KR101476755B1 - Apparatus and method for estimating location of an object - Google Patents

Abstract

An apparatus and method for estimating an object's position are disclosed. The storage unit stores the travel pattern of the object for each of the route data and the route data obtained by digitizing the location information of the route that the plurality of objects travels. The first position estimator estimates the position of the first object on the path data based on the GPS data input from the GPS reception module of the first object, which is the position estimation object, and outputs the first position information. The error correcting unit corrects the GPS data based on the measured GPS data and the acceleration / deceleration pattern for the path corresponding to each of the route data calculated by the operation pattern of the object for each of the route data while the plurality of objects travel on the route corresponding to the route data. 1 Correct the error present in the position information. The second position estimator estimates the position of the first object on the path data based on the corrected first position information. According to the present invention, it is possible to increase the positional accuracy of an object traveling with a certain movement pattern on a specific route.

Description

[0001] APPARATUS AND METHOD FOR ESTIMATING LOCATION [0002]

The present invention relates to an apparatus and method for estimating an object position, and more particularly, to an apparatus and method for accurately estimating the position of an object obtained based on position data input from a sensor.

Map matching is a technique for correcting inaccurate sensor data (for example, GPS data) to a more realistic position and expressing it through a digital map. Car navigation system is a typical example using map matching technique. It improves the accuracy of position by matching the estimated position to actual road under the assumption that the vehicle always travels only on the road.

Map matching techniques include Point to Point Matching, Point to Curve Matching, and Curve to Curve Matching using the geometric properties of location information. A technique using stochastic characteristics of position information, and a fuzzy-based technique.

Since the map matching technique applied in the car navigation system is modeled on the basis of an automobile, it only needs information on which road the vehicle is on and which speed it is traveling in which direction. Therefore, even if the sensor data contains some errors, there is no problem even if the sensor error is canceled by the map matching method.

However, in order to acquire information on the exact position, it is difficult to use the map matching technique applied to the car navigation system as it is. For example, in the situation where the position of the train is to be precisely detected, when the map matching method used in the car navigation system with the GPS data is used, there is an error in the GPS data itself. There is a problem that it is difficult to ensure accuracy.

Korean Patent Laid-Open No. 10-2002-0091389 (Title of the invention: Map matching method using satellite navigation device / speculative navigation device integration system and multiple hypothesis technique, publication date: 2002.12.06) Korean Patent Laid-Open No. 10-2009-0001176 (Title of the Invention: Vehicle Positioning Method Using Predictive Navigation and Vehicle Navigation Device Using It, Release Date: 2009.01.08) Korean Patent Laid-Open No. 10-2011-0126057 (entitled " Device for determining the moving state, method for determining the moving state and recording medium, published on November 22, 2011)

SUMMARY OF THE INVENTION It is an object of the present invention to provide an apparatus and method for correcting a position of an object that can travel with a certain movement pattern on a specific path and increase the positional accuracy of the object.

SUMMARY OF THE INVENTION The present invention provides a computer-readable recording medium recording a program for causing a computer to execute a method of correcting a position of an object that can travel with a certain movement pattern on a specific path and increase the positional accuracy of the object I have to.

According to an aspect of the present invention, there is provided an apparatus for correcting a position of an object, the apparatus comprising: a storage unit for storing path data obtained by digitizing position information of a path traveled by a plurality of objects; A storage unit; A first position estimator for estimating a position of the first object on the path data based on GPS data input from a GPS reception module of a first object, which is a position estimation object, and outputting first position information; A plurality of objects running on a route corresponding to the route data, and an acceleration / deceleration pattern for a route corresponding to each of the route data calculated by the GPS data measured by the operation pattern of the object for each of the route data, An error corrector for correcting an error existing in the first position information; And a second position estimator for estimating a position of the first object on the path data based on the first position information corrected by the error corrector.

According to another aspect of the present invention, there is provided a method of correcting a position of an object, the method comprising: (a) obtaining a plurality of objects stored in a database based on GPS data input from a GPS receiving module of a first object, Estimating the position of the first object on the path data obtained by digitizing the position information of the path on which the first object is traveling, and outputting the first position information; (b) an acceleration / deceleration pattern for a path corresponding to each of the path data calculated by the GPS data measured while the plurality of objects travels along the path corresponding to the path data and the operation pattern of the object for each of the path data Correcting an error existing in the first position information based on the first position information; And (c) estimating a position of the first object on the path data based on the corrected first position information.

According to the apparatus and method for correcting the position of an object according to the present invention, the position accuracy of an object traveling with a certain movement pattern on a specific path can be enhanced.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a configuration of a preferred embodiment of an apparatus for estimating a position of an object according to the present invention;
2 is a diagram showing an acceleration / deceleration pattern with respect to a section between a dongbong station and a dongbong station of National railway line 1,
FIG. 3 is a diagram showing a change in latitude according to time measured for different objects in a section between a docking station and a Dobong-son station of National railway line 1,
4 is a diagram showing an acceleration / deceleration pattern for obtaining a predicted acceleration component,
5 is a view showing an object position, an acceleration / deceleration pattern of an object, and an object position corrected by an error corrector 130, which are detected by GPS data in a section between a docking station and a Dobong-son station of a national railway line 1,
6 shows the movement path (red) of the object by the GPS data corrected by the error corrector 130 on the data map (source: Google Earth) corresponding to the section between the unloading station and the Dobong station of National Railway Line 1 drawing,
7 shows a second position estimating unit 140 for the position of an object corrected by the error corrector 130 on a data map (source: Google Earth) corresponding to a section between the unloading station and the Dobong station of National Railway Line 1 (Pin) of an object after map matching is performed,
8 is a flowchart illustrating a method of estimating a position of an object according to the present invention.

Hereinafter, a preferred embodiment of an apparatus and method for estimating an object position according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a diagram showing a configuration of a preferred embodiment of an apparatus for estimating a position of an object according to the present invention.

Referring to FIG. 1, an apparatus for estimating an object position according to the present invention includes a storage unit 110, a first position estimating unit 120, an error correcting unit 130, and a second position estimating unit 140 .

The storage unit 110 stores path data obtained by digitizing the position information of the path on which the object moves. An object of the present invention is to estimate an accurate position of an object traveling on a predetermined route such as a train, a ship, an aircraft or the like in a predetermined pattern. Therefore, the path data is composed of the latitude and longitude coordinates such as the railroad track and the route. In addition, the storage unit 110 stores the operation pattern of the object for each route. The running pattern of the object consists of the acceleration / deceleration pattern in the latitudinal direction and the acceleration / deceleration pattern in the longitudinal direction.

An object traveling on a route defined by a certain pattern such as a train travels in a constant acceleration / deceleration pattern in a specific section when the vehicle travels in a normal state (that is, in a state of operation except for a specific situation such as a signal waiting or a train accident). The acceleration / deceleration pattern may be different for each section during which the object is traveling, and there is a slight difference for each object within the same section. Therefore, it is necessary to classify the respective paths into a plurality of sections, and to approximate the acceleration / deceleration pattern for each section (for example, acceleration section, constant speed section, deceleration section).

2 is a diagram showing an acceleration / deceleration pattern with respect to a section between a dongbong station and a dongbong station of National railway line 1. In Fig. 2 (a) is the acceleration / deceleration pattern in the latitudinal direction, and (b) is the acceleration / deceleration pattern in the longitudinal direction. In FIG. 2, circles represent acceleration / deceleration data measured for each object, and rectangles represent acceleration / deceleration patterns obtained by approximating acceleration / deceleration data measured for each object. Referring to FIG. 2, the acceleration / deceleration data is different for each object, but approximating the acceleration / deceleration data can obtain an acceleration / deceleration pattern for each section.

The first position estimating unit 120 estimates the position of the object on the path data stored in the storage unit 110 based on the GPS data input from the GPS receiver (not shown) (i.e., the latitude and longitude coordinates of the object) . In this process, the first position estimating unit 120 outputs the first position information by estimating the position of the object closest to the input GPS data among the respective longitudinal degree coordinates constituting the path data, as the position of the object. The technique for estimating the position of an object traveling on a constant path based on the GPS data is well known to those skilled in the art, and thus a detailed description thereof will be omitted. In this case, the GPS receiver may be implemented as a separate module from the object position estimating apparatus according to the present invention. In this case, the object position estimating apparatus according to the present invention includes a receiver for receiving GPS data from the GPS receiver. Alternatively, the GPS receiver may be implemented integrally with the object position estimating apparatus according to the present invention.

The error corrector 130 corrects an error existing in the first position information which is the position of the object estimated by the first position estimator 120. [ GPS data itself contains errors (ie, noise, error, etc.), so to estimate the exact position of an object, errors present in the GPS data must be removed. The error corrector 130 may be implemented by a Kalman filter. When the error corrector 130 is implemented by a Kalman filter, the characteristic matrix of the Kalman filter must first be obtained. The characteristic matrix of the Kalman filter is calculated by the GPS data received while the object moves. In general, a Kalman filter is used to detect a signal from noise so that one system can predict the change over time appropriately. Therefore, the sampling unit of a conventional Kalman filter is time, but in the case of the present invention, the position is used in units of sampling in accordance with the characteristics of data to be processed.

FIG. 3 is a diagram showing a change in latitude with respect to time measured for different objects in a section between a dongbong station and a dongbong station of National railway line 1. In FIG. 3 (a) is a change in latitude with time measured for the first object, and (b) is a change in latitude with time measured for the second object.

Referring to FIG. 3, the GPS data in circle A in FIGS. 3 (a) and 3 (b) are not constant in interval, which means that GPS data is partially missing during the time corresponding to circle A. Also, in FIG. 3A and FIG. 3B, point B, which is the starting point of the GPS data input, and point C, which is the end point, are different from each other, and this corresponds to the train corresponding to the first object and the second object It is because the departure times of the trains are different. Therefore, considering that the characteristic of the Kalman filter having a constant sampling interval and the starting point and the ending point are different from each other, it is difficult to accurately grasp the driving time point of the Kalman filter. Therefore, It is not appropriate. On the contrary, it can be seen that the time variation from point C, which is the starting point where the actual positions of the first object and the second object move, to point B, which is the end point, This means that the time taken for the actual object to arrive and arrive is somewhat constant. From this, it can be assumed that the acceleration / deceleration pattern of each object is similar within a certain interval. If the path of a specific section is known and the acceleration / deceleration pattern of the object in the section is known, it is more appropriate to set the sampling unit of the Kalman filter as the position because the object always passes through the path. Therefore, the configuration of the Kalman filter employed in the error corrector 130 can be expressed by the following equation.

,

이고, Δt는 현재 GPS 데이터를 받은 시간과 이전 GPS 데이터를 받은 시간에 대한 변화량, α는 가감속 패턴의 근사화로부터 얻어진 예측 가속도 성분이다.Here, k is a natural number,

,

.DELTA.t is a change amount with respect to the time when the current GPS data was received and the time when the previous GPS data was received, and .alpha. Is the predicted acceleration component obtained from the approximation of the acceleration / deceleration pattern.

On the other hand, the predicted acceleration component? In Equation (1) is expressed by the following equation.

In Equation (2),? Is the slope of the acceleration section or the deceleration section in the acceleration / deceleration pattern shown in FIG.

Accordingly, the error corrector 130 may calculate the first position information, which is the position of the object received from the first position estimator 120, and the velocity of the object using the Kalman filter model implemented based on the Kalman filter model expression expressed by Equation (1) The position value is output as the position value of the corrected object with respect to each sampling point (that is, the point at which the GPS data is received while moving the object). This can be expressed as follows.

Where Z _k is the position value of the corrected object at time _k , x _k is the output of the Kalman filter, and H is a 1 × 2 matrix with [10].

5 is a diagram showing an object position, an acceleration / deceleration pattern of an object, and an object position corrected by the error corrector 130, which are detected by GPS data in a section between a docking station and a Dobongsan station of National Railway Line 1. [ 5 (a) is a result calculated for latitude and (b) is a result calculated for hardness.

Referring to FIG. 5, it can be seen that the object position (dotted line) grasped by the GPS data with respect to the acceleration / deceleration pattern (solid line) of the object shows a large deviation in both latitude and longitude, (Dot-dash line) is close to the acceleration / deceleration pattern of the object. From this, it can be confirmed that the GPS data corrected by the error corrector 130 has a smaller data noise than that before the correction.

The second position estimation unit 140 estimates the position of the object on the path data stored in the storage unit 110 based on the position of the object corrected by the error correction unit 130. [ In this process, the second position estimating unit 140 estimates the position of the object closest to the position of the input object among the respective longitudinal degrees of coordinates constituting the path data, and outputs the second position information. At this time, the second position estimating unit 140 can estimate the position of the object using a known point-to-curve matching technique.

6 shows the movement path (red line) of the object by the GPS data corrected by the error correction unit 130 on the data map (source: Google Earth) corresponding to the section between the unloading station and the Dobong- FIG. 7 is a view showing the position of the object corrected by the error corrector 130 on the data map (source: Google Earth) corresponding to the section between the unloading station and the Dobong station of the National Railroad No. 1, (Yellow pin) of the object after the map matching 140 performs map matching. As can be seen from FIGS. 6 and 7, the position of the object corrected by the error corrector 130 indicates that the error in the longitudinal direction is larger than that of the actual object in the latitudinal direction have. Therefore, since the position of the object corrected by the error corrector 130 is unreliable in the hardness direction, the value approximates to the acceleration / deceleration pattern despite the increase / decrease of the sensor value. The position of the object after the second position estimator 140 performs the map matching with respect to the position of the object corrected by the error corrector 130 accurately follows the line.

8 is a flowchart illustrating a method of estimating a position of an object according to the present invention.

Referring to FIG. 8, the first position estimating unit 120 estimates the position of the object on the path data stored in the storage unit 110 based on the GPS data input from the GPS receiver (S800). In this process, the first position estimating unit 120 outputs the first position information by estimating the position of the object closest to the input GPS data among the respective longitudinal degree coordinates constituting the path data, as the position of the object. Next, the error corrector 130 corrects an error existing in the first position information, which is the position of the object estimated by the first position estimator 120 (S810). For this, the error corrector 130 corrects the position of the object obtained by using the GPS data received during the movement of the object and the velocity of the object at the time of reception of each GPS data as the input of the Kalman filter implemented by Equation (1) Position. Next, the second position estimation unit 140 estimates the position of the object on the path data stored in the storage unit 110 based on the first position information corrected by the error correction unit 130 (S820) . In this process, the second position estimating unit 140 estimates the position of the object closest to the input GPS data among the respective longitudinal degree coordinates constituting the path data to output the second position information.

The present invention can also be embodied as computer-readable codes on a computer-readable recording medium. A computer-readable recording medium includes all kinds of recording apparatuses in which data that can be read by a computer apparatus is stored. Examples of the computer-readable recording medium include a ROM, a RAM, a CD-ROM, a magnetic tape, a floppy disk, an optical data storage device, and the like in the form of a carrier wave . In addition, the computer-readable recording medium may be distributed to computer devices connected to a wired / wireless communication network, and a computer-readable code may be stored and executed in a distributed manner.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the appended claims.

Claims (6)

A storage unit for storing route data obtained by digitizing location information of a route that a plurality of objects travel on and a travel pattern of an object for each of the route data;
A first position estimator for estimating a position of the first object on the path data based on GPS data input from a GPS reception module of a first object, which is a position estimation object, and outputting first position information;
A plurality of objects running on a route corresponding to the route data, and an acceleration / deceleration pattern for a route corresponding to each of the route data calculated by the GPS data measured by the operation pattern of the object for each of the route data, An error corrector for correcting an error existing in the first position information; And
And a second position estimator for estimating a position of the first object on the path data based on the first position information corrected by the error corrector,
Wherein the error corrector corrects an error existing in the first position information by a Kalman filter having a model expression expressed by the following equation A and using a position as a sampling unit:
[Mathematical formula A]

Here, k is a natural number,

,

.DELTA.t is a change amount with respect to the time when the current GPS data was received and the time when the previous GPS data was received, and .alpha. Is the predicted acceleration component obtained from the approximation of the acceleration / deceleration pattern. delete The method according to claim 1,
Wherein the driving pattern of the object includes an acceleration / deceleration pattern in the latitudinal direction and an acceleration / deceleration pattern in the longitudinal direction. (a) locating the position of the first object on the path data obtained by digitizing the position information of the path traveled by the plurality of objects stored in the database based on the GPS data input from the GPS receiving module of the first object, Estimating and outputting first position information;
(b) an acceleration / deceleration pattern for a path corresponding to each of the path data calculated by the GPS data measured while the plurality of objects travels along the path corresponding to the path data and the operation pattern of the object for each of the path data Correcting an error existing in the first position information based on the first position information; And
(c) estimating a position of the first object on the path data based on the corrected first position information,
Wherein in the step (b), an error existing in the first position information is corrected by a Kalman filter having a model expression expressed by the following equation (A) and using a position as a sampling unit: Way:
[Mathematical formula A]

Here, k is a natural number,

,

.DELTA.t is a change amount with respect to the time when the current GPS data was received and the time when the previous GPS data was received, and .alpha. Is the predicted acceleration component obtained from the approximation of the acceleration / deceleration pattern. delete A computer-readable recording medium having recorded thereon a program for causing a computer to execute the method for estimating the position of an object according to claim 4.

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