KR101750514B1 - Apparatus for correcting attitude and positioning sensor node with multi-antenna - Google Patents

Abstract

More particularly, the present invention relates to a method for acquiring ranging information between a reference antenna of a sensor node and each terminal, An information obtaining unit obtaining information; A position estimator for estimating a first position of each terminal through position estimation using the obtained ranging information; The sensor node estimates the error prediction value of each terminal, selects the reference sensor node and the reference terminal by comparing the estimated error value and the reference value, and determines coordinates of each predetermined sensor node, coordinates of the selected reference sensor node, An attitude information estimating unit that estimates attitude information of each sensor node using coordinates and relative direction information of the selected reference terminal; And a direction information estimator for estimating absolute direction information by correcting relative direction information obtained using the estimated attitude information of each sensor node, wherein the position estimator uses the obtained ranging information and the estimated absolute direction information Thereby estimating the location of each terminal.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an apparatus and a method for correcting attitude of a sensor node using multiple antennas,

The present invention relates to a method and apparatus for attitude correction and positioning of a sensor node using multiple antennas, and more particularly, to a method and apparatus for attitude correction and positioning of a sensor node using multiple antennas, And to a method and apparatus for position correction and positioning of a sensor node to which multiple antennas are applied.

Demand for location-based services is increasing in various industries such as mobile communications, aviation, and defense. For example, the location-based service includes a location-based service for locally replacing a GPS navigation system represented by GPS, and a location-based service in an indoor environment.

In the case of a satellite navigation system represented by GPS (Global Positioning System), location information can not be provided in an indoor environment or in a situation where jamming occurs.

In this case, there are many researches on alternative navigation, and the standardization of IEEE 802.15.4a has already been completed in 2007 for the positioning of narrow areas.

On the other hand, in order to use the direction information of the terminal in the sensor node using multiple antennas for positioning, it is necessary to know the absolute direction information in which the attitude information of the sensor node is corrected. In order to know the absolute direction information, it is necessary to know the attitude information of the sensor node.

To this end, the attitude information of a sensor node must be measured through a geomagnetic sensor and an accelerometer. In other words, the attitude information should be measured through the geomagnetic sensor and the accelerometer in order to know the attitude information of the sensor node using multiple antennas.

However, in the process of measuring the attitude information using the conventional geomagnetic sensor and the accelerometer, the attitude measurement error is considerably large. In case of indoor environment, measurement errors of geomagnetic sensor and accelerometer are considerably large due to the influence of conductors such as reinforcing bars, and as a result, positioning performance is deteriorated when performing positioning using direction information.

Also, it takes a long time to install the sensor node because the attitude information needs to be measured in advance through the geomagnetic sensor and the accelerometer when the sensor node is installed.

Korean Public Release No. 10-2014-0093896 (published on April 29, 2014)

Embodiments of the present invention can be applied to a sensor node attitude sensor that uses multiple antennas without a geomagnetic sensor and an accelerometer and can perform posture correction and terminal positioning of a sensor node using position and direction information of the terminal And to provide a calibration and positioning method and apparatus.

Embodiments of the present invention provide a sensor node and attitude sensor that can acquire attitude information of a sensor node using position information of a sensor node and a terminal and result of direction detection without a geomagnetic sensor and an accelerometer, Method, and apparatus.

In addition, embodiments of the present invention require only the position of the sensor node to be measured in advance when arranging the sensor node, and since it is not necessary to measure the attitude information of the sensor node, it is possible to easily arrange the sensor node at the time of placement, And a method and an apparatus for positioning and positioning a sensor node using multiple antennas.

Also, embodiments of the present invention do not require the use of a geomagnetic sensor and an accelerometer to measure the attitude information of the sensor node. Therefore, the attitude correction and positioning method of the sensor node using the multiple antennas, Device.

According to a first aspect of the present invention, there is provided a method for acquiring ranging information between a reference antenna of a sensor node and each terminal, and acquiring relative direction information for each terminal in a sensor node; Estimating a first location of each terminal through location estimation using the obtained ranging information; Selecting a reference sensor node and a reference terminal by estimating an error prediction value of each terminal in the sensor node, comparing the estimated error value with the reference value, Estimating attitude information of each sensor node using coordinates of each predetermined sensor node, coordinates and relative direction information of the selected reference sensor node, and coordinates and relative direction information of the selected reference terminal; Estimating absolute direction information by correcting the obtained relative direction information using the estimated attitude information of each sensor node; And estimating a location of each terminal using the obtained ranging information and the estimated absolute direction information.

The method further comprises re-estimating an error prediction value from the estimated position of each terminal, and if the difference between the re-estimated error prediction value and the previous error prediction value is equal to or greater than a reference point, The method further includes the step of updating.

The step of estimating the first position of each of the terminals may be performed by using one of a Taylor series function, a Kalman filter function, and a function of finding a solution by a closed-loop method based on a least squares method The first location of each terminal can be estimated.

Wherein the step of selecting the reference sensor node and the reference terminal calculates a matrix from a coordinate of a predetermined sensor node and a first position of each of the estimated terminals and calculates a standard deviation of a distance between the sensor node and the terminal, An error prediction value constant can be calculated from the discrete reception signal of the terminal and the error prediction value of each terminal can be estimated from the sum of the diagonal elements of the calculated matrix and the calculated error prediction value constant at the sensor node.

Wherein the reference sensor node and the reference terminal are selected when the reference value is not set, the reference terminal is not selected when the number of the reference sensor nodes is three or more, and the number of the reference sensor nodes is three , It is possible to select the terminal having the smallest error prediction value as the reference terminal so that the sum of the number of reference sensor nodes and the number of reference terminals is three or more.

The step of selecting the reference sensor node and the reference terminal may include selecting a reference terminal when the reference value is not set and the number of reference sensor nodes is two or more, , It is possible to select the terminal having the smallest error prediction value as the reference terminal so that the sum of the number of reference sensor nodes and the number of reference terminals is two or more.

Wherein estimating the location of each terminal comprises estimating a second location of each terminal using the obtained ranging information and the estimated absolute direction information, The location of each terminal can be estimated by combining the second location of each terminal with a predetermined proportionality constant.

The step of estimating the position of each terminal may include estimating a position of the terminal by using a Brown algorithm using an azimuth angle, an elevation angle, a coordinate of a predetermined sensor node, or a function for an algorithm for repeatedly calculating a solution through linearization, The location can be estimated.

According to a second aspect of the present invention, there is provided an information obtaining apparatus comprising: an information obtaining unit obtaining ranging information between a reference antenna of a sensor node and each terminal and obtaining relative direction information for each terminal from the sensor node; A location estimator for estimating a first location of each terminal through location estimation using the obtained ranging information; A sensor node estimates an error prediction value of each terminal, selects a reference sensor node and a reference terminal by comparing the estimated error prediction value and the reference value, and determines coordinates of each predetermined sensor node, coordinates of the selected reference sensor node, An attitude information estimating unit that estimates attitude information of each sensor node using direction information, coordinates of the selected reference terminal, and relative direction information; And a direction information estimating unit for estimating absolute direction information by correcting the obtained relative direction information using the estimated attitude information of each sensor node, wherein the position estimating unit estimates absolute direction information by using the obtained ranging information, A posture correction and positioning apparatus of a sensor node using multiple antennas that estimate the position of each terminal using absolute direction information can be provided.

Wherein the posture information estimation unit re-estimates an error prediction value from the estimated position of each terminal, and if the difference between the re-estimated error prediction value and the previous error prediction value is equal to or greater than the reference point, The terminal can be updated.

The attitude information estimation unit calculates a matrix from coordinates of a predetermined sensor node and a first position of each of the estimated terminals, calculates a matrix of the standard deviation of the distance between the sensor node and the terminal, and the error from the discrete reception signal of the terminal received at the sensor node The estimated value of each terminal can be estimated by using the sum of the diagonal elements of the calculated matrix and the calculated error predicted value constants in the sensor node.

The posture information estimating unit does not select a reference terminal when the reference value is not set and the number of reference sensor nodes is three or more in consideration of three-dimensional coordinates, and when the number of reference sensor nodes is less than three, It is possible to select the terminal having the smallest error prediction value as the reference terminal so that the sum of the number of reference terminals and the number of reference terminals is three or more.

The posture information estimating unit does not select the reference terminal when the reference value is not set and the number of reference sensor nodes is two or more in consideration of the two-dimensional coordinates, and when the number of reference sensor nodes is less than two, It is possible to select the terminal having the smallest error prediction value as the reference terminal so that the sum of the number of reference terminals and the number of reference terminals can be two or more.

The position estimating unit estimates a position of a first terminal of each terminal using one of a Taylor series function, a Kalman filter function, and a function of finding a solution by a closed- The location can be estimated.

Wherein the position estimating unit estimates a second position of each terminal using the obtained ranging information and the estimated absolute direction information, and estimates a first position of each of the estimated terminals and a second position of each of the estimated terminals To a predetermined proportional constant to estimate the location of each terminal.

The position estimating unit may estimate the second position of each terminal by using a function for an algorithm for calculating the solution repeatedly through linearization or a brown algorithm using azimuth angle, elevation angle, coordinates of a predetermined sensor node .

Embodiments of the present invention can perform posture correction and terminal positioning of a sensor node using position and direction information of a sensor node and a terminal to which multiple antennas are applied without a geomagnetic sensor and an accelerometer.

Embodiments of the present invention can acquire attitude information of a sensor node using position information of a sensor node and a terminal and a direction detection result without using a geomagnetic sensor and an accelerometer.

In addition, embodiments of the present invention can measure only the position of the sensor node when arranging the sensor node, and it is not necessary to measure the attitude information of the sensor node, so that the sensor node can be easily disposed at the time of arrangement and can be easily maintained .

Also, embodiments of the present invention do not require the use of a geomagnetic sensor and an accelerometer to measure the attitude information of the sensor node, so that the sensor node can be manufactured at a low price.

FIG. 1 is a diagram illustrating a sensor node and a posture correction and position estimation process of each terminal using multiple antennas according to an embodiment of the present invention. Referring to FIG.
FIG. 2 is a diagram illustrating a posture correction and positioning method of a sensor node using multiple antennas according to an embodiment of the present invention. Referring to FIG.
FIG. 3 is a diagram illustrating a sensor node using multiple antennas according to another embodiment of the present invention and a posture correction and position estimation process of each terminal.
4 is a flowchart illustrating a selection process of a reference sensor node and a reference terminal according to an embodiment of the present invention.
FIG. 5 is a diagram illustrating a configuration of a posture correction and positioning apparatus of a sensor node using multiple antennas according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The present invention will be described in detail with reference to the portions necessary for understanding the operation and operation according to the present invention. In describing the embodiments of the present invention, description of technical contents which are well known in the art to which the present invention belongs and which are not directly related to the present invention will be omitted. This is for the sake of clarity of the present invention without omitting the unnecessary explanation.

In describing the constituent elements of the present invention, the same reference numerals may be given to constituent elements having the same name, and the same reference numerals may be given to different drawings. However, even in such a case, it does not mean that the corresponding component has different functions according to the embodiment, or does not mean that it has the same function in different embodiments, and the function of each component is different from that of the corresponding embodiment Based on the description of each component in FIG.

FIG. 1 is a diagram illustrating a sensor node and a posture correction and position estimation process of each terminal using multiple antennas according to an embodiment of the present invention. Referring to FIG.

As shown in FIG. 1, a sensor node and each terminal employing multiple antennas according to an embodiment of the present invention are each composed of three sensor nodes having multiple antennas and one terminal. Here, each sensor node has multiple antennas of five elements.

The sensor node 1 101, the sensor node 2 102, and the sensor node 3 103 are located at coordinates of a predetermined sensor node.

The sensor node 1 101, the sensor node 2 102 and the sensor node 3 103 are each subjected to ranging with the terminal A 111. In addition, a relative direction between the sensor node 1 101, the sensor node 2 102, and the sensor node 3 103 and the terminal A 111 is estimated.

와 같이 보정함으로써, 단말의 위치해 추정 성능을 향상시킬 수 있다. 여기서, D_nm은 센서노드 n과 단말 m 사이의 레인징을 나타낸다.

는 센서노드 n과 단말 m 사이의 상대 방향을 나타낸다.

는 센서노드 n과 단말 m 사이의 절대 방향을 나타낸다.

및

는 각각 상대 앙각 및 상대 방위각을 나타낸다.

및

는 각각 절대 앙각 및 절대 방위각을 나타낸다.

는 5소자 다중안테나를 나타낸다.In an embodiment of the present invention, when estimating the position of a terminal in a sensor node using multiple antennas, the orientation information of each sensor node is estimated to determine relative direction information as absolute direction information

It is possible to improve the positioning performance of the terminal. Here, D _nm denotes a ranging between the sensor node n and the terminal m.

Represents the relative direction between the sensor node n and the terminal m.

Represents the absolute direction between the sensor node n and the terminal m.

And

Represent relative elevation angles and relative azimuth angles, respectively.

And

Respectively represent an absolute elevation angle and an absolute azimuth angle.

Represents a five-element multiple antenna.

Hereinafter, the specific operation of the sensor node and each terminal shown in FIG. 1 will be described with reference to FIG.

FIG. 2 is a diagram illustrating a posture correction and positioning method of a sensor node using multiple antennas according to an embodiment of the present invention. Referring to FIG.

As shown in FIG. 2, the attitude correction and positioning method of a sensor node using multiple antennas according to an embodiment of the present invention is a method of orientation correction and positioning of a sensor node using multiple antennas without a geomagnetic sensor and an accelerometer.

For this purpose, the attitude correction and positioning method of the sensor node using the multiple antennas according to the embodiment of the present invention includes a step of acquiring ranging information and relative direction information (S110), a first position estimating step (S120) A reference terminal selection step S130, a sensor node attitude information estimation step S140, an absolute direction information estimation step S150, and a terminal location estimation step S160. In addition, the attitude correction and positioning method of the sensor node using the multiple antennas according to the embodiment of the present invention may further include an estimation end determination step (S170) and a reference terminal update determination and update step (S180).

Hereinafter, an attitude correction and positioning method of a sensor node using multiple antennas according to an embodiment of the present invention will be described.

The ranging information and relative direction information acquisition step (S110) acquires ranging information between the reference antenna and each terminal of the sensor node, and obtains relative direction information for each terminal from the sensor node.

The ranging information and relative direction information acquiring step (S110) is a step of acquiring relative information between the sensor node and the terminal, ranging information from the sensor node using the multiple antennas shown in FIG. 1, (1) and (2). &Quot; (2) "

는 센서노드 1(101)과 단말 A(111) 사이의 레인징 정보를 나타내며, 레인징은 단방향 레인징(One-Way Ranging), 양방향 레인징(Two-Way Ranging) 등 일반적인 레인징 기술로 센서노드 1(101)과 단말 A(111) 사이의 거리를 측정할 수 있다.

는 상대 방향정보로써, 방위각

와 앙각

로 구성된다.here,

Ranging ranging between the sensor node 1 101 and the terminal A 111. The ranging is a general ranging technique such as one-way ranging and two-way ranging, The distance between the node 1 101 and the terminal A 111 can be measured.

Is relative direction information, and the azimuth angle

And elevation angle

.

는 다중안테나의 조향벡터를 나타내며,

은 다중안테나에 수신되는 단말 신호의 공분산 행렬을 나타낸다.Can be estimated by a general direction detection technique such as a Minimum Variance Distortionless Response (MVDR) technique or a MUSIC (Multiple SIgnal Classification) technique as shown in Equation (2). From here

Denotes the steering vector of the multiple antennas,

Represents a covariance matrix of the terminal signals received by the multiple antennas.

It is impossible to estimate the position due to the ambiguity of the direction when it is directly used to estimate the position of the terminal by using the relative direction information estimated by each sensor node. Therefore, it is necessary to change the relative direction information between the sensor node and the terminal to the absolute direction information by using the attitude information of each sensor node.

The terminal first estimation step (S120) estimates the first position of each terminal through the ranging using the ranging information and the ranging information obtained in the relative direction information acquiring step (S110). The terminal location estimation step S120 is a step of estimating a rough first location of each terminal using only the ranging information obtained in step S110. The ranging information can be expressed by the following equation (3) as a combination of a known coordinate of each sensor node and a terminal coordinate to be estimated.

은 단말 m의 좌표,

는 사전에 알고 있는 센서노드 n의 좌표를 나타낸다. 상기의 [수학식 3]에 나타난 레인징 정보는 하기의 [수학식 4]와 같이 벡터로 표현된다.here,

The coordinates of the terminal m,

Represents the coordinates of the sensor node n that is known in advance. The ranging information shown in Equation (3) is expressed as a vector as shown in Equation (4) below.

In the above, R denotes a natural number.

The approximate first local estimation from the above equation (4) is performed as the following equation (5).

Here, function G is the inverse of function F. As an example of the function G, there is a technique for estimating the position repeatedly by linearizing the function F through Taylor Series. In addition to the functions using the Taylor series (Taylor series), general techniques such as the Kalman filter technique and the closed-loop solution technique based on the least squares method can be used.

In this manner, the terminal first estimation step S120 may be performed using any one of a Taylor series function, a Kalman filter function, and a function which obtains a solution by a closed-loop based on a least squares method The first location of each terminal can be estimated.

Then, the reference sensor node and the reference terminal selection step (S130) select the reference sensor node and the reference terminal by estimating the error prediction value of each terminal in the sensor node, and comparing the estimated error prediction value and the reference value.

Specifically, the reference sensor node and the reference terminal selection step (S130) calculate a matrix from the coordinates of the predetermined sensor node and the first position of the estimated terminal, and calculate a standard deviation of the distance between the sensor node and the terminal, And estimates an error prediction value of each terminal in the sensor node using the sum of the diagonal elements of the calculated matrix and the calculated error prediction value constants.

That is, the reference sensor node and the reference terminal selection step (S130) are performed using previously known sensor node coordinates and the coordinates of the terminal estimated in (S120). The sensor node other than the sensor node for which the attitude information is to be estimated is selected as the reference sensor node. In addition, in order to select a reference terminal, an error prediction value of each terminal must be estimated, and can be expressed as the following Equation (6).

Here, diag {} represents the sum of the diagonal elements of the matrix, and w is an error predictive constant, which can be expressed by Equation (7) below.

는 표준편차를 나타내고,

는 센서노드 n에 수신되는 단말 m의 이산 수신신호를 나타내며,

는 0보다 크거나 같은 임의의 실수를 나타낸다. 또한, 행렬 H는 센서노드와 추정된 단말의 좌표를 이용하여 계산되며, 하기의 [수학식 8]과 같이 나타낼 수 있다.From here

Represents the standard deviation,

Represents the discrete reception signal of the terminal m received at the sensor node n,

Represents any real number greater than or equal to zero. The matrix H is calculated using the coordinates of the sensor node and the estimated terminal, and can be expressed by Equation (8) below.

을 나타낸다.here,

.

The reference sensor node and the reference terminal selection step S130 select a terminal having an estimated error value estimated through Equation (6) that is smaller than the reference value as a reference terminal.

The reference sensor node and the reference terminal selection step (S130), if the reference value is not set, the reference terminal is not selected if the number of reference sensor nodes is 3 or more, and the number of reference sensor nodes is 3 , It is possible to select the terminal having the smallest error prediction value as the reference terminal so that the sum of the number of reference sensor nodes and the number of reference terminals is three or more.

In addition, the reference sensor node and the reference terminal selection step (S130) may consider that if the reference value is not set and the number of reference sensor nodes is two or more, the reference terminal is not selected, If the number is less than two, the terminal having the smallest error prediction value can be selected as the reference terminal so that the sum of the number of reference sensor nodes and the number of reference terminals is two or more.

The step of estimating the attitude information of the sensor node (S140) may include the step of estimating the attitude information of the sensor node, the coordinates of the predetermined sensor node, the coordinates of the reference sensor node selected in the reference sensor node and the reference terminal selecting step (S130) In the reference terminal selection step (S130), the attitude information of each sensor node is estimated using the coordinates of the selected reference terminal and the relative direction information.

That is, the step of estimating the attitude information of the sensor node (S140) may be performed by using the reference sensor node coordinates of the sensor node to which the attitude information is to be estimated, the relative direction information of the reference sensor node, , And can be expressed by the following equation (9).

을 나타낸다.here,

.

은 자세정보 행렬을 나타내며,

는 복소수의 실수부,

는 복소수의 허수부를 나타낸다. 그리고

는 의사 역행렬을 나타낸다. 상기 [수학식 8]은 자세정보 추정의 일실시 예로써 센서노드 1(101)이 자세정보를 추정하고자 하는 센서노드이고, 기준 센서노드는 센서노드 2, 3, 4(102, 103, 104)이고, 기준 단말은 단말 A(111)인 경우를 나타낸다.Also,

Represents an attitude information matrix,

Is the real part of the complex number,

Represents the imaginary part of the complex number. And

Represents a pseudoinverse. The reference sensor node includes sensor nodes 2, 3 and 4 (102, 103, and 104), and the reference sensor node is a sensor node 1, , And the reference terminal is the terminal A (111).

Then, the absolute direction information estimation step S150 uses the posture information of each sensor node estimated in the posture information estimation step S140 of the sensor node to calculate the absolute direction information of the sensor node using the relative information obtained in the ranging information and relative direction information acquiring step S110 Direction information is corrected to estimate absolute direction information.

That is, the absolute direction information estimation step S150 is performed using the estimated attitude information at each sensor node. Estimation of the absolute direction information at the sensor node n can be expressed as Equation (10) below.

를 나타낸다.here,

.

The terminal location estimation step S160 uses the ranging information obtained in the relative direction information obtaining step S110 and the absolute direction information estimated in the absolute direction information estimating step S150 to estimate the location of each terminal .

The terminal location estimation step S160 is performed using each sensor node coordinate and absolute direction information. For this purpose, the second location is first estimated using the absolute direction information, which is expressed by the following equation (11).

Here, the Q function may be a general technique such as Brown algorithm for estimating the position using azimuth angle, elevation angle, and sensor node coordinates, or algorithms for repeatedly calculating solutions through linearization. In this manner, the terminal location estimation step S160 may be performed using a Brownian algorithm that uses azimuth angles, elevation angles, coordinates of a predetermined sensor node, or a function for an algorithm that repeatedly calculates solutions through linearization, The location can be estimated.

Finally, the terminal location estimation step S160 is performed by combining the second location estimated in the above equation (11) and the first location estimated in the above equation (5), and the following equation (12) and As shown in Fig.

Where k represents a proportional constant and has a value between [0, 1].

In this manner, the terminal location estimation step S160 is performed by using the ranging information, the ranging information obtained in the relative direction information acquiring step S110, and the absolute direction information estimated in the absolute direction information estimating step S150, Estimates a second location, combines the first location of each terminal estimated roughly in the terminal first location estimation step (S120) and the second location of each estimated terminal with a predetermined proportionality constant to determine the location of each terminal Can be estimated.

Meanwhile, the location estimation termination step S170 re-estimates the error prediction value from the location of each terminal estimated in the terminal location estimation step S160, and determines whether the difference between the re-estimated error prediction value and the previous error prediction value is equal to or greater than the reference point And estimates the end of the estimation.

The reference terminal update update and update step S180 updates the reference sensor node and the reference terminal selected in the reference terminal selection step S130 on the basis of the re-estimated error prediction value in the estimation termination determination step S170.

In this manner, the reference terminal update update and update step S180 re-estimates the error prediction value from the location of each terminal estimated by the above equation (12). If the error prediction value differs from the previous error prediction value through the reference terminal update update and update step (S180), it is determined whether the difference between the previous value and the current value is equal to or greater than the reference point, The terminal can be updated. The reference point can be expressed by the following equation (13).

는 기준점 상수를 나타낸다.here,

Represents the reference point constant.

Meanwhile, the location estimation termination determination step (S170) determines whether the location estimation is terminated. In the case where the position estimation and the positioning are continuously performed, the sensor node posture correction and positioning method using the multiple antennas according to the embodiment of the present invention is repeatedly performed at step S180 through step S140 through step S160. If it is determined that the location estimation is to be ended, the posture correction and positioning method of the sensor node using the multiple antennas according to the embodiment of the present invention ends the location and estimation.

FIG. 3 is a diagram illustrating a sensor node using multiple antennas according to another embodiment of the present invention and a posture correction and position estimation process of each terminal.

As shown in FIG. 3, a sensor node and each terminal employing multiple antennas according to an embodiment of the present invention are each composed of three sensor nodes having multiple antennas and two terminals. Here, each sensor node has multiple antennas of five elements.

The sensor node 1 101, the sensor node 2 102, and the sensor node 3 103 are located at coordinates of a predetermined sensor node.

The sensor node 1 101, the sensor node 2 102 and the sensor node 3 103 are subjected to ranging with the terminal A 111 and the terminal B 112, respectively. The relative directions between the sensor node 1 101, the sensor node 2 102 and the sensor node 3 103 and between the terminal A 111 and the terminal B 112 are estimated.

First, the attitude correction and the position estimation process of the sensor node and each terminal are performed, and a ranging process and a relative direction information calculation process are performed.

로 계산된다. 그리고 레인징 수행 및 상대 방향정보 계산 과정은 상대 방향정보를 계산한다.Specifically, the ranging process and the relative direction information calculation process calculate the distance between the sensor node and the terminal by performing ranging. For example, the distance between the sensor node 1 (101) and the terminal A (111)

. The ranging process and the relative direction information calculation process calculate the relative direction information.

로 계산된다.Here, the ranging process and the calculation process of the relative direction information also calculate the relative direction information of sensor nodes other than the sensor nodes. For example, the relative direction information of the sensor node 1 (101) other than the sensor node 2 (102)

.

Then, a rough estimation process of each terminal location is performed.

를 이용하여 단말 A(111)의 개략적인 제1 위치해를 추정한다.Assuming that the position of the terminal A 111 is estimated, the distance between the sensor node 1 101 and the terminal A 111

Estimates the approximate first location of the terminal A (111).

Then, an error prediction value estimation process of each terminal is performed.

The error prediction value estimation process of each terminal calculates a criterion for selecting a reference terminal, and is expressed by Equation (6).

Then, the attitude information estimation process of the sensor node is performed.

In one embodiment, the case of estimating the attitude information of the sensor node 1 (101) will be described. In the attitude information estimation process, the sensor node 2 (102) and the sensor node 3 (103) become reference sensor nodes.

At this time, if the error prediction value of the terminal A 111 is smaller than the reference value and the error prediction value of the terminal B 112 is larger than the reference value, the terminal A 111 is selected as the reference terminal.

First, if the reference value is not set and the number of reference sensor nodes is 3 or more, the reference terminal is not selected. On the other hand, if the number of reference sensor nodes is less than three, the terminal with the smallest error prediction value is selected as the reference terminal so that the sum of the number of reference sensor nodes and the number of reference terminals is three or more.

Second, if two-dimensional coordinates are taken into consideration and reference values are not set and the number of reference sensor nodes is two or more, the reference terminal is not selected. On the other hand, if the number of reference sensor nodes is less than two, the terminal with the smallest error prediction value is selected as the reference terminal so that the sum of the number of reference sensor nodes and the number of reference terminals is two or more.

Accordingly, the attitude information estimation process of the sensor node 1 (101) estimates the attitude information using the reference sensor node coordinates, the relative direction information with respect to the reference sensor node, the reference terminal coordinates, and the relative direction information with respect to the reference terminal, (9). &Quot; (9) "

The relative direction information of the terminal A 111 and the terminal B 112 estimated by the sensor node 1 101 is corrected to the absolute direction information using the attitude information of the sensor node 1 101, .

Then, the location information of each terminal is estimated using the ranging information and the absolute direction information. In the process of estimating the location of each mobile station, Equation (12) is used to combine the approximate first location according to Equation (5) with the second location of Equation (11). Equation (11) indicates that the second location of each terminal is estimated with absolute direction information.

And a reference terminal update and determination process can be performed. The reference terminal update and determination process determines whether to update the reference terminal by recalculating Equation (8) from the location of each terminal estimated through Equation (12), and updates the reference terminal when the reference terminal is more than the reference point .

4 is a flowchart illustrating a selection process of a reference sensor node and a reference terminal according to an embodiment of the present invention.

As shown in FIG. 4, a case of selecting a reference sensor node and a reference terminal in the first sensor node 101 will be described.

Case 1 in FIG. 4 shows a range of a reference sensor node and a reference terminal selected when the error prediction value of the terminal A 111 is smaller than the reference value and the error prediction value of the terminal B 112 is larger than the reference value. The reference sensor node index selected in case 1 is 2 and 3, and the reference terminal index is A.

Case 2 of FIG. 4 shows a range of a reference sensor node and a reference terminal selected when the error predicted value of the terminal A 111 and the terminal B 112 is smaller than the reference value. The reference sensor node indexes selected in Case 2 are 2 and 3, and the reference terminal indexes are A and B, respectively.

FIG. 5 is a diagram illustrating a configuration of a posture correction and positioning apparatus of a sensor node using multiple antennas according to an embodiment of the present invention.

5, the sensor node posture correcting and positioning apparatus 100 using multiple antennas according to an embodiment of the present invention includes an information obtaining unit 110, a position estimating unit 120, an attitude estimating unit 130 and a direction information estimating unit 140. Here, the position estimating unit 120 may include a first position estimating unit 121 and a second position estimating unit 122.

The detailed configuration and operation of each component of the posture correction and positioning apparatus 100 of the sensor node to which the multiple antennas of FIG. 5 are applied will be described.

The information obtaining unit 110 obtains ranging information between the reference antenna and each terminal of the sensor node and obtains relative direction information for each terminal from the sensor node.

The location estimating unit 120 estimates the first location of each terminal through location estimation using the ranging information obtained by the information obtaining unit 110. [ Here, the first position estimating unit 121 of the position estimating unit 120 may include a Taylor series function, a Kalman filter function, and a function that obtains a solution by a closed-loop based on a least squares method The first location of each terminal can be estimated using any one of the functions of the terminal.

The attitude information estimation unit 130 estimates an error prediction value of each terminal in the sensor node, compares the estimated error value with the reference value, and selects the reference sensor node and the reference terminal.

The posture information estimating unit 130 calculates the posture information of each sensor node using the coordinate of each predetermined sensor node, the coordinates of the selected reference sensor node and the relative direction information, the coordinates of the selected reference terminal, .

The attitude information estimation unit 130 calculates a matrix from the coordinates of the predetermined sensor node and the first position of each of the estimated terminals, calculates a standard deviation of the distance between the sensor node and the terminal, The error prediction value constants are calculated from the signals and the error prediction values of the respective terminals can be estimated from the sum of the diagonal elements of the calculated matrix and the calculated error prediction value constants in the sensor node.

Here, the attitude information estimation unit 130 does not select a reference terminal when the reference value is not set and the number of reference sensor nodes is three or more in consideration of three-dimensional coordinates, and when the number of reference sensor nodes is less than three The terminal having the smallest error prediction value can be selected as the reference terminal so that the sum of the number of reference sensor nodes and the number of reference terminals is three or more.

The attitude information estimation unit 130 does not select a reference terminal when the reference value is not set and the number of reference sensor nodes is two or more in consideration of the two-dimensional coordinates, The terminal having the smallest error prediction value can be selected as the reference terminal so that the sum of the number of sensor nodes and the number of reference terminals is two or more.

The direction information estimating unit 140 estimates the absolute direction information by correcting the relative direction information obtained by the information obtaining unit 110 using the attitude information of each sensor node estimated by the attitude information estimating unit 130. [

The location estimating unit 120 estimates the location of each terminal using the ranging information obtained by the information obtaining unit 110 and the absolute direction information estimated by the direction information estimating unit 140. [ Here, the second position estimating unit 122 of the position estimating unit 120 may calculate a Brownian algorithm that uses azimuth angles, elevation angles, coordinates of a predetermined sensor node, or a function for an algorithm that repeatedly calculates a solution through linearization The second location of each terminal can be estimated.

The location estimating unit 120 estimates the second location of each terminal using the ranging information obtained by the information obtaining unit 110 and the absolute direction information estimated by the direction information estimating unit 140, The location of each terminal can be estimated by combining the first location of each terminal and the estimated second location of each terminal into a predetermined proportionality constant.

On the other hand, the attitude information estimating unit 130 re-estimates the error predicted value from the estimated position of each terminal, and if the difference between the re-estimated error predicted value and the previous error predicted value is equal to or greater than the reference point, The selected reference terminal can be updated.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or essential characteristics thereof. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present invention.

Sensor nodes 1 to 4: 101 to 104 Terminals A and B: 111 and 112
100: attitude correction and positioning apparatus 110: information obtaining unit
120: Position estimating unit 121: First position estimating unit
122: second position estimating unit 130: attitude information estimating unit
140: direction information estimating unit

Claims (8)

An information acquiring unit acquiring ranging information between a reference antenna of the sensor node and each terminal and acquiring relative direction information for each terminal in the sensor node;
A location estimator for estimating a first location of each terminal through location estimation using the obtained ranging information;
A sensor node estimates an error prediction value of each terminal, selects a reference sensor node and a reference terminal by comparing the estimated error prediction value and the reference value, and determines coordinates of each predetermined sensor node, coordinates of the selected reference sensor node, An attitude information estimating unit that estimates attitude information of each sensor node using direction information, coordinates of the selected reference terminal, and relative direction information; And
And a direction information estimator for estimating absolute direction information by correcting the obtained relative direction information using the estimated attitude information of each sensor node,
Wherein the position estimating unit applies multiple antennas for estimating the position of each terminal using the obtained ranging information and the estimated absolute direction information. The method according to claim 1,
The posture information estimating section may calculate,
Estimating an error prediction value from the estimated location of each terminal and updating the selected reference terminal based on the re-estimated error prediction value if the difference between the re-estimated error prediction value and the previous error prediction value is equal to or greater than a reference point, A Posture Correction and Positioning Apparatus for Sensor Nodes Applying. The method according to claim 1,
The posture information estimating section may calculate,
Calculating a matrix from the coordinates of the predetermined sensor node and a first position of each of the estimated terminals and calculating an error predicted value constant from the standard deviation of the distance between the sensor node and the terminal and the discrete received signal of the terminal received at the sensor node, And a multi-antenna for estimating an error prediction value of each terminal in the sensor node using the calculated sum of diagonal elements of the matrix and the calculated error prediction value constant. The method according to claim 1,
The posture information estimating section may calculate,
If the reference value is not set and the number of reference sensor nodes is 3 or more, the reference terminal is not selected. If the number of reference sensor nodes is less than 3, the number of reference sensor nodes and the number of reference terminals Of the sensor node is selected from the terminal having the smallest error prediction value to the reference terminal so that the sum of the minimum error prediction value and the minimum error prediction value is three or more. The method according to claim 1,
The posture information estimating section may calculate,
If the reference value is not set and the number of reference sensor nodes is 2 or more, the reference terminal is not selected. If the number of reference sensor nodes is less than 2, the number of reference sensor nodes and the number of reference terminals Of the sensor node is selected from the terminal having the smallest error predicted value to the reference terminal so that the sum of the sum of the plurality of antennas is 2 or more. The method according to claim 1,
The position estimating unit may calculate,
A method of estimating the first position of each terminal by using any one of a Taylor series function, a Kalman filter function, and a function of finding a solution by a closed-loop solution based on a least square method, Attitude Correction and Positioning Apparatus of Sensor Node with Antenna. The method according to claim 1,
The position estimating unit may calculate,
Estimating a second position of each terminal using the obtained ranging information and the estimated absolute direction information, and calculating a first position of each of the estimated terminals and a second position of each of the estimated terminals by a predetermined proportional constant And a positioning device for a sensor node applying multiple antennas for estimating the location of each terminal. 8. The method of claim 7,
The position estimating unit may calculate,
A sensor node that applies multiple antennas that estimate the second location of each terminal using a function of the Brownian algorithm that uses azimuth angle and elevation angle, coordinates of a predetermined sensor node, or algorithms that repeatedly calculate solutions by linearization Posture correction and positioning device.

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