JP6573313B2 - Altitude estimation apparatus, program and method for estimating altitude and error using barometric pressure value - Google Patents

Description

  The present invention relates to a technique for estimating altitude from the ground using atmospheric pressure values.

  In recent years, with the miniaturization and high accuracy of sensors, various sensors have been built in mobile terminals such as mobile phones and smartphones. In particular, a GPS (Global Positioning System) sensor is common, and by receiving a positioning radio wave from a satellite, the current position and altitude of the mobile terminal can be measured. Accordingly, it is possible to search the surrounding area information from various viewpoints using the position and altitude measured. However, since the GPS sensor needs to receive positioning radio waves from satellites, it is mainly limited to outdoor positioning.

On the other hand, for indoor positioning, the following three methods using a wireless LAN or a cellular communication network are mainly used (for example, refer to Non-Patent Documents 1 and 2).
"Multiple base station positioning method": Positioning by communication radio waves from multiple adjacent base stations "Hybrid positioning method": GPS positioning method + multiple base station positioning method
“Cell-based positioning method”: The position of the connected base station is the current position of the mobile terminal. According to these positioning methods that can be measured indoors, the latitude and longitude are estimated and the error for the estimated position is calculated. You can also

  FIG. 1 is a map image in which position estimation errors are represented by circles.

  According to FIG. 1, the circle size changes depending on the positioning accuracy of the current position (see, for example, Non-Patent Document 3). That is, the larger the circle size, the lower the positioning accuracy, and the smaller the circle size, the higher the positioning accuracy. According to the map display application, the current position is marked and a circle is displayed around the mark as shown in FIG. The circle size increases as the current location cannot be measured accurately.

  In order to estimate the altitude in addition to the position, there is a method using a “barometric pressure sensor” in addition to a GPS sensor.

  Conventionally, there is a technique for calculating an altitude difference between two arbitrary points using an atmospheric pressure sensor (see, for example, Patent Document 8). According to this technology, it is possible to estimate an altitude difference between two points whose altitude is unknown in order to specify a charging fee such as heli skiing (skiing from the top of a mountain using a helicopter). Further, it is possible to calculate an error in altitude estimated by using a known atmospheric pressure measurement device. Here, the error of the calculated altitude difference is reduced by adding or subtracting the error.

  There is also a technique for estimating the altitude of a mobile terminal equipped with a barometric sensor and having an unknown altitude, based on the barometric pressure value of a reference wireless sensor terminal whose ground height is known (see, for example, Patent Document 1). There is also a technique for deriving the altitude of the mobile terminal from the barometric pressure value measured by a barometric pressure sensor of the surrounding mobile terminal using a barometric pressure measuring device installed in a place where the altitude is known in advance (for example, Patent Literature 2).

  Furthermore, there is a technique for estimating the altitude based on a mountain climbing port whose position and altitude are known (see, for example, Patent Document 3). According to this technique, the mountain climbing support device installed at the mountain entrance transmits the predicted atmospheric pressure value and the predicted atmospheric pressure fluctuation pattern at the installation location of the mountain climbing support device calculated by the server to the mobile terminal. The mobile terminal calculates the atmospheric pressure offset value by using the atmospheric pressure value and the predicted atmospheric pressure value measured at the mountain climbing entrance. Thereafter, the mobile terminal can continue to estimate the altitude without communicating during the climbing of the user based on the observed atmospheric pressure value taking into account the value of the predicted atmospheric pressure fluctuation pattern and the atmospheric pressure offset value.

  Further, there is a technique for estimating the altitude change from the change amount of the atmospheric pressure value (see, for example, Patent Document 4). According to this technology, the user's action state is determined based on the transition of the detection value of the acceleration sensor, and the altitude change is only performed when the atmospheric pressure change is observed even in the moving state or in the stationary state. Is estimated. Thereby, the error of the estimated altitude can be reduced due to changes in atmospheric pressure such as weather.

  Furthermore, there is a technique for calculating the altitude using the positioning altitude value only when the fluctuation of the positioning altitude value based on GPS positioning is small (see, for example, Patent Document 5). According to this technique, the altitude is calculated by using the calculated altitude value and then adding the altitude change calculated from the fluctuation of the atmospheric pressure value.

  In addition, there is a technique for correcting a conversion table that is stored in a mobile terminal and includes an atmospheric pressure value and an altitude (see, for example, Patent Document 6). According to this technique, the “elevation value” is calculated based on the current position information based on GPS and the atmospheric pressure value measured by the atmospheric pressure sensor. Next, “elevation data” is received from the server based on the current position information. Then, the calculated altitude value and altitude data are compared to correct the pressure and altitude conversion table. By executing this periodically, it is possible to reduce the influence of atmospheric pressure fluctuation due to the weather on the calculated altitude.

  Further, there is a technique for calculating an altitude value obtained by calibrating altitude data depending on whether the mobile terminal stays indoors or outdoors (see, for example, Patent Document 7). According to this technology, the mobile terminal calculates the altitude value based on the current position information and the atmospheric pressure value measured by the atmospheric pressure sensor. The mobile terminal receives map data and elevation data from the server based on the current position information. Then, when the current position information is inside a building or facility on the map data, the mobile terminal sets the calculated altitude value as the current altitude value. On the other hand, when the current position information is outside the building or facility on the map data, the altitude value calculated to match the received altitude data is calibrated to obtain the current altitude value. Thereby, when the mobile terminal stays indoors, it is possible to prevent the altitude value based on the altitude data from being erroneously set. Further, once the calibration is performed outside the building or facility, the altitude inside and outside the building can be accurately calculated as long as the atmospheric pressure fluctuation due to the weather does not increase.

JP 2013-002933 A Japanese Patent Application Laid-Open No. 2013-221887 JP 2011-257260 A JP 2013-2000156 A JP 2014-021036 A JP 2006-145340 A JP 2013-231634 A JP 2013-222385 A

Takeshi Hattori, Masanobu Fujioka, “Wireless Broadband Textbook-3.5G / Next Generation Mobile Edition”, Impress R & D, July 21, 2007, first edition, third volume, p. 56-61 Sirin Tekinay, `` Next generation wireless networks '', p.143- Apple, "iOS 6: Location Information Service", [online], [Search June 14, 2015], Internet <URL: https://support.apple.com/en-us/HT202588> Tatsunori Sada, “GPS Surveying Technology”, Ohmsha, October 2003, p.32-36

  The ground height at which the user is located indoors (height from the ground) is required as a location service that is practically necessary in a city-like place where high-rise buildings are lined up. At this time, it is important to present a position estimation error to the user who uses the service. By presenting the estimated degree of position error to the user, the user can know the range of the actual position including the error, and can recognize the position service while allowing the error.

  Even with the technique described in any of Patent Documents 1 to 8, the altitude at which the mobile terminal stays can be estimated, but the error cannot be estimated. In other words, the estimated altitude can only be presented to the user pinpointed, and the user may have an estimated value that falls within an error of about 1 to 2 meters or includes an error of about several tens of meters. It cannot be recognized.

  In particular, according to the techniques described in Patent Documents 3, 6, 7, and 8, by using an atmospheric pressure measuring device whose position is known, an error in the output value of the atmospheric pressure sensor is calculated, and the error is added or subtracted. The estimation accuracy is increased. However, since the error is not taken into consideration for the known atmospheric pressure measurement device itself as a reference point, the estimated altitude itself already includes an error.

  Therefore, an object of the present invention is to provide an altitude estimation apparatus, program, and method capable of estimating an error included in an altitude calculated from an atmospheric pressure value when estimating the ground height from the atmospheric pressure value.

According to the present invention, each atmospheric pressure value measured by the atmospheric pressure sensor is stored in association with the positional information and the positioning error radius measured by the positioning unit when measuring the atmospheric pressure value, and the altitude estimation for estimating the altitude and the error. A device,
Altitude estimation means for estimating altitude from the target atmospheric pressure value among a plurality of atmospheric pressure values,
A pressure distribution calculating means for calculating a pressure distribution based on a difference between a plurality of pressure values and a model pressure value calculated from the plurality of pressure values;
Elevation value acquisition means for acquiring a plurality of elevation values included in the positioning error radius around the position information;
An elevation scatter degree calculating means for calculating an elevation scatter degree based on a difference between each of the plurality of elevation values and a model elevation value calculated from the plurality of elevation values;
The altitude spread degree is calculated from the difference between the target altitude based on the target atmospheric pressure value to be estimated and the spray altitude resulting from the atmospheric pressure spread degree from the target atmospheric pressure value, and the altitude based on the altitude spread degree and altitude spread degree is calculated. And altitude error estimating means for estimating the error.

According to another embodiment of the altitude estimation apparatus of the present invention,
Regarding the atmospheric pressure distribution calculating means, the atmospheric pressure distribution is preferably the root mean square of the difference between each atmospheric pressure value and the model atmospheric pressure value.

According to another embodiment of the altitude estimation apparatus of the present invention,
Regarding the atmospheric pressure distribution degree calculation means, the model atmospheric pressure value is preferably an average value for a plurality of atmospheric pressure values or an estimated value based on a single regression analysis.

According to another embodiment of the altitude estimation apparatus of the present invention,
It is also preferable that the distribution altitude in the altitude error estimation means is based on a value obtained by adding or subtracting the atmospheric pressure distribution to the target atmospheric pressure value.

According to another embodiment of the altitude estimation apparatus of the present invention,
The altitude error estimation means is
HRMS: High spread rate (m)
PRMS: Barometric pressure spread (hPa)
Pb: Reference atmospheric pressure value (atmospheric pressure value on the ground surface)
P: Target atmospheric pressure value (atmospheric pressure value to be estimated for altitude, for example, the last atmospheric pressure value in time series)
(Pb / P) ^{(1 / 5.257)} x (Temp + 273.15)) / 0.0065
: Target altitude based on target pressure value to be estimated
(Pb / (P-PRMS)) ^{(1 / 5.257)} x (Temp + 273.15)) / 0.0065
： Spraying altitude caused by atmospheric pressure spreading degree to target air pressure value
Temp: temperature
HRMS = ((Pb / (P-PRMS)) ^{(1 / 5.257)} -(Pb / P) ^{(1 / 5.257)} )
× (Temp + 273.15)) / 0.0065
It is also preferable to estimate the altitude dispersion degree as an altitude error.

According to another embodiment of the altitude estimation apparatus of the present invention,
It is also preferable that the altitude error estimating means sets the altitude error to a real number multiple of HRMS with respect to the altitude spread degree HRMS.

According to another embodiment of the altitude estimation apparatus of the present invention,
With respect to the altitude spread degree calculation means, the altitude spread degree is preferably the root mean square of the difference between each elevation value and the model elevation value.

According to another embodiment of the altitude estimation apparatus of the present invention,
The altitude error estimation means is the square root of the sum of squares of the altitude distribution and the altitude distribution, which is the difference between the target altitude based on the target atmospheric pressure value to be estimated and the distribution altitude resulting from the atmospheric pressure distribution. It is also preferable to estimate the altitude error based on the cumulative altitude spread degree.

According to another embodiment of the altitude estimation apparatus of the present invention,
Regarding the altitude spread degree calculation means, the model altitude value is preferably an average value for a plurality of altitude values.

According to another embodiment of the altitude estimation apparatus of the present invention,
A 2D or 3D map database;
It is also preferable to further include map application means for generating a map expressing position information, a positioning error radius, and an altitude error on the map of the map database.

According to another embodiment of the altitude estimation apparatus of the present invention,
The map application means uses the map database to search for one or more buildings that match the estimated altitude and altitude error among the buildings included in the range based on the location information and the positioning error radius, It is also preferable to focus the position information.

According to the present invention, each atmospheric pressure value measured by the atmospheric pressure sensor is stored in association with the positional information and the positioning error radius measured by the positioning unit when measuring the atmospheric pressure value, and the altitude estimation for estimating the altitude and the error. A program for causing a computer mounted on a device to function,
Altitude estimation means for estimating altitude from the target atmospheric pressure value among a plurality of atmospheric pressure values,
A pressure distribution calculating means for calculating a pressure distribution based on a difference between a plurality of pressure values and a model pressure value calculated from the plurality of pressure values;
Elevation value acquisition means for acquiring a plurality of elevation values included in the positioning error radius around the position information;
An elevation scatter degree calculating means for calculating an elevation scatter degree based on a difference between each of the plurality of elevation values and a model elevation value calculated from the plurality of elevation values;
The altitude spread degree is calculated from the difference between the target altitude based on the target atmospheric pressure value to be estimated and the spray altitude resulting from the atmospheric pressure spread degree from the target atmospheric pressure value, and the altitude based on the altitude spread degree and altitude spread degree is calculated. A computer is made to function as altitude error estimation means for estimating an error.

According to the present invention, an apparatus for estimating altitude and error is stored by associating and storing each atmospheric pressure value measured by an atmospheric pressure sensor with positional information and a positioning error radius measured by a positioning unit when measuring the atmospheric pressure value . An altitude estimation method comprising:
The device
Estimate altitude from the target pressure value among multiple pressure values ,
Calculating a pressure dispersion degree based on a difference between each of a plurality of pressure values and a model pressure value calculated from the plurality of pressure values ;
Centering on location information, obtain multiple elevation values included in the positioning error radius, and calculate elevation dispersion based on the difference between each elevation value and the model elevation value calculated from the elevation values And
The altitude spread degree is calculated from the difference between the target altitude based on the target atmospheric pressure value to be estimated and the spray altitude resulting from the atmospheric pressure spread degree from the target atmospheric pressure value, and the altitude based on the altitude spread degree and altitude spread degree is calculated. Estimate error
It is characterized by performing as follows.

  According to the altitude estimation apparatus, program, and method of the present invention, when the ground height is estimated from the atmospheric pressure value, an error included in the altitude calculated from the atmospheric pressure value can be estimated. As a result, the user who receives the location service using the altitude can receive the location service while allowing the error.

It is the map image which expressed the estimation error of the position with the circle. It is explanatory drawing showing the implementation environment in this invention. It is a block diagram of the altitude estimation function of the present invention configured as a server. It is a block diagram of the altitude estimation function of this invention comprised as a portable terminal. 3 is a map image expressing altitude and error according to the present invention. It is the 1st explanatory view which corrects the position information measured from the estimated ground height and altitude error. It is the 2nd explanatory view which corrects position information measured from estimated ground height and altitude error. It is the 3rd explanatory view which corrects position information measured from estimated ground height and altitude error. It is the 4th explanatory view which corrects position information measured from an estimated ground height and altitude error.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 2 is an explanatory diagram showing an implementation environment in the present invention.

  The mobile terminal 2 such as a smartphone can generally determine its current position by a GPS sensor or base station positioning. The portable terminal 2 of the present invention can measure the atmospheric pressure by further mounting an atmospheric pressure sensor. When the mobile terminal is located indoors, the mobile terminal can communicate with the base station of the mobile phone network, but cannot receive positioning radio waves from GPS satellites.

  The atmospheric pressure sensor mounted on the portable terminal outputs an atmospheric pressure value corresponding to the altitude as an electric power value. The lower the altitude, the higher the atmospheric pressure value. Conversely, the higher the altitude, the lower the atmospheric pressure value. Therefore, even in the same building, the atmospheric pressure value observed by the atmospheric pressure sensor differs depending on the floor where the user is located. Estimate the ground height (height from the ground surface) and the number of floors in the building using the standard pressure value (atmospheric pressure value based on the ground surface) observed on the ground part (the first floor) of the building. Can do. In the present invention, how much error does the altitude based on the atmospheric pressure value of the atmospheric pressure sensor include? Is estimated.

  Normally, when a train enters a subway platform or when a car enters a narrow space such as a tunnel, the atmospheric pressure value is not stable even at the same altitude. That is, in this case, when the altitude is estimated only by the atmospheric pressure value of the atmospheric pressure sensor, the altitude error must be increased. Even in such a case, if the user himself can consider the altitude error, the location service can be used appropriately.

FIG. 3 is a block diagram of the altitude estimation function of the present invention configured as a server.
FIG. 4 is a configuration diagram of the altitude estimation function of the present invention configured as a mobile terminal.

  The altitude estimation function estimates the altitude and error from a plurality of barometric pressure values measured by the barometric sensor. The altitude estimation function may be implemented in the server 1 that communicates with the mobile terminal 2 or may be implemented in the mobile terminal 2 itself. The server 1 receives a plurality of atmospheric pressure values from the mobile terminal 2 and returns the altitude and the error estimated thereby to the mobile terminal 2.

  The altitude estimation function of the present invention includes a map database 10, an atmospheric pressure value acquisition unit (reception of atmospheric pressure value or measurement of an atmospheric pressure sensor) 11, and a position information acquisition unit (reception of position information or measurement of a positioning unit). 12, an altitude estimation unit 13, an atmospheric pressure dispersion degree calculation unit 14, an altitude error estimation unit 15, a map application unit 16, an elevation value acquisition unit 17, and an elevation distribution degree calculation unit 18. These functional components are realized by executing a program that causes a computer installed in the apparatus to function. Further, the processing flow of these functional components can be understood as a method of calculating the magnitude of the estimated altitude estimation error.

[Atmospheric pressure value acquisition unit 11]
The atmospheric pressure value acquisition unit 11 acquires a plurality of atmospheric pressure values by receiving an atmospheric pressure value or measuring by an atmospheric pressure sensor. For example, a predetermined number (for example, five) of atmospheric pressure values are acquired in a time-series order within a predetermined time (for example, five seconds). Here, it is assumed that a plurality of atmospheric pressure values are acquired in the following three patterns.
(First atmospheric pressure value sequence / stationary) When the user holding the mobile terminal is stationary
1023.528 hPa
1023.129 hPa
1023.277 hPa
1023.075 hPa
1023.586 hPa
(2nd barometric pressure value sequence / stationary) When the user holding the mobile terminal is stationary
1023.592 hPa
1023.642 hPa
1023.632 hPa
1023.665 hPa
1023.586 hPa
(Third barometric pressure value sequence / movement) When the user holding the portable terminal is descending in the elevator
1023.031 hPa
1023.207 hPa
1023.637 hPa
1024.034 hPa
1024.085 hPa
These atmospheric pressure values are output to the altitude estimation unit 13 and the atmospheric pressure dispersion degree calculation unit 14.

In the case of continuously acquiring the atmospheric pressure value, there are the following two embodiments as a plurality of atmospheric pressure value blocks.
(Division acquisition type) The acquired atmospheric pressure value is divided into n pieces (for example, 5 pieces).
_{[P 1, P 2, P} 3, P 4, P 5]
_{[P 6, P 7, P} 8, P 9, P 10]
_{[P 11, P 12, P} 13, P 14, P 15]
...
(Slide acquisition type) Slide the acquired atmospheric pressure values by n pieces (for example, 5 pieces).
_{[P 1, P 2, P} 3, P 4, P 5]
_{[P 2, P 3, P} 4, P 5, P 6]
[P ₃ , P ₄ , P ₅ , P ₆ , P ₇ ]
...

[Position information acquisition unit 12]
The position information acquisition unit 12 acquires position information by receiving position information (latitude / longitude) or by measurement by a positioning unit. The position information may be acquired by GPS, or may be based on base station positioning. The position information is acquired in association with the atmospheric pressure value of the atmospheric pressure value acquisition unit 11. The position information is output to the map application unit 16 and the elevation value acquisition unit 17.

[Altitude estimation unit 13]
The altitude (ground height) based on the atmospheric pressure value is calculated by the following equation, for example.
h: Ground clearance (m: meter)
Pb: Reference atmospheric pressure value (atmospheric pressure value on the ground surface)
P: Target pressure value
Temp: temperature h = (((Pb / P) ^{(1 / 5.257)} −1) × (Temp + 273.15)) / 0.0065

  The “target atmospheric pressure value” is an atmospheric pressure value at a location where the user who owns the mobile terminal is actually located. It is also preferable that the atmospheric pressure value acquisition unit 11 sets the last atmospheric pressure value as the target atmospheric pressure value, considering that the last atmospheric pressure value is closest to the current time in a block including n atmospheric pressure values, for example. However, it is not limited to the last atmospheric pressure value, and the target atmospheric pressure value may be the first atmospheric pressure value of the block or the average value of all the atmospheric pressure values of the block.

  “Temp (temperature)” may be one in which the portable terminal 2 is equipped with a temperature sensor and acquires the temperature. Further, when the reference atmospheric pressure value is acquired from an external reference atmospheric pressure database or a climate database, the temperature corresponding to the position of the reference atmospheric pressure value may be acquired at the same time. Furthermore, the temperature corresponding to the month, season, and time zone may be fixedly defined in advance.

The altitude can be estimated by applying the following numerical values to the above formula.
(1st barometric pressure value sequence / stationary)
Target pressure value P: 1023.586 hPa
Reference pressure value Pb: 1025.019 hPa
Temperature: 20.0 degrees Ground clearance h = ((1025.019 / 1023.586) ^{(1 / 5.257)} -1) x (20.0 + 273.15)) / 0.0065
= 12.00368m
The ground clearance here is estimated to be 12m. According to the present invention, it is possible to estimate the altitude error relative to the ground height.

[Atmospheric pressure spread calculation unit 14]
The atmospheric pressure spread degree calculation unit 14 calculates an “atmospheric pressure spread degree” based on a difference between a plurality of atmospheric pressure values and a model atmospheric pressure value calculated from the plurality of atmospheric pressure values. The atmospheric pressure dispersion degree is output to the altitude error estimation unit 15.

  Here, the “model atmospheric pressure value” is an estimated value based on <average value> or <single regression analysis> for a plurality of atmospheric pressure values. The “atmospheric pressure dispersion degree” is, for example, the root mean square of the difference between each atmospheric pressure value and the model atmospheric pressure value.

<When model air pressure value is “average value”>
(1st barometric pressure value sequence / stationary)
The average value and the atmospheric pressure dispersion degree PRMS are as follows for the first atmospheric pressure value column.
Average = (1023.528 + 1023.129 + 1023.277 + 1023.075 + 1023.586) / 5
= 1023.319 hPa
PRMS = Sqrt (((1023.528−1023.319) ² + (1023.129−1023.319) ² +
(1023.277−1023.319) ² + (1023.075−1023.319) ² +
(1023.586−1023.319) ² )) / 5)
= 0.2060922 hPa
(2nd barometric pressure value series / stationary)
With respect to the above-described second atmospheric pressure value sequence, the average value and the atmospheric pressure dispersion degree PRMS are as follows.
Average = (1023.592 + 1023.642 + 1023.632 + 1023.665 + 1023.586) / 5
= 1023.623 hPa
PRMS = Sqrt (((1023.592−1023.623) ² + (1023.642−1023.623) ² +
(1023.632−1023.623) ² + (1023.665−1023.623) ² +
(1023.586−1023.623) ² )) / 5)
= 0.03011710 hPa
(Third barometric pressure value sequence, movement, average value)
For the above-described third atmospheric pressure value sequence, the average value and the atmospheric pressure dispersion degree PRMS are as follows.
Average = (1023.031 + 1023.207 + 1023.637 + 1024.034 + 1024.085) / 5
= 1023.599hPa
PRMS = Sqrt (((1023.031−1023.599) ² + (1023.207−1023.599) ² +
(1023.637−1023.599) ² + (1024.034−1023.599) ² +
(1024.085−1023.599) ² )) / 5)
= 0.4248664hPa
According to the above-described atmospheric pressure value sequence, it can be understood that the third atmospheric pressure value sequence that is moving has the highest atmospheric pressure dispersion degree.

<When the model barometric pressure value is “Single regression analysis”>
(Third barometric pressure value series, movement, single regression analysis estimate)
The following single regression equation is calculated using the least square method as the single regression analysis for the above-described third atmospheric pressure value sequence.
Single regression equation: Observed atmospheric pressure = 0.293436 * Index + 1022.71918267
Index: Time series order of acquired barometric pressure
(1023.031hPa is the first and 1024.085hPa is the fifth)
The pressure dispersion degree PRMS of the difference (residual) between the model pressure value (model) obtained by this regression equation and each of a plurality of pressure values is calculated.
PRMS = Sqrt (((1023.012−1023.031) ² + (1023.306−1023.207) ² +
(1023.599−1023.637) ² + (1023.892−1024.034) ² +
(1024.186-1024.085) ² ) / 5)
= 0.091116004hPa

  It can be understood that the atmospheric pressure distribution PRMS of the single regression analysis is smaller than the atmospheric pressure distribution PRMS of the average value analysis for the third atmospheric pressure value sequence measured while descending by the elevator. That is, according to the average value analysis, it is merely determined that the atmospheric pressure is unstable, and the atmospheric pressure dispersion degree PRMS is merely increased. On the other hand, according to the single regression analysis, unlike the atmospheric pressure fluctuation, the atmospheric pressure dispersion degree does not actually increase. This is because the rate of change in altitude is constant, and the air pressure distribution of single regression analysis is also small. Therefore, although the single regression analysis increases the amount of calculation, it means that it is suitable for estimating the altitude error.

[Altitude error estimation unit 15]
The altitude error estimator 15 calculates an “altitude distribution degree” from the difference between the target altitude based on the target atmospheric pressure value to be estimated and the distribution altitude resulting from the atmospheric pressure distribution degree from the target atmospheric pressure value. Is estimated as “altitude error”. The calculated altitude error is output to the map application unit 16.

The altitude spreading degree is calculated by the following formula, for example.
HRMS: High spread rate (m)
PRMS: Barometric pressure spread (hPa)
Pb: Reference atmospheric pressure value (atmospheric pressure value on the ground surface)
P: Target atmospheric pressure value (atmospheric pressure value to be estimated for altitude, for example, the last atmospheric pressure value in time series)
(Pb / P) ^{(1 / 5.257)} x (Temp + 273.15)) / 0.0065
: "Target altitude" based on the target pressure value to be estimated
(Pb / (P-PRMS)) ^{(1 / 5.257)} x (Temp + 273.15)) / 0.0065
: “Spreading altitude” due to the atmospheric pressure dispersion degree in the target atmospheric pressure value
Temp: temperature
HRMS = ((Pb / (P-PRMS)) ^{(1 / 5.257)} -(Pb / P) ^{(1 / 5.257)} )
× (Temp + 273.15)) / 0.0065
In addition, according to the above formula, the “spreading altitude” is based on the value obtained by subtracting the air pressure scattering degree from the target air pressure value by (P-PRMS). May be.

When the reference atmospheric pressure value Pb = 1025.019 hPa and the temperature Temp = 20.0 degrees, it is calculated as follows.
(First barometric pressure value sequence, static, average value)
HRMS = ((1025.019 / (1023.586-0.2060922)) ^{(1 / 5.257)} −
(1025.019 / 1023.586) ^{(1 / 5.257)} ) × (20 + 273.15)) / 0.0065
= 1.73m
(2nd barometric pressure value sequence, static, average value)
HRMS = 0.25m
(Third barometric pressure value sequence, movement, average value)
HRMS = 3.6m
(Third barometric pressure value sequence, movement, single regression analysis)
HRMS = 0.76m

The altitude error estimation unit 15 estimates the altitude spread degree HRMS as an altitude error with respect to the altitude estimated atmospheric pressure value. Here, the altitude error estimation unit 15 may use an altitude error that is a real number multiple of HRMS (1 HRMS, 2 HRMS, or 3 HRMS) with respect to the altitude distribution HRMS. Regarding the root mean square RMS, the RMS of the difference between a certain value and the average value of the group to which the value belongs is equal to the standard deviation σ. In this case, it is easy to understand if the error is expressed as σ, 2σ, and 3σ.
For example, in the case of 2HRMS, the altitude error is estimated as follows.
(First barometric pressure value sequence, static, average value)
Altitude error = 2 x HRMS = 2 x 1.73m = 3.46m
(2nd barometric pressure value sequence, static, average value)
Altitude error = 2 x HRMS = 2 x 0.25m = 0.50m
(Third barometric pressure value sequence, movement, single regression analysis)
Altitude error = 2 x HRMS = 2 x 0.76m = 1.52m

  The first atmospheric pressure value example and the second atmospheric pressure value example are compared, and both are the same as “altitude 12 m” at the last atmospheric pressure value. However, it can be understood that the altitude error is smaller in the second atmospheric pressure value sequence than in the first atmospheric pressure value sequence due to atmospheric pressure fluctuation.

[Map application unit 16]
The map application unit 16 stores the position information and the positioning error radius measured by the positioning unit when measuring the atmospheric pressure value in association with the atmospheric pressure value. The map application unit 16 displays position information and a positioning error radius on a map using the two-dimensional or three-dimensional map database 10. Furthermore, according to the present invention, an altitude error can be expressed on a map. Of course, the estimated altitude and altitude error may be linked and recorded and transmitted to an external server without requiring the map application unit 16.

  FIG. 5 is a map image expressing altitude and error according to the present invention.

  According to Fig.5 (a), about the two-dimensional map image, the vertical number showing the floor number of a building is represented by the screen lower left. Here, the fact that the user who owns the mobile terminal is located on the fourth floor is expressed in black (outlined). In addition, the altitude error is expressed in gray to indicate that it may be located on the third or fifth floor. That is, the rank included in the lower limit to the upper limit of the estimated altitude error can be clearly shown to the user.

  For example, according to the first atmospheric pressure value sequence, it is estimated that the altitude error (2 HRMS) = 3.46 m at the altitude of 12 m. That is, the altitude with a width of 12 ± 3.46m is estimated. When the floor height of the building is estimated to be 3.5 m, for example, an altitude of 12 m is estimated to be 4.4 floors (= 12 / 3.5 + 1). Altitude error = 3.46m, so the ± 1st floor from the 4th floor is the altitude error.

  According to FIG. 5B, a three-dimensional map image is represented by a cylinder in which the height error is extended in the height direction with the positioning error of the position as the bottom circle. The center of the cylinder is a point represented by the positioning position and altitude. A user who visually recognizes such a three-dimensional map image can understand the position and altitude of the user and the positioning error and altitude error at a glance.

<Embodiment to further apply altitude error estimation and positioning error>
According to the above-described embodiment, the altitude error is estimated based on the fluctuation of only the atmospheric pressure value measured by the atmospheric pressure sensor. For this reason, the estimation error becomes larger as the change in atmospheric pressure becomes more unstable. On the other hand, the ground level estimation error is also affected by the horizontal positioning error. Specifically, according to the above-described equation for calculating the ground height h, the reference atmospheric pressure value (atmospheric pressure value on the ground surface) based on the position corresponding to the last measured atmospheric pressure value is used. However, when the altitude difference in the range of the positioning error (2DRMS or the like) is large (that is, when the difference due to the location of the reference atmospheric pressure value is large), the estimation error of the ground height becomes large, and as a result, the altitude error becomes unstable.

[Altitude value acquisition unit 17]
The elevation value acquisition unit 17 acquires a plurality of elevation values included in the positioning error radius with the position information as a center. Assume that an external database such as an altitude database stores altitude values for every 5 m × 5 m mesh, for example. On the other hand, the elevation value acquisition unit 17 acquires each elevation value for one or more meshes included in the range derived from the position information and its positioning error.

For example, if the position information error is 12.5m and the elevation value is expressed in tile units of 5m x 5m, 25 elevation values included in the circle range centered on the location are acquired. The
3.00m, 2.80m, 2.80m, 2.80m, 3.08m, 3.08m, 3.08m, 3.08m, 3.74m,
3.74m, 3.74m, 3.74m, 3.04m, 3.98m, 2.72m, 2.67m, 2.74m, 2.81m,
2.86m, 2.91m, 2.83m, 3.00m, 3.10m, 3.12m, 2.80m

[Altitude distribution calculation unit 18]
The altitude spread degree calculation unit 18 calculates an altitude spread degree based on a difference between each of the plurality of elevation values and a model elevation value calculated from the plurality of elevation values. The “elevation spread degree” is the root mean square ARMS of the difference between each elevation value and the model elevation value. The “model elevation value” is an average value for a plurality of elevation values. The calculation method of the altitude distribution is exactly the same as the calculation method of the atmospheric pressure distribution described above (when the model atmospheric pressure value is an average value). According to the above-mentioned altitude value sequence, the altitude spread degree ARMS = 0.375 m.

When the altitude spread degree calculation unit 18 is used, the altitude error estimation unit 15 estimates an altitude error with respect to the altitude estimated atmospheric pressure value based on the “altitude spread degree HRMS” and the “altitude spread degree ARMS”. Specifically, the altitude error estimator 15 includes an altitude distribution degree HRMS, which is a difference between a target altitude based on the target atmospheric pressure value to be estimated and an application altitude resulting from the atmospheric pressure distribution degree from the target atmospheric pressure value, and altitude distribution. The square root of the sum of squares in degrees is defined as “cumulative height dispersion degree CRMS”.
CRMS = Sqrt (HRMS ² + ARMS ² )
When HRMS = 1.73m and ARMS = 0.75m, CRMS = 1.89m.
The altitude error estimation unit 15 estimates the accumulated altitude distribution degree CRMS as an altitude error with respect to the altitude estimated atmospheric pressure value.

<Correction of location information on the map>
FIG. 6 is a first explanatory diagram for correcting the position information determined from the estimated ground height and altitude errors.

  The map application unit 16 of the present invention inputs the position information (latitude, longitude, positioning error) from the positioning unit, the altitude (ground height) from the altitude estimating unit 13, and the error from the altitude error estimating unit, With reference to the map database 10, the position information on the map can be corrected.

  Specifically, the map application unit 16 uses the map database 10 to search for building information in a circle centered on position information (latitude and longitude) and whose positioning error is a radius, Acquire the maximum number of floors and basement floors). Moreover, the range of the height error of the ground height is calculated from the estimated height and the height error. Then, the map application unit 16 focuses the position information only on the building information included in the altitude error width of the ground height within the circle area representing the positioning error. As a result, the position information narrowed down and displayed can be clearly shown to the user.

  According to FIG. 6, the range of the height error (for example, 8.5 to 15.5 m) of the ground height is calculated from the estimated height (for example, the height of 12 m) and the height error (for example, ± 3.5 m). Further, according to FIG. 6, a building with a ground height of 53 m and a building with a height of 7 m are searched for as building information in the error circle of the position information. At this time, since the estimated ground height is 8.5 m or more, it can be estimated that it is not at the ground level or in a building having a height of 7 m. Therefore, the map application unit 16 can focus the position information (latitude and longitude) on the position of the building having a ground height of 53 m, which is consistent even if the estimated ground height is 8.5 to 15.5 m.

  FIG. 7 is a second explanatory diagram for correcting position information determined from estimated ground height and altitude errors.

  According to FIG. 7, a building with a ground height of 53 m and a building with a ground height of 18 m are retrieved as building information in the error circle of the position information. At this time, the map application unit 16 provides position information (latitude and longitude) to the positions of both the building with the ground height of 53 m and the building with the ground height of 18 m, which is consistent even if the estimated ground height is 8.5 to 15.5 m. Can focus.

  FIG. 8 is a third explanatory diagram for correcting the position information determined from the estimated ground height and altitude errors.

  According to FIG. 8, the range of height error (for example, −15.5 to −8.5 m) of the ground height is calculated from the estimated height (for example, ground height of −12 m) and the height error (for example, ± 3.5 m). Here, it is assumed that there is no building having a basement as building information in the error circle of the position information. At this time, if there is a building that fits in the vicinity of the error circle (for example, in a circle having a radius of twice the positioning error), the position information can be focused on that building. According to FIG. 8, the map application unit 16 has position information (latitude and longitude) in the position of the building on the 5th basement floor (−20 m), which is consistent even if the estimated ground height is −15.5 to −8.5 m. Can be focused.

  FIG. 9 is a fourth explanatory diagram for correcting the position information measured from the estimated ground height and altitude error.

  When the estimated altitude error width includes 0 m, the map application unit 16 does not need to correct the position information. According to Fig. 9, if there is a bridge with a ground height of about 8m over the river and there is an area where the estimated ground height is inconsistent with the ground level, the position information is corrected at the position of the ground height of 0m. It is also preferable to do.

  As described above in detail, according to the altitude estimation device, program, and method of the present invention, when the ground height is estimated from the atmospheric pressure value, an error included in the altitude calculated from the atmospheric pressure value can be estimated. it can. As a result, the user who receives the location service using the altitude can receive the location service while allowing the error.

  Various changes, modifications, and omissions of the above-described various embodiments of the present invention can be easily made by those skilled in the art. The above description is merely an example, and is not intended to be restrictive. The invention is limited only as defined in the following claims and the equivalents thereto.

DESCRIPTION OF SYMBOLS 1 Altitude estimation server 10 Map database 11 Atmospheric pressure value acquisition part 12 Position information acquisition part 13 Altitude estimation part 14 Atmospheric pressure dispersion degree calculation part 15 Altitude error estimation part 16 Map application part 17 Elevation value acquisition part 18 Altitude dispersion degree calculation part 2 Mobile terminal

Claims (13)

An altitude estimation device that stores each barometric pressure value measured by a barometric sensor in association with position information and a positioning error radius measured by a positioning unit when measuring the barometric pressure value, and estimates an altitude and an error,
Altitude estimation means for estimating altitude from the target atmospheric pressure value among a plurality of atmospheric pressure values,
A pressure distribution calculating means for calculating a pressure distribution based on a difference between a plurality of pressure values and a model pressure value calculated from the plurality of pressure values;
Elevation value acquisition means for acquiring a plurality of elevation values included in the positioning error radius around the position information;
An elevation scatter degree calculating means for calculating an elevation scatter degree based on a difference between each of the plurality of elevation values and a model elevation value calculated from the plurality of elevation values;
The altitude spreading degree is calculated from the difference between the target altitude based on the target atmospheric pressure value to be estimated and the spreading altitude caused by the atmospheric pressure spreading degree for the target atmospheric pressure value, and based on the altitude spreading degree and the altitude spreading degree. And an altitude error estimating means for estimating altitude error. The altitude estimation device according to claim 1, wherein the atmospheric pressure dispersion degree is a root mean square of a difference between each atmospheric pressure value and the model atmospheric pressure value. The altitude estimation device according to claim 1 or 2, wherein the model atmospheric pressure value is an average value for the plurality of atmospheric pressure values or an estimated value based on a single regression analysis. . The altitude according to any one of claims 1 to 3, wherein the scattering altitude in the altitude error estimating means is based on a value obtained by adding or subtracting the atmospheric pressure spreading degree to the target atmospheric pressure value. Estimating device. The altitude error estimating means includes
HRMS: High spread rate (m)
PRMS: Barometric pressure spread (hPa)
Pb: Reference atmospheric pressure value (atmospheric pressure value on the ground surface)
P: Target atmospheric pressure value (atmospheric pressure value to be estimated for altitude, for example, the last atmospheric pressure value in time series)
(Pb / P) ^{(1 / 5.257)} x (Temp + 273.15)) / 0.0065
: Target altitude based on target pressure value to be estimated
(Pb / (P-PRMS)) ^{(1 / 5.257)} x (Temp + 273.15)) / 0.0065
： Spraying altitude caused by atmospheric pressure spreading degree to target air pressure value
Temp: temperature
HRMS = ((Pb / (P-PRMS)) ^{(1 / 5.257)} -(Pb / P) ^{(1 / 5.257)} )
× (Temp + 273.15)) / 0.0065
The altitude estimation apparatus according to claim 4, wherein the altitude distribution degree is estimated as the altitude error. 6. The altitude estimation apparatus according to claim 5, wherein the altitude error estimation means sets the altitude error to a real number multiple of HRMS with respect to the altitude distribution degree HRMS. For the altitude spraying calculation means, the altitude degree of dispersion is high according to any one of claims 1 6, characterized in that the root mean square of the difference between the model altitude value and each altitude value Estimating device. The altitude error estimating means accumulates a difference between a target altitude based on a target atmospheric pressure value to be estimated and an altitude distribution resulting from the atmospheric air pressure distribution from the target atmospheric pressure value, and a square root of a sum of squares in the altitude distribution. The altitude estimation apparatus according to any one of claims 1 to 7 , wherein an altitude error is estimated based on the accumulated altitude spreading degree. The altitude estimation apparatus according to any one of claims 1 to 8 , wherein the model altitude value is an average value with respect to the plurality of altitude values with respect to the altitude distribution degree calculation means. A 2D or 3D map database;
On the map of the map database, and the position information and the positioning error radius, any one of claims 1 to 9, further comprising a map application means for generating a map that expresses said altitude error 1 The altitude estimation apparatus according to the item. The map application means uses the map database to search for one or more buildings that match the estimated altitude and altitude error among the buildings included in the range based on the location information and the positioning error radius. 11. The altitude estimation apparatus according to claim 10 , wherein position information is focused on the building. A computer mounted in an altitude estimation device that estimates the altitude and error by storing each barometric pressure value measured by the barometric sensor in association with the position information and positioning error radius measured by the positioning unit when measuring the barometric pressure value. Is a program that allows
Altitude estimation means for estimating altitude from the target atmospheric pressure value among a plurality of atmospheric pressure values,
A pressure distribution calculating means for calculating a pressure distribution based on a difference between a plurality of pressure values and a model pressure value calculated from the plurality of pressure values;
Elevation value acquisition means for acquiring a plurality of elevation values included in the positioning error radius around the position information;
An elevation scatter degree calculating means for calculating an elevation scatter degree based on a difference between each of the plurality of elevation values and a model elevation value calculated from the plurality of elevation values;
The altitude spreading degree is calculated from the difference between the target altitude based on the target atmospheric pressure value to be estimated and the spreading altitude caused by the atmospheric pressure spreading degree for the target atmospheric pressure value, and based on the altitude spreading degree and the altitude spreading degree. program for causing a computer to function as a highly error estimating means for estimating the altitude error Te. An altitude estimation method for an apparatus that stores each atmospheric pressure value measured by an atmospheric pressure sensor in association with position information and a positioning error radius measured by a positioning unit when measuring the atmospheric pressure value, and estimates an altitude and an error. ,
The device is
Estimate altitude from the target pressure value among multiple pressure values ,
Calculating a pressure dispersion degree based on a difference between each of a plurality of pressure values and a model pressure value calculated from the plurality of pressure values ;
Elevation scatter degree based on the difference between each of the plurality of elevation values and the model elevation value calculated from the plurality of elevation values while obtaining the plurality of elevation values included in the positioning error radius with the position information as a center To calculate
The altitude spreading degree is calculated from the difference between the target altitude based on the target atmospheric pressure value to be estimated and the spreading altitude caused by the atmospheric pressure spreading degree for the target atmospheric pressure value, and based on the altitude spreading degree and the altitude spreading degree. to estimate the altitude error Te
An altitude estimation method for an apparatus, which is executed as follows.

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