KR100978060B1 - Method for position adjustment in indoor position determination system - Google Patents

Abstract

PURPOSE: A method for position adjustment in an indoor position determination system is provided to minimize errors by correcting position data when the generated position information of the indoor measurement system is in a shadow region. CONSTITUTION: When a position is changed, an indoor position determination system performs the correction of position information based on movement speed(S102,S104). Based on the acceleration variation for each axis of an inertial sensor, the indoor measurement system corrects the position information(S106). Based on the candidate position, the indoor measurement system searches a candidate link from indoor network data(S108). If the candidate link is not searched, the indoor measurement system identifies a previous compensated coordinate as a current position(S110,S112).

Description

Method for position adjustment in indoor position determination system

The present invention relates to a method for correcting the position of an indoor positioning system. In more detail, when the location information data calculated by the indoor positioning system generates an error, it is corrected by reflecting a conventional moving speed, in the case of a shaded area, the current position is estimated by using an inertial sensor, or indoor path information, etc. The present invention relates to a location correction method of a wireless LAN-based indoor positioning system for correcting a current location to a location where a network data including a location can be constructed.

The Global Positioning System (GPS), developed by the US Department of Defense, detects the position of satellites in orbit in real time and receives the time and the satellite signal from the GPS receiver through a triangulation. This is how you determine your location. However, in the satellite-based positioning system, errors may occur due to the weather at the time of positioning or the surrounding environment of the location point, and may be reflected and refracted by the outer wall of the building or building, resulting in an error that cannot be utilized indoors. .

In order to configure a positioning system indoors, various schemes are in progress. Among them, a WLAN-based positioning system wirelessly inquires the signal information of each access point (AP) wirelessly, thereby establishing the position information of the previously constructed access point. Position calculation method using the sensitivity of each signal using. However, this method has an error of about 5m indoors, so if you want to determine the position in the indoor navigation system, there is a problem that the position can be displayed on the other pedestrian path by the error. In addition, since the location of the access point can be changed or removed, the location information of the access point must be kept up-to-date to improve the reliability of the location.In case of pedestrians moving continuously and positioning, an error is required. The range of may be larger, and there is a problem in that it is impossible to determine whether the user is moving or stationary in the shaded area where the reception is impossible (a position where the radio wave cannot be received due to the structure of the building).

In addition, since the WLAN-based positioning system calculates and provides only the location information of the user, there is no information for correcting the error occurring in the indoor environment, which is very vulnerable to positioning. However, the wireless LAN-based positioning system applied indoors calculates only the location information, so there is no information to optimize the positioning by correcting errors caused by interference due to interference, surrounding environment, and communication status of the wireless terminal. . In addition, in the case of the shaded area where positioning is impossible, there is no criterion to determine whether the user is moving or stopping even if the user is actually stopped. Therefore, the user needs to use location determination, route search, and voice guidance using continuous location information like a navigation system. In this case, it is necessary to correct the position because it causes the wrong position to be displayed.

Network data in outdoor satellite-based navigation system is used for location determination, route search, and voice guidance, but it is prepared based on the road where the vehicle can move, so there is a lot of unnecessary information and considering pedestrian movement and characteristics Since the conditions are not included, it is necessary to construct network data suitable for pedestrians considering the indoor environment.

In short, the existing WLAN-based positioning system is a system for estimating the location through pre-established AP information. There is an error of 5m indoors and 10-20m outdoors, and if the user moves continuously, the terminal accesses it. The error becomes more severe when considering the time of collecting the information of the point, the time of transmitting the collected access point to the server and receiving the information calculated by the server, and the processing speed of the terminal. In addition, there is a problem in that the location is not received or the error is greater in the area where the access point is not established or in the shadow area where radio wave reception is difficult.

The technical problem to be solved by the present invention is to solve the above problems, and corrects the current position data calculated by the indoor positioning system based on the conventional position, the movement situation of the terminal generated by the inertial sensor and the indoor network data. It is to provide a position correction method of the indoor positioning system to provide a current position more accurately.

Another technical problem to be solved by the present invention is to define a network data for the position correction in the indoor positioning system so that the position information provided by the positioning system to reflect the indoor space information location correction method of the indoor positioning system To provide.

The technical problems of the present invention are not limited to the above-mentioned technical problems, and other technical problems not mentioned will be clearly understood by those skilled in the art from the following description.

The position correction method of the indoor positioning system according to an aspect of the present invention for achieving the technical problem is to calculate the moving speed of the positioning terminal by using the position information of the positioning terminal and the previous position information measured by the indoor positioning system And a movement speed based position correction step of correcting position information of the positioning terminal to reduce the movement speed to a threshold when the movement speed is greater than or equal to a threshold; If a signal for indoor positioning is not received, the movement speed is estimated by comparing the acceleration change amount data generated by the inertial sensor provided in the positioning terminal with the acceleration change amount table for each movement speed, and then the conventional movement direction and the An inertial signal based position correction step of correcting position information of the positioning terminal based on an estimated moving speed; And selecting a link closest to the corrected position among the links included in the indoor network data, and further correcting the corrected position information based on the attribute data of the selected link. .

According to another aspect of the present invention, there is provided a method for correcting a position of an indoor positioning system, the method comprising: receiving current position data of a positioning terminal measured by an indoor positioning system; Selecting a candidate link closest to a current position of the positioning terminal from among links included in indoor network data; And correcting the location information such that the positioning terminal is located within an area of the candidate link based on the attribute data of the candidate link.

According to the present invention as described above, the location information generated by the indoor positioning system indicates a location that cannot be compared with the conventional location, or the location information is not updated in the shaded area where positioning is impossible, or the indoor network data When pointing to a position that cannot be compared with, there is an effect that the error can be minimized by correcting the position data.

Advantages and features of the present invention, and methods for achieving them will be apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but can be implemented in various forms. The embodiments of the present invention make the posting of the present invention complete and the general knowledge in the technical field to which the present invention belongs. It is provided to fully convey the scope of the invention to those skilled in the art, and the present invention is defined only by the scope of the claims. Like reference numerals refer to like elements throughout.

Hereinafter, the present invention will be described with reference to a block diagram or a flowchart for explaining a position correction method and system of an indoor positioning system. At this point, it will be understood that each block of the flowchart illustrations and combinations of flowchart illustrations may be performed by computer program instructions. Since these computer program instructions may be mounted on a processor of a general purpose computer, special purpose computer, or other programmable data processing equipment, those instructions executed through the processor of the computer or other programmable data processing equipment may be described in flow chart block (s). It creates a means to perform the functions. These computer program instructions may be stored in a computer usable or computer readable memory that can be directed to a computer or other programmable data processing equipment to implement functionality in a particular manner, and thus the computer usable or computer readable memory. It is also possible for the instructions stored in to produce an article of manufacture containing instruction means for performing the functions described in the flowchart block (s). Computer program instructions may also be mounted on a computer or other programmable data processing equipment, such that a series of operating steps may be performed on the computer or other programmable data processing equipment to create a computer-executable process. Instructions for performing data processing equipment may also provide steps for performing the functions described in the flowchart block (s).

In addition, each block may represent a portion of a module, segment, or code that includes one or more executable instructions for executing a specified logical function (s). It should also be noted that in some alternative implementations, the functions noted in the blocks may occur out of order. For example, the two blocks shown in succession may in fact be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending on the corresponding function.

First, a position correction method of an indoor positioning system according to an embodiment of the present invention will be described with reference to FIG. 1. 1 is a flow chart of a position correction method of the indoor positioning system according to the present embodiment.

The candidate position S100 according to the coordinates calculated by the positioning system is compared with the previously calculated coordinates to determine whether the position is changed (S102).

If it is changed, the position information is corrected based on the movement speed (S104). Criteria for determining the validity of the moving distance will be described in detail below.

Next, the position information is corrected based on the acceleration change amount for each axis of the inertial sensor (S106). The current position after the correction based on the movement speed (S104) and the correction based on the signal of the inertial sensor (S106) will be referred to as a candidate position.

The candidate link is searched for in the indoor network data based on the candidate location (S108). The link is a concept corresponding to a pedestrian path, which will be described in more detail below. That is, the operation of searching for a candidate link may be interpreted as an operation of determining a pedestrian path determined to be located at the terminal according to the candidate position. In this case, when a previously found link exists, a new candidate link may be found by searching for a link connected to the previous link, or when a previously found link does not exist, a link that is a candidate for all links may be found.

If the candidate link cannot be found (S110), the previous correction coordinate is determined as the current position (S112). If the candidate link exists, the coordinates to be displayed on the terminal based on the attribute of the link is corrected (S114). For example, when the candidate location is outside the area of the candidate link, the location information may be corrected inside the candidate link. A more detailed description of the method of correcting the coordinates based on the candidate link is described in more detail below.

Hereinafter, an operation related to the movement speed based position information correction S104 according to the present embodiment will be described in detail with reference to FIG. 2. It is assumed that the moving speed cannot suddenly change beyond the reference value unless the moving distance is valid unless it is a special case. For example, when the positioning system generates location information by moving to 2m / s and suddenly moving to 100m away, the generated location information is an error and needs to be corrected. Hereinafter, related operations will be described in more detail.

Position correction considering the moving speed is performed by using the average walking speed of the general user and the moving speed of the wireless terminal user. To this end, the average walking speed for the moving means is defined, and this is set as a threshold (S200) to perform correction in consideration of the moving speed of the user. That is, when the positioning system generates position information by setting a threshold of the distance that can be moved per unit time of the positioning terminal user and moving above the threshold, the position information is corrected. The threshold may be determined according to the mobile means used by the positioning terminal user. For example, a threshold of a distance that can be moved per second may be set, such as 3 m / s for general walking and 7 m / s for a cart.

If the moving speed is calculated (S202), it is determined whether the moving speed is less than or equal to the threshold (S204). If the moving speed is less than the threshold, since the position information generated by the positioning system is normal in terms of the moving speed, no special position correction is performed (S210).

On the other hand, if the moving speed exceeds the threshold (S204), it is determined whether the difference between the immediately preceding moving speed and the threshold value is different (S206). If the calculated moving speed increases by more than a predetermined threshold than the previous moving speed, the location information generated by the positioning system is determined to be abnormal, and the moving speed is reduced to a threshold to generate the corrected location information accordingly (S208). For example, if the previous movement speed was 2m / s, and the current movement speed is 20m / s, this movement speed may be determined to be abnormal. However, if the current movement speed is greater than or equal to the threshold, but the previous movement speed is also greater than or equal to the threshold, and the current movement speed and the previous movement speed do not differ by more than the threshold, the positioning terminal is actually moving at an abnormal speed. Because it means, the position correction using the moving speed is not performed (S210).

Next, the operation related to the position information correction S106 based on the amount of change in each axis acceleration of the inertial sensor will be described in detail.

3 is a diagram illustrating an X, Y, Z axis change amount of the inertial sensor according to the moving speed.

In a region where a signal for positioning is not received, the location information is not updated even though the positioning terminal is actually moved. The signal for positioning may be interpreted as a WLAN signal, for example, in a WLAN-based positioning system. In this case as well, the moving speed can be estimated using the X, Y, Z axis variation of the inertial sensor. In addition, even when the position information is corrected by performing the correction of the position information based on the movement speed and thus the position information is corrected, since the actual movement speed of the positioning terminal may not be the threshold value, refer to the acceleration change amount of each axis of the inertial sensor. Then, the actual moving speed of the positioning terminal can be estimated.

When the user operates the positioning terminal or moves at a constant speed, a change occurs in the X, Y, and Z axes of the inertial sensor, and as shown in FIG. There will be a difference. In this way, it can be used as data for judging movement by calculating the amount of change when the user moves at a constant speed or stops.

The information on 'X, Y, Z axis change amount' shows that when the wireless terminal is laid horizontally in a flat position, the amount of change in X axis is when the terminal is tilted left and right, and the amount of change in Y axis is when the terminal is tilted up and down. The change amount, and the Z-axis change amount, is a value when the terminal is tilted back and forth based on the vertical state.

The inertial sensor provided in the positioning terminal may not provide all of the three axes of change. Even in this case, since the speed can be estimated only by the amount of change provided, the present invention is not limited to using all the amount of change on all three axes.

When a signal for positioning is received, the acceleration variation data generated by the inertial sensor is accumulated. Since the movement speed has already been calculated in the operation (S104) based on the movement speed, the change amount data is accumulated in the change amount table according to the movement speed. The operation of accumulating the change amount data may be interpreted as an operation of updating the change amount table for each speed by checking the change amounts of X, Y, and Z. For example, if the current speed is 5m / s, it can be updated to the average value further reflects the amount of change in the X, Y, Z axis measured by the inertial sensor. For example, if the change amount of the X axis at 5 m / s is 10 and the result of three measurements is made, the change amount of the newly measured X axis at the speed of 5 m / s is 14 (10 * 3 + 14) / If 4 = 11, and the 5m / s stored in the table, the amount of change in the X-axis will be updated to 11.

On the contrary, when a signal for positioning is not received, the current moving speed is estimated by referring to the change amount table for each speed. In more detail, it can be estimated that the movement speed that minimizes the difference between the acceleration change amount of each axis included in the speed change amount table and the acceleration change amount value of the currently measured inertial sensor is the current movement speed of the positioning terminal. . In addition, the current candidate position according to the movement speed is determined. In determining the candidate position, a conventional direction of movement may be considered. That is, it is assumed that the movement in the same direction as the conventional movement direction, the current candidate position may be determined by applying the movement speed according to the X, Y, Z change amount of the inertial sensor.

Next, an operation related to the correction of the coordinates based on the candidate link S114 will be described in more detail.

Information about the indoor space where the positioning terminal is currently located is included in the indoor network data. The information on the indoor space includes location information on each space where pedestrians can be located, such as walkways, entrances, rooms, and lobby. In addition, it may include information on whether or not to allow access to each time zone for each space.

Pedestrian paths indoors are fixed if they are not for special purposes. Therefore, if the positioning system generated the current position where the pedestrian cannot be located, it is determined that there is an error in the position information, and the correction may be performed.

The indoor network data includes data on a pedestrian center line and pedestrian width for a path that a user can move, data on entrance and exit points according to facility entry, data on connection information between floors in consideration of movement between floors, and traffic / restriction information of a pedestrian path. May contain data. The indoor network data may be stored in the positioning terminal. In addition, the indoor network data may be stored in a positioning server that provides a positioning service.

4 is a conceptual diagram to help understanding the indoor network data.

The indoor network data is composed of spatial data and non-spatial data (property data). The spatial data includes a node corresponding to a point and a link composed of a point and a line. The attribute data refers to data defining information that a node and a link have, and the attribute information of the node includes information on directions that can be entered from the node (1 o'clock entry, 3 o'clock entry, etc.), facility information It may include information about a specific connection point, such as a shopping mall entry point, an inter-floor moving point, and the like. Further, the attribute information of the link may include, for example, the type of the link (general walkway, shopping street access, inter-floor moving path, etc.), the direction of the link, the facility name of the link (lake road, riverside road, etc.), the width of the link ( width) can be included.

5 is an example of position correction using a pedestrian width of network data.

The position correction shown in FIG. 5 may be performed through the following steps.

First, the candidate link located closest to the candidate position is found. For example, in the case of the error coordinates shown at the bottom of FIG. 5, the candidate link is a link having a value of 100 1003 as the link_ID. The distance between the candidate position and the candidate link may be measured as the length of the repair line, for example, when a line is drawn from the candidate position on the link.

The candidate link is searched first among the links connected to the previous candidate link when a previously matched candidate link exists. If the candidate link is not found among the links connected to the previous candidate link, it is preferable to extract the candidate link by inspecting the entire link.

In the case of large buildings, there are locations that cannot be moved over time, and there are traffic / restriction information on pedestrian paths, such as sections that can only be moved by pedestrians or certain means of transportation. By constructing the corresponding attribute information on the network link for such a position, when the coordinates are received, only the links suitable for the condition are used as the candidates for coordinate correction when the coordinates are received. More specifically, after receiving the means for moving the pedestrian through the positioning terminal, finding the closest candidate link using the position information of the positioning terminal calculated through the positioning system, the traffic / limiting information included in the attribute data of the candidate link. Determining whether the current traffic is possible with reference to, and if the current positioning terminal is a link that can not be located, finds another candidate link and performs the position correction.

In other words, if it is determined by referring to the attribute data of the candidate link, another link should be searched if the link cannot be located.

Next, it is determined whether the candidate position is outside the area of the candidate link. Since the attribute data of the candidate link includes data about the width of the candidate link, even if the width of the link is taken into consideration, if the candidate position is outside the area of the candidate link, as shown in FIG. The location information can be corrected to be located.

As a result, as shown in FIG. 5, the moving path of the positioning terminal (not shown) is not performed through indoor network data, and the moving path (in the solid line) is located inside the link where the positioning terminal may be located. Correction is performed).

Hereinafter, when the width of the pedestrian path is wide, an operation of more flexibly correcting the position of the pedestrian by forming a grid-shaped link will be described with reference to FIG. 6.

For points where it is difficult to determine the width of the pedestrian path, it is also possible to construct an additional network link for both sides of the corridor in addition to the pedestrian center line to properly express the position of the user. In addition, it is possible to stop and move left and right while walking, so that each network link can be configured in a grid form and displayed on the screen in consideration of the left and right movement of pedestrians.

In the case of outdoor network data, a link having a property capable of bidirectionally proceeding with one link with respect to one road or a bidirectional link with each other may be configured with a maximum of two links. However, indoors have large areas of pedestrian space, such as food courts and exhibition halls, so when expressing pedestrian movement with up to two links, even if pedestrians move freely, position correction using indoor network data is possible It exists on the link. As a result, problems arise that pedestrians always appear to move along a fixed walkway. In order to solve this problem, it is possible to cope with the case where the user does not move along the corridor center line in a wide pedestrian path by constructing a pedestrian link at a predetermined distance apart from the pedestrian center line. When a pedestrian moves to the edge of a wide pedestrian path, the position correction will include the correction of the position, including the corridor centerline as well as the added pedestrian link. In addition, considering the case of moving sideways differently from the direction of the center line of the corridor, it is possible to adjust the natural position even when moving sideways when constructing a grid type by adding a link link that can move between the actual corridor center line and the virtual link. Do. In other words, the outdoor network data is composed of up to 1: 2 links of roads including turning sections, whereas up to 1: n links are constructed indoors. It is characterized in that the position can be expressed naturally even when moving.

In addition, since there is an entry point and an entry point into the facility, an entry / exit link is established separately for the facility, and if the coordinates match the entry link, the user judges that the user enters the facility. It is possible to match the correction to the link including the link in the facility, and if the entry link is matched, it is determined that the user is advancing from the facility to another facility or the pedestrian path. It is possible to include and match.

In the building of connection information between floors considering the movement of floors, the existing outdoor navigation system considers cars and builds 2D-based network information, but it is possible to move to other floors in buildings, so elevators, stairs, escalators, etc. Separate data must be defined and constructed for the path that can be moved to to be used for locating pedestrians using 3D spatial network connection technology. In the interior, it is only possible to enter a specific passage to move between floors, so when entering this inter-floor connection information, the pedestrian's position is determined by adjusting the position to the floor that can be entered by the inter-floor connection information. shall. For example, when the positioning terminal located on the second floor moves to an upstream escalator entry point, it is preferable to correct the position based on the indoor network data for the third floor instead of the second floor.

Although the embodiments of the present invention have been described above with reference to the accompanying drawings, those skilled in the art to which the present invention pertains may implement the present invention in other specific forms without changing the technical spirit or essential features thereof. I can understand that. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive.

1 is a flow chart of a position correction method of the indoor positioning system according to an embodiment of the present invention.

2 is a flowchart illustrating a movement speed based position information correction related operation according to an embodiment of the present invention.

3 is a diagram illustrating an X, Y, Z axis change amount of the inertial sensor according to the moving speed.

4 is a conceptual diagram to help understanding indoor network data according to an embodiment of the present invention.

5 is an example of position correction using a pedestrian path width of network data according to an exemplary embodiment.

6 is a conceptual diagram of a grid-shaped link according to an embodiment of the present invention.

Claims (10)

The moving speed of the positioning terminal is calculated by using the current position information of the positioning terminal and the previous position information measured by an indoor positioning system, and when the moving speed is greater than or equal to a threshold, the positioning speed can be reduced to a threshold. A movement speed based position correction step of correcting current position information of the terminal; If a signal for indoor positioning is not received, the movement speed is estimated by comparing the acceleration change amount data generated by the inertial sensor provided in the positioning terminal with the acceleration change amount table for each movement speed, and then the conventional movement direction and the estimation. An inertial signal based position correction step of correcting current position information of the positioning terminal based on the moved speed; And And selecting a link closest to the corrected position among the links included in the indoor network data, and further correcting the corrected current position information based on the attribute data of the selected link. How to calibrate the position of the indoor positioning system. The method of claim 1, The moving speed based position correction step, And receiving the moving means of a positioning terminal and setting the threshold accordingly. The method of claim 1, The moving speed based position correction step, Even if the moving speed is greater than or equal to the threshold, the position correction of the indoor positioning system comprising the step of correcting the position information of the positioning terminal to reduce the moving speed to the threshold only when the moving speed is increased to the threshold or more from the previous moving speed Way. The method of claim 1, The inertial signal based position correction step, Position correction of the indoor positioning system performed not only when a signal for indoor positioning is received but also when the position information of the positioning terminal is corrected to reduce the movement speed to a threshold value by the movement speed based position correction step. Way. Receiving current location data of the positioning terminal measured by the indoor positioning system; Selecting a candidate link closest to a current position of the positioning terminal from among links included in indoor network data; And Correcting the current position data of the positioning terminal so that the positioning terminal is located within an area of the candidate link based on the attribute data of the candidate link. The method of claim 5, The attribute data of the link included in the indoor network data includes data on the width of the link. The method of claim 5, The indoor network data, 12. A method for calibrating a location in an indoor positioning system comprising at least one walkway composed of grid-shaped links. The method of claim 5, The indoor network data, A method for calibrating a location of an indoor positioning system comprising at least one piece of data about an entry point capable of moving between floors. The method of claim 5, Selecting the candidate link, And if a previous candidate link has been selected, first selecting a candidate link among links linked with the previous candidate link. The method of claim 5, Selecting the candidate link, Select a candidate link that is closest to the current location of the positioning terminal among the links included in the indoor network data, and if the current positioning terminal cannot be located according to the attribute data of the candidate link, select the candidate link for another link. Position correction method of the indoor positioning system comprising a step.

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