KR20210017527A - Indoor positioning apparatus and method - Google Patents

Abstract

The present invention relates to an indoor positioning device and a method therefor, capable of providing an indoor position service when any emergency situation occurs. According to one embodiment of the present invention, the indoor positioning device is configured to: receive position information from a satellite; receive position information from at least one outdoor anchor installed in a mobile vehicle; and calculate a current indoor position based on the position information received from the indoor anchor. Accordingly, when an emergency situation such as a disaster and an act of terrorism occurs, the present invention can provide an indoor position-based service in a building on which a radio wave transmission device is not installed in advance.

Description

Indoor positioning apparatus and method

The present invention relates to an indoor location estimation apparatus and method.

Location-based services are expanding from map guidance applications including vehicle navigation in the past to various IoT services using mobile terminals. However, until now, location-based services provide services only outdoors where signals can be received from GPS satellites, and various location tracking technologies are being developed to provide such services indoors. Technologies that provide indoor location-based services can be roughly divided into two. One is a method using a sensor, and the other is a method using radio waves. There is also a way to mix the two.

The technology using a sensor is a technology that estimates the position according to the moving direction and speed from the current position using a gyroscope, a geomagnetic sensor, or an altitude sensor. In this method, the exact position of the initial starting point and the alignment of the sensor affect the positioning performance. In addition, there is a problem that errors accumulate over time, so as the service time increases, a sudden position error increases. The method using radio waves is a method of estimating the location using ultrasonic waves, Bluetooth, WiFi, UWB, and pseudo-satellite (or GPS radio wave method), which are widely used in everyday life. As for the estimation algorithm, there are various methods such as TOA (Time of Arrival), TDOA (Time Difference of Arrival), AOA (Angle of Arrival), ROA, and Finger print. In order to use such radio waves, an anchor that transmits radio waves or is the basis for position estimation must be installed in advance, and its position must be estimated or measured in advance. Here, the name of the reference transceiver is an anchor, a satellite, an AP (Access Point), and the like, which are different for each technology, but are unified and described as an anchor. In certain algorithms, the environment and even environmental variables must be measured in advance. Otherwise, the system cannot be used or system errors occur.

The location estimation technique through wireless communication is widely used not only in the military field but also in the general public and has become an indispensable technique. In outdoor location estimation, a GPS-based satellite is playing its role as a well-established system. In addition, indoor location estimation is also being studied in various fields and is slowly applied to real life. However, a general position estimation technique suffers serious performance degradation when an obstacle exists between an anchor that knows the position and a tag that wants to estimate the position for position estimation. This is because the measured distance between the anchor and the tag is measured somewhat longer than the actual due to the delay caused by the obstacle. For this reason, there is a problem that the GPS system estimates an incorrect location when the terminal is located in a building.

On the other hand, DoP (Dilution-of-Precision, hereinafter referred to as DoP) is a value indicating how efficiently anchors are arranged based on tags when the anchors and tags are arranged. Until now, the existing DoP has been proposed and widely used in consideration of the unbiased measurement distance error and the environment without walls. However, it can be seen that the assumed unbiased measurement distance error is unrealistic. This is because the error that occurs when measuring distance is always greater than zero.

[Prior technical literature number]

Prior 1: Korean Patent Registration No. 10-1470694

Prior 2: Korean Patent Registration No. 10-1515013

Embodiments provide an indoor location estimation apparatus and method capable of accurately estimating a location even when a wall exists by improving an existing location estimation technique.

In addition, efficient indoor estimation is possible considering the improved enhanced-DoP (E-DoP) that can be used even when there is a wall.

An indoor location estimation apparatus according to an embodiment, comprising: at least three or more anchors disposed at different locations outdoors to measure a distance from a tag located indoors where a plurality of walls exist; And a controller configured to calculate the position of the tag based on the distances to the tag measured from the anchors and delay information due to the plurality of walls.

The delay information is characterized in that it is determined by the refractive index and thickness of each wall.

In order to calculate the delay information, the indoor position estimation apparatus estimates the positions of the at least three or more anchors, and sets a line connecting each of the anchors to include all walls existing in the room. Characterized in that.

The distance between the anchors is characterized in that it is calculated by the following equations 2 and 3.

[Equation 2]

,

,

:

번째 앵커와

번째 앵커를 선으로 그었을 때 지나치는 벽의 집합을 의미하고,

:

First anchor and

It means the set of walls that pass when the first anchor is drawn with a line,

[Equation 3]

,

,

: 다중 경로로 인해 생기는 오차의 평균 값이고,

: 측정 기기로 인해 생기는 오차의 평균 값임

: It is the average value of the error caused by multiple paths,

: This is the average value of errors caused by the measuring device

The indoor position estimation apparatus is characterized in that the E-DoP value for evaluating the appropriateness of the tag and the arrangement of at least three or more anchors arranged at different positions is calculated by Equation 10 below.

[Equation 10]

,

,

는 대각성분을 1, 비대각 성분을

로 갖는

행렬.

Is 1 for the diagonal component and 1 for the non-diagonal component

Having as

procession.

In the indoor location estimation method according to another embodiment, in order to measure a distance from a tag located indoors where a plurality of walls exist, a distance from the tag from at least three or more anchors disposed at different locations outdoors Receiving; And calculating the position of the tag based on the distances to the tag measured from the anchors and delay information due to the plurality of walls.

The delay information is characterized in that it is determined by the refractive index and thickness of each wall.

In the indoor location estimation method, in order to calculate the delay information, the positions of the at least three or more anchors are estimated, and a line connecting each of the anchors is set to include all walls existing in the room. Characterized in that.

The distance between the anchors is characterized in that it is calculated by the following equations 2 and 3.

[Equation 2]

,

,

:

번째 앵커와

번째 앵커를 선으로 그었을 때 지나치는 벽의 집합을 의미하고,

:

First anchor and

It means the set of walls that pass when the first anchor is drawn with a line,

[Equation 3]

,

,

: 다중 경로로 인해 생기는 오차의 평균 값이고,

: 측정 기기로 인해 생기는 오차의 평균 값임.

: It is the average value of the error caused by multiple paths,

: This is the average value of the errors caused by the measuring device.

The indoor location estimation method is characterized in that an E-DoP value for evaluating the appropriateness of the tag and the arrangement of at least three or more anchors arranged at different locations is calculated by Equation 10 below.

[Equation 10]

,

,

는 대각성분을 1, 비대각 성분을

로 갖는

행렬.

Is 1 for the diagonal component and 1 for the non-diagonal component

Having as

procession.

It includes a recording medium recording a program for executing the indoor location estimation method according to another embodiment on a computer.

The embodiments may improve the existing position estimation technique to accurately estimate the position even when the wall exists.

In addition, efficient indoor estimation is possible considering the improved enhanced-DoP (E-DoP) that can be used even when there is a wall.

1 is a schematic diagram of a positioning system according to an embodiment.
2 is a schematic diagram of a positioning system according to an embodiment.
3 is an exemplary diagram of a usage environment of a positioning system according to an exemplary embodiment.
4 is an exemplary diagram illustrating a method of extracting wall information according to an exemplary embodiment.
5 is a diagram illustrating the performance of a method for estimating a location in an environment and a situation where there is no wall according to an exemplary embodiment.
6 is a diagram illustrating the performance of a method for estimating a location in an environment and a situation with walls, according to an exemplary embodiment.
7 is a diagram showing the performance of LM and E-LM in an environment and a situation with a wall of 2 m according to an exemplary embodiment.
8 is a diagram illustrating DoP and E-DoP values in various environments according to an embodiment.
9 is a diagram showing the performance of an LM and an E-LM in a situation with a wall and without a wall in various environments according to an exemplary embodiment.

The terms used in the embodiments have been selected as currently widely used general terms as possible while considering functions in the embodiments, but this may vary depending on the intention or precedent of a technician working in the art, the emergence of new technologies, etc. . In addition, in certain cases, there are terms that are arbitrarily selected, and in this case, the meaning will be described in detail in the description of the corresponding embodiment. Therefore, the terms used in the present embodiments should be defined based on the meaning of the term and the contents of the present embodiments, not a simple name of the term.

In the description of the embodiments, when a certain part is connected to another part, this includes not only a case in which it is directly connected, but also a case in which it is electrically connected with another component interposed therebetween. In addition, when a certain part includes a certain component, it means that other components may be further included rather than excluding other components unless specifically stated to the contrary. In addition, the term "... unit" described in the embodiments means a unit that processes at least one function or operation, which may be implemented as hardware or software, or a combination of hardware and software.

Terms such as “consisting of” or “comprising” used in the present embodiments should not be construed as necessarily including all of the various constituent elements or various steps described in the specification, and some constituent elements or some of them It should be construed that the steps may not be included, or may further include additional components or steps.

The description of the following embodiments should not be construed as limiting the scope of the rights, and what those skilled in the art can easily infer should be construed as belonging to the scope of the rights of the embodiments. Hereinafter, embodiments for illustration only will be described in detail with reference to the accompanying drawings.

Indoor anchors can also be used to eliminate shaded areas indoors. When using the outdoor anchor in this way, the problem in the method of using the sensor disappears, and it is possible to provide a location-based service even inside a building where the anchor is not installed in advance.

The positioning system according to the embodiment may be applied, for example, a navigation system such as eLORAN (enhanced-long range navigation), a wireless personal area network (WPAN) system such as UWB (Ultra-Wide Band), etc. It is for the purpose of information exchange and remote control.

The positioning system according to the embodiment may be located adjacent to the ground (G) or spaced apart from the ground (G) by a certain distance, and compensate for the propagation delay time between the remote node and the positioning device using the separately obtained altitude information (H). can do. Such additional altitude information (H) is, for example, Indicated Altitude information, True Altitude information, Absolute Altitude information, Pressure Altitude information, and Density Altitude information. It may include at least one of information.

1 is a schematic diagram of a positioning system according to an embodiment.

Referring to FIG. 1, it is a schematic diagram of providing an indoor location-based service using only an outdoor anchor. Here, the outdoor anchor is expressed as a vehicle or a truck, but other forms of implementation are also possible. In addition, the tag is also expressed as a human, but it can also be installed and operated on an unmanned robot, and as a positioning device indoors, it can be implemented in various forms, such as a helmet and a portable terminal.

Anchors installed outdoors (outdoor anchors 1 to 4) can be configured with a plurality. The outdoor anchor has a GPS receiver so that its own location can be easily known, and optionally, when using an RTK-GNSS receiver, it has a positioning performance of several tens of mm. If the outdoor anchor uses two antennas, two-dimensional positioning is possible with one anchor, and if two outdoor anchors (for example, four antennas) are used, three-dimensional positioning can be performed. In addition, if the outdoor anchor is implemented as a means of transportation such as a car, the service can be started as soon as it arrives at the outside of the building, resulting in quick installation time.

Figure 2 is a schematic block diagram of the positioning system shown in Figure 1;

Referring to FIG. 2, the outdoor anchor 200 receives location information from a plurality of satellites 300 to 330. The outdoor anchor 200 transmits the received location information to the positioning device 100. As shown in FIG. 2, the positioning system includes a positioning device 10, and the positioning device 10 receives signals from GPS (Global Positioning System) satellites 2a to 2d located at a remote location to determine its position. Can be measured.

In the positioning system as shown in FIG. 2, a plurality of GPS satellites, for example, four GPS satellites 300 to 330, may communicate signals with the outdoor anchor 200 with each other. The GPS satellites 300 to 330 shown in FIG. 2 are only examples, and there is no need to limit the number of them. For example, in the case of a positioning system performing two-dimensional positioning, the latitude and longitude can be calculated using three GPS satellites, and in the case of a positioning system performing three-dimensional positioning, the latitude and longitude are calculated using four or more GPS satellites. Hardness and altitude can be calculated. The location information received from the GPS satellites 300 to 330 is transmitted to the positioning device 100. The positioning device 100 may include a receiver that receives location information from the outdoor anchor 200 and a control unit that calculates its own location based on the location information.

3 is an exemplary diagram of a usage environment of a positioning system according to an exemplary embodiment.

번째 앵커에서 측정한 거리 정보는 다음과 수학식 1과 같다.A situation assumed in the embodiment will be described first with reference to FIG. 3. First, assume a three-dimensional space, and assume that there are anchors, tags, and buildings in this space. The estimated position of the tag can be estimated by changing from a relative position to an absolute position through the absolute position of the anchor. It is assumed that the anchors are located outside the wall. The anchor measures the distance between each anchor and the tag through wireless communication with the tag. Through the distance estimated by each anchor, the integrated processor estimates the position of the tag. At this time, it is assumed that the integrated processor knows the geometry of the wall, but information about the thickness and refractive index of the walls is not required. In addition, the measurement error is considered as the sum of the two errors. The first is an error due to the measuring device and the second is an error due to multiple paths. Taking this into account

Distance information measured at the th anchor is as follows in Equation 1.

[Equation 1]

,

,

: 앵커의 순서

,

: Order of anchors

,

: 추정한 태그의 위치,

: Estimated tag location,

,

,

:

번째 앵커의 위치,

:

The position of the first anchor,

: 벽 순서의 집합,

: Set of wall order,

:

와

번째 앵커 사이에 있는 벽들의 순서,

:

Wow

The order of the walls between the th anchor,

,

,

:

번째 벽의 두께,

:

Th wall thickness,

:

번째 벽의 굴절률,

:

The refractive index of the th wall,

: 다중경로로 인해 생기는 오차,

: Error caused by multipath,

: 측정기기로 인해 생기는 오차.

: Error caused by measuring equipment.

는 직선으로 진행하는 빛이 벽 속에서 진행하는 거리와 벽의 두께의 비를 의미한다. 예를 들어, 벽이

평면과 평행할 때

의 값을 가지며,

평면과 평행하면

의 값을 갖게 된다. here

Means the ratio of the distance that the light traveling in a straight line travels in the wall and the thickness of the wall. For example, the wall

When parallel to the plane

Has the value of,

Parallel to the plane

Will have the value of

4 is an exemplary diagram illustrating a method of extracting wall information according to an exemplary embodiment.

정보를 추출하는 것을 설명한다.4, each wall

Explain extracting information.

값을 알아야 한다. 따라서 실시 예에서, 먼저 이 값들을 추정하기 위한 방법을 제시한다. 위치 추정 전에 앵커들끼리 서로의 위치를 추정하기를 가정한다. 그 방법은 다음과 같다. 먼저 벽 주변에 앵커들이 서로의 위치를 측정하는데, 앵커들끼리 그은 선이 통과하는 벽들이 모든 벽을 포함해야 하고, 그 수는 적어도 벽의 수만큼 된다. 이러한 집합을

라고 한다. 이 집합

에 속한 앵커들끼리 사이의 거리를 측정하여 이를 수식으로 나타내면 다음과 수학식 2와 같다. In the above-described assumption described with reference to FIG. 3, it is assumed that the refractive index and thickness of each wall are not known, but in the embodiment, in order to estimate the position of the tag,

You need to know the value. Therefore, in an embodiment, first, a method for estimating these values is presented. It is assumed that anchors estimate each other's positions before position estimation. The method is as follows. First, anchors around the wall measure each other's positions, and the walls through which the lines drawn between the anchors pass must include all the walls, and the number is at least as many as the number of walls. These sets

It is called. This set

If the distance between the anchors belonging to the is measured and expressed by an equation, it is as shown in Equation 2 below.

[Equation 2]

,

,

:

번째 앵커와

번째 앵커를 선으로 그었을 때 지나치는 벽의 집합을 의미한다.

:

First anchor and

It means the set of walls that pass when the second anchor is drawn with a line.

After repeatedly doing this, the average value is calculated as shown in Equation 3 below.

[Equation 3]

,

,

: 다중 경로로 인해 생기는 오차의 평균 값이고,

: 측정 기기로 인해 생기는 오차의 평균 값이다.

: It is the average value of the error caused by multiple paths,

: This is the average value of the errors caused by the measuring device.

과

를 둘 다 알고 있다면 위의 연립방정식을 품으로써

,

를 얻을 수 있다. 하지만 더 현실적인 상황을 위해서 모르고 있다고 가정하여 본 발명에서는 이를 0으로 둔다. 이것이 정확한 위치 추정에 있어서 큰 영향을 끼치지 않는다는 것은 뒤에서 확인할 수 있다. 이를 다르게 표현하면

는 다음 수학식 4와 같은 연립방정식을 품으로써 얻을 수 있는

로 추정할 수 있다.if

and

If you know both, by having the above system of equations

,

Can be obtained. However, for a more realistic situation, it is assumed that it is unknown and is set to 0 in the present invention. It can be seen later that this does not have a significant effect on accurate position estimation. In other words,

Is obtained by having a system of equations such as the following Equation 4

Can be estimated as

[Equation 4]

.

.

Next, a location estimation technique will be described.

In an embodiment, the existing repetitive position estimation is basically developed. A brief description of this is as follows. In addition to methods such as trilateration and multilateral surveying, there are repetitive position estimation techniques that are more robust against measurement errors as techniques for estimating a location based on distance information. This technique is aimed at estimating the location of minimizing the value as shown in Equation 5 below as a cost function.

[Equation 5]

,

,

.

.

를 잔차라고 부른다. 이와 같은 비용함수의 값을 더 작게하기 위해

를 변화시켜 가는데, 변화시킬 때에 잔차의 자코비안 행렬 값이 쓰이게 된다. here,

Is called the residual. To make this cost function smaller

When changing is changed, the Jacobian matrix value of the residual is used.

In an embodiment, in this repetitive position estimation technique, a measured distance value is modeled as a new value including a delay due to a wall, and the residual is corrected as shown in Equation 6 below.

[Equation 6]

,

,

,

.

,

.

평면 혹은

평면에 평행하다고 가정한다면 자코비안 행렬은

행렬로서, 다음 수학식 7과 같이 표현할 수 있다.All the walls

Flat or

Assuming it is parallel to the plane, the Jacobian matrix is

As a matrix, it can be expressed as in Equation 7 below.

[Equation 7]

,

,

,

,

.

.

는

중에서

평면에 평행한 벽의 집합,

는

중에서

평면에 평행한 벽의 집합을 의미한다. At this time

Is

Between

Assembly of walls parallel to the plane,

Is

Between

It means a set of walls parallel to the plane.

Next, a method of inducing E-DoP will be described. Here, the DoP is a value indicating how efficiently the anchors are arranged based on the tag when the anchor and the tag are arranged, and is a value considering an unbiased measurement distance error and an environment without walls. In the embodiment, the improved DoP is defined as E-DoP, and an improved enhanced-DoP (E-DoP) that can be used even when there is a wall will be described.

The E-DoP mentioned above is derived as follows. First, looking at the derivation of DoP, the following equation (8) is derived through a linear approximation.

[Equation 8]

,

,

:

의 자코비안 행렬,

:

Jacobian procession of,

는 서로 독립적임.

Are independent of each other.

는

로 추정되며 DoP는 그 정의에 따라 다음 수학식 9와 같다.because of this

Is

It is estimated as and DoP is as shown in Equation 9 below according to its definition.

[Equation 9]

가 편향되지 않음을 기반으로

가 된다. 실시 예에서, 앞서 언급한대로 현실성을 고려하여 평균을

, 분산을

으로 갖는 오차를 고려한다. 이와 더불어 앞서 유도한

를 대입하여 다음 수학식 10과 같은 E-DoP를 유도할 수 있다. In the end

Based on is not biased

Becomes. In the embodiment, the average is calculated in consideration of reality as mentioned above.

, Variance

Consider the error with In addition to this,

E-DoP as shown in Equation 10 below can be derived by substituting.

[Equation 10]

,

,

는 대각성분을 1 비대각 성분을

로 갖는

행렬임.

Is the diagonal component 1 non-diagonal component

Having as

It's a procession.

형태의 직육면체로 가정한다. 이 때 모든 벽의 굴절률과 두께는 2.73과 0.5m이며 위치 추정을 위해 배치하는 앵커의 위치는

이다. 측정 오차에서

는 평균과 분산을 0.1m로 갖는 정규분포를 따른다고 가정하고,

은 IEEE 802.15.4a에 명시되어 있는 1-5번 채널에 따라 얻은 오차를 가정한다. 벽의

값을 추출하기 위해

에 배치할 수 있고 앞서 언급한 방법대로 벽의

를 얻을 수 있는데, 얻어진 값은 1.385m, 1.080m, 1.385m, 1.080m이다. 실제로

는 0.865m이다. 본 발명에서 추정 정확도는 오차의 제곱 평균 제곱근으로 나타낸다. 이를 얻기 위해서 10000번의 반복 동안 태그를 건물 안에 균일한 분포를 따르도록 임의로 배치하여 계산한다. 또한 본 발명에서 고려하는 위치 추정 기법은 다변측량법, multilateration, GN, LM, SD, enhanced Gauss-Newton algorithm (E-GN), enhanced Levenberg-Marquardt algorithm (E-LM), enhanced Steepest Descent algorithm (E-SD)을 고려한다. 도 5는 벽이 없는 상황에서 위치 추정 기법들의 성능을 나타낸 표이고, 도 6은 벽이 있는 상황을 가정한다. 도 5 및 6에 도시된 바와 같이, 다변측량법은 굉장히 좋지 않은 성능을 나타낸다. 도 5를 분석한 것은 다음과 같다. 벽이 없음에도 불구하고 다중 경로의 효과가 높은 3번과 5번 채널에서는 본 발명이 제안한 기법을 적용하였을 때 더 좋은 성능을 보임을 확인할 수 있고, 다중 경로의 효과가 적은 1번, 2번, 4번 채널에서는 거의 같은 성능을 보임을 확인할 수 있다. 도 6을 분석한 것은 다음과 같다. 먼저는 본 발명의 기법을 제안하였을 때 현저한 성능 향상을 확인할 수 있다. 심지어 벽이 없는 상황에서 본 기법을 적용하였을 때, 벽이 없는 상황인 도 5와 비교해보더라도 더 좋은 성능을 나타냄을 확인할 수 있다. 도 7은 벽의 두께를 2m로 늘려서 벽으로 인해 더 위치추정을 하기 어려운 상황을 가정하였을 때 LM 및 E-LM이 성능을 나타낸다. 도 7을 분석한 결과는 다음과 같다. 기존의 기법은 심각하게 성능이 떨어지지만, 본 발명이 제안한 기법을 적용하면 오히려 성능이 더 향상하여 기존의 기법과의 성능차이가 더 커진다는 것을 확인할 수 있다.A simulation was conducted to explain the effect of the invention, and the environment of the simulation is as follows. First, as before, assuming a three-dimensional Euclidean space. The building is

It is assumed to be a rectangular shape. At this time, the refractive index and thickness of all walls are 2.73 and 0.5m, and the position of the anchor placed for position estimation is

to be. In measurement error

Assume that follows a normal distribution with a mean and variance of 0.1m,

Assumes an error obtained according to channels 1-5 specified in IEEE 802.15.4a. Of the wall

To extract the value

Can be placed in the wall

Can be obtained, and the obtained values are 1.385m, 1.080m, 1.385m, and 1.080m. in reality

Is 0.865m. In the present invention, the estimation accuracy is expressed as the root mean square of the error. To obtain this, tags are randomly placed and calculated to follow a uniform distribution in the building during 10000 iterations. In addition, the position estimation technique considered in the present invention is multilateral survey method, multilateration, GN, LM, SD, enhanced Gauss-Newton algorithm (E-GN), enhanced Levenberg-Marquardt algorithm (E-LM), enhanced Steepest Descent algorithm (E- SD). FIG. 5 is a table showing the performance of location estimation techniques in a situation where there is no wall, and FIG. 6 assumes a situation where there is a wall. As shown in Figs. 5 and 6, the multilateral survey method shows very poor performance. Analysis of FIG. 5 is as follows. In channels 3 and 5, which have high multipath effects despite the absence of walls, it can be seen that better performance is shown when the scheme proposed by the present invention is applied. It can be seen that the 4th channel shows almost the same performance. Analysis of FIG. 6 is as follows. First, when the technique of the present invention is proposed, remarkable performance improvement can be confirmed. Even when this technique is applied in a situation where there is no wall, it can be seen that even when compared with FIG. 5, a situation where there is no wall, better performance is displayed. 7 shows the performance of LM and E-LM assuming a situation where it is difficult to estimate the position due to the wall by increasing the thickness of the wall to 2m. The results of analyzing FIG. 7 are as follows. Although the performance of the existing technique is seriously degraded, it can be seen that when the technique proposed by the present invention is applied, the performance is further improved and the difference in performance from the existing technique is increased.

Next, the effect of the E-DoP proposed in the present invention will be shown by simulation. Considering the three environments, the differences from the above-mentioned simulation are as follows.

(i) Conditions are (27,0,0), (-27,0,0), (0,27,20), (0,-27,20) for anchor placement, and the wall thickness is 0.5m.

(ii) Conditions are (27,20,0),(20,27,0),(-,27,-20,0),(-20,-27,0),(27,20, 20), (20,27,20),(-27,-20,20), (-20,-27,20), and the wall thickness is 0.5m.

(iii) The anchor arrangement is the same arrangement as the (ii) condition, and the wall thickness is 1m.

DoP and E-DoP are calculated for the tags uniformly randomly placed over 10000 iterations to obtain an average value. FIG. 8 shows the DoP and E-DoP for the above conditions (i) to (iii), and FIG. 9 shows the average value of the root mean square of the error obtained for the tag at the same location as LM and E-LM. 8 and 9, the following analysis can be performed. First, conditions (i) to (iii) obtain similar LM and E-LM performance when there is no wall, because the three environments have the same DoP value. On the other hand, when there is a wall, the square root of the squared error of the LM and E-LM in the three environments is the following large and small relationship, (i) condition <(ii) condition <(iii) condition, which is exactly the magnitude of E-DoP. You can see that it matches the relationship.

Therefore, the improved E-DoP according to the embodiment can be used even when there is a wall, and through this, efficient indoor location estimation is possible.

An embodiment of the present invention may also be implemented in the form of a recording medium including instructions executable by a computer, such as a program module executed by a computer. Computer-readable media may be any available media that can be accessed by a computer, and includes both volatile and nonvolatile media, removable and non-removable media. Further, the computer-readable medium may include both computer storage media and communication media. Computer storage media includes both volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data. Communication media typically includes computer readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave, or other transmission mechanism, and includes any information delivery medium.

The above description of the present invention is for illustrative purposes only, and those of ordinary skill in the art to which the present invention pertains will be able to understand that it can be easily modified into other specific forms without changing the technical spirit or essential features of the present invention. will be. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not limiting. For example, each component described as a single type may be implemented in a distributed manner, and similarly, components described as being distributed may also be implemented in a combined form.

The scope of the present invention is indicated by the claims to be described later rather than the detailed description, and all changes or modified forms derived from the meaning and scope of the claims and their equivalent concepts should be interpreted as being included in the scope of the present invention. do.

Claims (11)

In the indoor position estimation device,
At least three or more anchors disposed at different locations outdoors to measure a distance from a tag located indoors where a plurality of walls are present; And
Indoor position estimation apparatus comprising a control unit for calculating the position of the tag based on the distances to the tag measured from the anchors and delay information due to the plurality of walls. The method of claim 1,
The delay information,
Indoor location estimation apparatus, characterized in that determined by the refractive index and thickness of each wall. The method of claim 2,
In order to calculate the delay information, the positions of the at least three or more anchors are estimated, and a line connecting each of the anchors is set to include all walls existing in the room. Position estimation device. The method of claim 3,
The indoor position estimation apparatus, characterized in that the distance between the anchors is calculated by the following equations 2 and 3.
[Equation 2]

,

:

First anchor and

It means the set of walls that pass when the first anchor is drawn with a line,
[Equation 3]

,

: It is the average value of the error caused by multiple paths,

: This is the average value of errors caused by the measuring device The method of claim 1,
An indoor position estimation apparatus, characterized in that the E-DoP value for evaluating the appropriateness of the tag and the arrangement of at least three or more anchors arranged at different positions is calculated by Equation 10 below.
[Equation 10]

,

Is 1 for the diagonal component and 1 for the non-diagonal component

Having as

procession. In the indoor location estimation method,
Receiving a distance to the tag from at least three or more anchors disposed at different locations outdoors to measure a distance to a tag located indoors where a plurality of walls are present; And
And calculating the position of the tag based on the distances to the tag measured from the anchors and delay information due to the plurality of walls. The method of claim 6,
The delay information,
Indoor location estimation method, characterized in that determined by the refractive index and thickness of each wall. The method of claim 7,
In order to calculate the delay information, the positions of the at least three or more anchors are estimated, and a line connecting each of the anchors is set to include all walls existing in the room. Location estimation method. The method of claim 8,
The indoor position estimation method, characterized in that the distance between the anchors is calculated by the following equations 2 and 3.
[Equation 2]

,

:

First anchor and

It means the set of walls that pass when the first anchor is drawn with a line,
[Equation 3]

,

: It is the average value of the error caused by multiple paths,

: This is the average value of errors caused by the measuring device The method of claim 6,
The indoor position estimation method, characterized in that the E-DoP value for evaluating the appropriateness of the tag and the arrangement of at least three or more anchors arranged at different positions is calculated by Equation 10 below.
[Equation 10]

,

Is 1 for the diagonal component and 1 for the non-diagonal component

Having as

procession. A recording medium on which a program for executing the indoor position estimation method according to any one of claims 6 to 10 on a computer is recorded.

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