JP6486234B2 - Positioning device and positioning method - Google Patents

Description

  The present invention relates to a positioning technique using a navigation signal by a global navigation satellite system (GNSS).

  A global navigation satellite system (hereinafter also referred to as “GNSS”) that can know the position of its own terminal on the earth using radio waves supplied from a plurality of satellites has been put into practical use. In GNSS, it is possible to obtain the terminal position by receiving navigation signals from a plurality of navigation satellites and solving simultaneous equations relating to the distance between these navigation satellites and the terminal position of the terminal. As the GNSS, there are known a GPS (Global Positioning System) operated by the United States, a GLONASS (Global Navigation Satellite System) operated by the Russian Federation, and a Galileo system operated by the European Union.

  Since the navigation satellite is a mobile satellite that orbits the earth, the azimuth and elevation angles of the navigation satellite with respect to the receiving antenna are not constant. For this reason, when it is going to perform highly accurate positioning of a terminal position, favorable phase stability is calculated | required by a receiving antenna. However, if importance is attached to phase stability, there is a problem that the reception antenna becomes large and it is difficult to mount the reception antenna on a small terminal such as a portable terminal. On the other hand, when the receiving antenna is downsized, the phase stability may be reduced. In other words, when the receiving antenna is downsized, the amount of change in the phase center position of the receiving antenna increases with respect to changes in the azimuth and elevation angles of the navigation satellite as seen from its own terminal position, which may degrade positioning accuracy. Arise.

  In this regard, Patent Document 1 discloses a GPS positioning apparatus that can determine the amount of deviation of the antenna phase center according to the azimuth angle and elevation angle of the GPS satellite as viewed from the antenna phase center. Specifically, this GPS positioning device includes an azimuth / elevation angle calculation device for calculating the azimuth angle and elevation angle of the GPS satellite viewed from the center of the antenna phase, and a receiving antenna fixed according to the azimuth angle and elevation angle. A phase shift amount storage device that outputs a shift amount of the phase center with respect to the positioning reference point, and a distance correction calculation device that corrects the distance from the GPS satellite to the positioning reference point by using the azimuth angle, the elevation angle, and the shift amount. I have. These azimuth / elevation angle calculation device, phase shift amount storage device, and distance correction calculation device repeatedly perform calculation until the amount of change in the correction amount in the distance correction calculation device becomes a predetermined value or less.

JP-A-3-142389 (for example, page 602, lower right column to page 603, upper left column and FIG. 2)

  However, in the case of a mobile communication terminal, for example, since the attitude of the mobile communication terminal is not always constant, the attitude of the receiving antenna that receives the navigation signal can change. In the prior art of Patent Document 1, when the attitude of the receiving antenna is changed, there is a problem that the amount of deviation of the antenna phase center cannot be obtained with high accuracy according to the change of the attitude, and the positioning accuracy is lowered.

  In view of the above, an object of the present invention is to provide a positioning device and a positioning method that can perform positioning with high accuracy even when the attitude of a receiving antenna that receives a navigation signal changes.

A positioning apparatus according to an aspect of the present invention is a positioning apparatus that uses navigation signals transmitted from N (N is an integer of 3 or more) navigation satellites of a global navigation satellite system, and receives the navigation signals. a receiving antenna, based on the received navigation signals, detects a positioning unit for calculating a current position of the orbital position and the positioning device of the respective navigation satellite in the Earth reference frame, the orientation of the receiving antenna with respect to the Earth For calculating the coordinate position of the navigation satellite viewed from the current position based on the orbital position and the current position calculated by the positioning unit, and the calculated coordinate position is calculated based on the attitude of the receiving antenna. into a local coordinate position in local coordinate system with reference to the, based on the local coordinates, and calculates the relative angular position of each navigation satellite before Symbol station locations coordinate system corner A calculation unit, and a shift amount determination unit that determines a shift amount of the antenna phase center position from a predetermined reference point of the reception antenna according to the relative angular position calculated by the angle calculation unit, The positioning unit calculates a current position of the positioning device in the earth reference coordinate system based on the navigation signal received by the receiving antenna using the determined deviation amount.

A positioning method according to another aspect of the present invention includes a receiving antenna that receives navigation signals transmitted from N (N is an integer of 3 or more) navigation satellites of a global navigation satellite system, and an attitude of the receiving antenna with respect to the earth. A positioning method including a sensor unit for detecting a position of each navigation satellite in the earth reference coordinate system based on a navigation signal received by the receiving antenna and a current position of the positioning device. A step of calculating a position; a step of calculating a coordinate position of the navigation satellite viewed from the current position based on the calculated orbital position and the current position; and a position of the reception antenna based on the calculated coordinate position. and converting the local coordinates in the reference and the local coordinate system, based on the local coordinate position, said each navigation satellite before Symbol station locations coordinate system A step of calculating a diagonal position, a step of determining a deviation amount of the antenna phase center position from a predetermined reference point of the receiving antenna according to the calculated relative angular position, and the determined deviation Calculating a current position of the positioning device in the earth reference coordinate system based on a navigation signal received by the receiving antenna using a quantity.

  According to the present invention, the relative angular position of each navigation satellite in the local coordinate system based on the attitude of the receiving antenna is calculated, and then the deviation amount of the antenna phase center position is determined according to the relative angular position. . Therefore, even when the attitude of the receiving antenna with respect to the navigation satellite changes, the deviation amount of the antenna phase center position can be determined with high accuracy. Thereby, even when the positioning device moves or when the orientation of the positioning device with respect to the navigation satellite changes, highly accurate positioning can be performed.

It is a functional block diagram which shows schematic structure of the terminal which is a positioning apparatus of Embodiment 1 which concerns on this invention. It is a figure which shows the relationship between the orbit position of the navigation satellite in the earth reference coordinate system XYZ, and the present position of a terminal. 6 is a diagram for explaining a relative angle position calculation method according to Embodiment 1. FIG. 3 is a flowchart schematically showing an example of a procedure of positioning processing according to Embodiment 1.

  Hereinafter, a positioning device according to an embodiment of the present invention will be described in detail with reference to the drawings.

Embodiment 1 FIG.
FIG. 1 is a functional block diagram showing a schematic configuration of a main part of a terminal 1 which is a positioning apparatus according to Embodiment 1 of the present invention. The terminal 1 is a portable electric / electronic device or other portable terminal including a mobile communication terminal, and uses its own navigation signals transmitted from a plurality of navigation satellites of the GNSS (Global Navigation Satellite System). It has a positioning function that calculates the position.

  As shown in FIG. 1, the terminal 1 includes a receiving antenna device 10 connected to a receiving antenna AN that receives navigation signals from N (N is an integer of 3 or more) navigation satellites, and the receiving antenna device 10. A positioning unit 11 that performs a positioning calculation based on the received navigation signal supplied from the gyro sensor 12, a gyro sensor 12, an elevation angle calculating unit 13 that calculates the elevation angle El of the terminal 1 based on the detection output of the gyro sensor 12, and a geomagnetic sensor 14, the azimuth angle calculation unit 15 that calculates the azimuth angle Az of the terminal 1 based on the detection output of the geomagnetic sensor 14, and the shift of the phase center position of the reception antenna AN from a predetermined reference point of the reception antenna AN A calculation unit 20 for calculating the quantity and a determination unit 24 are provided. Here, the receiving antenna AN is one of the components of the terminal 1.

  The receiving antenna AN is not particularly limited as long as it has a function of receiving a navigation signal from a navigation satellite. For example, a linearly polarized antenna or a circularly polarized antenna having a linear polarization characteristic such as an inverted F antenna can be used as the receiving antenna AN.

  The positioning unit 11 can calculate the orbital position α of each navigation satellite at the time of transmitting the navigation signal based on the satellite orbit information included in the received navigation signal. Here, the orbital position α is obtained as a coordinate position in an earth reference coordinate system such as an ECEF (Earth Centered, Earth Fixed) orthogonal coordinate system. For example, in GPS, satellite orbit information called a navigation message is included in a navigation signal.

In addition, the positioning unit 11 determines the distances ρ ₁ ,... Between the orbital positions α ₁ ,..., Α _{N of the N} navigation satellites and the current position β of the terminal 1 based on the received navigation signals. by solving the N simultaneous equations relating [rho _N, it is possible to determine the current position of the terminal 1 beta in the earth reference coordinate system. Here, the distance ρ _i related to the i-th navigation satellite is a geometrical relationship between the phase center position of the transmission antenna of each navigation satellite when the navigation signal is transmitted and the phase center position of the reception antenna AN when the navigation signal is received. Distance. The phase center position of the receiving antenna AN (hereinafter also referred to as “antenna phase center position”) depends on the relative angular position (for example, elevation angle and azimuth angle) of the navigation satellite as viewed from the receiving antenna AN, and the relative angle. The antenna phase center position can change in accordance with the change in position. Furthermore, the antenna phase center position also depends on the attitude of the receiving antenna AN with respect to each navigation satellite. As will be described later, the computing unit 20 of the present embodiment computes the relative angular position of each navigation satellite in the local coordinate system with reference to the attitude of the receiving antenna AN, and the receiving antenna is determined according to the relative angular position. The deviation amount of the antenna phase center position from the reference point of AN can be determined with high accuracy.

The positioning unit 11 supplies the angle calculation unit 21 with data indicating the orbital position α of each navigation satellite and the current position β of the terminal 1 obtained by the calculation. FIG. 2 is a diagram showing the relationship between the orbital position α of the navigation satellite 2 and the current position β of the terminal 1 in the earth reference coordinate system XYZ. When the earth reference coordinate system XYZ is an ECEF orthogonal coordinate system, the origin O is the center of gravity of the earth, the Z axis is the north pole direction of the earth's rotation axis, the X axis is the direction of the intersection of the Greenwich meridian and the equator, Y The axis indicates the direction of 90 degrees east longitude. In the example of FIG. 2, the orbital position α of the navigation satellite 2 is expressed in vector format as (x _g , y _g , z _g ), and the current position β of the terminal 1 is expressed in vector format (x _t , y _{t 1} , z _t ). FIG. 2 also shows a local coordinate system X ₁ Y ₁ Z ₁ based on the attitude of the receiving antenna AN. The local coordinate system X ₁ Y ₁ Z ₁ will be described later.

  On the other hand, the elevation angle calculator 13 shown in FIG. 1 detects the amount of change in the angular velocity of the terminal 1 based on the detection output of the gyro sensor 12, and calculates the elevation angle El of the terminal 1 based on the amount of change. Further, the azimuth calculation unit 15 calculates the azimuth Az of the terminal 1 based on the detection output of the geomagnetic sensor 14. With the elevation angle El and the azimuth angle Az, it is possible to detect the attitude of the receiving antenna AN of the terminal 1 with respect to the earth, that is, the direction in which the receiving antenna AN faces the earth. Data indicating the elevation angle El and the azimuth angle Az is supplied to the calculation unit 20. Here, instead of the gyro sensor 12, an acceleration sensor may be employed. In addition, the sensor part of this invention can be comprised by the gyro sensor 12, the elevation angle calculating part 13, the geomagnetic sensor 14, and the azimuth angle calculating part 15. FIG.

As shown in FIG. 1, the calculation unit 20 includes an angle calculation unit 21, a deviation amount determination unit 22, and a data storage unit 23. The angle calculation unit 21 detects the attitude of the reception antenna AN of the terminal 1 with respect to the earth based on the elevation angle El and the azimuth angle Az of the terminal 1 supplied from the elevation angle calculation unit 13 and the azimuth angle calculation unit 15. Here, since the receiving antenna AN is attached to a predetermined position of a casing (not shown) of the terminal 1 in a predetermined posture, the receiving antenna AN with respect to the earth based on the elevation angle El and the azimuth angle Az of the terminal 1. Can be detected. The angle calculation unit 21 determines a local coordinate system X ₁ Y ₁ Z ₁ with reference to the attitude of the receiving antenna AN. For example, the local coordinate system X ₁ Y ₁ Z ₁ can be determined so that the specific direction of the receiving antenna AN coincides with the direction of the Z ₁ axis. Further, the angle calculation unit 21 calculates the angular position of each navigation satellite in the local coordinate system X ₁ Y ₁ Z ₁ based on the orbital position α and the current position β calculated by the positioning unit 11.

Specifically, as shown in FIG. 2, the angle calculation unit 21 calculates the coordinate position γ of the navigation satellite 2 viewed from the terminal 1 in the earth reference coordinate system XYZ. This coordinate position γ is calculated by the following formula in a vector format.
γ = α−β = (x _g −x _t , y _g −y _t , z _g −z _t )

Next, the angle calculation unit 21 converts the position γ expressed in the earth reference coordinate system XYZ into a position γ ₁ expressed in the local coordinate system X ₁ Y ₁ Z ₁ . When the transformation matrix from the earth reference coordinate system XYZ to the local coordinate system X ₁ Y ₁ Z ₁ is represented by E, the position vector γ ₁ can be calculated by the following equation.
γ ₁ = E · γ = (x _r , y _r , z _r )

Then, the angle calculation unit 21 calculates a relative angular position (θ, φ) in the local coordinate system X ₁ Y ₁ Z _{1 as shown} in FIG. Here, θ is an angle formed by a line segment connecting the relative angular position and the origin O ₁ with the Z ₁ axis. φ is an angle, that is, an azimuth angle formed by a line segment connecting the point obtained by projecting the relative angular position on the X ₁ Y ₁ plane and the origin O ₁ with respect to the X ₁ axis. For example, the relative angular position (θ, φ) can be calculated by the following equations (1) to (3).

φ = Arccos [x _r / (x _r ² + y _r ² ) ^1/2 ] (1)
φ = Arcsin [y _r / (x _r ² + y _r ² ) ^1/2 ] (2)
θ = Arccos [z _r / (x _r ² + y _r ² + z _r ² ) ^1/2 ] (3)

  Note that the angle calculator 21 may calculate a combination of the elevation angle (= 90 ° −θ) and the azimuth angle φ as the relative angle position instead of the combination of the angle θ and the azimuth angle φ.

  The shift amount determination unit 22 has a function of determining the shift amount of the antenna phase center position from the reference point of the reception antenna AN according to the relative angular position (θ, φ) calculated by the angle calculation unit 21. This deviation amount may be expressed, for example, as a vector amount or may be expressed approximately as a scalar amount. The data storage unit 23 stores data indicating the correspondence between the numerical value of the relative angular position (θ, φ) and the deviation amount of the antenna phase center position. The numerical value stored in the data storage unit 23 is an actual measurement value or a calculated value prepared in advance for each terminal based on the phase pattern of the receiving antenna AN.

  The deviation amount determination unit 22 can acquire the deviation amount corresponding to the value of the relative angular position (θ, φ) from the data storage unit 23. Also, the deviation amount determination unit 22 is based on the data stored in the data storage unit 23 when the deviation amount corresponding to the relative angle position (θ, φ) is not stored in the data storage unit 23. The deviation amount corresponding to the relative angular position (θ, φ) may be calculated by interpolation. Data indicating the amount of deviation is supplied to the determination unit 24.

  The determination unit 24 determines whether or not the deviation amount determined by the deviation amount determination unit 22 meets a preset condition. For example, the determination unit 24 determines that the deviation amount meets a condition when the estimated deviation amount is equal to or less than a predetermined threshold, and the estimated deviation amount exceeds the threshold. It can be determined that the amount of deviation does not meet the conditions. The determination unit 24 supplies data of the deviation amount to the positioning unit 11 only when the deviation amount meets the condition.

The positioning unit 11 recalculates the current position of the terminal 1 in the earth reference coordinate system XYZ using the deviation amount of the antenna phase center position supplied for each navigation satellite. For example, the positioning unit 11, orbital position alpha ₁ of each navigation _satellite, ..., alpha distance [rho ₁ between the current position β of the _N and the terminal _1, ..., the correction amount [delta] ₁ in accordance with the deviation amount to [rho _N ,..., Δ _N are added to solve the simultaneous equations, whereby the new current position of the terminal 1 can be obtained with high accuracy.

  The positioning unit 11, the elevation calculation unit 13, the azimuth calculation unit 15, the calculation unit 20, and the determination unit 24 are configured with a semiconductor integrated circuit such as an FPGA (Field-Programmable Gate Array) or an ASIC (Application Specific Integrated Circuit). Alternatively, it may be configured by a one-chip microcomputer which is a kind of microcomputer including a CPU (Central Processing Unit). The data storage unit 23 can be composed of a nonvolatile memory.

  Next, an operation example of the terminal 1 according to the present embodiment will be described with reference to FIG. FIG. 4 is a flowchart schematically showing an example of the procedure of the positioning process according to the present embodiment.

  Referring to FIG. 4, first, the elevation angle calculator 13 calculates the elevation angle El of the terminal 1 based on the detection output of the gyro sensor 12 (step ST1). Further, the azimuth calculating unit 15 calculates the azimuth Az of the terminal 1 based on the detection output of the geomagnetic sensor 14 (step ST2). Further, the positioning unit 11 calculates the orbital position of each navigation satellite and the current position β of the terminal 1 based on the received navigation signal (step ST3). Here, steps ST1, ST2 and ST3 need not be executed in this order. For example, steps ST1, ST2, and ST3 may be executed in parallel.

Next, the angle calculation unit 21 is based on the local coordinate system X ₁ Y ₁ Z based on the attitude of the receiving antenna AN based on the elevation angle El and the azimuth angle Az supplied from the elevation angle calculation unit 13 and the azimuth angle calculation unit 15. ₁ is determined (step ST4). Furthermore, as described above, the angle calculation unit 21 is based on the orbital position and the current position calculated by the positioning unit 11, and the relative angular position (θ, φ) of each navigation satellite in the local coordinate system X ₁ Y ₁ Z ₁ ) Is calculated (step ST5). And the deviation | shift amount determination part 22 determines the deviation | shift amount of the antenna phase center position corresponding to the value of relative angle position ((theta), (phi)) (step ST6).

  Thereafter, the determination unit 24 determines whether or not the deviation amount determined in step ST6 meets the set condition (step ST7). When it determines with the said deviation | shift amount not matching setting conditions (NO of step ST7), the determination part 24 returns a positioning process to step ST1. On the other hand, when the amount of deviation matches the set condition (YES in step ST7), the positioning unit 11 performs positioning by recalculating the current position of the terminal 1 in the earth reference coordinate system XYZ using the amount of deviation. Execute (step ST8).

  As described above, in the present embodiment, the relative angular position (θ, φ) of each navigation satellite in the local coordinate system based on the attitude of the receiving antenna is calculated, and this relative angular position (θ, φ) The amount of deviation of the antenna phase center position is determined accordingly. Therefore, even when the attitude of the receiving antenna AN changes with respect to each navigation satellite, the deviation amount of the antenna phase center position can be determined with high accuracy. Thereby, even when the terminal 1 moves or when the orientation of the terminal 1 with respect to the navigation satellite changes, highly accurate positioning can be performed.

  Further, the data storage unit 23 stores deviation amount data prepared in advance based on the phase pattern of the receiving antenna AN. The deviation amount determination unit 22 acquires a deviation amount corresponding to the value of the relative angular position (θ, φ) from the data storage unit 23. For this reason, it is possible to store in advance in the data storage unit 23 and use data of a deviation amount that matches the phase characteristics of the receiving antenna AN with relatively low phase stability, so a small antenna with low phase stability is used. can do. Therefore, highly accurate positioning is possible even when a receiving antenna having linear polarization characteristics such as an inverted F antenna is used.

  As mentioned above, although embodiment which concerns on this invention was described with reference to drawings, this embodiment is an illustration of this invention and can also employ | adopt various forms other than this embodiment. For example, the terminal 1 may include a functional block (for example, a map information display block or a wireless communication module) that uses the current position β obtained by the positioning unit 11.

  Within the scope of the present invention, any combination of any component of this embodiment, any modification of any component of this embodiment, or omission of any component of this embodiment is possible.

  1 terminal, 2 navigation satellites, 10 receiving antenna device, 11 positioning unit, 12 gyro sensor, 13 elevation angle calculating unit, 14 geomagnetic sensor, 15 azimuth angle calculating unit, 20 calculating unit, 21 angle calculating unit, 22 deviation amount determining unit, 23 Data storage unit, 24 determination unit.

Claims (6)

A positioning device that uses navigation signals transmitted from N navigation satellites (N is an integer of 3 or more) of the global navigation satellite system,
A receiving antenna for receiving the navigation signal;
Based on the received navigation signal, a positioning unit that calculates the orbit position of each navigation satellite in the earth reference coordinate system and the current position of the positioning device;
A sensor unit for detecting the orientation of the receiving antenna with respect to the earth,
Based on the orbital position calculated by the positioning unit and the current position , the coordinate position of the navigation satellite viewed from the current position is calculated, and the calculated coordinate position is determined based on the attitude of the receiving antenna. into a local coordinate position in the coordinate system, an angle calculation unit based on the local coordinates, and calculates the relative angular position of each navigation satellite before Symbol station locations coordinate system,
A shift amount determination unit that determines a shift amount of the antenna phase center position from a predetermined reference point of the reception antenna according to the relative angular position calculated by the angle calculation unit;
The positioning unit calculates the current position of the positioning device in the earth reference coordinate system based on the navigation signal received by the receiving antenna using the determined deviation amount.
A positioning device characterized by that. The positioning device according to claim 1, further comprising a data storage unit storing data indicating a correspondence relationship between a relative angular position of the navigation satellite and a deviation amount of the antenna phase center position.
The positioning apparatus is characterized in that the shift amount determination unit acquires the shift amount corresponding to the relative angular position calculated by the angle calculation unit from the data storage unit.   The positioning device according to claim 1 or 2, wherein the sensor unit includes a geomagnetic sensor and an angular velocity sensor.   4. The positioning device according to claim 1, wherein the receiving antenna is a circularly polarized antenna. 5.   4. The positioning device according to claim 1, wherein the receiving antenna is a linearly polarized antenna. 5. A receiving antenna that receives navigation signals transmitted from N (N is an integer of 3 or more) navigation satellites of the global navigation satellite system, and a sensor unit that detects the attitude of the receiving antenna with respect to the earth. A positioning method in a positioning device,
Calculating the orbital position of each navigation satellite in the earth reference coordinate system and the current position of the positioning device based on the navigation signal received by the receiving antenna;
Calculating the coordinate position of the navigation satellite viewed from the current position based on the calculated orbital position and the current position ;
Transforming the calculated coordinate position into a local coordinate position in a local coordinate system based on the attitude of the receiving antenna;
A step of based on the local coordinates, and calculates the relative angular position of each navigation satellite before Symbol station locations coordinate system,
Determining a deviation amount of the antenna phase center position from a predetermined reference point of the receiving antenna according to the calculated relative angular position;
And a step of calculating a current position of the positioning device in the earth reference coordinate system based on a navigation signal received by the receiving antenna using the determined deviation amount.

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