KR20120068668A - Apparatus and method for detecting a position - Google Patents

Abstract

PURPOSE: A location measuring apparatus and method are provided to precisely measure positions using information provided by a visible-ray wireless communication device and an image sensor and the inclination of the image sensor. CONSTITUTION: A location measuring method comprises the steps of: acquiring the focal distance of an image sensor(S100), acquiring virtual coordinates(S110), acquiring a first virtual light-source distance on the image sensor tilting based on the virtual coordinates(S120), measuring the inclination of the image sensor(S130), acquiring a virtual height(S140), calculating a second virtual light-source distance(S150), acquiring first and second virtual distances(S160), calculating first and second distances(S170), and acquiring the position of the image sensor(S180).

Description

Apparatus and method for detecting a position}

The present invention relates to a position measuring apparatus and a method thereof, and more particularly, to a position measuring apparatus and method using an image sensor.

In general, a GPS (Global Positioning System) is used as a method of measuring the position of a predetermined target. The GPS method calculates the distance from the GPS satellite by measuring the time taken by the location measurement target to receive the location information from the GPS satellite and receiving the location information. However, the distance from one GPS satellite is the same for any location on the sphere that is measured away from the GPS satellite. However, if this information is more than three, that is, knowing the orbit information (longitude and latitude) and distance of the satellites from three or more GPS satellites, there will be a point where virtual spheres made from three GPS satellites meet and the location is located. It becomes the position of a measurement object. However, the GPS-based location information may generate an error depending on the precision of the positioning information provided by the GPS satellites and the accuracy of the current time information required to calculate the distance between the GPS satellites and itself, which may be several tens of meters. In addition, GPS satellite signals have a disadvantage that cannot be received indoors.

In order to overcome this disadvantage, the mobile station may use location information of a base station being accessed or access location information of a wireless LAN such as WiFi. However, the biggest disadvantage of the location information service using the radio waves is that it is difficult to provide three-dimensional location information. That is, it is possible to obtain information that the location of the object is located in a building, but it is difficult to provide information on the level of being located on a certain floor or in a few rooms. In order to overcome this disadvantage, there is a technology for measuring the location by receiving the location information using the visible light wireless communication technology, in this case, the location information for the location measurement target can be provided up to the floor, the room level in the building.

SUMMARY OF THE INVENTION The present invention has been made in an effort to provide an apparatus and method for more accurately measuring position when performing position measurement using visible light wireless communication technology.

The position measuring method according to an aspect of the present invention for the above problem is a method for measuring the position based on information provided from at least one communication device including a transmission light source, the light transmitted from the transmission light source using an image sensor Imaging the image including the signal to obtain precision position information indicative of the position relative to the transmission light source; Calculating an actual light source distance between transmission light sources based on the precise position information; Calculating a virtual light source distance for transmission light sources formed on the image sensor from the captured image; Measuring a tilt of the image sensor; And measuring a position based on the actual light source distance, the virtual light source distance, and the slope.

The measuring of the position may include a first virtual light source distance, which is a virtual light source distance for transmission light sources formed on the image sensor, and a second virtual light source corresponding to the image sensor being in a parallel state based on the inclination. Calculating a distance; And calculating a position based on the second virtual light source distance, the actual light source distance, and precision position information about each transmitted light source.

According to another aspect of the present invention, a position measuring method is a method of measuring a position based on information provided from at least one communication device including a transmitting light source, and includes an optical signal transmitted from the transmitting light source using an image sensor. Acquire an accurate position information indicating a position with respect to the transmission light source, the precision position information including respective coordinates of the X and Y axes on a two-dimensional plane using the X and Y axes Making; Calculating the actual light source distance between the transmission light sources for each of the X and Y axes based on the precision position information when the received precision position information is received from at least two transmission light sources, respectively; Calculating a virtual light source distance for transmission light sources formed on the image sensor for each of X and Y axes from the captured image; Measuring an inclination of the image sensor for each of X and Y axes; Calculating a parallel virtual light source distance for each X-axis and Y-axis corresponding to the image sensor being in a parallel state based on the virtual light source distance and the inclination; And measuring positions on the X and Y axes of the object to be measured, based on the actual light source distance, the parallel virtual light source distance, the slope, and the precise position information measured for each of the X and Y axes.

In addition, the position measuring device according to another aspect of the present invention is a device for measuring the position based on information provided from at least one communication device including a transmission light source, using an image sensor to receive an optical signal transmitted from the transmission light source Accurate position information indicating a position with respect to the transmission light source by capturing an image including the position information, wherein the precise position information includes respective coordinates of the X and Y axes on a two-dimensional plane using the X and Y axes. Obtaining location information receiving unit; An actual light source distance measuring unit configured to calculate an actual light source distance between transmission light sources for each of X and Y axes based on the precise position information; A virtual light source distance measuring unit configured to calculate a virtual light source distance for transmission light sources formed on the image sensor for each of the X and Y axes from the captured image; An inclination measuring unit measuring an inclination of the image sensor for each of X and Y axes; And a position information processor configured to measure positions on the X and Y axes of the object to be measured based on the actual light source distance, the virtual light source distance, the slope, and the precise position information measured for each of the X and Y axes.

Wherein the location information processing unit

Calculating a parallel virtual light source distance for each of the X and Y axes corresponding to the image sensor being in a parallel state based on the virtual light source distance and the inclination; and the precision position information for each of the X and Y axes based on the parallel virtual light source distance. A distance for calculating a first distance, which is a distance from a position of a transmission light source based on a distance to a position to be measured, and a second distance, which is a distance from a position of another transmission light source based on the precision position information, to the position to be measured. A measurement module; And a location calculation module configured to calculate a location of the object based on the first distance, the second distance, and the precise location information of the transmission light sources for each of the X and Y axes.

According to an embodiment of the present invention, when performing position measurement using a visible light wireless communication technology, the position may be measured more precisely using information provided from the visible light wireless communication device, information on an image sensor, and tilt information. .

In addition, with respect to a portable terminal such as a smart phone having an image sensor and an inclination sensor, the position of the portable terminal can be accurately measured without adding a separate component.

1 is a diagram illustrating a concept of providing location information using visible light wireless communication according to an exemplary embodiment of the present invention.
2 is a diagram illustrating a positional relationship between an image sensor and transmission light sources according to an exemplary embodiment of the present invention.
3 is an exemplary view illustrating positions of transmission light sources formed on an image sensor according to an exemplary embodiment of the present invention.
3 is an exemplary view illustrating positions of transmission light sources formed on an image sensor according to an exemplary embodiment of the present invention.
4 is an exemplary view illustrating a state in which an image sensor is inclined with respect to transmission light sources according to an exemplary embodiment of the present invention.
5 is a flowchart illustrating a position measuring method according to an exemplary embodiment of the present invention.
6 is a schematic structural diagram of a position measuring device according to an embodiment of the present invention.
7 is a detailed structural diagram of a position measuring device according to an embodiment of the present invention.
8 is a flowchart illustrating a position measuring method according to another embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

Throughout the specification, when a part is said to "include" a certain component, it means that it can further include other components, except to exclude other components unless specifically stated otherwise.

Hereinafter, a position measuring apparatus and a method thereof according to an embodiment of the present invention will be described with reference to the drawings.

Position measuring apparatus and method according to an embodiment of the present invention, the position measurement using the information provided from the wireless communication system using the visible light.

Visible light is a light ray having a wavelength in the visible range of the human eye and corresponds to a wavelength of 380 nm to 780 nm. In visible light, the change of the properties according to the wavelength appears in color, and the wavelength becomes shorter from red to purple. Light with a longer wavelength than red is called infrared, and light with a shorter wavelength than purple is called ultraviolet. In the case of monochromatic light, 700-610 nm appears red, 610-590 nm orange, 590-570 nm yellow, 570-500 nm green, 500-450 nm blue, and 450-400 nm purple. In the case of mixing colors of each wavelength, the mixture of various colors appears to be various colors.

Visible light, unlike ultraviolet and infrared light, is visible to humans, and there are various requirements such as accurate color representation for lighting that emits light. One of them should be no flickering. Since humans can't recognize more than 200 flickers per second, lighting using LEDs (light emitting diodes) takes advantage of the fast flashing performance of LEDs to extend lighting life and save energy. Is blinking using PWM (Pulse Width Modulation).

Communication technologies using light include infrared data wireless communication (IrDA) using an infrared region, visible light wireless communication using visible light, and optical communication using optical fiber. Infrared Data Association (IrDA) is a technology for communication using an infrared region having a wavelength of 850 nm to 900 nm, and visible light wireless communication is a communication technique using a wavelength in the 380 nm to 780 nm region.

Such wireless communication using visible light (hereinafter, referred to as visible light wireless communication) is a wireless communication technology using a wavelength in the visible region of 380 nm to 780 nm, and has a different wavelength range from infrared communication. And to provide a location information service, for this purpose it can provide precise location information by using LED lighting.

1 is a diagram illustrating a concept of providing location information using visible light wireless communication according to an exemplary embodiment of the present invention.

As shown in FIG. 1, the visible light wireless communication devices 11, 12,..., 1n and n are positive integers, and for convenience of explanation, the representative numbers “1” are assigned to image sensors (eg, cameras). Location information may be provided to the mobile terminal 2 including the. In this case, the visible light radio communication apparatus 1 includes the transmission light sources L1, L2, ..., Ln, n are positive integers and may be assigned a representative number "L" for convenience of description, and the transmission light source L ) To provide the mobile terminal 2 with the precise location information. Here, the precise location information is location information of the visible light wireless communication device 1, and may include various location information such as a floor, a room, several meters / centimeters / millimeters, as well as a longitude and latitude according to the location where the visible light wireless communication device is installed. have. The precise positional information provided from the transmission light source L of the visible light wireless communication device 1 may have an accuracy that can provide the distance difference between the transmission light sources from several cm to precisely several mm.

LED may be used as the transmission light source L, and the LED may be a white LED, a red (R) LED, a green (G: Green) LED, or a blue (B: Blue) LED.

The portable terminal 2 receives and processes the precise position information provided from the visible light wireless communication device 1. To this end, the portable terminal 2 receives the precise position information provided from the visible light wireless communication device 1 by using the image sensor, the position measuring device 100 according to an embodiment of the present invention is received by the portable terminal The position of the portable terminal is measured using the precise position information and the tilt information of the portable terminal secured by itself. The position to be measured by the position measuring device 100 is substantially the position of the mobile terminal in which the position measuring device 100 is included, but since such a position is measured based on the image sensor of the position measuring device 100, The position may be expressed as the position of the image sensor and the position of the portable terminal.

The position measuring apparatus 100 receives a signal transmitted from a plurality of transmission light sources using an image sensor.

The image sensor captures location information transmitted in the form of an optical signal from the visible light wireless communication devices 1 and outputs a corresponding electric signal, and a camera may be included therein. Acquiring the data transmitted by the visible light wireless communication device 1 from the electrical signal picked up by the image sensor is a technique known in the art, and thus a detailed description thereof will be omitted.

In the environment in which the position measuring device 100 communicates with the plurality of visible light wireless communication devices 1, as shown in FIG. 1, for example, the positional relationship between the two transmitting light sources and the image sensor of the position measuring device 100 may be determined. Looking at it as follows.

2 is a diagram illustrating a positional relationship between an image sensor and transmission light sources according to an exemplary embodiment of the present invention.

As shown in FIG. 2, the image sensor 111 of the position measuring apparatus 100 may receive precision position information from two transmission light sources L1 and L2. In this case, for example, based on the axis where the first transmission light source L1 and the second transmission light source L2 are located, the image sensor 111 may have a first distance d1 from the first transmission light source L1. It may be said that it is located at a position P1 apart from the second transmission light source L2 by a second distance d2. In this case, if the first distance d1 and the second distance d2, which are actual distances, are known, the precision position information transmitted from the first transmission light source L1 and the precision position transmitted from the second transmission light source L2 are known. The position of the image sensor 111 may be measured based on the information. That is, when the position of the first transmission light source L1 is called PI1 and the position of the second transmission light source L2 is called PI2, the actual position P1 of the image sensor 111 is defined as PI1 + d1 or PI2-d2. Based on this. The first distance d1 represents the actual distance from the actual position of one transmitting light source to the actual position of the image sensor, and the second distance d2 is the actual position of the other transmitting light source from the actual position of the image sensor. It represents the actual distance. Here, the distance between the position PI1 of the first transmission light source L1 and the position PI2 of the second transmission light source L2 is called an actual light source distance.

In an embodiment of the present invention, in order to know the first distance d1 and the second distance d2 with respect to the image sensor 111 based on the actual positions of the transmission light sources L1 and L2, the image sensor 111 may be reversed. It uses the position of the transmission light sources to form an image.

For example, as shown in FIG. 2, it is assumed that the transmission light sources L1 and L2 are located on the same axis (for example, a ceiling of a predetermined building), and the image sensor 111 of the position measuring device 100 is used. Is assumed to be located on an axis parallel to the axis where the transmitting light sources L1, L2 are located. In this case, the image sensor 111 captures an image of the corresponding transmission light sources together with the optical signal from the transmission light sources L1 and L2, so that the reversed phase with respect to the transmission light sources L1 and L2 is the image sensor 111. It is formed in). That is, as shown in FIG. 2, the image for the first transmission light source L1 is imaged at the position SPI1 on the image sensor 111, and the image for the second transmission light source L2 is displayed on the image sensor 111. It can be imaged at position SPI2. When the center SC of the image sensor 111 corresponds to the actual position P1 of the image sensor 111, the positions SPI1 and SPI2 of the transmission light sources formed on the image sensor 111 and the center point of the image sensor are described. Based on SC, the first virtual distance sd1 and the second virtual distance sd2 may be obtained. The first virtual distance sd1 is a distance between the position SPI1 of the first transmission light source formed in the image sensor 111 and the center point SC of the image sensor, and corresponds to the first distance d1. The second virtual distance sd2 is a distance between the position SPI2 of the second transmission light source formed in the image sensor 111 and the center point ISC of the image sensor, and corresponds to the second distance d2. As such, since the distance calculated based on the positions of the transmission light sources formed on the image sensor is not the actual distance but the distance on the image sensor, it may be referred to as a virtual distance. For convenience of explanation, the distance between the transmitting light sources formed on the image sensor is referred to as "virtual light source distance". The virtual light source distance between the first transmission light source L1 and the second transmission light source L2 is represented by "SD".

Meanwhile, the first distance d1 and the first virtual distance sd1 are in proportion to each other, and the second distance d2 and the second virtual distance sd2 are in proportion to each other. Accordingly, the following conditions are satisfied.

[Equation 1]

d1: d2 = sd1: sd2

d1: d1 + d2 = sd1: sd1 + sd2

Here, d1 + d2 may be calculated based on the precise position information of the actual positions PI1 and PI2 of the transmission light sources, and sd1 and sd2 based on the positions SPI1 and SPI2 of the transmission light sources formed in the image sensor 111. Able to know. Therefore, the value of d1 can be calculated from Equation 1 above as follows.

[Equation 2]

d1 = (d1 + d2) × sd1 / (sd1 + sd2)

Since d1, that is, the first distance may be calculated from the above Equation 2, d2, that is, the second distance may also be calculated based on the calculated d1.

Since the first distance d1 and the second distance d2 are obtained, the actual position P1 of the image sensor 111 can be known from PI1 + d1 or PI2-d2 in the environment as shown in FIG. 2. The actual position P1 of the image sensor 111 obtained here represents a position on one axis. For example, the position on the X axis is shown. For the Y axis, the actual position P1 on the Y axis of the image sensor 111 may be measured through the same process as described above.

Meanwhile, the distance on the image sensor may be converted into an actual distance. That is, it can be seen how much the pixel distance corresponding to the pixel in which the transmission light source is formed on the image sensor actually corresponds. The distance (virtual distance) on the image sensor can be measured based on the pixel distance, where the pixel distance includes pixel size, pixel spacing.

The virtual light source distance SD between the positions SPI1 and SPI2 of the imaging light sources formed on the image sensor is the actual light source distance D according to the precise position information PI1 and PI2 of the transmission light sources as shown in FIG. 2. Since it is proportional to, the virtual distance (unit virtual distance) between one pixel may be calculated as follows.

&Quot; (3) "

Unit virtual distance = (d1 + d2) / (sd1 + sd2)

Based on the unit virtual distance, the virtual distance on the image sensor may be converted into an actual distance.

Meanwhile, the transmission light sources formed on the image sensor may not be positioned in a straight line as shown in FIG. 2 based on the center point SC of the image sensor.

3 is an exemplary view illustrating positions of transmission light sources formed on an image sensor according to an exemplary embodiment of the present invention.

For example, as shown in FIG. 3, the positions of the transmission light sources formed in the image sensor 111 may be located on different axes with respect to the center point SC of the image sensor. When the positions formed on the image sensor are represented by a two-dimensional plane using the X axis and the Y axis as shown in FIG. 3, let the coordinates of the center point SC of the image sensor 111 be (X, Y). In this case, the coordinates (X, Y) of the center point may be a position to be measured.

Assume that the coordinates of the first transmission light source L1 are (A1, B1) and the coordinates of the second transmission light source L2 are (A2, B2), and A1> A2, B1> B2 is established. In addition, the distance from the coordinates A1 and B1 of the first transmission light source L1 to the Y axis and the distance to the X axis are referred to as x1 and y1, respectively, and the coordinates A2 and B2 of the second transmission light source L2. Let the distance to the Y axis and the distance to the X axis to be x2, y2, respectively.

In this state, the coordinates of the center point SC of the image sensor, that is, the current position (X, Y) may be calculated as follows.

&Quot; (4) "

X = A1-x1 = A2 + x2

Y = B1-y1 = B2 + y2

Here, x1, x2, y1, y2 may be measured based on the pixel distance and then converted into the actual distance based on the unit virtual distance. That is, each virtual distance x1, x2, y1, y2 is converted into the actual distance based on the unit virtual distance, and the coordinates (A1, B1) of the first transmission light source L1 and the coordinates of the second transmission light source L2 ( Corresponding to the coordinates (X, Y) of the center point of the image sensor based on the positions PI1, PI2 of the actual transmission light sources corresponding to A2, B2, respectively, and the actual distances corresponding to the virtual distances x1, x2, y1, y2 Can measure the actual position.

The position measuring method on the two-dimensional plane of the X-axis and the Y-axis as described above can be equally applied to the three-dimensional plane. Also in this case, the condition that the axis where the transmission light sources are located and the image sensor are parallel to each other apply.

On the other hand, the position measuring object, for example, the portable terminal equipped with the image sensor cannot always be parallel to the axis on which the transmission light sources are mounted. That is, the position measuring object may be inclined at a predetermined angle with respect to the axis on which the transmission light sources are mounted.

4 is an exemplary view illustrating a state in which an image sensor is inclined with respect to transmission light sources according to an exemplary embodiment of the present invention.

As illustrated in the accompanying FIG. 4, the image sensor may be inclined at an angle in a state parallel to the axis in which the transmission light sources are formed. Although FIG. 4 shows that only one axis is inclined, this inclination may occur for each of the X and Y axes.

For example, when the image sensor is positioned at a predetermined angle inclined state TS relative to the parallel state PS, the distance between transmission light sources obtained from an image captured by the image sensor in the inclined state TS is determined. On the basis of this, it can be assumed that the image sensor is in the parallel state PS and the distance between the transmitting light sources on the image picked up by the image sensor in the parallel state can be taken into account. For convenience of explanation, if the distance between the transmission light sources obtained from the image actually captured by the image sensor in the inclined state is " first virtual light source distance ", the transmission imaged by the image sensor assumed to be in parallel state The distance between the light sources may be referred to as the "second virtual light source distance".

The first virtual light source distance and the second virtual light source distance with respect to the transmission light sources have a relationship as shown in FIG. 4.

When the image sensor 111 of the position measuring device 100 receives an optical signal from the transmission light sources in an inclined state TS, the first virtual light source distance is measured, but when the first virtual light source distance is used as it is. An error occurs. When the error in the unit of pixel distance on the image sensor is converted into the actual distance, it appears as a very large error. Therefore, in the embodiment of the present invention, such an error is corrected based on the inclination information of the image sensor.

For this purpose, the second virtual light source distance b + c, which is the distance of the transmission light sources formed in the image sensor in the parallel state PS, is required. This is to obtain a virtual distance corresponding to the actual distance between the actual transmission light sources, as shown in FIG.

The tilted state TS in order to calculate the second virtual light source distance b + c in a state where the first virtual image light source distance a is obtained from the image captured by the image sensor in the tilted state TS. The inclination α of is measured and a second virtual light source distance is calculated based on the measured inclination α. Meanwhile, when the center point SC of the image sensor is converted to a parallel state based on the inclination while the image sensor is inclined, the image sensor is positioned at a predetermined position SC ′ as shown in FIG. 4. The distance between the center point SC 'of the parallel image sensor and a predetermined transmission light source formed on the parallel image sensor may be referred to as "g", and this "g" may be referred to as the first virtual distance sd1 in FIG. 2. ) Corresponds to For convenience of explanation, g is referred to as "first-first virtual distance".

In FIG. 4, a straight line positioned perpendicular to the image sensor in parallel state PS at the position of an arbitrary transmitting light source formed in the image sensor in an inclined state TS is defined as the virtual height h. A right triangle is formed having a height h and having a hypotenuse of the first virtual light source distance a. The base side of such a right triangle is called an imaginary base side b, and using this right triangle, the following relationship is established.

[Equation 5]

b = a × cosα

h = a × sinα

γ = 90-α

Here, α represents the inclination angle of the image sensor 111, and becomes an angle formed by the hypotenuse a and the base b in the right triangle.

In the right triangle shown in FIG. 4, the sum of β, γ, and δ is used as the height of the focal length f of the image sensor in the tilted state TS to know the angle between β and δ under the condition of 180 °. If a right triangle is formed, and the base side of the right triangle is " e ", the following conditions are satisfied for β and δ.

&Quot; (6) "

tan β = f / e-> β = tan ^-1 (f / e)

δ = 180-β-γ = 180 -β-(90 -α) = 90-β + α

Through the above process, since the angle between β and δ was calculated, the angle of γ can also be known based on these.

Since the angle of δ has been calculated, the value of c constituting the second virtual light source distance can be calculated as follows.

[Equation 7]

c = h × tan δ = (a × sin α) × tan δ

= (a × sin α) × tan (90-β + α)

Further, the first-first virtual distance g, which is the distance from the center point SC 'of the parallel image sensor to the transmission light source, is calculated. Specifically, the hypotenuse (i) can be obtained from a right triangle having a bottom angle of β and a bottom angle of "e" while increasing the focal length f of the image sensor in an inclined state TS, and the virtual height The hypotenuse d can be obtained from a right triangle having a height of (h) and having a base of "c" and having an angle δ. Therefore, the hypotenuse side is i + d, the base side g, i.e., 1-1 virtual distance, can be calculated from a right triangle having a height of k and g being the base side and having one angle δ.

Also, an image sensor assumed to be in a parallel state PS based on the first virtual light source distance a, which is a distance between transmission light sources formed on the image sensor in an inclined state TS, and the inclination α of the image sensor. The second virtual light source distance between the transmitting light sources on the phase can be represented as follows.

[Equation 8]

Second virtual light distance (b + c) = a × cosα + {(a × sinα) × tan (90−β + α)}

Obtaining the second virtual light source distance in this way, based on the relationship between the distance between the transmitting light sources on the image sensor (second virtual light source distance) and the distance between the actual transmitting light sources as illustrated in FIG. The light source distance can be known. In detail, the obtained second virtual light source distance b + c and the 1-1 virtual distance g correspond to the virtual light source distance SD and the first virtual distance sd1 illustrated in FIG. 2, respectively. Therefore, the second virtual distance sd2 may also be calculated from the virtual light source distance SD and the first virtual distance sd1. The first distance d is calculated using (d1 + d2), the first virtual distance sd1, and the second virtual distance sd2 obtained according to the precise position information received based on Equation 2 above. Therefore, based on the calculated 1st distance d1, it can calculate as 2nd distance d2. Since the first distance d1 and the second distance d2 are obtained, the actual position P1 of the image sensor 111 can be known from PI1 + d1 or PI2-d2 in the environment as shown in FIG. 2.

On the other hand, in the above, only the distance and the slope are taken into consideration for one axis, and in the two-dimensional plane composed of two axes, the virtual distance and the actual light source distance for each axis (X-axis, Y-axis) are used to measure the position. , Virtual light source distance, tilt, etc. should be considered.

5 is a flowchart illustrating a position measuring method according to an embodiment of the present invention based on the process described above.

As shown in FIG. 5, in order to measure the position of the image sensor, the position measuring apparatus 100 first acquires a focal length f of the image sensor 111 (S100). In operation S110, virtual coordinates which are positions of transmission light sources formed on the image sensor 111 are obtained.

Acquire a first virtual light source distance a on the image sensor in an inclined state based on the acquired virtual coordinates (S120), measure an inclination α of the image sensor (S130), and obtain a virtual height h. (S140). The second virtual light source distance b + c when the image sensor is assumed to be in parallel is calculated based on the virtual height h, the measured tilt α and the first virtual light source distance a (S150). . Based on the second virtual light source distance b + c, the first virtual distances sd1 and g and the second virtual distance sd2 which are distances from the center point of the image sensor to the imaged transmission light source are obtained (S160).

Next, based on the second virtual light source distance b + c, the first virtual distance sd1, and the second virtual distance sd2, the first distance d1 and the second distance d2 which are actual distances according to the position of the actual light source. ) Is calculated (S170). The position of the image sensor is obtained based on the calculated first distance d1, the second distance d2, and the actual positions of the transmission light sources according to the received precise position information (S180). For example, the X coordinate of the image sensor on the X axis or the Y coordinate of the image sensor on the Y axis is obtained.

On the other hand, if the position is obtained for all axes, for example, the X axis and the Y axis, respectively, the position measurement is terminated (S190, S200). In step S120-S180, the position of the image sensor on the corresponding axis is acquired by repeatedly performing the step S120 to S180 on the corresponding axis that the position cannot be obtained.

Through this process, the position of the image sensor, for example, (X, Y) coordinates can be obtained.

Next, the structure of the position measuring device according to an embodiment of the present invention will be described.

6 is a schematic structural diagram of a position measuring apparatus according to an embodiment of the present invention, Figure 7 is a detailed structural diagram of a position measuring apparatus according to an embodiment of the present invention.

As shown in FIG. 6, the position measuring apparatus 100 according to an exemplary embodiment of the present invention includes a position information receiver 110, a tilt measuring unit 120, an actual distance measuring unit 130, and a virtual distance measuring unit ( 140, an information processing unit 150.

The location information receiver 110 receives location information transmitted from the plurality of visible light wireless communication devices 1. The location information receiver 110 includes an image sensor 111 that captures location information transmitted from the visible light wireless communication devices 1 in the form of an optical signal, that is, precise location information, and outputs a corresponding electrical signal.

The tilt measuring unit 120 measures the tilt of the position measuring device 100. In the exemplary embodiment of the present invention, the position measuring apparatus 100 is mounted on the portable terminal 2 as an example, and the tilt measuring unit 120 is configured as the portable terminal 2 on which the position measuring apparatus 100 is mounted. In measuring the tilt, the tilt of the image sensor 111 is measured. Since the image sensor 111 may be inclined with respect to the X and Y axes on a two-dimensional plane formed of the X and Y axes, respectively, the image sensor 111 measures the inclination with respect to the X axis and the inclination with respect to the Y axis. To this end, the tilt measuring unit 120 includes an X-axis tilt measuring module 121 and a Y-axis tilt measuring module 122, as shown in FIG. The tilt measuring unit 120 may be formed of a two-axis tilt sensor.

The actual light source distance measuring unit 130 measures the actual light source distance between the transmission light sources based on the precise position information of the visible light wireless communication devices transmitted by the transmission light sources. The actual light source distance between the transmitting light sources on the X axis and the actual light source distance between the transmitting light sources on the Y axis based on the precise position information provided from the visible light wireless communication devices on the two-dimensional plane composed of the X axis and the Y axis. Calculate. To this end, as shown in FIG. 7, the actual light source distance measuring unit 130 includes an X-axis actual light source distance measuring module 131 and a Y-axis actual light source distance measuring module 132.

The virtual light source distance measuring unit 130 measures a virtual light source distance between transmission light sources formed in the image sensor from an image captured by the image sensor 111 included in the location information receiving unit 110. That is, the position (virtual position information) of the transmission light sources formed in the image sensor is confirmed from the captured image, and the virtual distance between the imaged transmission light sources on the image sensor is measured based on the pixel distance constituting the image sensor. Also in this case, the virtual light source distance between the transmitting light sources on the X axis and the virtual light source between the transmitting light sources on the Y axis based on the virtual position information obtained from the image on the two-dimensional plane on the image sensor composed of the X axis and the Y axis. Calculate the light source distance. To this end, as shown in FIG. 7, the virtual light source distance measuring unit 140 includes an X-axis virtual light source distance measuring module 141 and a Y-axis virtual light source distance measuring module 142.

The location information processor 150 measures the current location based on the precise location information, the actual light source distance, the slope, and the virtual light source distance provided from the visible light wireless communication devices. Here, the current position to be measured is for the image sensor 111, but as a result, indicates the position of an object (for example, a mobile terminal) on which the position measuring device 100 is mounted.

The location information processor 150 according to an embodiment of the present invention includes a distance measuring module 151, a location calculation module 152, and a distance conversion module 153, as shown in FIG. 7.

The distance measuring module 151 measures the actual distance to the image sensor corresponding to the position to be measured, based on the slope, the actual light source distance of the transmission light sources, and the virtual light source distance of the transmission light sources. Here, in FIG. 2, the actual distance is a first distance d1, which is a distance from any transmission light source to the position of the image sensor based on the actual position of the transmission light sources, and a second distance d2, which is a distance from another transmission light source to the position of the image sensor. ). In order to measure the actual distance, the virtual light source distance (first virtual light source distance) provided from the virtual light source distance measuring unit 140 and the tilt measurement unit 120 are provided based on the process as illustrated in FIG. 5. The virtual light source distance second parallel light source distance of the parallel state is computed based on the inclination which becomes. The first virtual distance sd1 and the second virtual distance sd2 based on the center point of the image sensor are calculated based on the second light source distance, and the calculated first virtual distance sd1 and the second virtual distance sd2 are calculated. ), The first distance d1 and the second distance d2 which are actual distances are calculated based on the actual light source distances.

Based on the two-axis plane, the distance measuring module 151 measures the actual distance with respect to the X axis and the actual distance with respect to the Y axis, respectively, and for this purpose, as shown in FIG. 7, the X axis actual distance measurement module 1511 and Y-axis actual distance measurement module 1512.

The position calculation module 152 calculates the position of the image sensor, that is, the position of the object to be measured, based on the precise position information of the received transmission light sources and the actual distance measured based on the virtual distance on the image sensor. In this case, the actual position on the predetermined axis is calculated by adding or subtracting the actual distance from the actual position coordinates based on the received precise position information. This process is performed for each axis to calculate the X coordinate of the actual position and the Y coordinate of the actual position. The X coordinate and the Y coordinate calculated as described above become the position of the object to be measured. To this end, the position calculation module 152 may include an X-axis position calculation module 1521 and a Y-axis position calculation module 1522, as shown in FIG. 7.

The distance conversion module 153 converts the virtual distance into an actual distance, and specifically, converts the measured predetermined virtual distance into an actual distance using a unit virtual distance based on the pixel distance on the image sensor.

In addition, the position measuring apparatus 100 according to the embodiment of the present invention may further include a processing method determination unit 160, as shown in FIG. The processing method determiner 160 performs location measurement according to different methods based on the number of received location information. That is, the processing method is determined according to the number of position information received from the transmission light sources. For example, when the received position information is one, the center point of the image sensor, the received precision position information, and the image sensor The position is measured based on the position of the transmitting light source formed at.

On the other hand, if there is more than one location information, the location measurement is performed without using the center point of the image sensor. That is, the position is measured based on the received precision position information and the positions of the transmission light source formed on the image sensor.

The method of performing the position measurement without using the center point of the image sensor is called "first method", and the method of performing the position measurement using the center point of the image sensor is called "second method".

When the position measurement is performed according to the second method, the processing method determination unit 160 provides the virtual light source distance measuring unit 130 with coordinate information about the center point of the image sensor, which is set in advance, and the center point and the image of the image sensor. The virtual light source distance is calculated based on the position of the transmitting light source formed in the sensor. Thereafter, the actual light source distance, which is a distance between the actual position according to the precise position information of the transmission light source and the position to be measured, is measured based on the calculated virtual light source distance, and in this case, a process of converting the virtual distance into the actual distance may be performed. . In the conversion process, a conversion process using a unit virtual distance may be performed, or a separate distance conversion table may be used.

Next, a position measuring method according to another embodiment of the present invention will be described based on the structure as described above.

8 is a flowchart illustrating a position measuring method according to another embodiment of the present invention.

The position measuring apparatus 100 first determines whether the tilt measurement is possible before performing the position measurement (S300).

If the tilt measurement is not possible, in order to minimize the error of the measured position, a warning message may be output to guide the image sensor to maintain the level (S310).

The position measuring device 100 captures an image including an optical signal transmitted from the transmission light source L of the visible light wireless communication device 1, and performs image processing on the captured image to transmit from the transmission light source L. Obtained accurate position information (S320).

The position measuring apparatus 100 determines whether there are two or more precision position information acquired through this process (S330), and when the two or more precision position information are obtained, the position measuring apparatus 100 performs the position according to the first method. Measurement is performed (S340).

In the case of performing the position measurement according to the first method, the position measuring apparatus 100 calculates an actual light source distance for each of the X and Y axes based on the precise position information of the received transmission light sources (S350). The virtual light source distance is calculated on each of the X and Y axes from the captured image (S360). When the inclination occurs due to the movement of the mobile terminal equipped with the position measuring device 100, the state of the image sensor 111 is changed, and thus the inclination of each of the axis and the Y axis of the image sensor 111 is measured. (S370, S380). In this case, when tilt measurement is not possible, as described above, a warning message for maintaining a horizontal state may be output in order to minimize the occurrence of an error (S390).

Thereafter, the actual distance to the image sensor corresponding to the position to be measured is measured as shown in FIG. 5 based on the measured light source, the actual light source distance, the virtual light source distance, and the slope of each of the Y axes (S400).

The position of the mobile terminal is measured based on the actual distances (first distance d1, second distance d2) and the precise position information of the transmission light sources with respect to the X and Y axis image sensors obtained as described above.

In an embodiment of the present invention, for more accurate position measurement, it is determined whether the actual distance of the image sensor with respect to each of the X-axis and the Y-axis is converted distance (S410). That is, since the actual distance is calculated using the virtual distance based on the pixel distance on the image sensor, distance conversion may be necessary to compensate for an error generated while using the virtual distance. Here, when the conversion process for the measured actual distance is not performed, the position measuring device 100 performs the conversion process for the measured actual distance (S420). For example, when the virtual distance is 15 pixels, it may be converted into an actual 1m distance by a conversion process. In this conversion process, the unit virtual distance according to Equation 3 described above may be used, or the conversion process may be performed using a preset virtual / real distance conversion table. This conversion process may optionally be performed.

The position measuring apparatus 100 may determine the position of the mobile terminal based on the actual distance (first distance d1, second distance d2) and the precise position information of the transmission light sources with respect to the image sensor for each of the X and Y axes. It is measured (S430).

On the other hand, the position measuring device 100 determines whether there is one piece of precision position information received in step S330 (not more than two) (S450). It is determined to measure the position according (S460). In the case of performing the position measurement according to the second method, since there is one piece of precise position information on the received transmission light source, the position measurement is performed based on the coordinates of the center point of the image sensor. The center point coordinates of the image sensor are preset coordinates. The virtual light source distance is measured based on the coordinates of the center point of the given image sensor and the position of one transmitting light source formed on the image sensor (S460), and the tilt measurement is performed based on the measured virtual light source distance as described above. The processing of is performed. In this case, the virtual light source distance is calculated based on the center point of the given image sensor, and the second virtual light source distance corresponding to the parallel image sensor is calculated based on the calculated virtual light source distance and the slope. Instead of obtaining the first distance d1 and the second distance d2 based on the second light source distance as in the first method above, the actual light source distance is calculated directly based on the second virtual light source distance, and then this actual The actual position of the mobile terminal can be measured from the precise position information of one transmission light source based on the light source distance. Also in this case, a process of converting the virtual distance into the actual distance can be performed. In the conversion process, a conversion process using a unit virtual distance may be performed, or a separate distance conversion table may be used.

Meanwhile, after the position measurement is made, the position measurement is optionally continued (S470). End position measurement.

According to the exemplary embodiment of the present invention, the position of the object to be measured is determined based on the precise position information of the transmission light sources received from the visible light wireless communication device, the actual light source distance based thereon, and the virtual light source distance of the transmission light sources formed on the image sensor. You can measure more accurately.

Meanwhile, the order in which the steps of performing the position measuring method according to FIG. 8 are performed is only one example, and the order in which the steps are performed may be changed in some cases.

The embodiments of the present invention are not limited to the above-described apparatuses and / or methods, but may be implemented through a program for realizing functions corresponding to the configuration of the embodiment of the present invention, a recording medium on which the program is recorded And such an embodiment can be easily implemented by those skilled in the art from the description of the embodiments described above.

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, It belongs to the scope of right.

Claims (15)

In a method for measuring position based on information provided from at least one communication device comprising a transmission light source,
Capturing an image including an optical signal transmitted from the transmission light source using an image sensor to obtain precise position information indicating a position with respect to the transmission light source;
Calculating an actual light source distance between transmission light sources based on the precise position information;
Calculating a virtual light source distance for transmission light sources formed on the image sensor from the captured image;
Measuring a tilt of the image sensor; And
Measuring a position based on the actual light source distance, the virtual light source distance, the slope, and the precise position information;
Position measuring method comprising a. The method of claim 1
Measuring the position
Calculating a first virtual light source distance, which is a virtual light source distance for transmission light sources formed on the image sensor, and a second virtual light source distance corresponding to the image sensor being in parallel, based on the inclination; And
Calculating a position based on the second virtual light source distance, the actual light source distance, and the precise position information for each transmitted light source;
Including, position measuring method. The method of claim 2
The step of calculating the position
Calculating a first virtual distance from a center point of the image sensor to one transmission light source formed on the image sensor based on the second virtual light source distance;
Calculating a second virtual distance from a center point of the image sensor to another transmission light source formed on the image sensor based on the second virtual light source distance; And
Calculating a position based on the first virtual distance, the second virtual distance, the actual transmission light source distance, and the precise position information;
Including, position measuring method. The method of claim 3, wherein
The step of calculating the position
The first virtual distance and the second virtual distance,
A first distance, which is a distance from a position of a transmission light source based on the precision position information to a position to be measured, and a second distance, which is a distance from a position of another transmission light source based on the precision position information, to the position to be measured And calculating the position based on the ratio proportional to the. The method of claim 4
The step of calculating the position
d1 = (d1 + d2) x sd1 / (sd1 + sd2), where d1 represents the first distance, d2 represents the second distance, sd1 represents the first virtual distance, and sd2 represents Calculating the first distance based on the second virtual distance; And
Calculating a position based on the position of one transmission light source based on the precise position information and the first distance;
Including, position measuring method. The method of claim 5
If the position of one transmission light source based on the precise position information is x1, which is the coordinate on the X axis, the coordinate of the position to be measured is a coordinate corresponding to x1 + first distance. The method according to any one of claims 1 to 6
In the case of measuring a position in a two-dimensional plane using an X axis and a Y axis, the precise position information includes an X axis and respective coordinates with respect to the Y axis.
Respectively for the X and Y axes,
Acquiring the precision position information, calculating the actual light source distance, calculating the virtual light source distance, measuring the inclination, and measuring the position to perform the measurement. A method of measuring the position, to find the x-axis and y-axis coordinates of. In a method for measuring position based on information provided from at least one communication device comprising a transmission light source,
Precise position information indicating a position with respect to a transmission light source by capturing an image including an optical signal transmitted from the transmission light source using an image sensor--the precision position information is represented by the X axis and the X axis on a two-dimensional plane using the X and Y axes. , Each coordinate with respect to the Y-axis;
Calculating the actual light source distance between the transmission light sources for each of the X and Y axes based on the precision position information when the received precision position information is received from at least two transmission light sources, respectively;
Calculating a virtual light source distance for transmission light sources formed on the image sensor for each of X and Y axes from the captured image;
Measuring an inclination of the image sensor for each of X and Y axes;
Calculating a parallel virtual light source distance for each X-axis and Y-axis corresponding to the image sensor being in a parallel state based on the virtual light source distance and the inclination; And
Measuring positions on the X and Y axes of the object to be measured based on the measured actual light source distance, parallel virtual light source distance, slope, and precise position information;
Position measuring method comprising a. The method of claim 8, wherein
Measuring the position
Calculating a first virtual distance from a center point of the image sensor to one transmission light source formed on the image sensor for each of X and Y axes based on the parallel virtual light source distance;
Calculating a second virtual distance from the center point of the image sensor to another transmission light source formed on the image sensor for each of X and Y axes based on the parallel virtual light source distance;
Based on the first virtual distance and the second virtual distance, based on the first position and the position to be measured from the position of the transmission light source based on the precision position information for each X-axis and Y-axis based on the precision position information Calculating a second distance, which is a distance from a position of another transmission light source to the position to be measured; And
Measuring the position of the object based on the first distance, the second distance, and precise position information on transmission light sources for each of the X and Y axes;
Including, position measuring method. The method of claim 9
Converting the first distance and the second distance into an actual distance;
The measuring of the position may include measuring the position using the converted first and second distances. In an apparatus for measuring position based on information provided from at least one communication device comprising a transmission light source,
Precise position information indicating a position with respect to a transmission light source by capturing an image including an optical signal transmitted from the transmission light source using an image sensor--the precision position information is represented by the X axis and the X axis on a two-dimensional plane using the X and Y axes. A location information receiver for obtaining each coordinate of the Y axis;
An actual light source distance measuring unit configured to calculate an actual light source distance between transmission light sources for each of X and Y axes based on the precise position information;
A virtual light source distance measuring unit configured to calculate a virtual light source distance for transmission light sources formed on the image sensor for each of the X and Y axes from the captured image;
An inclination measuring unit measuring an inclination of the image sensor for each of X and Y axes; And
Position information processing unit for measuring the position on the X-axis and Y-axis of the object to be measured, based on the actual light source distance, virtual light source distance, slope, and precise position information measured for each X axis and Y axis
Position measuring device comprising a. The method of claim 11,
The location information processing unit
Calculating a parallel virtual light source distance for each of the X and Y axes corresponding to the image sensor being in a parallel state based on the virtual light source distance and the inclination; and the precision position information for each of the X and Y axes based on the parallel virtual light source distance. A distance for calculating a first distance, which is a distance from a position of a transmission light source based on a distance to a position to be measured, and a second distance, which is a distance from a position of another transmission light source based on the precision position information, to the position to be measured. A measurement module; And
Position calculation module for calculating the position of the object based on the first distance, the second distance and the precise position information for the transmission light sources for each of the X axis and Y axis
Comprising a position measuring device. The method of claim 12,
The distance measuring module,
A first virtual distance from the center point of the image sensor to one transmitting light source formed on the image sensor, the other image formed on the image sensor from the center point of the image sensor, calculated based on the parallel virtual light source distance The position measuring apparatus which calculates the said position based on the 2nd virtual distance to a transmission light source being proportional to the said 1st distance and a 2nd distance. The method of claim 12,
The location information processing unit,
And a distance conversion module for converting the first distance and the second distance into an actual distance. The method of claim 11,
A processing method selection unit which selects one of a first method and a second method according to the number of received precision position information
Further comprising:
And the first method measures a position based on the received precision position information, and the second method measures the position using the received precision position information and a center point of a given image sensor.

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