JP2009288173A - Position estimation terminal, position estimation method, and position estimation program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To calculate own position highly accurately in a wider range by a visible light reception terminal for estimating own position based on visible light ID transmitted from a visible light transmission device. <P>SOLUTION: This position estimation terminal for receiving a signal using visible light as a transmission medium and calculating own position obtains an elevation angle and an azimuth angle when receiving the visible light, calculates a light receiving angle by adding a view angle of a reception part receiving the visible light corresponding to the obtained elevation angle, and calculates a relative position to a light source of the visible light based on the calculated light receiving angle, the obtained azimuth angle, and a stored height of own terminal. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a position estimation terminal, a position estimation method, and a position estimation program that receive a visible light signal transmitted from a visible light transmitter and calculate its own position based on the received visible light signal.

  Conventionally, as a technique for a terminal such as a mobile phone to acquire its own position information, GPS that receives a signal transmitted from a GPS (Global Positioning System) satellite and calculates its current position has spread. ing. In such GPS, an error occurs in the estimated position to be calculated due to delay and attenuation due to the influence of the ionosphere and convection layer in the signal path from the GPS satellite to the GPS receiving terminal, and shielding by terrain and clouds. Also, it is difficult to receive signals accurately indoors. Therefore, as a technique for detecting the position of the terminal indoors, a method using an IC tag such as RFID (Radio Frequency IDentification) has been proposed. However, as a problem of this method, IC tag readers are installed in various places indoors. There is a need for infrastructure development.

  On the other hand, research on a light emitting diode (LED) as a next-generation energy-saving illumination light source is underway. Such an LED has excellent characteristics such as long life, small size, and low power consumption. For this reason, the substitution from the light bulb which is a conventional illumination light source to the illumination by LED has begun. Unlike LED fluorescent lamps and incandescent lamps, LED lighting does not require any remaining heat time, and therefore has a high response speed. Therefore, visible light communication that performs information communication by light intensity modulation (IM: Intensity Modulation) in a short time that cannot be recognized by the human eye using such properties of LEDs has been studied. Such an LED lighting device sends an identifier (ID) given to itself in advance by a signal using visible light as a transmission medium. The visible light receiving terminal that receives the visible light transmitted from the LED lighting device reads the identifier included in the received visible light, and estimates the position of the LED lighting device that is predetermined corresponding to the identifier as the current position. It becomes possible.

Furthermore, in visible light communication using visible light recognizable by the user, it is easy for the user to specify the direction of the light source, so that the user directs the visible light receiving terminal to the light source, so that the visible light receiving terminal Visible light can be received even if the field of view (FOV) is narrowed down. For this reason, the visible light receiving terminal can calculate the relative position between the visible light transmitting apparatus and itself by obtaining the elevation angle of the visible light receiving terminal with a sensor when receiving visible light having directivity. Non-Patent Document 1 describes a visible light ID system that estimates the position of a terminal using an elevation angle when such visible light is received as a light reception angle.
Mio Komine, Shinichiro Haruyama, Masao Nakagawa, “Proposal of high-precision position estimation method using visible light ID system and 6-axis sensor”, IEICE Technical Report, IN2006-254, March 2007

  However, as described above, when the position of the terminal is measured using the elevation angle of the receiving unit when receiving visible light as it is as the light receiving angle, if the elevation angle of the terminal when receiving visible light is large, the elevation angle is directly received by the light source. It can be estimated as an angle. On the other hand, when the terminal moves away from the light source and the elevation angle becomes small, there is a problem that the angle error within the range of the viewing angle of the visible light receiving terminal becomes a large position estimation error when calculating the position. For this reason, even if it is a range in which visible light from the light source can be received, the error increases when the elevation angle is small, and the range in which the position of the terminal can be calculated with high accuracy is limited to a range where the elevation angle is large. It was.

  The present invention has been made in view of such a situation, and a terminal that estimates its own position based on a visible light ID transmitted from a visible light transmitting apparatus can accurately determine its own position in a wider range. An object of the present invention is to provide a position estimation terminal, a position estimation method, and a position estimation program.

  In order to solve the above-described problems, the present invention provides a position estimation terminal that calculates its own position based on visible light transmitted from a visible light transmission device that transmits a signal using visible light as a transmission medium, When a visible light receiving unit that receives light and a visible light receiving unit receive visible light, a sensor that acquires an elevation angle and an azimuth angle of the position estimation terminal, and an elevation angle that is visible according to the elevation angle acquired by the sensor. A light reception angle calculation unit that calculates the light reception angle at which the position estimation terminal receives visible light transmitted from the visible light transmission device by adding the viewing angle of the light reception unit, the light reception angle calculated by the light reception angle calculation unit, and a sensor And a position estimation unit that calculates a relative position of the position estimation terminal with respect to the visible light transmission device based on the azimuth angle acquired by the device and the stored height of the terminal itself.

  Further, according to the present invention, the above-described light reception angle calculation unit adds the viewing angle to the error between the elevation angle acquired by the sensor measured in advance and the actual light reception angle, and the elevation angle acquired by the sensor. If the difference between the measured angle and the actual light reception angle is larger than the same angle, the elevation angle is used as the light reception angle, and if it is smaller, the angle obtained by adding the viewing angle to the elevation angle is calculated as the light reception angle.

  Further, the present invention is characterized in that the light reception angle calculation unit described above calculates a value of a reception angle corresponding to an error measured in advance according to an elevation angle acquired by a sensor.

  The present invention also relates to a position estimation method using a position estimation terminal that calculates its own position based on visible light transmitted from a visible light transmission device that transmits a signal using visible light as a transmission medium. The light receiving unit receives the visible light, the sensor acquires the elevation angle and the azimuth angle of the position estimation terminal when the visible light receiving unit receives the visible light, and the light reception angle calculating unit includes the sensor. A step of adding a viewing angle of the visible light receiving unit to the elevation angle in accordance with the obtained elevation angle, and calculating a light receiving angle at which the position estimation terminal receives the visible light transmitted from the visible light transmitting device, and a position estimation unit. Calculating the relative position of the position estimation terminal with respect to the visible light transmission device based on the light reception angle calculated by the light reception angle calculation unit, the azimuth angle acquired by the sensor, and the stored height of the terminal. Special features To.

  Further, according to the present invention, the above-described light reception angle calculation unit adds the viewing angle to the error between the elevation angle acquired by the sensor measured in advance and the actual light reception angle, and the elevation angle acquired by the sensor. If the difference between the measured angle and the actual light reception angle is larger than the same angle, the elevation angle is used as the light reception angle, and if it is smaller, the angle obtained by adding the viewing angle to the elevation angle is calculated as the light reception angle.

  Further, the present invention is characterized in that the light reception angle calculation unit described above calculates a value of a reception angle corresponding to an error measured in advance according to an elevation angle acquired by a sensor.

  In addition, the present invention provides a visible light receiving unit connected to a computer of a position estimation terminal that calculates its own position based on visible light transmitted from a visible light transmitting device that transmits a signal using visible light as a transmission medium. The step of receiving light, the step of acquiring the elevation angle and the azimuth angle of the position estimation terminal when the visible light reception unit receives the visible light, and the light reception angle calculation unit according to the elevation angle acquired by the sensor The step of adding the viewing angle of the visible light receiving unit to the elevation angle and calculating the light receiving angle at which the position estimating terminal receives the visible light transmitted from the visible light transmitting device, and the position estimating unit is configured to receive the light receiving angle calculating unit. Calculating the relative position of the position estimation terminal with respect to the visible light transmitting device based on the received light angle calculated by the sensor, the azimuth angle acquired by the sensor, and the stored height of the terminal. is there

  As described above, according to the present invention, a position estimation terminal that receives a signal using visible light as a transmission medium and calculates its own position acquires an elevation angle and an azimuth angle when the visible light is received. Depending on the acquired elevation angle, the viewing angle of the receiving unit that has received visible light is added to calculate the light reception angle, and the calculated light reception angle, the acquired azimuth angle, and the stored height of the terminal itself Based on this, the relative position of the visible light with respect to the light source is calculated. Therefore, by calculating the light receiving angle in consideration of the viewing angle according to the elevation angle, the position of the subject can be calculated with high accuracy in a wider range. It becomes possible.

  Further, according to the present invention, the elevation angle acquired by the sensor is equal to the error between the elevation angle measured in advance and the actual light reception angle, and the error between the angle obtained by adding the viewing angle to the elevation angle and the actual light reception angle. When the angle is larger than the angle, the elevation angle is set as the light reception angle, and when the angle is small, the angle obtained by adding the viewing angle to the elevation angle is calculated as the light reception angle. The light receiving angle can be calculated.

  Further, according to the present invention, since the value of the light receiving angle corresponding to the error measured in advance according to the elevation angle acquired by the sensor is calculated, it is possible to calculate the light receiving angle with higher granularity. .

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
<First Embodiment>
FIG. 1 is a diagram showing a configuration of a position estimation system according to the first embodiment of the present invention.
The visible light transmitting device 100 is an LED lighting device, and sends an identifier (ID) given to itself in a signal using visible light as a power transmission medium. Hereinafter, visible light including the identifier of the visible light transmitting apparatus 100 as a signal is referred to as a visible light ID.
The visible light receiving terminal 200 includes a visible light ID receiving unit 210, a six-axis sensor 220, an angle calculation unit 230, an angle calculation unit 230, and a position estimation unit 240, and a visible light ID transmitted from the visible light transmission device 100. And estimate and calculate its own position.

When the visible light ID receiving unit 210 receives the visible light transmitted from the visible light transmitting device 100 at a reception angle equal to or higher than the reception sensitivity of the visible light ID receiving unit 210, the visible light ID receiving unit 210 reads the visible light ID included in the received visible light. .
The six-axis sensor 220 includes an acceleration sensor 221 that acquires triaxial acceleration and a geomagnetic sensor 222 that acquires triaxial geomagnetism.

The acceleration sensor 221 is a sensor that measures gravitational acceleration with respect to itself. The acceleration sensor 221 includes a sensor that measures the gravitational acceleration of the X axis, the Y axis, and the Z axis in the three-dimensional coordinate space, and the visible light receiving terminal 200 in the three-dimensional space is based on the measured gravitational acceleration. It is possible to calculate the elevation angle of the visible light ID receiving unit 210 provided.
The geomagnetic sensor 222 is a sensor that measures the geomagnetism with respect to itself. The geomagnetic sensor 222 includes a sensor that measures the three-axis geomagnetism of the X, Y, and Z axes in the three-dimensional coordinate space, and the azimuth angle of the visible light receiving terminal 200 in the three-dimensional space based on the measured geomagnetism. Can be calculated.

The angle calculation unit 230 includes an elevation angle calculation unit 231 that calculates the elevation angle ξ and an azimuth angle calculation unit 232 that calculates the azimuth angle φ based on the measurement result of the six-axis sensor 220.
The elevation angle calculation unit 231 calculates the elevation angle ξ of the visible light receiving terminal 200 from the gravitational acceleration measured by the three axes included in the acceleration sensor 221.
The azimuth calculation unit 232 calculates the azimuth angle φ of the visible light receiving terminal 200 from the geomagnetism measured by the three axes provided in the geomagnetic sensor 222.

  The position estimating unit 240 includes a light reception angle calculating unit 241 and a position calculating unit 242, and the visible light transmitting device 100 of the visible light receiving terminal 200 at the time when the visible light ID receiving unit 210 receives the visible light ID. Is calculated using the elevation angle ξ and the azimuth angle φ calculated by the angle calculation unit 230.

  The light reception angle calculation unit 241 compares the elevation angle ξ calculated by the elevation angle calculation unit 231 of the angle calculation unit 230 with a threshold value α stored in its own storage area, and when the elevation angle ξ is greater than the threshold value α. When it is determined, the elevation angle ξ is set as the light receiving angle θ. On the other hand, if it is determined that it is smaller than the threshold value α, a value obtained by adding a predetermined viewing angle ψ to the elevation angle ξ is calculated as the light receiving angle θ. The viewing angle ψ is the viewing angle of the visible light ID receiving unit 210, and is stored in advance in the storage area of the received light angle calculating unit 241, for example. Here, the elevation angle threshold value α will be described.

FIG. 2 is a diagram illustrating a relationship among the viewing angle ψ, the elevation angle ξ, and the light receiving angle θ. In FIG. 2, the horizontal height of the visible light receiving terminal 200 that receives visible light is assumed to be constant. A point where the elevation angle ξ of the visible light receiving terminal 200 and the light receiving angle θ from the visible light receiving terminal 200 to the visible light transmitting apparatus 100 coincide with each other is a point A, the elevation angle at the point A is ξ _A , and the light receiving angle is θ _A And At point A, the elevation angle ξ _A = light receiving angle θ _A.

When the viewing angle of the visible light ID receiving unit 210 of the visible light receiving terminal 200 is ψ, a point where the angle obtained by adding the viewing angle ψ to the elevation angle ξ coincides with the light receiving angle θ is defined as a point B. The elevation angle, the light reception angle, and the viewing angle at point B are defined as an elevation angle ξ _B , a light reception angle θ _B , and a viewing angle ψ _B , respectively. At the point B, the light receiving angle θ _B = the elevation angle ξ _B + the viewing angle ψ _B. The point B is one end of a range in which visible light transmitted from the visible light transmitting device 100 can be received with respect to the elevation angle ξ.
Further, a point where the angle obtained by subtracting the viewing angle ψ from the elevation angle ξ coincides with the light receiving angle θ is defined as a point C. The elevation angle, the light reception angle, and the viewing angle at point C are defined as an elevation angle ξ _C , a light reception angle θ _C , and a viewing angle ψ _C , respectively. At the point C, the light receiving angle θ _C = the elevation angle ξ _C −the viewing angle ψ _C. The point C is the other end with respect to the point B in a range where the visible light transmitted from the visible light transmitting device 100 can be received with respect to the elevation angle ξ.

  Here, when the viewing angle ψ of the visible light receiving terminal 200 is constant with respect to the elevation angle ξ of the visible light receiving terminal 200 and the light receiving sensitivity of the visible light ID receiving unit 210 is ignored, visible light reception is performed. The range in which terminal 200 can receive light is between point C and point B. At this time, the received light power of the visible light receiving terminal 200 at each point on the line CB is calculated from a transfer function based on the Lambert model, and is proportional to K expressed by the following equation (1).

  In the formula (1), d is a distance from the visible light transmitting device 100 to the visible light receiving terminal 200, and m is represented by the following formula (2).

In Expression (2), Φ _1/2 is a half-value angle of directivity of the light source of the visible light transmitting apparatus 100. 2, equation (1), the equation (2), the visible light reception terminal 200 is away from the visible light transmission apparatus 100, in accordance with the elevation angle ξ becomes smaller, the light reception power _{K B} of the visible light reception terminal 200 at point B, It becomes larger than the light receiving power K _A at the point A. Therefore, if the elevation angle ξ is sufficiently small, the light receiving power K _A at the point A is also equal to or smaller than the light receiving sensitivity of the visible light reception terminal 200, so that if possible the reception at the point B occurs. Thus, when the elevation angle ξ is equal to or smaller than a certain threshold value α, it is assumed that the elevation angle and the light reception angle are equal, and the position of the visible light receiving terminal 200 is set to the point A, rather than one end near the light source in the light receiving range. It is considered more accurate to calculate the light receiving angle with the point B as the position of the visible light receiving terminal 200. On the other hand, when the elevation angle ξ is large, the elevation angle ξ is not easily affected by the angle error of the elevation angle ξ accompanying the measurement error of the six-axis sensor 220. Therefore, when the elevation angle ξ is equal to or greater than a certain threshold value α, the light reception angle is calculated with the point A as the estimated position. By performing position calculation based on the value of the light reception angle calculated in this way, highly accurate position estimation can be performed.

  Here, the threshold value α is a position estimation error between the case where the light reception angle θ coincides with the elevation angle ξ and the case where the light reception angle θ and the angle obtained by adding the viewing angle ψ coincide with each other. The angle at which the standard deviation is equal. FIG. 3 shows an example of the relationship between the elevation angle and the position estimation error obtained in the experiment. In this case, by setting the elevation angle 50 degrees as the threshold value α, it can be seen that higher position estimation accuracy can be achieved in a wider elevation angle range than the conventional method in which the elevation angle is the light reception angle.

The position calculation unit 242 receives the light reception angle θ calculated by the light reception angle calculation unit 241, the azimuth angle φ calculated by the angle calculation unit 230, and the height H of the visible light receiving terminal 200 stored in its own storage area. From the above, the horizontal position of the visible light receiving terminal 200 at the height H is calculated. As shown in FIG. 4, when the horizontal position and height of the visible light transmitting apparatus 100 are (X ₀ , Y ₀ , H ₀ ), the horizontal position of the visible light receiving terminal 200 at the height H is Is calculated by the following equation (3). Here, (X ₀ , Y ₀ , H ₀ ) indicating the horizontal position and height of the visible light transmitter 100 may be stored in advance, or a visible light signal transmitted by the visible light transmitter 100. May be included as information. Further, the height H stored in the position calculation unit 242 may be input in accordance with the user's operation input during the estimated position calculation process, or the height at which the terminal is operated even when the user moves the place. Is considered to be substantially constant, the height value previously input by the user may be stored.

FIG. 5 is a flowchart showing an operation example in which the visible light receiving terminal 200 according to the present embodiment calculates its own estimated position.
The user visually confirms the position of the visible light transmitting device 100 and directs the visible light ID receiving unit 210 of the visible light receiving terminal 200 to the visible light transmitting device 100. The visible light ID receiver 210 determines whether or not the visible light ID transmitted from the visible light transmitter 100 has been received within its own viewing angle (step S1). When the visible light ID receiving unit 210 does not receive the visible light ID, the operation of step S1 is continued (step S1: NO).

  When the visible light ID receiving unit 210 receives the visible light ID (step S1: YES), the angle calculation unit 230 reads information from the six-axis sensor 220 (step S2), the elevation angle ξ of the visible light receiving terminal 200, and the visible light ID. The azimuth angle φ of the optical receiving terminal 200 is calculated and calculated (step S3). When the position estimation unit 240 acquires the elevation angle ξ and the azimuth angle φ calculated by the angle calculation unit 230, the position estimation unit 240 compares the acquired elevation angle ξ with the threshold α stored in advance in its own storage area (step S4). ). If the position estimation unit 240 determines that the elevation angle ξ is greater than the threshold value α, the position estimation unit 240 sets the elevation angle ξ to the light reception angle θ (step S4: YES). On the other hand, if it is determined that it is smaller than the threshold value α, a value obtained by adding the determined viewing angle ψ to the elevation angle ξ is calculated as the light receiving angle θ (step S4: NO).

  Then, the position estimation unit 240 receives the light reception angle θ calculated by the angle calculation unit 230, the elevation angle ξ acquired by the elevation angle calculation unit 231, the azimuth angle φ acquired by the azimuth angle calculation unit 232, and a high level stored in advance. From the value of the height H, the position in the horizontal direction of the visible light transmitting apparatus 100 is calculated by the above equation (3) (step S5).

<Second Embodiment>
Next, a second embodiment of the present invention will be described with reference to the drawings. The visible light receiving terminal 200 in the second embodiment has the same configuration as in the first embodiment, but the angle calculation unit 230 in the first embodiment determines whether the elevation angle ξ exceeds the threshold value α. In contrast to calculating the light reception angle θ by determining whether to add the viewing angle ψ to the elevation angle ξ, the angle calculation unit 230 of the second embodiment calculates the light reception angle θ according to the value of the elevation angle ξ. In order to calculate, the value added to the elevation angle ξ is changed. Here, the angle calculation unit 230 may store a correspondence table in which the elevation angle ξ is associated with the light reception angle θ with respect to the elevation angle ξ in advance in its own storage area, or the following equation (4) is calculated. The light reception angle θ may be calculated by a function to be performed.

  Expression (4) is an arithmetic expression for calculating the light reception angle θ corresponding to the elevation angle ξ based on the relationship between the elevation angle and the position estimation error shown in FIG. Here, Err (A (ξ)) and Err (B (ξ)) are position estimation errors at point A and point B in FIG. 2 when the elevation angle is ξ. By setting in this way, the light reception angle becomes a light reception angle at a point with a smaller position estimation error between point A and point B, and therefore position estimation with higher accuracy is possible.

  FIG. 6 is a flowchart showing an operation example of the position estimation system according to the second exemplary embodiment of the present invention. Steps S11 to S13 are the same as the steps S1 to S3 in the first embodiment. In step S14, the angle calculation unit 230 calculates the light reception angle by the above-described equation (3) based on the measurement result obtained by the 6-axis sensor 220 in step S13. In step S15, the process in which the position estimation unit 240 calculates the position of the visible light receiving terminal 200 based on the light reception angle calculated in step S14 is the same as the process in step S5 in the first embodiment.

It is also possible to divide the elevation angle ξ into several sections and refer to the light receiving angle according to the equation (4) at the midpoint of each section as the light receiving angle in each section with the same high accuracy as described above. Estimation is possible.
Further, the relational expression between the elevation angle and the light receiving angle shown in Expression (4) is merely an example, and high-precision position estimation can be performed using a function expression other than Expression (4) depending on the configuration of the transmission / reception optical system.

Note that the position estimation calculation in the present embodiment can be realized by hardware by combining logic circuits. However, a CPU or the like may be mounted on the visible light receiving terminal 200 and realized by software by a computer program. Is possible.
It should be noted that a program for realizing the function of the processing unit in the present invention is recorded on a computer-readable recording medium, and the program recorded on the recording medium is read into a computer system and executed to perform position estimation. May be. The “computer system” here includes an OS and hardware such as peripheral devices. The “computer system” includes a WWW system having a homepage providing environment (or display environment). The “computer-readable recording medium” refers to a portable medium such as a flexible disk, a magneto-optical disk, a ROM, and a CD-ROM, and a storage device such as a hard disk built in the computer system. Further, the “computer-readable recording medium” refers to a volatile memory (RAM) in a computer system that becomes a server or a client when a program is transmitted via a network such as the Internet or a communication line such as a telephone line. In addition, those holding programs for a certain period of time are also included.

  The program may be transmitted from a computer system storing the program in a storage device or the like to another computer system via a transmission medium or by a transmission wave in the transmission medium. Here, the “transmission medium” for transmitting the program refers to a medium having a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line. The program may be for realizing a part of the functions described above. Furthermore, what can implement | achieve the function mentioned above in combination with the program already recorded on the computer system, and what is called a difference file (difference program) may be sufficient.

It is a figure which shows the terminal structure by the 1st Embodiment of this invention. It is a figure explaining the relationship of the elevation angle by the 1st Embodiment of this invention, a viewing angle, and a light reception angle. It is a figure which shows the example of the relationship between an elevation angle and the position estimation error by the 1st Embodiment of this invention. It is a figure which shows the positional relationship of the visible light transmitter by the 1st Embodiment of this invention, and a visible light receiving terminal. It is a flowchart which shows the operation example by the 1st Embodiment of this invention. It is a flowchart which shows the operation example by the 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Visible light transmitter 200 Visible light receiving terminal 210 Visible light ID receiving part 220 6 axis sensor 221 Acceleration sensor 222 Geomagnetic sensor 230 Angle calculation part 231 Elevation angle calculation part 232 Azimuth angle calculation part 240 Position estimation part 241 Light reception angle calculation part 242 Position Calculation unit

Claims (7)

A position estimation terminal that calculates its own position based on the visible light transmitted from a visible light transmission device that transmits a signal using visible light as a transmission medium,
A visible light receiver for receiving the visible light;
When the visible light receiving unit receives the visible light, a sensor that acquires an elevation angle and an azimuth angle of the position estimation terminal;
In accordance with the elevation angle acquired by the sensor, the viewing angle of the visible light receiving unit is added to the elevation angle, and the light reception angle at which the position estimation terminal receives visible light transmitted from the visible light transmission device is calculated. A light receiving angle calculation unit for
Based on the light reception angle calculated by the light reception angle calculation unit, the azimuth angle acquired by the sensor, and the stored height of the terminal, the relative position of the position estimation terminal with respect to the visible light transmission device is calculated. A position estimation unit to calculate;
A position estimation terminal comprising: The light reception angle calculation unit adds the viewing angle to the elevation angle acquired by the sensor, the error between the elevation angle acquired by the sensor measured in advance and the actual light reception angle, and the elevation angle acquired by the sensor. When the angle is larger than the angle at which the error of the actual light reception angle is equal, the elevation angle is used as the light reception angle, and when the angle is smaller, the angle obtained by adding the viewing angle to the elevation angle is calculated as the light reception angle. The position estimation terminal according to claim 1. The position estimation terminal according to claim 1, wherein the light reception angle calculation unit calculates a value of a reception angle corresponding to an error measured in advance according to an elevation angle acquired by the sensor. A position estimation method using a position estimation terminal that calculates a position of itself based on the visible light transmitted from a visible light transmission device that transmits a signal using visible light as a transmission medium,
A visible light receiving unit receiving the visible light; and
A sensor, when the visible light receiving unit receives the visible light, obtaining an elevation angle and an azimuth angle of the position estimation terminal;
The light reception angle calculation unit adds the viewing angle of the visible light receiving unit to the elevation angle according to the elevation angle acquired by the sensor, and the position estimation terminal generates visible light transmitted from the visible light transmission device. Calculating the received acceptance angle;
The position estimation unit estimates the position of the visible light transmission device based on the light reception angle calculated by the light reception angle calculation unit, the azimuth angle acquired by the sensor, and the stored height of the terminal. Calculating the relative position of the device;
A position estimation method comprising: The light reception angle calculation unit adds the viewing angle to the elevation angle acquired by the sensor, the error between the elevation angle acquired by the sensor measured in advance and the actual light reception angle, and the elevation angle acquired by the sensor. When the angle is larger than the angle at which the error of the actual light reception angle is equal, the elevation angle is used as the light reception angle, and when the angle is smaller, the angle obtained by adding the viewing angle to the elevation angle is calculated as the light reception angle. The position estimation method according to claim 4. The position estimation method according to claim 4, wherein the light reception angle calculation unit calculates a value of a reception angle corresponding to an error measured in advance according to an elevation angle acquired by the sensor. To a computer of a position estimation terminal that calculates its position based on the visible light transmitted from a visible light transmission device that transmits a signal using visible light as a transmission medium,
A visible light receiving unit receiving the visible light; and
A sensor, when the visible light receiving unit receives the visible light, obtaining an elevation angle and an azimuth angle of the position estimation terminal;
The light reception angle calculation unit adds the viewing angle of the visible light receiving unit to the elevation angle according to the elevation angle acquired by the sensor, and the position estimation terminal generates visible light transmitted from the visible light transmission device. Calculating the received acceptance angle;
The position estimation unit estimates the position of the visible light transmission device based on the light reception angle calculated by the light reception angle calculation unit, the azimuth angle acquired by the sensor, and the stored height of the terminal. Calculating the relative position of the device;
A program that executes

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