmitting end and the Wei end can be obtained. And determining the relative distance between the user device disk pickers (or base stations). In addition, U.S. Patent Application Serial No. 2/5/96,68, the entire disclosure of which is incorporated herein by reference. Under the environment of building a wireless network, the notebook computer and the deployed base station are used for signal strength measurement and positioning. First, a notebook type 1360659 P07960015TW 24821twf.doc/n brain is used as a signal source' to simultaneously record its position. Then, in the environment with the deployment, the receiver (considered as the base station), the signal is transmitted through the notebook computer to record the signal strength of all the base stations. The position of the source of the transmitted signal (i.e., the notebook computer) and the strength of the ^ measured by the above-mentioned steps are established. In this environment, once the user transmits the number at an unknown location, the location of the producer can be derived from the signal strength measured by the base station and the established correspondence table. SUMMARY OF THE INVENTION In view of the above problems, the present invention is considered to be based on the presence of a wireless network (inside or outside the environment), and the received signal strength (generation (3) is calculated as signal strength). Parameters, positioning - to complete the functions of personnel monitoring or equipment asset management. Therefore, an example of the present invention discloses a wireless positioning method. In a wireless network area, there are a number of base stations and at least one learning point. Calculate the reference power and path loss parameters based on the learning point. Receive the intensity of the 彳§ issued by the target. The position of the target to be tested is obtained based on the signal strength, the reference power, and the path loss parameter' and using a positioning algorithm. In addition, another example of the present invention discloses a wireless positioning system that is configured in a wireless network area to measure the position of a target to be measured. The wireless positioning system can include at least one removable learning point and a plurality of base stations. The learning point can be removed at a known location in the wireless network area. Most base stations are used to receive and calculate the signal strength of the removable learning point and the target to be tested. The I test and the path loss parameter based on the removable learning point are calculated by the base station receiving the 7 < S ) 1360659 P07960015TW 24821twf.doc/n # intensity of the learnable point. The strength, power, and path loss parameters issued by the target, and the _location algorithm, determine the position of the target. When the target is positioned with the received signal strength as the positioning parameter, since it is impossible to know that the secret signal travels between the transmitting end and the receiving end, and indeed, the position and the orientation thereof, most of them can only perform relative position branches. . but

By the above method and architecture, in an indoor or external environment with a built-in wireless network, the strength of the receiving 彳g can be utilized and the appropriate method can be used for positioning. In addition, the new positioning technology based on the strength of the receiving 彳s, the foot position technology proposed by the present invention can obtain the absolute position of the target. The above and other objects, features and advantages of the present invention will become more apparent from the <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; [Embodiment]

Figure 1 is a schematic illustration of a positioning system in accordance with an embodiment of the present invention. As shown in FIG. 1, the positioning system is built in a wireless network area, and the wireless, road, and domain are, for example, any-indoor areas, particularly areas that cannot receive the G-S. In the wireless secret area 10 t, a plurality of base stations 14 such as a wireless pick-up, a signal receiver, and the like are provided, and j of 1 is set. frequency. In addition, set a learning point (plus (five) P · ) 12 this learning point is - known position (x 〇, y 〇). The distance between the learning point 各 and each base station 14 is, /=1,...,#. The distance between the learning point 12 and the reference 1360659 P07960015TW 24821twf.doc/n point 16 is for the work. The received power is measured at all base stations 14 via the learning point 12, and the reference point power referenced to the learning point 12, as well as the path loss parameter, is calculated accordingly. Figure 丨 positioning system can also include a feeding device

20. It can perform wireless communication with each base station and perform various control and data processing. I

In addition, the learning point 12 set above is a dynamic form and is not necessarily a fixed deployment. In addition, the number of the learning points 12 is not limited to one, and a plurality of them can be set to increase the accuracy of positioning. In addition, when the relevant parameters (i.e., reference power and path loss parameters, etc.) are completed, the signal transmitting device of the learning point 12 can be removed.

各When a target of an unknown position χ(χ,Υ) emits a signal, each base 14 can receive the signal strength of the target. Using the reference power and the path loss parameter previously obtained by the learning point, the position of the target object (χ, γ) can be calculated by the bit algorithm '' of the present embodiment. Next, the positioning method will be described in more detail. Figure 2 is a schematic diagram of the process of positioning the method to perform the positioning method. = Figure 2 and Figure ,, first in the step, in the - wireless network ιΐ secret 'equipped with a number of base stations and at least "learning point" in the wireless network:. The reference power loss parameter with the above learning point is calculated in step S1G2'. At step s, the target to be tested is received (ie, the signal strength of the target β Chengcheng set (X, Y). Finally, in step S106, the strength of the ^, the reference power, and the path loss parameter, and P07960015TW 24821twf.doc/n Use: Bit: The different method 'Get the position of the target to be tested. The actual calculation example of the implementation example of the + U 儿 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 The flow example of the path loss parameter is first in step S2GG' to obtain the (four) signal strength of each base station, and the distance between the learning point and each of the base stations is calculated in step S2G2. In step S2G4, the learning point and the reference are calculated. The distance between the points is finally 'utilized by a number ϋ=1〇ε1〇&lt;), and the signal strength received from the reference point relative to the ^spoint is obtained. Λ·. and -path^失' ζ· = 1,.·.,# is the number of base stations. Preferably, the distance between the sub-point and the reference point &amp; can be set to about 1 meter. There is no fixed execution order, as long as the reference power and path loss parameters can be calculated g. Next, a detailed calculation method will be described. It is assumed that the power transmitted by the learning point 12 is YES, the number of base stations 14 is w. The distance between the learning point 12 and the base station 14, and the base station 14 receives The signal strength, the relationship between the two is shown in the following equation (丨). 弋1010do^)+v, i = \,...,N (1) Here the signal strength received by each base station ^: relative to The signal strength received by the reference point of the learning point: the distance between the learning point and the base station &amp; the distance between the learning point and the reference point v' · The shadow fading effect generated by the multi-path environment. At 1360659 P07960015TW 24821twf.doc/n

Variable), whose statistical property is νΓ^(〇, σν2) ε : path-loss parameter In general, it is assumed that the distance between the learning point 12 and the reference point 16 is lm' and Vi• is ignored. Then the above formula (1) can be rewritten as follows. W 〇) i = h..., N (2) Next, 'the reference point power and the path loss parameter based on the learning point 12 are calculated, that is, the above-described step S102. - Assume that the number of base stations 14 to be deployed is V, and its position is 匕 brother), ,...,V. According to the formula (2), the following equations (3) / =1, · γ1 [Λ 钱 Λ Λ Λ Λ Λ 钱 钱 钱 钱 钱 钱 钱 钱 钱 钱 钱 钱 钱 钱 钱 钱 钱 钱 钱 钱 钱 钱 钱 钱...the position of the learning point 12 is (~eight), and the distance between it and the base station 14 is V-1 λ Γ _ person &gt; - 丄 · ...... 一 一 Λ Λ = 1 - lOlogi / j 1 - 101ogc/2 Λ_ Λ. _1 -l〇logdN_ ε

DC Next, use the minimum sheep t, soil n (3) face number formula (4). + square to go (least squares method), you can get

C = (DrD) 'DrP According to the above method, two important parameters are obtained in (4): phase: the strength of the line network and the path loss are received by the reference point of the emitter. The signal can be set to multiple learning points ['in the above case, the parameter is lost. More accurate reference point power and path loss 1360659 PO7960015TW 24821twf.doc/n Next, a positioning algorithm according to an embodiment of the present invention will be described. FIG. 4 is a schematic flow chart of the positioning algorithm in the positioning method. As shown in Fig. 4 and Fig. 1, first, in step S300, the calculation initial value of the target position to be measured is set to calculate the distance formula between the target P to be measured and each base station. Next, in step S302, the received signal strength difference β between each base station and the reference point is calculated. In step S304, the distance between the target to be measured and the base station and the signal strength difference ^='_6 are brought into the above number ^(丨)^, and the calculated number (1) is not Linear functions are expanded into polynomials. Finally, in step S306, the error method is used to solve the position (Χ, Υ) of the target Ρ to be measured after the expansion. (4) The evening term method Next, the calculation method of the positioning algorithm will be described in detail. According to the equation 以及) and its associated assumptions, the distance between the learning point 12 and the reference point is set to be, for example, lm. Within the signal sampling period (sampUng peri〇d)r, the time interval between the signal sampling and the M' sampling signals is Ty(Af-i)', which is milliseconds (ms). Assume that the user's position is Ρ(χ, γ), that is, the position of the target to be tested, and the distance between it and the respective base stations 14 is: ==7^77^7 people/^&quot;)=corpse (m) _ 尸 (― ° fly r〇, ',; = 1, ..., ^, =1".., from, and 3 = [Yu 叮. Consider the reference point power calculated by learning point 12 (10) = e, then the above formula (1) can be rewritten into the following formula (small O) = i〇fi〇g(d·) + ' =/ (a) + Then 'consider the base station, and reference the number The relationship between the signal strength and the user's position can be expressed as 'two-two form · (here for all base stations, consider single-sampling points, ie two &quot; 12 1360659 P07960015TW 24821twf.doc/n for the convenience of discussion , ignore this superscript variable) P = f(a) + v L , (6) where Ρ = [Ρι户2... household, f(a) = [/^a) /2(a)...厶(4) 『 丨 丨 nr. From and from the equation (5)', (4) is a nonlinear function, and f(a) is a vector composed of a non-linear! For ease of analysis, the following equation (7) is calculated for f(a) ' using the -stage series system. f(4)= + ^-a. ) here. [No 1 r. ] is the initial calculated value of the position (X, Y) of the target to be tested 'J Jia Kebi matrix (4) secret gift (4), the elements of each component are the upper 2 (x-Xi) & 11110 ΟΓ-Λ:, .)2 +(y^yf 1^〇.^〇汹= 2(少-兄〇(8)

^10 (xX^2 +(_y-3;.)2 I Combine with (6)(7), we can get the following formula (9). P = f(a〇) + J(aa〇) + v Let u = Pf(a())+ja (9), the hills take ^ / ie ❻. Assume that during the signal sampling Γ square chain to i from the received signal power sampling points. With the minimum average a, the corpse Mean Called E Dirty MMSE), the oblique pair and the difference function are shown in equation (10). e(a) = £[]u_J5|2l (a) 13 (10) 1360659 P07960015TW 24821twf.doc/n The estimate of the M juice is a & the test vector is prepared as follows. In the fine direction. From (10), it can be estimated that a = J-'Rur at this time R = £[w], and U-i (11) (pseudo-inverse matrix). u The virtual matrix is in the state where the user has not moved the position, and the user is paid by Zhan Tian a - + pipe private ~ &gt; ice "in the case of heart condition, calculated according to the iteration method" Position, as: will: : r. The equation (9) is used = P = fK) + Jt(a, +1-at) + v The method for solving the estimate vector ^ here is the same as ^. By this algorithm, it can be accurately calculated (X, Y). J knows the location of P. In order to verify whether the positioning technology proposed can operate correctly. Here, the IPLin manufacturer Hehcomn, Inc. using the Zigbee module is used as the test device of the present embodiment. Qing, is a wireless network protocol, mainly by the ZigBee Alliance 2 to use the media access layer of the 1EEE8G2.15·4 standard specification, the physical layer. The main features are low speed, low power consumption, support for a large number of scale nodes, support ZigBee module is suitable for lying in the network environment (4) sub-product. ZigBee module is a brief communication architecture, and extends the star and mesh communication architecture, 1360659 P07960015TW 24821twf.doc/ n

ZigBe: In addition to modules that can be independent or (10) responsible for terminal sensing of various 3C products, each ZigBee module can act as a relay packet router (Router), and no physical line connection is required between each ZigBee module.

IP-Link2220 module can set its communication frequency (set to 2.4GHz) via software and role function setting (this module has both base station (receiver) function and user (transmitter) function, which can be set by itself) . In the case of multiple users, the IP-Link 2220 can issue a query command for each user, store each user's acknowledgment command (ackn〇wiedgement command) and transmit the relevant signal. Therefore, positioning can be performed for each user. Before performing the positioning, first use the learning point to calculate the reference point power and path loss parameters based on the learning point. A total of 16 base stations (receivers) are built in the whole system. Example 1: First, as shown in Figure 5, when positioning is performed, coordinate points are used for positioning (the actual length of the coordinates is GG55

Set. The positioning coordinates calculated by the above embodiment are calculated as _qing. Example 2 Next, as shown in Fig. 6, the transmitter (f? 57) is changed. Using the positioning algorithm of the above embodiment, the positioning coordinates of the calculations of the above-mentioned embodiments are (10), 365), and the method and architecture examples disclosed in the present invention are

Claims (1)

1360659 P079600I5TW 2482Itwf.doc/n X. Patent application scope: 1. A wireless positioning method, including: · arranging a plurality of base stations and at least one learning point in a wireless network area; the juice nose is based on the learning point a reference power and a path loss parameter; receiving a signal strength sent by a target to be tested; and determining the target to be tested by using a positioning algorithm according to the signal strength, the reference power, and the path loss parameter position. 2. The wireless positioning method according to claim 1, wherein the reference power and the path loss parameter based on the learning point further comprise: ' ' obtaining a signal strength household received by each base station „·; β varies from the distance between the learning point and each of the base stations &amp;;s the distance between the learning point and a reference point; and based on the reference point relative to the learning point The received signal strength Λ·., and the signal strength of each base station, there is a signal strength difference, wherein the signal strength is poor, the distance between the learning point and each of the base stations, and the learning point The logarithm of the ratio of the distance to a reference point is proportional to the relationship, and the proportional relationship is utilized to obtain the signal strength received relative to the reference point of the learning point, and the path loss parameter , wherein / = i, ... is the number of the base stations. 3. The wireless positioning method according to claim 2, wherein the distance between the learning point and the reference point is set to be approximately 丨meter 】7 &lt; S ) 1360659 P07960015TW 24821twf.doc/n The signal strength of the target to be tested, the weight of the signal is calculated by the touch of the base Point-based reference power and two path loss parameters, and using a signal strength, the reference power, and the path loss parameter issued by the object to be tested, and using a positioning algorithm to obtain the target to be tested 12. The wireless positioning system of the invention of claim 11, wherein the reference power and the path loss i number based on the learning point further comprise: obtaining signals received by each base station The strength household~; the distance between the learning point and each of the base stations is calculated; the distance between the learning point and a reference point is calculated; and the reference point is received based on the reference point relative to the learning point The signal strength is different from the signal strength received by each base station. There is a difference in signal strength, wherein the signal strength is poor, and the distance between the learning point and each of the base stations must be And a logarithm of the ratio of the distance between the learning point and a reference point, in a proportional relationship, and using the proportional relationship to obtain the signal strength received by the reference point relative to the learning point and the path loss The parameter, wherein /=丨,...,# is the number of the base stations. 13. The wireless positioning system according to claim 12, wherein the distance between the learning point and the reference point is further set to 14. The wireless positioning system of claim n, wherein the positioning algorithm further comprises: